Tesi: "Vitamin A in the body"

1

Logan, Kathryn G. "Seasonal Variation in Vitamin D Levels in Adolescent Girls in Maine". Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/LoganKG2003.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Beildeck, Marcy Ellen. "The role of vitamin D and the vitamin D receptor in TCF-4 regulation and silencing of CYP24A1". Connect to Electronic Thesis (CONTENTdm), 2009. http://worldcat.org/oclc/454140383/viewonline.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Herselman, Marietjie. "Vitamin D : miracle cure-for-all or cart before the horse?" Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/86816.

Testo completo

Abstract (sommario):

Inaugural address delivered on 2 November 2011
Marietjie Herselman was born in the Langkloof, where she matriculated at the McLachlan High School. She obtained a BSc (Physiology and Dietetics) degree at Stellenbosch University and for the next 18 years worked as a dietitian at Tygerberg Hospital, where she specialised in renal nutrition. She obtained a master’s degree in nutrition in 1985 and in 1991 was appointed as a lecturer in the Department of Human Nutrition, Faculty of Health Sciences, at Stellenbosch University. In the same year she obtained her PhD in nutritional sciences at this university, where she was later promoted to senior lecturer (1995), associate professor (2001) and full professor (2010). From 2008 to 2010 she was appointed first as acting head and later as head of the Division of Human Nutrition. She served on the Professional Board of Dietetics from 1998 to 2003 and also on various sub-committees of the Board. She regularly reviews papers and research applications for scientific councils/associations as well as five national and four international scientific journals. Currently, she serves on the editorial boards of four international scientific journals and in 2008 she was elected as the co-editor (Africa region) of the international journal Nutrition. She successfully delivered 17 master’s students and published 29 scientific papers in national and international journals and three chapters in textbooks. Marietjie also presented papers at 19 international and 37 national conferences. Three international and four national awards were bestowed on her for her research in renal nutrition. She played a leading role in the initiation of the Community Nutrition Security Project (CNSP) in the Breede Valley, as part of Stellenbosch University’s HOPE Project, as well as the NOMA master’s programme in Nutrition, Human Rights and Governance in collaboration with the universities of Oslo and Akershus (Norway) as well as Makerere and Kyambogo (Uganda).

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Pinnock, Carole B. "Vitamin A status and susceptibility to respiratory illness /". Title page, table of contents and abstract only, 1987. http://web4.library.adelaide.edu.au/theses/09PH/09php656.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Billing, Georgia. "Determinants of vitamin D status in mother and infant pairs". Thesis, University of Cambridge, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709059.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Hamill, Matthew. "HIV, body composition, bone and vitamin D status in South African women". Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/270410.

Testo completo

Abstract (sommario):

Cross sectional and observational data suggest that HIV-positive individuals and those receiving antiretroviral (ARV) therapy are prone to higher rates of osteoporosis and osteopaenia than HIV-negative individuals. Likewise, HIV-positive individuals often have low vitamin D status. Evidence is emerging more generally of a strong association between HIV infection and poor bone health. There is also evidence that treatment with ARV therapy (ART) and suboptimal vitamin D status may exacerbate this problem (Brown et al, 2006a, 2010). But, to date, causal relationships have not been fully established. This thesis explores the interactions between these separate factors and provides novel data about the effects of HIV infection and its treatment, on bone health in a particular group of black, South African women. Bone loss and poor vitamin D status in the context of HIV infection are important global health issues because these conditions may affect millions of individuals. If HIVassociated bone loss is causally associated with an increased risk of bone fracture then it is possible that there will be an epidemic of HIV-associated fractures in coming decades, particularly in the developing world, including Africa. Study data have so far often been limited by several factors, including cross-sectional design, absence of control groups, a preponderance of attention to bone outcomes in males and in Caucasians, and a lack of good quality data in Africans living in Africa. Th is study aimed to -assess the magnitude of HIV- and ART-associated changes in areal bone mineral density (aBMD), size-adjusted bone mineral content (SA-BMC) and vitamin D status in adult, premenopausal women living in Johannesburg, South Africa. Ninetyeight HIV-negative (Negative reference: Nref) and 149 HIV-positive women were enrolled to allow for comparison between groups. The HIV-positive women were recruited into those eligible to start ART (Positive low CD4 : Plow, n=75) and those unlikely to require ART (Positive preserved CD4 : Ppres, n=74) during a 12-month followup period. The design was longitudinal with visits at 0, 6 and 12 months for measurement of body composition, bone measures and dietary assessment. Blood and urine samples were collected for the evaluation of relevant musculoskeletal analytes, including 25(0H)D at each time point. Most women ( > 80%) who received ART during the course of the study received South African standard first-line therapy consisting of lamivudine, tenofovir and efavirenz. A post hoe analysis of possible effects of ART was performed by retrospectively dividing HIV-positive women into ART-unexposed (n=66) and ART-exposed (n=74). At baseline there was a high prevalence of overweight with 65%, 65% and 44% with BMI > 25 kg/m2 in Nref, Ppres and Plow respectively. Plow had lower weight, BMI, fat mass, lean mass, waist and hip circumferences than the other groups. Nref and Ppres were not different from each other. There were no differences in aBMD or SA-BMC 1 between groups at baseline and no significant differences in vitamin D status between the groups. The mean ±SD serum 25(0H)D concentrations were 59.7 ±16.5, 59.2 ±16.5 and 61.6 ±22.3 nmol/1 in Nref, Ppres and Plow respectively. Plow had significantly lower serum albumin concentration (p < 0.0001) and higher serum phosphate concentration (p < 0.0001). The magnitude of differences in serum phosphate was: Ppres-Nref = 12. 7 ±2.9%; Plow-Nref = 20.3 ±2.9% and Plow-Ppres = 7.6 ±3.1% (p < 0.001). Tubular maximum Reabsorption of Phosphate/Glomerular Filtration Rate (TmP/GFR) was 11.2 ±3.2% and 27.4 ±3.2% respectively greater in Ppres and Plow than Nref (p < 0.0001), and higher in the Plow compared to Ppres 16.2 ±3.4%, (p=0.0002). Serum alkaline phosphatase and urine phosphate to creatinine ratio were not significantly different (p > 0.05). At the 12-month follow-up, Plow subjects remained lighter than their Nref and Ppres counterparts. However, there was a 3.9 ±0.9% increase in mean weight in the Plow group over 12 months (p < 0.001), which represented 10.2 ±0.8% (p < 0.001) increase in fat, rather than lean, mass accumulation. There were significant mean decreases in aBMD and SA-BMC in Plow subjects, and those exposed to ART of the order of 2-3% at total hip, femoral neck and lumbar spine. There were no significant differences in mean vitamin D status between the groups and no significant changes, the mean 25(0H)D concentrations were 63.3 ±17.7, 66.0 ±18.4 and 61.1 ±20.1 nmol/1 in Nref, Ppres and Plow respectively. Serum albumin concentrations had risen by a mean of 9.1 ±1.1% in the Plow group to reach comparable concentrations with the other groups. Alkaline phosphatase activity had significantly risen in the Plow group compared with the other groups (p < 0.001). Serum phosphate concentration remained higher in Plow than the other groups, though the mean value had not increased. Serum phosphate had significantly increased in Nref from baseline to 12 months 7.0 ±2.3% (p=0.05) and non-significantly in Ppres 5.2 ±2.4%. TmP/GFR had declined from baseline by 11.2 ±3.6% in Plow and non-significantly increased in Nref and Ppres (6.4 ±3.3% and 3.8 ±3.5% respectively). These data suggest that HIV infection in South African women is associated with differences in body composition but not with differences in bone measures or vitamin D status. However, being in the Plow group, and ART exposure, was associated with a significant decrease in mean aBMD and SA-BMC, of the order of 2-3%, over 12 months of observation at the hip, femoral neck and lumbar spine. These decreases, in young women, exceed those seen in early menopause, which is of the order of 1-2% annual decrease. The decreases were evident despite the fact that HIV-positive women exposed to ART had increases in fat mass, weight and serum albumin and alkaline phosphatase over time. In this group serum phosphate concentration and TmP/GFR decreased after the introduction of ART, suggesting an effect of ART on renal phosphate handling. ART exposure was not associated with change in vitamin D status. In the post hoe analysis the biochemical results in ART-unexposed compared to ARTexposed was very similar to that in Ppres compared with Plow. Further studies to assess skeletal effects over a longer time in HIV-positive, ARTexposed and na"ive women are warranted. Studies are also required in post-menopausal women, children and men. Given the high prevalence of overweight and obesity recorded in the study population, there may also be a need for interventions to reduce cardiometabolic disease risk in this population.

Gli stili APA, Harvard, Vancouver, ISO e altri

7

De, Villiers Diane Lynette. "Effects of vitamin A on tumour and untransformed cells". Thesis, Rhodes University, 1988. http://hdl.handle.net/10962/d1001615.

Testo completo

Abstract (sommario):

Vitamin A and its chemical analogues (retinoids) are known to play a role in the maintenance and differentiation of epithelial tissue. Retinoids have been shown to inhibit carcinogenesis in a number of tissues in experimental animals and to inhibit the growth of various untransformed and cancer cell lines in vitro. This study investigated the effect of retinyl acetate supplemented at concentrations of 1 μM, 5 μM, 10 μM and 100 μM to in vitro cultured untransformed LLCMK cells, and transformed BL-6 melanoma and human hepatoma cell lines. A small but non-significant effect of vitamin A addition on the growth of the untransformed cells was observed, while substantial inhibition of proliferation of the two tumour cell lines was found. At the cytotoxic level of 100 μM supplemented vitamin A, all three cell lines showed marked inhibition of growth. This led to an electron microscopy study to examine the ultrastructural effect of the vitamin A addition. At the low non-toxic levels of vitamin A addition (1 - 10 μM), no ultrastructural changes were observed in the untransformed cells. However, at a level of 5 μM and 10 μM vitamin A addition in the tumour cells, an increase in the size of suspected lipid droplets was observed. At the cytotoxic level of 100 μM supplemented vitamin A, large lipid droplets were very apparent, as was much cellular degeneration. This effect was more marked in the tumour cells than in the untransformed cells. The lipid nature of the droplets was confirmed by using the lipid stain, Sudan IV. In order to investigate the effect of added vitamin A at the cell surface level, an ELISA system was used to quantify the level of the cell surface glycoprotein, fibronectin, in the culture media. Vitamin A plays an important role in the production of mature fibronectin by participating in the glycosylation of the molecule. This study showed no major effect of added vitamin A on the release of fibronectin into the culture media. This did not, however, exclude the possibility that the vitamin A was involved in the production and enhanced binding of fibronectin to the cell surface, and was possibly also exerting an effect on the availability of fibronectin receptors. Further studies would, however, be required to substantiate such effects of vitamin A supplementation. No single mechanism of action of vitamin A on tumour cell growth inhibition was identified, but the possibility that at least two mechanisms exist, was suggested

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Landry, Denise. "Interrelationships Between Vitamin D and Body Mass Index and Waist Circumference in Canada". Thesis, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24344.

Testo completo

Abstract (sommario):

60 % of Canadians have suboptimal vitamin D (<75 nmol/L) and 25% are obese. Obesity has been reported to be a risk factor for low vitamin D, but there is uncertainty about the magnitude of the association. Linear regression was performed using data from the nationally representative cross-sectional Canadian Health Measures Survey (2007-2009). Height, weight, waist circumference (WC), and vitamin D levels were directly measured. There were 5298 participants aged 6 to 79 years. Using a conservative p value of 0.001, body mass index (BMI) category obese / obese I was positively associated and WC was inversely associated with vitamin D level in crude analysis. WC was inversely associated with vitamin D level in multivariate analysis. The pattern of relationship is not the same as other studies, yet this was a large study with direct measurements. There may be issues with linearity of relationships or subgroups disturbing the relationship.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Willis, Kentz S. "Vitamin D status & immune system biomarkers in athletes". Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1798967201&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Moon, Rebecca Jane. "Antenatal vitamin D supplementation and offspring body composition and muscle strength : a translational approach". Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/416626/.

Testo completo

Abstract (sommario):

The in utero environment to which a fetus is exposed might influence body composition and muscle strength in later life. Modulation of this environment could therefore represent an approach to addressing the increasing burden of obesity and sarcopenia. One potential modifiable exposure is vitamin D. The aim of this work was to explore the determinants of maternal serum 25-hydroxyvitamin D [25(OH)D] status in pregnancy and the use of antenatal vitamin D supplementation to improve offspring growth, body composition and muscle strength. The Southampton Women’s Survey (SWS) is a prospective birth cohort study that included assessment of maternal serum 25(OH)D at 11 (n=2019) and 34 weeks (n=2328) of gestation. Marked seasonal variation in serum 25(OH)D was observed at both gestations (p < 0.001 for both). After adjustment for season, 25(OH)D tracked moderately from early to late pregnancy (r=0.53), but supplementation use and pregnancy weight gain were significantly associated with changes in 25(OH)D status. The offspring of 678 women who had a late pregnancy 25(OH)D measurement were reviewed at 4 years of age. There were no significant associations between maternal 25(OH)D and offspring lean mass (LM) measured by dual-energy x-ray absorptiometry (DXA), but a positive association with grip strength was found (β=0.10 SD/SD, p=0.01). These findings were translated to an intervention study using the MAVIDOS trial, a randomised placebo-controlled trial of antenatal vitamin D supplementation (1000 IU/day cholecalciferol from 14 weeks of gestation until delivery) in women with a baseline 25(OH)D of 25-100 nmol/l. Offspring anthropometry was assessed at birth (n=768), 1 year (n=594) and 2 years (n=577) of age. At 4 years (n=378), body composition was assessed by DXA and grip strength by hand dynamometry. Weight, length/height and measures of adiposity (skinfold thicknesses at birth, 1 and 2 years of age; fat mass measured by DXA at 4 years) did not differ between the randomisation groups at any age (p > 0.05 for all) despite a significantly greater maternal 25(OH)D in the cholecalciferol supplementation group at 34 weeks of gestation (mean difference 24.7 nmol/l, p < 0.001). LM and grip strength at 4 years were also similar, but in women with baseline 25(OH)D < 30 nmol/l, offspring grip strength was greater in those randomised to cholecalciferol (0.70 SD [95% CI 0.02, 1.38], p=0.04). LM did not differ in this subgroup. These findings suggest that 1000 IU/day cholecalciferol supplementation during mid and late pregnancy in women with baseline 25(OH)D 25-100 nmol/l does not improve offspring body composition or muscle strength despite an increase in maternal 25(OH)D status. Supplementation increased muscle strength in offspring of women with the lowest 25(OH)D levels, highlighting the need for further trials of vitamin D supplementation in deficient women.

Gli stili APA, Harvard, Vancouver, ISO e altri

11

Zou, Wei. "Dietary L-carnitine alters the metabolism and body status of vitamin E in rats /". Search for this dissertation online, 2002. http://wwwlib.umi.com/cr/ksu/main.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

12

Natarajan, Radhika. "Vitamin D metabolites inhibit adipocyte differentiation in ₃T₃-L₁ preadipocytes". Connect to this title, 2008. http://scholarworks.umass.edu/theses/164/.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

13

Simões, Fernanda Franco Agapito. "Relação entre adiposidade materna e do recém-nascido com concentrações de vitamina D materna e do cordão umbilical". Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/6/6138/tde-03122015-143614/.

Testo completo

Abstract (sommario):

Introdução - A vitamina D desempenha funções na regulação da homeostase do cálcio e fósforo, diferenciação celular, metabolismo de hormônios e regulação do sistema imune. Sua deficiência em crianças pode ocasionar raquitismo, convulsões e insuficiência respiratória. Objetivo - Determinar a relação entre adiposidade materna e do recém-nascido com as concentrações de vitamina D materna e do cordão umbilical. Metodologia - Foram envolvidas 101 mães e seus respectivos recém-nascidos selecionados no Hospital Maternidade Vila Nova Cachoeirinha, São Paulo. A concentração de vitamina D foi determinada por cromatografia líquida. A composição corporal materna foi determinada por bioimpedância segmentada (InBody®, Coréia do Sul) e a dos recém-nascidos obtida por pletismografia por deslocamento de ar (PEA POD®, USA). Para análise estatística, utilizou-se análise de regressão linear múltipla e coeficiente de correlação de Spearman. Valores de p <0,05 foram considerados significantes. Resultados - As médias das concentrações de vitamina D da mãe e do cordão umbilical foram de 30,16 (DP=21,16) ng/mL e 9,56 (DP=7,25) ng/mL, respectivamente. As médias das porcentagens de massa gorda das mães e dos recém-nascidos foram de 32,32 (DP=7,74) por cento e 8,55 (DP=4,37) por cento , respectivamente. Foi observada relação positiva entre concentração de vitamina D materna e do cordão umbilical (r=0,210; p<0,04). Não foi observada associação entre adiposidade do recém-nascido e concentração de vitamina D do cordão umbilical, nem entre adiposidade materna e concentrações de vitamina D materna e do cordão umbilical. Conclusão Neste estudo, original na literatura internacional, foi utilizado método de referência, validado, de alta precisão e imparcial na estimativa do percentual de gordura neonatal, nem sempre utilizado em outros estudos. Foi observada relação positiva entre concentração de vitamina D materna e do cordão umbilical. A ausência de associação entre as variáveis analisadas pode ser devido à alta prevalência de sobrepeso e obesidade entre as gestantes, baixas concentrações de vitamina D nas gestantes e recém-nascidos, alteração do metabolismo da vitamina D e da composição corporal no período da gestação e imaturidade do processo de sequestro da vitamina D pelo tecido adiposo 1 neonatal. Torna-se relevante o desenvolvimento de estudos prospectivos do tipo coorte para avaliar desde o início da gestação a influência da adiposidaidade materna nas concentrações de vitamina D materna e do cordão umbilical.
Introduction - Vitamin D plays a role in the regulation of mineral homeostasis, cell differentiation, hormone metabolism, and regulation of the immune system. Its deficiency can cause rickets in children, convulsions and difficulty breathing. Objective - To determine the relationship between maternal adiposity and the newborn with concentrations of vitamin D maternal and umbilical cord. Methodology- 101 mothers and their newborns were involved. The prevalence of insufficiency (21-29 ng/ml) and deficiency (<20 ng/ml) of vitamin D were determined. The 25(OH)D concentration was analyzed by liquid chromatography, and the umbilical cord blood was collected for up to 10 minutes after childbirth. The maternal nutritional status was assessed by body mass index before pregnancy. Maternal body composition was determined by bioimpedance segmented. Body composition of newborns was obtained by technology plethysmography air displacement. For statistical analysis, multiple linear regression analysis and Pearsons correlation coefficient were used. P values <0.05 were considered significant. Results - The mean concentration of vitamin D from the mother and the umbilical cord were 30.16 (SD = 21.16) ng/mL and 9.56 (SD = 7.25) ng/mL, respectively. The observed prevalence of maternal vitamin D insufficiency and deficiency were 56.44 per cent and 41.58 per cent . Ninety-five percent (95.92 per cent ) and 89.80 per cent of the newborns had vitamin D insufficiency and deficiency, respectively. The mean maternal prepregnancy BMI was 27.79 (SD = 5.61) kg/m2. The mean percentages of fat mass of mothers and newborns were 32.32 (SD= 7.74) and 8.55 per cent (SD= 4.37) per cent , respectively. Positive relationship between concentration of vitamin D maternal and cord blood (r=0,248; p<0,013) was observed. No relationship between adiposity newborn and concentration of vitamin D in the umbilical cord, or relationship between maternal adiposity and concentrations of vitamin D maternal and umbilical cord was observed. Conclusion - Despite it is an original study, no relationship between maternal adiposity and concentrations of vitamin D maternal and umbilical cord was observed. It is significant further research to investigate the influence of maternal fat in neonatal body composition and vitamin D concentrations in maternal and cord blood.

Gli stili APA, Harvard, Vancouver, ISO e altri

14

Kaewsakhorn, Thattawan. "Roles of calcitriol and its analog on canine transitional cell carcinoma in vitro and in vivo, and in normal canine prostate tissue explants". Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1181937183.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

15

Guenther, Isabel. "The relationship between serum leptin, 25-hydroxyvitamin D₃, and body composition". Connect to this title, 2008. http://scholarworks.umass.edu/theses/196/.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

16

Anderson, Paul Hamill. "The regulation of Vitamin D metabolism in the kidney and bone". Title page, contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09PH/09pha5486.pdf.

Testo completo

Abstract (sommario):

Includes bibliographical references (leaves 226-273.) Investigates the regulation of the expression of CYP27B1, CYP24 and vitamin D receptor (VDR) mRNA, both in the bone and in the kidney, with the aim to determine whether the regulation of the vitamin D metabolism in the bone is independent from that in the kidney. The effects of age, dietary calcium and vitamin D status on the expression of these genes in both the kidney and the bone, as well as on a number of biochemical factors known to regulate the renal metabolism of 1,25D, such as PTH, calcium and 1,25D itself, were examined. CYP27B1 mRNA expression was also studied in histological sections of rat femoral bone.

Gli stili APA, Harvard, Vancouver, ISO e altri

17

Cavalieri, Vanessa Vicente de Souza. "Perfil de vitamina D e sua associação com adiposidade corporal e resistência à insulina em pacientes com doença renal crônica na fase não dialítica". Universidade do Estado do Rio de Janeiro, 2015. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=9438.

Testo completo

Abstract (sommario):

O termo vitamina D compreende um grupo de hormônios esteróides com ações biológicas semelhantes. O método mais acurado para determinar o estado de vitamina D é através dos níveis plasmáticos de 25 hidroxivitamina D [25(OH)D]. A deficiência de 25(OH)D é considerada um problema de saúde pública, tendo como principal causa à baixa exposição solar, idade avançada e doenças crônicas. A deficiência de 25(OH)D é frequente em pacientes com doença renal crônica (DRC) na fase não dialítica. Estudos têm evidenciado que os níveis séricos de 25(OH)D apresentam associação inversa com adiposidade corporal e resistência à insulina (RI) na população em geral e na DRC. O excesso de gordura corporal e o risco de Doença Cardiovascular (DVC) vêm sendo estudados em pacientes com DRC e dentre as complicações metabólicas associadas à adiposidade corporal elevada observa-se valores aumentados de HOMA-IR (Homeostasis Model Assessment of Insulin Resistance) um marcador para RI. Estudos avaliando o perfil da 25(OH)D na DRC na fase não dialítica, especialmente relacionados com a adiposidade corporal e RI são escassos. O presente estudo tem como objetivo avaliar a relação entre os níveis séricos de 25(OH)D, RI, e adiposidade corporal em pacientes com DRC na fase não dialítica. Trata-se de um estudo transversal observacional, incluindo pacientes adultos, clinicamente estáveis e com filtração glomerular estimada (FGe) ≤ 60 ml/min., em acompanhamento regular no Núcleo Interdisciplinar de Tratamento da DRC. Os participantes foram submetidos à avaliação do estado nutricional por antropometria (peso, altura, índice de massa corporal (IMC), circunferências e dobras cutâneas) e absorciometria de duplo feixe de raios X (DXA); foram avaliados no sangue: creatinina, uréia, glicose, albumina, colesterol total e frações e triglicérides, além de leptina, insulina e 25(OH)D. Níveis séricos < 20ng/dL de 25(OH)D foram considerados como deficiência. As análises estatísticas foram realizadas utilizando-se o software STATA versão 10.0, StataCorp, College Satation, TX, USA. Foram avaliados 244 pacientes (homens n=135; 55,3%) com média de idade de 66,3 13,4 anos e de FGe= 29,4 12,7 ml/min. O IMC médio foi de 26,1 kg/m (23,0-30,1) com elevada prevalência de sobrepeso/obesidade (58%). A adiposidade corporal total foi elevada em homens (gordura total-DXA= 30,2 7,6%) e mulheres (gordura total-DXA= 39,9 6,6%). O valor mediano de 25(OH) D foi de 28,55 ng/dL (35,30-50,70) e de HOMA-IR foi 1,6 (1,0-2,7). Os pacientes com deficiência de 25(OH)D (n= 51; 20,5%) apresentaram maior adiposidade corporal total (DXA% e BAI %) e central (DXA%) e valores mais elevados de leptina. A 25(OH)D apresentou correlação significante com adiposidade corporal total e central e com a leptina, mas não se associou com valores de HOMA-IR. Estes resultados permitem concluir que nos pacientes DRC fase não dialítica a deficiência de 25(OH)D e a elevada adiposidade corporal são frequentes. Estas duas condições estão fortemente associadas independente da RI; a alta adiposidade corporal total e central estão positivamente relacionadas com RI; 25(OH)H e RI não estão associados nessa população com sobrepeso/obesidade.
The term vitamin D comprises a group of steroid hormones with similar biological actions. The status of vitamin D is most accurately determined by measuring the plasma levels of 25-hydroxyvitamin D [25(OH) D]. The deficiency of 25(OH)D is considered a public health problem and the main cause is the low sun exposure, advanced age and chronic diseases. Patients with chronic kidney disease (CKD) non dialysis dependent show high prevalence of 25(OH)D deficiency. The 25(OH)D serum levels have been described, in many studies, as being inversely associated with total and abdominal adiposity and insulin resistance. The higher risk for CVD related with excess of body fat have been studied in patients with CKD and the high values of HOMA-IR (Homeostasis Model Assessment of Insulin Resistance), a marker for insulin resistance (RI), are described as metabolic complication strongly associated with excessive body fat. Nevertheless, studies evaluating the 25(OH)D status in patients with CKD non dialysis dependent, and its association with body adiposity and IR are scarce. The present study aims to evaluate the relationship between the levels of 25(OH)D, IR and body fat in patients with CKD non dialysis dependent. This is an observational cross-sectional study including adult patients, clinically stable and with estimated glomerular filtration rate (FGE)≤ 60 mL/min. The studied population receives regular care at the Interdisciplinary Center for treatment of CKD. Participants underwent assessment of nutritional status by anthropometry (weight, height, body mass index (BMI), circumferences and skinfolds) and by DXA (Dual-energy X-ray absorptiometry); blood samples were also analysed for creatinine, urea, glucose, albumin, total cholesterol and triglycerides, 25(OH)D, leptin and insulin. Levels of 25(OH)D <20ng/dL were considered deficient. Statistical analyzes were performed using STATA version 10.0 software, StataCorp, CollegeSatation, TX, USA. We evaluated 244 patients (men n= 135; 55.3%) with a mean age of 66.3 13.4 years and eGFR= 29.4 12.7 mL/min. The mean BMI was 26.1 kg/m (23.0 to 30.1) with a high prevalence of overweight/obesity (58%). Total body fat was high in men (total body fat by DXA= 30.2 7.6%) and women (total body fat by DXA= 39.9 6.6%). The median value of 25(OH)D was 28.55 (35.30 to 50.70) ng/dL and HOMA-IR was 1.6 (1.0 to 2.7) and patients with deficiency of 25(OH D n= 51 - 20.5%) had higher total (DXA% and BAI%) and central adiposity (DXA%) and higher levels of leptin. The 25(OH)D showed an inverse correlation with the total and central body fat and leptin, but was not associated with HOMA-IR values. These results allow to conclude that patients with CKD, non dialysis dependent, show deficiency of 25(OH)D and high body adiposity. These two conditions are strongly associated independent of the IR; the high total and central body adiposity is positively related with IR; the 25(OH)H and IR are not associated in this overweight/obese population.

Gli stili APA, Harvard, Vancouver, ISO e altri

18

Grages, Monica B. "Relationships Between Serum Cortisol, Vitamin D, Bone Mineral Density, and Body Composition in National Team Figure Skaters". Digital Archive @ GSU, 2013. http://digitalarchive.gsu.edu/nutrition_theses/47.

Testo completo

Abstract (sommario):

Background: Studies have not examined the relationships between serum vitamin D (SVitD), serum cortisol (SCort), bone mineral density (BMD), and body fat percent (BF%) in elite figure skaters. However, studies of non-athletes have found that BMD is inversely related to SCort and directly related to SVitD, and BF% is inversely related to SVitD and directly related to SCort. It was, therefore, the purpose of this study to assess the relationships between SCort, SVitD, BMD, and BF% in elite figure skaters. Methods: U.S. national team figure skaters were assessed at a national training camp during the summer, 2012. BMD and body composition were measured by dual energy x-ray absorptiometry (DEXA). Blood chemistry values for SVitD and SCort were obtained via venous puncture after an overnight fast, the same morning as the DEXA measurement. Georgia State University Institutional Review Board approval was obtained for the assessment of data collected at this training camp. Results: 24 out of 39 training camp attendees (61.5%) volunteered to be assessed as part of this study. Subjects ranged from 17 to 34 years and included males (n=11) and females (n=12). In all skaters statistically significant negative correlations (2-tailed Spearman) were found between SCort and BMD of the spine (r=-0.458, p=0.032), pelvis (r=-0.532, p=0.011), ribs (r=-0.517, p=0.014), and trunk (r=-0.538, p=0.010). In females, SCort was negatively correlated with BMD of the pelvis (r=-0.664, p=0.026) and trunk (r=-0.609, p=0.047), and was positively correlated with total BF% (r=0.657, p=0.020) and trunk fat % (r=0.708, p=0.010). In males, SCort was significantly correlated with BMD of the ribs (r=-0.627, p=0.039). The 3 skaters (all female) with SCort > 28 mcg/dL had significantly lower mean BMD of the total body, left femoral neck, legs, trunk, and pelvis, and significantly greater BF% of the total body and trunk when compared to the 20 skaters with SCort 7-28 mcg/dL. No significant correlations between SVitD and BMD or BF% were found. A Mann-Whitney U test found no significant differences in BMD and BF% between the 8 skaters with SVitD ≥ 30 ng/mL compared to the 15 skaters with SVitD < 30 ng/mL (p>0.05). Females with SVitD ≥ 30 ng/mL had significantly higher BMD (p=0.041) of the right femoral neck when compared to those with lower SVitD. Conclusions: Correlations consistently found negative associations between SCort cortisol and BMD in multiple assessment areas, particularly those composed of trabecular bone. Higher SCort was also associated with higher BF% in female skaters. Despite spending a great deal of time in indoor facilities, limiting vitamin D creation through sunlight exposure, no significant correlation between SVitD and BMD was found. Female athletes in ‘appearance’ sports, may be predisposed to restrained eating behaviors, which may be associated with elevated SCort. These findings suggest a need for further study of the interaction between SCort, BMD, and BF% in these athletes. The lack of a statistically significant relationship between SVitD and BMD suggests the need to investigate additional factors associated with bone injury risk in athletes.

Gli stili APA, Harvard, Vancouver, ISO e altri

19

Cobb, Jennifer L. "Validation of a Sun-Exposure Questionnaire for Adolescent Girls". Fogler Library, University of Maine, 2001. http://www.library.umaine.edu/theses/pdf/CobbJL2001.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

20

Maboshe, Wakunyambo. "Investigating the effects of dietary-derived and sunlight-derived vitamin D3 on markers of immune function". Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=237073.

Testo completo

Abstract (sommario):

Primarily synthesised via cutaneous exposure to solar ultraviolet B (UVB) radiation, serum vitamin D concentrations, measured as 25-hydroxyvitamin D (25(OH)D), fluctuate according to solar availability. Seasonal variations in vitamin D are common in areas of high or low latitude determined by the distance from the sun. Seasonal variations in blood pressure, immune markers and some diseases including influenza, have also been reported. However, the contributions of UVB light or vitamin D on the immune markers have not been fully determined. Against this background, the purpose of this research was to investigate the effects of UVB light therapy and dietary vitamin D supplementation on markers of immune function. The D SIRe1 study aimed to assess whether dietary-derived 25(OH)D could have similar effects on immune function as light-derived 25(OH)D. The study was an 8-week comparative intervention trial in healthy adults randomised to receive either 3 times weekly UVB radiation (equivalent to doses received during a Grampian-summer) for 4 weeks; or oral vitamin D3 (1000 IU a day for 8 weeks). Total 25(OH)D was measured by dual tandem mass spectrometry of serum samples following removal of protein and de-lipidation, whilst regulatory T cells (Tregs), known for maintaining immune system homeostasis, by flow cytometry. The study showed similar short-term effects between oral vitamin D and UVB exposure on measured outcomes. However, study interpretation was limited by the lack of a placebo group, yet, to our knowledge, this was the first study to directly compare dose-matched UVB therapy and vitamin D supplementation in healthy participants. Using similar laboratory techniques, the D-SIRe2 study, a placebo-controlled trial, assessed short-term (12 weeks) and long-term (43 weeks) effects of vitamin D supplementation on immune markers. Commencing in spring (March) and finishing in winter (January) 2015/2016, the study showed seasonal fluctuations in most immune markers. The fluctuations did not change according to variations in 25(OH)D concentrations nor were they correlated with solar UVB doses, with the exception of T cell proliferative responses, which were positively correlated with daily solar UVB doses. An interesting finding from this study was the prevention of increases in pro-inflammatory IFN-γ cytokine concentrations in the spring and summer time in the vitamin D3 supplemental group versus placebo. IFN-γ concentrations were raised from 7940 pg/mL at baseline in March, to roughly 12400 pg/mL at week 4 and to 13909 pg/mL at week 12 in the placebo group. The concentrations were roughly 1.3 times the mean concentrations measured in the vitamin D group at the timepoints following baseline concentrations of 10678 pg/mL, and 10013 pg/mL and 10233 pg/mL at weeks 4 and 12, respectively. The interactions between solar light or seasonal effects and oral vitamin D supplementation, as well as their individual and combined effects on immune function, are yet to be fully determined. Moreover, the metabolic and physiological implications of seasonal variation in serum 25(OH)D concentration and markers of immune function are currently unknown, requiring further investigation.

Gli stili APA, Harvard, Vancouver, ISO e altri

21

Orton, Sarah-Michelle. "Environmental factors in multiple sclerosis susceptibility and outcome : a focus on vitamin D". Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670043.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

22

Ousley, Amanda. "Engineering the human vitamin D receptor to bind a novel small molecule: investigating the structure-function relationship between human vitamin d receptor and various ligands". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39580.

Testo completo

Abstract (sommario):

The human vitamin D receptor (hVDR) is a member of the nuclear receptor superfamily, involved in calcium and phosphate homeostasis; hence implicated in a number of diseases, such as Rickets and Osteoporosis. This receptor binds 1α,25-dihydroxyvitamin D3 (also referred to as 1,25(OH)2D3) and other known ligands, such as lithocholic acid. Specific interactions between the receptor and ligand are crucial for the function and activation of this receptor, as implied by the single point mutation, H305Q, causing symptoms of Type II Rickets. In this work, further understanding of the significant and essential interactions between the ligand and the receptor were deciphered, through a combination of rational and random mutagenesis. A hVDR mutant, H305F, was engineered with increased sensitivity towards lithocholic acid, with an EC50 value of 10 µM and 40 + 14 fold activation in mammalian cell assays, while maintaining wild-type activity with 1,25(OH)2D3. Furthermore, via random mutagenesis, a hVDR mutant, H305F/H397Y, was discovered to bind a novel small molecule, cholecalciferol, a precursor in the 1α,25-dihydroxyvitamin D3 biosynthetic pathway, which does not activate wild-type hVDR. This variant, H305F/H397Y, binds and activates in response to cholecalciferol concentrations as low as 100 nM, with an EC50 value of 300 nM and 70 + 11 fold activation in mammalian cell assays.

Gli stili APA, Harvard, Vancouver, ISO e altri

23

White, Samantha. "The relationship of bone health to vitamin D status and body composition in pre-adolescent children (Pretoria, South Africa)". Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/65955.

Testo completo

Abstract (sommario):

Introduction: Bone health development and maintenance is important in children to reduce the risk for osteoporosis later in life. Knowledge on the vitamin D and bone health status of preadolescent children in South Africa is limited. Vitamin D and body composition both play important roles in bone health, but the relationship between adiposity and bone mass in children has been debated. The objective of this study was firstly, to describe the bone health status, body composition and vitamin D status of preadolescent children in Pretoria, South Africa. Secondly, the study examined bone health in relation to body composition and vitamin D status. Methods: A cross-sectional study, using conveniently sampled preadolescent black children aged 5-10, was conducted. Body weight was measured with the Seca medical body composition analyser and height using the Seca 274 stadiometer. Dual x-ray absorptiometry (DXA) was used for bone health (bone mineral content (BMC), areal bone mineral density (BMD) and bone area at the total body less the head (TBLH) and lumbar spine (LS) sites) and body composition (body fat percentage, fat mass and lean mass) assessments (n = 84). Vitamin D status (25(OH)D2 and 25(OH)D3) was determined from blood spot analysis (n = 59). To compare bone health means between vitamin D status groups, children were grouped as sufficient (25(OH)D ? 30 ng/ml), insufficient (25(OH)D = 21-29 ng/ml) or deficient (25(OH)D ? 20 ng/ml) accordingly. To compare bone health means between body composition groups, children were grouped as normal (BMIfor- age Z-score ? 1) or over-nourished (BMI-for-age Z-score > 1). Simple linear regression models were used in defining the relationship between bone health parameters and body composition components. Adjustments of bone health parameters for height-for-age, gender, age and body composition components was done using multiple linear regression. Comparison between adjusted bone health parameters of normal and over-nourished were made using the student’s two sample t-test. Results: The 59 children in the vitamin D study groups had a 24% prevalence of low BMD for chronological age and 7% presented with a low BMC for chronological age. A peculiar finding was that LS-BMAD differed significantly between the vitamin D insufficient and deficient groups. There was no relationship between any bone health parameters at all sites measured and serum levels of 25(OH)D (p > 0.05). Fat mass (FM) and body fat percentage least explained the observed variation in bone health parameters, whereas lean mass (LM) was the most important body composition component in explaining the variations observed in bone health parameters. The relationship between LS bone health parameters and body composition components was weaker than the relationship between TBLH bone health parameters and body composition components. Summary and / or Conclusion: In this population, 66% of preadolescents were vitamin D insufficient or deficient, but with a healthy bone health status and 40% of the preadolescents were over-nourished with greater crude BMD than those with healthy BMI Z-scores. Vitamin D status does not appear to be associated with parameters of bone health. Lean mass was the greatest body compositional determinant for variations observed in bone health parameters. Bone health parameters of healthy and over-nourished children did not differ after adjusting for body composition.
Dissertation (MSc)--University of Pretoria, 2017.
Food Science
MSc
Unrestricted

Gli stili APA, Harvard, Vancouver, ISO e altri

24

Sommerville, Racheal. "Vitamin D Supplements Intake among Americans: National Health and Nutrition Examination Survey 2001-2002, 2003-2004 and 2005-2006". Bowling Green, Ohio : Bowling Green State University, 2010. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=bgsu1269284002.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Rockell, Jennifer, e n/a. "Serum 25-hydroxyvitamin D concentrations and their determinants in the New Zealand population". University of Otago. Department of Nutrition, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080929.142611.

Testo completo

Abstract (sommario):

Adequate vitamin D status plays an important role in bone health and may also protect against Type 1 Diabetes (T1D), multiple sclerosis and certain cancers. Vitamin D is obtained from two sources; diet and through skin synthesis through the action of ultraviolet (UV) light. Dietary intakes of vitamin D are low in New Zealand (NZ) and the majority of our vitamin D comes from UV exposure. The NZ population may be at risk of low vitamin D status because of low dietary intakes, the country�s latitude (35-46 �S), and high proportion of darker skinned Maori and Pacific People. While case reports have described the occurrence of rickets, predominantly in immigrant groups, there are currently no national data on the vitamin D status of the NZ population. Reports of low vitamin D status in countries of similar latitude to NZ justify an examination of New Zealanders� vitamin D status. The best method to assess of vitamin D status is to measure circulating 25-hydroxyvitamin D concentrations. This thesis comprises three main studies. The first two had the following aims: to measure 25-hydroxyvitamin D concentrations and their determinants in a national sample (n=1585) of NZ children aged 5-14 y and to measure serum 25-hydroxyvitamin D concentrations and their determinants in a national sample (n=2948) of New Zealanders aged 15 y and over. The 2002 Children�s Nutrition Survey CNS02 was a year long (December, March-November) cross-sectional survey of a nationally representative sample of NZ school children 5-14 y. Over-sampling of Maori and Pacific children allowed ethnic specific analyses. The 1997 National Nutrition Survey (NNS97) participants were recruited over one year according to an area-based sampling frame with a 3 stage stratified design consisting of primary sampling units, households within each unit, and one randomly selected respondent from each household. Mean (99% CI) serum 25-hydroxyvitamin D concentrations were similar in children and adults (both 50 nmol/L). Among Maori, Pacific and NZEO children respectively, prevalence (%, 99% CI) of serum 25-hydroxyvitamin D deficiency (< 17.5 nmol/L) was 5% (2, 12), 8% (5, 14), and 3% (1,7). Based on a cutoff of < 37.5 nmol/L, prevalence of insufficiency was 41% (29, 53), 59% (42, 75) and 25% (15, 35), respectively. Based on a cutoff of 50 nmol/L, 56% of children were insufficient. Three percent of adult New Zealanders had serum 25-hydroxyvitamin D concentrations indicative of deficiency ([less than or equal to] 17.5 nmol/L); 48% and 84% were insufficient based on cutoffs of [less than or equal to] 50 and [less than or equal to] 80 nmol/L The main determinants of vitamin D status in NZ children were season, ethnicity and sex. After adjustment for other factors and covariates, boys had an adjusted mean (99% CI) 25-hydroxyvitamin D concentration 5 (1, 9) nmol/L higher than girls, Maori children were 7 (2, 11) and Pacific children 15 (11, 20) nmol/L lower than NZ European and Other (NZEO) children. Obese children were 7 (2, 11) nmol/L lower than overweight or �normal� weight. Children�s mean 25-hydroxyvitamin D concentrations (adjusted for other variables) peaked in March (69 nmol/L) and was at its lowest in August (36 nmol/L). In adults, there were effects of a similar magnitude of ethnicity and season on serum 25-hydroxyvitamin D concentrations. Obesity, latitude and age were determinants of vitamin D status in women but not men. Obese (BMI > 30) women had an adjusted mean vitamin concentration 6 (3, 10) nmol/L lower than women with BMI < 25. Women living in the South Island were 6 (3, 9) nmol/L lower than women living in the North Island. Additionally, adjusted mean serum 25-hydroxyvitamin D was 13 (8, 18) higher in women 15 -18 y than women 65 y or older. The third and final study aimed to determine whether the higher rates of vitamin D inadequacy reported in the winter than summer months in NZ also result in higher PTH concentrations, which would provide evidence for functional effect of inadequate vitamin D status. We also aimed to objectively explore the effect of natural skin colour on vitamin D status, given the higher prevalence of vitamin D insufficiency in dark-skinned groups living far from the equator. Skin colour measurements were taken with a hand-held light reflectometer (Datacolor Mercury[TM] 1000 colorimeter, Lawrenceville, NJ). In the 342 residents of Invercargill and Dunedin, mean serum 25-hydroxyvitamin D concentrations were lower in the late summer versus early spring (79 vs 51 nmol/L; P< 0.001). The lower serum 25-hydroxyvitamin D in early spring versus summer was associatedwith a 2 pg/mL (P< 0.001) higher parathyroid hormone (PTH) concentration. Interestingly, no significant effect of natural skin colour, based on light reflectance at the inside of the upper arm, was discovered, though there was a positive effect of tanning, based on light reflectance at the upper forearm, on serum 25-hydroxyvitamin D concentrations. Ethnicity and season are major determinants of serum 25-hydroxyvitamin D in New Zealanders. There is a high prevalence of vitamin D insufficiency in NZ children and adults, which may contribute to increased risk of osteoporosis and other chronic disease. While there is a pressing need for more convincing evidence with regards to the health risks associated with the low vitamin D status in children, evidence from the study of adults, where higher PTH concentrations were found during spring versus summer, suggests that the low 25-hydroxyvitamin D concentrations are having an adverse effect on bone health of adults. The high prevalence of vitamin D insufficiency in New Zealanders, warrants serious consideration of strategies such as fortification, to improve the vitamin D status of the population.

Gli stili APA, Harvard, Vancouver, ISO e altri

26

Sim, Wai-Lum Winnie. "Liver injury in hypervitaminosis A: Evidence for activation of Kupffer cell function". Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184410.

Testo completo

Abstract (sommario):

The most important and novel finding of this work was enhanced liver Kupffer cell phagocytic and metabolic function by hypervitaminosis A. An animal model of hypervitaminosis A was developed in male Sprague-Dawley rats gavaged with 250,000 I.U. retinol/Kg body weight/day for 3 weeks. Presence of hypervitaminosis A was indicated by characteristic changes in the fur coat, presence of brittle bones and spontaneous fractures and a significant increase in plasma and liver concentrations of retinyl palmitate while retinol levels remained the same as in controls. Hypervitaminosis A did not cause severe liver abnormalities as reflected by normal plasma glutamate pyruvate transaminase activity and bilirubin. Hepatic blood flow and portal pressure were also normal. Liver microsomal cytochrome P-450 was decreased while malondialdehyde, a by-product of lipid peroxidation, was increased by the Vitamin A treatment. Examination of liver tissue by light microscopy showed no signs of liver cell injury. The main change was a marked increase in size of the fat or Vitamin A storing cells. Although hypervitaminosis A itself did not cause severe liver damage, pretreatment with high doses of Vitamin A severely potentiated liver injury by known hepatotoxicants such as carbon tetrachloride, endotoxin and acetaminophen. The potentiation of hepatotoxicity was determined by activity of glutamate pyruvate transaminase in plasma as well as by histological examination of liver tissue. Measurement of clearance from blood of indocyanine green and ⁹⁹ᵐTc-disofenin indicated this hepatocyte function was normal. Kupffer cell phagocytic function was enhanced in hypervitaminosis A as determined by clearance from blood of ⁹⁹ᵐTc-sulfur colloid. In vitro, there was also evidence that treatment with high doses of Vitamin A activated or enhanced Kupffer cell function. Kupffer cells from control and Vitamin A treated rats were isolated by enzymatic dispersion, purified by centrifugal elutriation, and placed in culture. Activation was indicated by (1) increased phagocytosis of ⁵¹Cr-labeled opsonized sheep red blood cells (2) enhanced release of superoxide anion and (3) enhanced production of tumor cytolytic factor by Kupffer cells from Vitamin A treated rats. Stimulation of Kupffer cell function in hypervitaminosis A seemed to be via lymphokines produced by lymphocytes in response to the excess Vitamin A. We propose that activated Kupffer cells may play an important role in liver injury in hypervitaminosis A.

Gli stili APA, Harvard, Vancouver, ISO e altri

27

Genaro, Patricia de Souza. "Consumo alimentar e metabolismo mineral e ósseo em mulheres idosas com sarcopenia". Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/6/6133/tde-24052010-095200/.

Testo completo

Abstract (sommario):

Introdução a redução da massa muscular esquelética relacionada à idade, denominada sarcopenia, está associada com maior incidência de quedas, fraturas e dependência funcional em idosos. Muitos são os fatores que podem contribuir para o surgimento da sarcopenia, dentre eles a deficiência de vitamina D e a inadequação do consumo alimentar, principalmente a ingestão de proteína. Objetivos investigar a relação da sarcopenia com o consumo alimentar e concentração sérica de 25(OH)D. Métodos Foram avaliadas 200 mulheres acima de 65 anos, sendo 35 com sarcopenia e 165 sem sarcopenia. Avaliou-se a densidade mineral óssea (DMO) da coluna lombar, fêmur proximal e a composição corporal (massa muscular total, massa muscular esquelética, massa adiposa, conteúdo mineral ósseo do corpo total) por meio do densitômetro de dupla emissão com fonte de raios-X (DXA), avaliação radiográfica das colunas dorsal e lombar (T4 a L4). Foi realizada também avaliação da ingestão alimentar (diário de três dias), bioquímica do metabolismo mineral e ósseo (cálcio total, fósforo, creatinina, albumina, paratormônio intacto, calcidiol) e a história clínica das pacientes. Resultados O presente estudo observou que as pacientes que apresentavam um consumo de proteína acima de 1,2g/kg/dia apresentaram massa muscular total [33,94 (4,72) vs 31,87 (3,52) kg, p=0,020], massa muscular esquelética [14,54 (2,38) vs 13,38 (1,95) kg, p=0,013], CMO do corpo total [1,945 (0,325) vs 1784 (0,265) g, p=0,005], DMO de corpo total [1,039 (0,109) vs 0,988 (0,090) g/cm2, p=0,011], DMO coluna lombar [0,983 (0,192) vs 0,903 (0,131) g/cm2, p=0,014], DMO colo de fêmur [0,813 (0,117) vs 0,760 (0,944) g/cm2, p=0,017] e DMO fêmur total [0,868 (0,135) vs 0,807 (0,116) g/cm2, p=0,026] significativamente maior quando comparado com pacientes que apresentavam consumo de proteína abaixo de 0,8g/kg/dia. Além disso, a ingestão de aminoácidos essenciais, principalmente os de cadeia ramificada como a valina [3,10 (0,89) vs 3,40 (1,04) g/dia, p=0,044] foi significantemente menor em mulheres com sarcopenia. O consumo de proteína se correlacionou positivamente com o índice de massa muscular esquelética (r=0,157; p=0,028) e a DMO do trocânter (r=0,185; p=0,010). Adicionalmente, a deficiência de vitamina D associados ao PTH elevado (> 65pg/dL), hiperparatiroidismo secundário, a prevalência de sarcopenia aumentada (77,1 vs 22,9%, p=0,032), além disso mulheres com hiperparatiroidismo secundário apresentaram massa muscular total [29,70 ( 2,99) vs 31,84 (3,65), p=0,043], índice de massa muscular esquelética [5,51 (0,55) vs 5,92 (0,78), p=0,043] significativamente menor. Alta prevalência de deficiência de vitamina D em mulheres com sarcopenia (71,4%). As mulheres com deficiência de vitamina D apresentaram massa muscular total [30,30 (2,92) vs 32,14 (3,84) kg, p=0,007], massa muscular esquelética apendicular [12,71 (1,59) vs 13,55 (0,82) kg, p=0,031]; índice de massa muscular esquelética [5,67 ( 0,60) vs 5,98 (0,82) kg/m2, p=0,030] e fêmur total BMD [0,791 (0,107) vs 0,838 (0,116) g/cm2, p=0,035] significativamente menor. Conclusões - A ingestão de proteínas acima 1,2g/kg/d, especialmente aminoácidos essenciais e suplementação de vitamina D deve ser considerada como terapia preventiva na redução da massa muscular e óssea em mulheres idosas
Introduction - Reduction of skeletal muscle mass, called sarcopenia, is associated with increased incidence of falls, fractures and functional dependence in the elderly. There are many factors that can contribute to the development of sarcopenia, among them the vitamin D deficiency and inadequate food intake, especially protein intake. Objectives - to investigate the relationship among sarcopenia, dietary intake and serum concentration of 25(OH)D. Methods - We evaluated 200 women over 65 years, 35 with sarcopenia and 165 without sarcopenia. Bone mineral density of lumbar spine, proximal femur and body composition (total muscle mass, skeletal muscle mass, fat mass, bone mineral content of the whole body) were assessed by Dual energy X-ray absorptiometry (DXA), radiological evaluation of the dorsal columns and lumbar (T4 to L4). Three-day dietary records were undertaken to estimate dietary intake and serum total albumin, calcium, phosphorus, creatinin, intact parathyroid hormone, 25(OH)D were measured. Results - Patients who presented protein intake above 1.2g/kg/day showed total muscle mass [33.94 (4.72) vs 31.87 (3.52) kg, p=0.020], muscle mass skeletal [14.54 (2.38) vs 13.38 (1.95) kg, p=0.013], total body BMC [1.945 (0.325) vs 1784 (0.265) g, p=0.005], total body BMD [1.039 (0.109) vs 0.988 (0.090) g/cm2, p=0.011], lumbar spine BMD [0.983 (0.192) vs 0.903 (0.131) g/cm2, p=0.014], femoral neck BMD [0.813 (0.117) vs 0.760 (0.944) g/cm2, p=0.017] and total femur BMD [0.868 (0.135) vs 0.807 (0.116) g/cm2, p=0.026] significantly higher when compared with patients who presented protein intake below 0.8g/kg/day. Essential amino acids intake, especially branched chain such as valine [3.10 (0.89) vs 3.40 (1.04) g/day, p=0.044] was significantly lower in women with sarcopenia. Protein intake positively correlated to skeletal muscle mass index (r=0.157, p=0.028) and trochanter BMD (r=0.185, p=0.010). Additionaly, presence of sarcopenia increases more than 20% when vitamin D deficiency is associated to PTH levels higher than 65pg/dL (77.1 vs 22.9%; p=0.032). Women with secondary hyperparathyroidism presented significantly lower total muscle mass [29.70 (2.99) vs 31.84 (3.65); p=0.043], SMMI [5.51 (0.55) vs 5.92 (0.78); p=0.043]. it was also observed high prevalence of vitamin D deficiency in women with sarcopenia (71.4%). Women with deficiency of vitamin D presented significantly lower TSMM [30.30 (2.92) vs 32.14 (3.84) kg; p=0.007], ASMM [12.71 (1.59) vs 13.55 (0.82) kg; p=0.031]; SMMI [5.67 (0.60) vs 5.98 (0.82) kg/m2; p=0.030] and total femur BMD [0.791 (0.107) vs 0.838 (0.116) g/cm2; p=0.035]. Conclusions Protein intake above 1.2g/kg/d, particularly essencial amino acids and vitamin D supplementation should be considered as preventive therapy in reducing muscle and bone mass in elderly women

Gli stili APA, Harvard, Vancouver, ISO e altri

28

Xin, Liping. "Women of childbearing age dietary patterns and vitamin B12 status : a validation study : a thesis submitted to Auckland University of Technology in fulfilment of the degree of Master of Philosophy, 2008". Click here to access this resource online, 2008. http://hdl.handle.net/10292/457.

Testo completo

Abstract (sommario):

From conception the dynamic balance between nutritional and activity factors play a role in the accumulation of risk for future disease. Maternal nutrient balance and the subsequent dietary pattern of the family set the path for the growth and development of the individual and therefore also for their offspring. There is strong evidence from studies in India that mothers who have a low vitamin B12 status, but high folate, will have children with higher adiposity and more cardiovascular risk factors than those with adequate B12. The B12 status is closely linked to the dietary pattern particularly the consumption of red meat which has a high B12 content. In New Zealand there are an increasing number of Indian migrants. Vegetarianism is also practiced by an increasing number including young women. In addition, there is a high rate (up to 60%) of unplanned pregnancies in New Zealand. In the 1997 New Zealand National Nutrition Survey (NNS97) report, vitamin B12 intake appeared adequate for the New Zealand population and breakfast cereals were reported as one major dietary source of B12. Cereals in New Zealand however, were not fortified with B12 and there was an error in the FOODfile™ data entries for B12 in some cereals. The raw data of reported B12 intakes in the 24-hour diet recall (24HDR) of NNS97 was reanalysed at the individual level by subtracting the B12 derived from breakfast cereals and applying the 2005 revised estimated average requirement (EAR) value. The possible prevalence of B12 insufficiency was 2.4 times that originally reported by the NNS97, translating into a prevalence of up to 27% of the population sampled. This analysis was limited as it was not adjusted for day-to-day variance or to the New Zealand population. This apparently high prevalence of risk for inadequate B12 intake in the surveyed individuals required confirmation that the B12 intake from 24HDR and also a 7-day diet diary (7DDD) was a valid assessment of B12 status. The group of particular interest is women of childbearing age (18-50y) with a range of eating patterns. Thirty eight women aged 19-48y; 12 non-red-meat-eaters (5 Indians vs. 7 non-Indians) and 26 red-meat-eaters (1 Indian vs. 25 non-Indians) participated in this validation study. Anthropometry and hand-to-foot bioelectrical impedance (BIA) were measured on the same day as a 24HDR was recorded. Fasting serum lipids, glucose, haematological parameters, and serum B12, holotranscobalamin II (holo-TC II, a specific B12 biomarker), and folate concentrations were measured. Foods eaten and time spent in physical activity during the following 7 days were extracted from 7DDD and 7-day physical activity diary (7DPAD). There was no significant correlation between dietary intake (24HDR or 7DDD) and biomarkers for B12 status. Indians reported lower mean daily B12 intakes in 7DDD than non-Indians (1.6 vs. 4.5 μg/day, p<0.001) and this was confirmed by Indians’ significantly low serum B12 (203 vs. 383 pmol/L, p=0.04) and holo-TC II (35 vs. 72 pmol/L, p=0.02) concentrations compared to non-Indians. A similar pattern was found between non-red-meat-eaters and red-meat-eaters in daily B12 intake in 7DDD (2.3 vs. 4.8 μg/day, p<0.001) and in B12 biomarkers (serum B12, 263 vs. 397 pmol/L, p=0.01; holo-TC II, 43 vs. 77 pmol/L, p<0.005). Non-red-meat-eaters reported significantly higher daily folate intake in 7DDD (359 vs. 260 μg/day, p=0.01) than red-meat-eaters but no significant difference was found in serum folate concentration between these groups (29 vs. 24 pmol/L, p=0.10). Indians/non-red-meat-eaters also reported lower daily protein intake and higher percentage of total energy from carbohydrate in 7DDD compared to non-Indians/red-meat-eaters but total reported energy intake tended to be under-reported and physical activity over-reported when assessed against estimated basal metabolic rate (BMR). Body composition varied by dietary pattern. Indians/non-red-meat-eaters had higher body fat percentage (BF %) and weaker grip strength than non-Indians/red-meat-eaters. In addition, Indians had a significantly higher waist-to-hip ratio (WHR) than non-Indians. Overall, the whole group reported that they were inactive. The median time spent in moderate, high and maximal intensity activities was only 19 minutes a day, which did not meet the NZ guideline for adults of 30 minutes a day. In this small study nutrient analysis of diet by 24HDR or 7DDD, was not a reliable or accurate way to assess B12 insufficiency. Questions about dietary patterns such as “do you eat red meat”, and taking ethnicity into account could more easily identify the at risk population. Supplementation and/or fortification of B12 should be considered before pregnancy.

Gli stili APA, Harvard, Vancouver, ISO e altri

29

Villaverde, Haro Cecilia. "Interaction between dietary polyunsaturated fatty acids and vitamin e in body lipid composition and (alfa)-tocopherol content of broiler chickens". Doctoral thesis, Universitat Autònoma de Barcelona, 2005. http://hdl.handle.net/10803/5666.

Testo completo

Abstract (sommario):

El objetivo principal de esta memoria de tesis es evaluar la interacción entre ácidos grasos poliinsaturados y vitamina E dietéticos sobre la deposición corporal de ácidos grasos y -tocoferol en pollos broiler. Se diseñaron dos experimentos que basados en niveles crecientes de acetato de -tocoferol (0, 100, 200 y 400 mg/kg) y ácidos grasos poliinsaturados en los piensos. En la primera prueba, el gradiente de poliinsaturación se obtuvo mezclando una grasa saturada (sebo) con una mezcla de aceites insaturados (aceites de linaza y pescado), manteniendo el nivel de inclusión de la grasa constante (9%). En la segunda prueba, el gradiente se creó incrementando el nivel de inclusión de la grasa añadida (2, 4, 6 y 8%), utilizando aceites de linaza y pescado. Se realizaron 2 balances para determinar la energía metabolizable aparente, la absorción aparente de la materia orgánica, la grasa bruta, los ácidos grasos y el -tocoferol, y el porcentaje de hidrólisis del acetato de -tocoferol. Al final de cada estudio (44 y 40 días de edad), la mitad de los animales fueron sacrificados mediante inyección letal y la otra mitad en un matadero. Los primeros se conservaron enteros y los últimos se despiezaron, obteniéndose la grasa abdominal y el hígado. Se cuantificaron los ácidos grasos y el -tocoferol en el cuerpo entero. -tocoferol también se determinó en el hígado. También se analizó la composición química y el contenido en energía bruta del pollo entero. La poliinsaturación dietética manteniendo el nivel de grasa constante (prueba 1) tuvo efecto sobre la energía metabolizable aparente de los piensos. Los animales que ingirieron el pienso más saturado tuvieron una menor absorción aparente de la materia orgánica, disminuyendo así la energía metabolizable aparente de este pienso. A pesar de esto, los animales alimentados con 9% de sebo tuvieron un mayor contenido en grasa y energía en el cuerpo. Por el contrario, incrementar la poliinsaturación dietética mediante el aumento del nivel de inclusión de grasa (prueba 2) no tuvo ningún efecto sobre la composición química ni el contenido en energía del pollo. El aumento de la ingestión de ácidos grasos poliinsaturados resultó en incrementos lineales de su concentración en los pollos en ambos experimentos. La contribución de la síntesis endógena a la concentración corporal de ácidos grasos saturados y monoinsaturados se estimó utilizando los datos combinados de las dos pruebas. Ésta varia entre 17.7% (10% de grasa en el pienso) a 35.3% (0% de grasa) en el caso de los ácidos grasos saturados; y entre un 7.0% y 52.7% en el caso de los monoinsaturados. La inclusión de acetato de -tocoferol no tuvo efectos marcados sobre el contenido de ácidos grasos del pollo. Los valores de absorción aparente del -tocoferol variaron entre 11 y 50%, con un valor medio de 42.1% bajo nuestras condiciones experimentales. No hubo diferencias al comparar las dos edades (20 y 39 días de edad). La inclusión de sebo al 9% en el pienso afectó negativamente a la absorción aparente del -tocoferol y el porcentaje de hidrólisis de acetato de -tocoferol. Por otra parte, incrementos en el nivel de inclusión de la grasa añadida rica en ácidos grasos poliinsaturados no tuvieron efecto sobre estos parámetros. Niveles elevados de ácidos grasos poliinsaturados en la dieta no afectaron la absorción aparente de -tocoferol, pero redujeron la concentración de -tocoferol libre en heces, sugiriéndose un gasto en el tracto gastrointestinal previa absorción. El depósito de -tocoferol en el hígado fue menor en los animales alimentados con los piensos más insaturados comparados con los animales alimentados con el pienso saturado (prueba 1) y a los animales alimentados con el pienso bajo en grasa.
The main objective of this PhD dissertation is to evaluate the interaction between dietary poliunsaturated fatty acids and vitamin E on body deposition of fatty acids and -tocopherol in broiler chickens. Two experiments were designed based on -tocopheryl acetate supplementation (0, 100, 200 and 400 mg/kg) and a gradient of dietary poliunsaturation. In trial 1, this gradient was achieved blending tallow (rich in saturated fatty acids) with linseed and fish oil (unsaturated oils), keeping added fat constant (9%). In trial 2, the gradient was made increasing the inclusion level of dietary fat (2, 4, 6 and 8%), a blend of linseed and fish oil. Two balance studies were made in order to measure apparent metabolizable energy, apparent absorption of organic matter, crude fat, fatty acids and -tocopherol, and also -tocopheryl acetate percentage of hydrolysis. At the end of each trial (40 and 44 days of age), half of the animals were killed by lethal injection and the other half were killed in a slaughterhouse. The former were kept whole and the latter were quartered and the liver and absdominal fat pad were obtained. Fatty acids and -tocopherol were quantified in the whole body, and -tocopherol was also measured in the liver. Aslo, the chemical composition (Weende) and energy content of the whole body was analyzed. Dietary poliunsaturation, keeping added fat constant, had effect upon apparent metabolizable energy content of the diets. The animals fed the more saturated diet had lower apparent absorption of organic matter, resulting in a lower apparent metabolizable energy of this diet. However, the animals fed this saturated diet had higher energy and fat content in the whole body. On the other hand, increasing dietary poliunsaturation by means of increasing added fat inclusion level had no effect whatsoever upon chemical and energy content of the chickens. The increase in polyunsaturated fatty acids intake resulted in a linear increase in their body deposition in both trials. The contribution of endogenous synthesis to fatty acid composition of the body was estimated using the combined data of both trials. This contribution varies between 17.7% (10% of dietary fat) and 35.3% (0% dietary fat) for the saturated fatty acids; and between 7.0% and 52.7% for the monounsaturated ones. Vitamin E inclusion had no marked effects upon fatty acid content in the whole body. Apparent absorption coefficients for vitamin E varied between 10 and 50%, with an average value of 42.1% under our experimental conditions. There were no differences in this variable when comparing between the two ages (20 and 39 days of age). The inclusion of 9% of tallow affected negatively -tocopherol apparent absorption and -tocopheryl acetate % of hydrolysis. On the other hand, increases in added fat inclusion level had no effect on these parameters. High dietary poliunsaturation levels did not affect vitamin E apparent absorption but resulted in lower free -tocopherol excretion, suggesting a gastrointestinal waste by lipid oxidation previous to its absorption. -tocopherol deposition in the liver was lower in the animals fed the more unsaturated diets compared to the ones fed the saturated (trial 1) or the low-fat ones (trial 2).

Gli stili APA, Harvard, Vancouver, ISO e altri

30

Sulistyoningrum, Dian. "The role of vitamin D and adiponectin in ethnic-specific differences in body fat distribution and risk for cardiovascular disease". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42852.

Testo completo

Abstract (sommario):

Background: Body fat distribution, in particular visceral adipose tissue (VAT), contributes to risk of cardiovascular disease (CVD). The Multicultural-Community Health Assessment Trial (M-CHAT) reported that South Asians have greater VAT than Europeans despite similar BMIs, putting them at greater risk of CVD. However, the molecular mechanisms underlying ethnic-specific differences in body fat distribution are unclear. Low circulating 25-hydroxyvitamin D (25OHD) and adiponectin concentrations are prevalent in individuals with obesity (BMI ≥ 30kg/m²), and are associated with increased risk of CVD. Furthermore, 25OHD is inversely associated with blood pressure. Adiponectin is an adipokine that has insulin-sensitizing, anti-inflammatory, and anti-atherogenic properties. Adiponectin circulates as isoforms low (LMW), medium (MMW), and the reported most biologically active isoform, high (HMW) molecular weight. This thesis aims to investigate ethnic-specific differences in the relationship between plasma 25OHD and adiponectin concentrations with body fat distribution and CVD risk factors. Methods/Results: Europeans (n=171) and South Asians (n=176) from the M-CHAT cohort were assessed for demographics, plasma 25OHD, total and HMW adiponectin concentrations, and CVD risk factors. A computed tomography (CT) scan was used to quantify VAT and subcutaneous adipose tissue (SAT) deposition. South Asians had lower (p < 0.001) 25OHD in comparison to the Europeans (63.0 nmol/L vs. 39 nmol/L, respectively). VAT was inversely associated (p < 0.05) with 25OHD even after adjustment for age, sex, BMI, season of blood collection, SAT and total body fat (%). This suggests that VAT mediates the relationship between plasma 25OHD and CVD risk. Furthermore, the inverse association between systolic and diastolic blood pressure and 25OHD was no longer significant after adjustment for VAT. However, circulating plasma adiponectin concentrations remained strongly associated with fasting plasma HDL-cholesterol, triglycerides, insulin, and HOMA-insulin resistance (HOMA-IR), even after adjustment for VAT. Interestingly, South Asians also had lower (p<0.001) total and HMW adiponectin concentrations compared to Europeans. Conclusion: These findings demonstrate that plasma 25OHD and total and HMW adiponectin concentrations are associated with VAT deposition in Europeans and South Asians. Furthermore, plasma 25OHD and total and HMW adiponectin concentrations are lower in South Asians than the Europeans, which may contribute to elevated CVD risk in South Asians.

Gli stili APA, Harvard, Vancouver, ISO e altri

31

Kerr, Maeve Aine. "B vitamin status in healthy populations : relationship with body mass index and possible implications for risk of neural tube defects". Thesis, University of Ulster, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.444482.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

32

Anschütz, Wilma Margarete [Verfasser], e Michael [Akademischer Betreuer] Amling. "Untersuchungen von Einflussfaktoren auf den Body Sway mit besonderer Berücksichtigung des Vitamin D-Spiegels / Wilma Margarete Anschütz. Betreuer: Michael Amling". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2015. http://d-nb.info/1079002197/34.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

33

Anschütz, Wilma Margarete Verfasser], e Michael [Akademischer Betreuer] [Amling. "Untersuchungen von Einflussfaktoren auf den Body Sway mit besonderer Berücksichtigung des Vitamin D-Spiegels / Wilma Margarete Anschütz. Betreuer: Michael Amling". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2015. http://nbn-resolving.de/urn:nbn:de:gbv:18-76116.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

34

McAdler, Marisa M. "The Relationship Between Vitamin D Status of Adult Women and Diet, Sun Exposure, Skin Reflectance, Body Composition, and Insulin Sensitivity". DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1090.

Testo completo

Abstract (sommario):

As the prevalence of vitamin D deficiency continues to grow, mounting evidence supporting its link with chronic disease strengthens suggesting vitamin D’s candidacy in the prevention and treatment of multiple disease states and their complications. Dietary guidelines, however, do not take sun exposure into account. The present study sought to explore the impact of sun exposure on vitamin D status (serum 25(OH)D), and identify other significant determinants of serum levels which may have the greatest effects on overall health. Participants (n = 34) were pre-menopausal women aged 18 to 50 years (mean age 39 ± 6 years), who had their blood drawn at a local pathology lab and a follow-up appointment at a health assessment lab for the collection of other measurements. Mean serum 25(OH)D level was 64 ± 18 nmol/L, and mean dietary vitamin D intake was approximately 327 ± 229 IU/day. Although 82% of participants were below the RDA guidelines (600 IU/day for females ages 9-50 years) for dietary vitamin D intake, only 32% had serum 25(OH)D levels < 50 nmol/L (the recommended level of sufficiency for bone health) reflecting deficiency. While serum 25(OH)D levels were significantly correlated to dietary vitamin D intake (r = 0.42, p = 0.0139), it is reasonable to assume that participants obtained adequate vitamin D from sun exposure. Fasting serum insulin levels were significantly, positively correlated with BMI (r = 0.83, p < 0.0001), and sun exposure index (Body Surface Area x Minutes of Direct Sunlight) was significantly, positively correlated with serum 25(OH)D levels (fall weekend SEI: r = 0.47, p = 0.0059; spring weekend SEI: r = 0.43, p = 0.0135; average weekend SEI: r = 0.43, p = 0.013; and average overall SEI: r = 0.39, p = 0.0247). Reported sun exposure appeared to be least during winter weekdays and the most during summer weekends. Regression analysis was used to determine the strongest predictors of serum 25(OH)D levels, which were found to be sun exposure, dietary vitamin D intake, skin reflectance, age, BMI, and ethnicity (R2 = 0.58 , p = 0.0031), demonstrating that simple questionnaires, such as those employed in this study, can help to predict serum 25(OH)D status and thus be considered in the future treatment of vitamin D deficiency.

Gli stili APA, Harvard, Vancouver, ISO e altri

35

Leonard, Franciska. "Modulation of the intestinal vitamin D receptor and calcium ATPase activity by essential fatty acid supplementation". Diss., University of Pretoria, 1999. http://hdl.handle.net/2263/24269.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

36

Elnefily, Rasha. "Determinants of Bone Mineral Density Changes in Women Transitioning to Menopause: A MONET Group Study". Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24264.

Testo completo

Abstract (sommario):

Menopause is an important period for bone health in women. Objective: To assess the determinants of bone mineral density (BMD) changes in women transitioning to menopause. Method: A secondary data analysis of the MONET (Montreal-Ottawa New Emerging Team) study. Outcome measures included yearly assessment of menopause status, body composition, BMD, physical activity energy expenditure (PAEE) and dietary calcium and vitamin D intakes. Results: 84 of the original 102 women had complete data for the purpose of the present study. Repeated measures analysis revealed significant decreases in lumbar spine and femoral neck BMD (P< 0.01). Regression analysis revealed that baseline femoral neck BMD, changes in PAEE and trunk fat explained 31% of the variation of BMD changes at the femoral neck, while changes in both PAEE and trunk fat account for 27% of BMD change at lumbar spine. Conclusion: Baseline femoral neck and changes in physical activity energy expenditure and trunk fat are determinants of the reduction of bone mineral density in women transitioning to menopause.

Gli stili APA, Harvard, Vancouver, ISO e altri

37

Avila-Escalante, Maria L. "The association between dietary intake of folate (F) and vitamin B12 (VB12) with body composition (BC) of adolescents aged 10-18 years from Merida, Mexico". Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/20121.

Testo completo

Abstract (sommario):

Mexico has a high prevalence of stunting in children and adolescents, due to poor nutrition. Paradoxically, too many Mexican children and adolescents are currently overweight or obese (OW/OB). The dual-burden of stunting (low height for age) and OW/OB are nutritional conditions that increase the risk of developing chronic degenerative diseases in adulthood. The persistence of high levels of stunting in southern regions of Mexico, such as Yucatan, may be due to diet changes (nutrition transition) that Yucatecan population has experienced in recent years. Vitamins, such as folic acid (FA) and VB12 are micronutrients necessary for normal metabolism and growth. The relationships between the intake of these micronutrients and growth rate were identified. The impact of micronutrient consumption on body composition was also investigated. The sample population comprised 273 adolescents (152 females) aged 10-18 years, from Merida, Mexico. Dietary information was obtained using a food frequency questionnaire (FFQ) covering 106 local foods. Anthropometric and body composition measurements were taken, and socioeconomic data were gathered. Data were collected between September 2011 and July 2012. Over 50% of participants had inadequate consumption of both vitamins: 64% had inadequate intake of FA and 69% of VB12. Almost half (46.9%) were either short or stunted, and 33% were at risk of OW/OB. A higher risk of presenting OW/OB was found for participants with FA intake less than the RDI of 400 μg/day and for those with VB12 intake less than the RDI of 2.4 μg/day. No relationship was found between body fat percentage and the consumption of FA or VB12.

Gli stili APA, Harvard, Vancouver, ISO e altri

38

Fosson, Elizabeth Reid. "Relationship Between Total Body Mass, Fat-Free Mass, Fat Mass, and Bone Mineral Density of the Hip In Middle-Age Women: The Roles of Diet, Physical Activity, and Menopause". BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3706.

Testo completo

Abstract (sommario):

Objective: This study was conducted to investigate the relationship between hip bone mineral density (BMD), fat free mass (FFM), fat mass (FM), and total body mass (TBM) and the extent to which these relationships were modified by various confounding factors. The cross-sectional analysis included 262 healthy females (mean age 41.6±3.0 years). Methods: BMD of the hip and body composition were assessed by the Hologic 4500W dual energy x-ray absorptiometry (DXA) system. Total and intensity of physical activity (PA) were objectively measured using an Actigraph accelerometer. Dietary calcium and vitamin D from food and beverages, as well as from supplements, were measured separately using the Block food frequency questionnaire. Menopause status and prescription bone drug use were measured by a questionnaire. Results: The relationship between FFM and hip BMD was strong and robust (F=24.5, P<0.0001). Using the pooled standard deviation revealed a large effect size of 1.2 when comparing hip BMD of women with low FFM and high FFM. Potentially confounding variables, considered individually and collectively, did not change this relationship. The association between FM and hip BMD was also substantial (F=9.9, P<0.0001) and remained significant when controlling for all potentially confounding variables, except differences in FFM. The relationship between TBM and hip BMD was also strong and dose-response (F=21.5, P<0.0001) and remained significant, except when differences in FFM were controlled. Conclusion: The relationships between body mass (total, fat, and fat free) and BMD of the hip in middle-age women are strong and significant. The associations are not influenced by differences in age, height, menopause status, calcium or vitamin D intake, volume or intensity of PA, or the use of bone enhancing prescription drugs. The findings suggest that women with low body mass, particularly low FFM, tend to have low hip BMD and there is little that can be done to change this association.

Gli stili APA, Harvard, Vancouver, ISO e altri

39

Davis, Shani Vann. "The Relationship Between Socioeconomic Status and Body Mass Index on Vitamin D Levels in African American Women with and without Diabetes Living in Areas with Abundant Sunshine". Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4660.

Testo completo

Abstract (sommario):

OBJECTIVE: To examine the relationships between socioeconomic status (SES), body mass index (BMI), and vitamin D levels in African American (AA) women living in areas with abundant sunshine; and to explore if diabetes moderates these relationships. SIGNIFICANCE: More AA's live in poverty, and experience obesity, diabetes, and chronic disease compared to other groups. Eighty percent of AA women are overweight or obese, and rates of type 2 diabetes is highest in this group. Minority race, obesity, and diabetes increase risks for low vitamin D, and are associated with p DESIGN AND METHOD: A cross-sectional descriptive research design was used to examine the specified relationships. Data from 611 non-pregnant AA women ≥ age 20 from the National Health and Nutrition Examination Survey (NHANES) cycles 2003 - 2006 were studied. SES was measured as poverty to income ratio (PIR), education level, and annual household income. Mean ± SD for BMI was 31 ± 8, and 14ng/ml ± 7ng/ml for vitamin D level. Only 8% of the sample had diabetes (n = 49). One hundred-eighty lived in areas with abundant sunshine. RESULTS: BMI independently predicted the vitamin D level without regard for SES, or geographical locale. Vitamin D supplement use emerged as an independent predictor of vitamin D on covariate analysis. SES did not explain significant variation in the vitamin D level. A moderating influence of diabetes could not be determined. CONCLUSIONS: BMI inversely predicts vitamin D level independent of geographic locale in AA women. Ethno/cultural measures to reduce BMI should be standard in caring for AA women which may affect vitamin D level and/or reduce morbidity and mortality in this group. Persons with low vitamin D suffer with more adverse health outcomes, and future research should examine if vitamin D deficiency accelerates risks for poor health outcomes where BMI is high.

Gli stili APA, Harvard, Vancouver, ISO e altri

40

Sebadelhe, Vittória Regina Rodrigues Jacob. "Relação entre o consumo alimentar habitual de vitamina D, estado nutricional e estilo de vida em todas as faixas etárias de uma mesma população". Universidade Federal da Paraíba, 2015. http://tede.biblioteca.ufpb.br:8080/handle/tede/8812.

Testo completo

Abstract (sommario):

Submitted by Maike Costa (maiksebas@gmail.com) on 2017-02-01T15:13:39Z No. of bitstreams: 1 arquivototal.pdf: 1758046 bytes, checksum: e968ad7641c02183aec5207b275d0343 (MD5)
Made available in DSpace on 2017-02-01T15:13:39Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1758046 bytes, checksum: e968ad7641c02183aec5207b275d0343 (MD5) Previous issue date: 2015-02-17
In addition to the importance of vitamin D for bone health, is of great interest to elucidate its relationship with obesity. The objective of this study was to examine the relationship between habitual dietary intake of vitamin D and body weight in all age groups of the same population. A cross-sectional population-based study, involving 866 individuals from a city in northeastern Brazil. Demographic data were collected and 24-hour recalls, and held anthropometric assessment. The adequacy of nutrients was estimated by adjusting the person variance of nutrient intake. Applied to multiple regression between variables. In the total sample, 45.27% of the participants were overweight or obese. The average habitual intake of vitamin D is approximately 2mg. There was a relationship between habitual dietary intake of vitamin D and body weight in the total sample (t = -2.34, p = 0.019), in adolescents (t = -2.51, p = 0.012) and adults (t = -2.75, p = 0.006). For children and the elderly these relationships were observed. The existence of a relationship between habitual dietary intake of vitamin D and body weight in adolescents and adults but not in children and the elderly, suggests that those most vulnerable age groups the metabolic pathways of vitamin D, which may favor weight loss, are not being stimulated or active, although the intake of children was higher and the elderly similar to the other groups.
Além da importância da vitamina D para a saúde óssea, é de grande interesse elucidar sua relação com a obesidade. O objetivo deste estudo foi examinar a relação entre o consumo alimentar habitual de vitamina D e o peso corporal em todos os grupos etários de uma mesma população. Estudo epidemiológico transversal de base populacional, envolvendo 866 indivíduos de um município do nordeste do Brasil. Foram coletados dados demográficos e recordatórios de 24 horas, e realizou-se a avaliação antropométrica. A adequação de nutrientes foi estimada ajustando a variância intrapessoal da ingestão de nutrientes. Aplicou-se a regressão múltipla entre as variáveis estudadas. Na amostra total, 45,27% dos participantes apresentavam sobrepeso ou obesidade. A média de ingestão habitual de vitamina D foi aproximadamente 2μg. Houve relação entre consumo alimentar habitual de vitamina D e peso corporal na amostra total (t=-2,34; p=0,019), no grupo de adolescentes (t=-2,51; p=0,012) e de adultos (t=-2,75; p=0,006). Para as crianças e idosos estas relações não foram observadas. A existência de relação entre consumo alimentar habitual de vitamina D e peso corporal em adolescentes e adultos, mas não em crianças e idosos, sugere que nesses grupos etários mais vulneráveis as vias metabólicas da vitamina D, que provavelmente favorecem a perda de peso, não estão sendo estimuladas ou atuantes, embora o consumo das crianças foi superior e o dos idosos semelhante aos demais grupos.

Gli stili APA, Harvard, Vancouver, ISO e altri

41

Castillo, Hilda S. "Mutational analysis and engineering of the human vitamin D receptor to bind and activate in response to a novel small molecule ligand". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39502.

Testo completo

Abstract (sommario):

Nuclear receptors (NRs) are ligand-activated transcription factors that regulate the expression of genes involved in all physiological activities. Disruption in NR function (e.g. mutations) can lead to a variety of diseases; making these receptors important targets for drug discovery. The ability to bind a broad range of 'drug-like' molecules also make these receptors attractive candidates for protein engineering, such that they can be engineered to bind novel small molecule ligands, for several applications. One application is the creation of potential molecular switches, tools that can be used for controlling gene expression. Gaining knowledge of specific molecular interactions that occur between a receptor and its ligand is of interest, as they contribute towards the activation or repression of target genes. The focus of this work has been to investigate the structural and functional relationships between the human vitamin D receptor (hVDR) and its ligands. To date, mutational assessments of the hVDR have focused on alanine scanning and residues typically lining the ligand binding pocket (LBP)that are involved in direct interactions with the ligand. A comprehensive analysis of the tolerance of these residues in the binding and activation of the receptor by its ligands has not been performed. Furthermore, residues not in contact with the ligand or that do not line the LBP may also play an important role in determining the activation profiles observed for NRs, and therefore need to be explored further. In order to engineer and use the hVDR in chemical complementation, a genetic selection system in which the survival of yeast is linked to the activation of a NR by an agonist, the hVDR gene was isolated from cDNA. To gain insight into how chemical and physical changes within the ligand binding domain (LBD) affect receptor-ligand interactions, libraries of hVDR variants exploring the role and tolerance of hVDR residues were created. To develop a comprehensive mutational analysis while also engineering the hVDR to bind a novel small molecule ligand, a rational and a random mutagenic approach were used to create the libraries. A variant, hVDRC410Y, that displayed enhanced activity with lithocholic acid (LCA), a known hVDR ligand, and novel activation with cholecalciferol (chole), a precursor of the hVDR's natural ligand known not to activate the wild-type hVDR, was discovered. The presence of a tyrosine at the C410 position resulting in novel activation profiles with both LCA and chole, and the fact that this residue does not line the hVDR's LBP led to interest in determining whether a physical or chemical property of the residue was responsible for the observed activity. When residue C410 was further assessed for its tolerance to varying amino acids, the results indicated that bulkiness at this end of the pocket is important for activation with these ligands. Both LCA and chole have reduced molecular volumes compared to the natural ligand, 1alpha, 25(OH)2D3. As a result, increased bulkiness at the C410 position may contribute additional molecular interactions between the receptor and ligands. Results obtained throughout this work suggest that the end of the hVDR's LBP consisting of two ligand anchoring residues, H305 and H397, and residue C410 tolerates structural variations, as numerous variants with mutations at these positions displayed enhanced activity. The receptor contains two tyrosines, Y143 and Y147, which were targeted for mutagenesis in one of the rationally designed libraries, located at the exact opposite end of the pocket. In an effort to gain further insight into the role of these residues at the other end of the LBP, mutagenesis assessing the tolerance of tyrosines 143 and 147 was performed. Overall, most changes at these positions proved to be detrimental to the function of the receptor supporting the hypothesis that this end of the LBP is less tolerant of structural changes, compared to the opposite end consisting of residues H305, H397 and C410. Overall, a better understanding of the structural and functional relationships between the human vitamin D receptor (hVDR) and its ligands was achieved. The effects of residue C410 on specificity and activation with the different ligands studied were unforeseen, as this residue does not line the receptor's ligand binding pocket (LBP). However, they serve as an example of the significant impact distant residues can have on receptor activation and also emphasize the important role physical properties of residues, such as volume, can play for specific ends of the LBP compared to chemical properties.

Gli stili APA, Harvard, Vancouver, ISO e altri

42

Santos, Elizabete Alexandre dos. "Relação entre ingestão de vitamina K, gordura corporal, perfil lipídico e homeostase da glicose em adultos e idosos". Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/6/6138/tde-02102018-131651/.

Testo completo

Abstract (sommario):

Introdução: Especula-se que exista uma possível relação entre a ingestão de vitamina K e a diminuição da gordura corporal. Além disso, embora os resultados permaneçam controversos, há um número crescente de estudos que apoiam um papel chave dessa vitamina na melhora do perfil lipídico, da sensibilidade à insulina e na redução do risco de diabetes mellitus tipo 2, contudo pouco se sabe sobre quais mecanismos estariam envolvidos. Objetivo: Investigar as relações entre a ingestão de vitamina K (na forma de filoquinona - PK), gordura corporal, perfil lipídico e marcadores da homeostase da glicose em adultos e idosos. Métodos: Estudo transversal com 298 indivíduos de ambos os sexos, participantes do inquérito ISA - Capital 2015. Amostras de sangue foram coletadas para determinação do perfil lipídico, glicemia de jejum e concentrações de insulina; e índice de estimativa de resistência à insulina (HOMAIR), índice de estimativa da função de células β-pancreáticas (HOMA-β) e índice de estimativa da sensibilidade à insulina (QUICKI) foram calculados. A ingestão de vitamina K foi avaliada por meio de um recordatório alimentar de 24hrs (repetido em 75% da amostra), e a investigação quantitativa da massa gorda foi conduzida por meio da absorciometria de feixe duplo (DXA). Indivíduos com ingestão de vitamina K inferior aos valores de AI foram divididos em subgrupos de acordo com o estado nutricional e faixa etária. Foi realizada a Correlação de Spearman em grupos estratificados de acordo com o Índice de Massa Corporal (IMC) e com o Índice de Gordura Corporal (IGC). Para avaliar as associações entre a ingestão de vitamina K e cada uma das medidas bioquímicas e de adiposidade, foi realizada a regressão linear múltipla. Resultados: Dentre os avaliados, 46% eram do sexo masculino (n=136), com idade mediana de 61 anos (20 - 94 anos), e 56,4% apresentavam sobrepeso ou obesidade (n=168). A mediana de ingestão de vitamina K foi de 102,7 μg, ou 59,9 μg,/1000 kcal, sem diferença de acordo com sexo ou idade. A ingestão de vitamina K apresentou correlação negativa com o HOMA-IR (r = -0,603; p = 0,0134) e correlação positiva com QUICKI (r = 0,603; p = 0,0134) entre os adultos eutróficos do sexo masculino (n = 16). Em idosas com baixo peso (n = 12), a ingestão de vitamina K foi negativamente correlacionada com o Colesterol Total (CT) (r = -0,644; p = 0,0443). Entre as mulheres com elevado IGC e ingestão de vitamina K inferior aos valores de AI (n = 117), foram observadas correlações negativas entre a ingestão de vitamina K e HOMA-IR (r = -0,187; p = 0,0451) e correlações positivas com QUICKI (r = 0,187; p = 0,0451). Conclusões: Os resultados encontrados sugerem uma possível relação entre a ingestão dietética de filoquinona, gordura corporal, perfil lipídico e marcadores da homeostase da glicose, em amostra de adultos e idosos.
Introduction: Recent research have investigated a possible inverse relationship between vitamin K intake and body fat. In addition, although the results remain controversial, there is an increasing number of studies supporting a key role of this vitamin in improving lipid profile, insulin sensitivity and reducing the risk of type 2 diabetes mellitus, but little is known about what mechanisms would be involved. Objective: To investigate the relationship between vitamin K intake (in the form of phylloquinone - PK), body fat, lipid profile and markers of glucose homeostasis in adults and elderly. Methods: Cross-sectional study with 298 individuals of both sexes, participants in the ISA - Capital 2015 survey. Blood samples were collected for determination of lipid profile, fasting glycemia and insulin concentrations, and homeostasis model assesment estimate for insulin resistance (HOMA-IR), homeostasis model assessment estimate for β-cell function (HOMA-β) and the quantitative insulin sensitivity check index (QUICKI) were calculate accordingly. Vitamin K intake was assessed by a 24-hour dietary recall (repeated in 75% of the sample) and quantitative investigation of fat mass was conducted using dual-energy x-ray absorptiometry (DXA). Subjects with vitamin K intake lower than AI values were divided into subgroups according to nutritional status and age group. Spearman correlation was performed in stratified groups according to Body Mass Index (BMI) and Fat Mass Index (FMI). To evaluate the associations between vitamin K intake and each of the biochemical and adiposity measures, multiple linear regression were performed. Results: Among the sample, 46% were male (n = 136), with a median age of 61 years (20 - 94 years), and 56.4% were overweight or obese (n= 168). The median vitamin K intake was 102.7 μg, or 59.9 μg, / 1000 kcal, with no difference according to sex or age. Vitamin K intake presented negative correlation with HOMA-IR (r = -0.603; p = 0.0134) and positive correlation with QUICKI (r = 0.603; p=0.0134) among normal weight male adults (n=16). In underweight elderly women (n=12), vitamin K intake was negatively correlated with total cholesterol (TC) (r = -0.644, p = 0.0443). Among females with high FMI and vitamin K intake lower than AI values (n=117), vitamin K intake was negatively correlated with HOMA-IR (r = -0.187; p = 0.0451) and positively correlated with QUICKI (r 12 = 0.187; p = 0.0451). Conclusions: Results suggest a possible relationship between dietary intake of phylloquinone, body fat, lipid profile and glucose homeostasis, among a sample of adults and elderly.

Gli stili APA, Harvard, Vancouver, ISO e altri

43

Gailytė, Ieva. "Jaunų sveikų vyrų vitamino D koncentracijos, kūno sandaros, endokrininės ir psichologinės būklės bei gyvenimo kokybės sąsajos". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2013~D_20130611_083433-13656.

Testo completo

Abstract (sommario):

Pastarąjį dešimtmetį nustatyta, kad vitaminas D dalyvauja ne tik skeleto sistemos metaboliniuose procesuose, bet jo trūkumas siejamas ir su įvairiomis kitomis patologinėmis būsenomis, nes daugumoje organizmo ląstelių yra išsidėstę vitamino D receptoriai. Įvertinę šią vitamino D svarbą, epideminio pobūdžio jo trūkumą įvairiose šalyse bei tai, kad iki šiol panašaus pobūdžio mokslinių tyrimų mūsų šalyje neatlikta, nuspendėme įvertinti jaunų vyrų – Lietuvos kariuomenės šauktinių – vitamino D koncentracijos, kūno sandaros, endokrininės, psichologinės būklės ir gyvenimo kokybės rodiklių tarpusavio sąsajas. Daugumai tirtųjų nustatytas ženklus vitamino D trūkumas (95 proc. tyrimo pradžioje ir 96,7 proc. tyrimo pabaigoje). Tyrimo pabaigoje buvo nustatytas didesnis vitamino D trūkumas, kuris sąlygojo reikšmingą prieskydinių liaukų hormono koncentracijos padidėjimą, tačiau osteokalcino koncentracija reikšmingai nesikeitė. Taip pat nustatyta, kad didesnė vitamino D koncentracija teigiamai koreliuoja su didesne raumenų ir liesąja kūno mase, o tiems, kuriems nustatytas ryškus vitamino D trūkumas (≤10 ng/ml), būdinga mažesnė testosterono koncentracija. Be to, nustatyta, kad mažesnė vitamino D koncentracija sąlygoja depresiškumą–liūdesį ir įtampą–nerimą bei blogesnę psichologinę ir fizinę gyvenimo kokybę. Reikšmingų vitamino D koncentracijos ir pažintinių funkcijų tarpusavio ryšių bei sąsajų su tirtais stresiniais hormonais (kortizoliu, prolaktinu, tireotropiniu hormonu) nenustatyta.
Over the last decade it has been established that vitamin D is involved not only in the skeletal system metabolic processes, but its deficiency is associated with a variety of other pathological conditions, because vitamin D receptors are located in most of the body cells. Taking into consideration the importance of vitamin D, epidemic deficiency in different countries worlwide and the fact that similar studies in our country have not been performed yet, we evaluated vitamin D levels, body composition, endocrine, psychological status and quality of life in young men - Lithuanian army conscripts. Vitamin D deficiency was determined in the majority of the studied young men (95% at the beginning and 96.7% at the end of the study). There was a greater vitamin D deficiency determined at the end of the study, which conditioned a significant increase in parathyroid hormone concentration; however, there were no significant changes in the osteocalcin concentration observed. Vitamin D deficiency correlated with a smaller amount of lean body and muscle mass. A significantly smaller testosterone concentration was determined in the group of a lower vitamin D concentration (≤10 ng/mL). It was determined that a lower vitamin D concentration conditioned depression-sadness and tension-anxiety as well as psychological and physical life quality. No significant correlations between vitamin D concentration and cognitive functions, concentrations of cortisol, prolactin and thyreotropic hormone... [to full text]

Gli stili APA, Harvard, Vancouver, ISO e altri

44

Stawasz, Lydia-Anne. "Vegan and omnivore diets : an examination of dietary intake, body composition, serum lipids, parathyroid and vitamin D hormones, acid-base balance, urinary calcium excretion and bone parameters in pre-menopausal women /". For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

45

Brenten, Thomas [Verfasser]. "Investigations on age and breed-associated differences in energy intake, growth rate, body composition, haematological and biochemical values of Labrador Retrievers and Miniature Schnauzers fed different dietary levels of vitamin A / Thomas Brenten". Berlin : Freie Universität Berlin, 2016. http://d-nb.info/111088415X/34.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

46

Oliveira, Maria Beatriz Sobral de. "Avaliação da frequência de doença osteometabólica entre portadores de pancreatite crônica alcoólica e sua correlação com os hábitos alimentares e a composição corporal". Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/5/5168/tde-24022016-090200/.

Testo completo

Abstract (sommario):

O tecido ósseo é extremamente complexo que, juntamente com a cartilagem, constitui o sistema esquelético. Tanto os ossos quanto a cartilagem são compostos por tecido metabolicamente ativo com duas funções básicas para o organismo, uma mecânica e outra bioquímica. O impacto do déficit calórico e da perda de peso pode reduzir a massa óssea e mudar a composição corpórea. Na pancreatite crônica alcoólica o paciente relata ingestão alcoólica por longo período, além da referência do alto consumo de cigarros e de uma alimentação deficiente. Os objetivos do presente estudo foram avaliar a frequência da doença osteometabólica, os hábitos alimentares, a frequência de deficiência de vitamina D assim como, se os achados de massa corpórea por densitometria de corpo total se relacionam à deficiência de massa óssea, em indivíduos portadores de pancreatite crônica de etiologia alcoólica. Foram avaliados três grupos de pacientes do sexo masculino com pancreatite crônica alcoólica. Foram divididos de acordo com o resultado da densitometria óssea: 5 pacientes no grupo da osteoporose, 26 no grupo da osteopenia e 8 no grupo normal. Todos os pacientes foram submetidos ao registro alimentar de três dias, mensuração de peso, altura, cintura e quadril, Índice de Massa Corpórea (IMC) e exames laboratoriais. A composição corpórea foi avaliada pela densitometria óssea por raios X de dupla energia (DXA) e por bioimpedância elétrica. 79% dos pacientes do sexo masculino com pancreatite crônica alcoólica tiveram densidade mineral óssea comprometida. Os pacientes que tinham vitamina D prescrita foram excluídos porém nos nossos resultados a maioria dos pacientes apresentavam níveis normais da vitamina. Em relação ao tabagismos, dos pacientes fumavam. Os pacientes com maior comprometimento ósseo eram mais magros,contudo, não houve diferença entre os pacientes de acordo com o IMC. Os pacientes classificados pelo DXA como normais eram mais jovens do que os pacientes com osteopenia e osteoporose. Em síntese, a osteoporose e osteopenia são fontes subvalorizadas de morbidade em pacientes com pancreatites crônicas sendo necessárias diretrizes de gestão de saúde óssea neste grupo de pacientes
The bone tissue is extremely complex, along with cartilage constitutes the skeletal system. Both bones as cartilage are composed of metabolically active tissue with two basic functions for the body, mechanical and biochemistry. The impact of the caloric deficit and weight loss can reduce bone mass and change body composition. In chronic alcoholic pancreatitis patients alcohol intake over a long period, in addition to reference the high consumption of cigarettes and poor nutrition. The objectives were to evaluate the frequency of osteometabolic disease, eating habits, the frequency of vitamin D deficiency and how the body mass found by total body densitometry relate to bone deficiency in individuals with chronic pancreatitis of alcoholic etiology . We evaluated three groups of male patients with chronic pancreatitis alcoholic. They were according to the results of bone densitometry. 5 in osteoporosis group, 26 in the osteopenia group and 8 in the normal group. All patients underwent three-day food record, measurements of weight, height, waist and hip, body mass index (BMI) and laboratory tests. The body composition was evaluated by densitometry by dual energy X-ray absorptiometry (DXA) and electrical bioimpedance. 79% of male patients with alcoholic chronic pancreatitis had compromised bone mineral density. Patients were prescribed vitamin D were excluded however results in the majority of patients had normal levels of the vitamin. Half of all patients smoking. Patients with higher bone involvement were thinner, there was no difference between patients according to BMI. Patients classified as normal by DXA were younger than patients with osteopenia and osteoporosis. In summary, osteoporosis and osteopenia are undervalued sources of morbidity in patients with chronic pancreatitis and necessary health management guidelines bone in this group of patients

Gli stili APA, Harvard, Vancouver, ISO e altri

47

Al, Ghannami Samia. "Nutritional intake, body composition, plasma lipids and fat-soluble vitamins, red blood cell fatty acid profile and behaviour of Omani school children". Thesis, London Metropolitan University, 2016. http://repository.londonmet.ac.uk/1223/.

Testo completo

Abstract (sommario):

Background: The traditional Omani diet of dates, milk, rice, brown bread, fish and vegetables has undergone considerable change, now resembling a Western diet that is high in calories, high glycaemic index carbohydrates, total fat and saturated, trans and omega 6 fatty acids, and low in omega-3 fatty acids and essential micronutrients. The available data on daily food intake and its impact on micro- and macro-nutrients are scanty in the Arab world. Obtaining these data is especially important in light of the growing prevalence of non-communicable diseases (NCDs) - cardiovascular diseases, diabetes, cancer and respiratory diseases - which now account for more than 60% of the global disease burden and mortality, and contribute to more than 50% of annual deaths in Arabian countries, including Oman. Moreover, obesity, an antecedent of NCDs, has reached epidemic proportions in the region. Since NCDs develop gradually during the course of the lifespan, various national and international committees on NCDs have recommended that children and young adults be the primary focus of any action plan that aims to prevent and control non-communicable diseases. Specific aims: The aims of the study are: a) To assess the nutrient intake, body composition, blood lipids, blood pressure, blood glucose and cognitive behaviour of Omani school children; b) To assess the level of Vitamin A, D, E, and Beta Carotene among the Omani school children c) To assess the level of red blood cell fatty acids of Omani school children d) To investigate the effect of fish consumption on red blood cell omega-3 fatty acids and plasma fat-soluble vitamins; e) To investigate the impact of omega-3 fatty acids obtained from fish oil capsule on the red blood cell omega-3 fatty acids and plasma fat-soluble vitamins. Methods: Children ages 9 and 10 years (n = 314) were recruited from three randomly selected schools in the Muscat Governorate. The schools were assigned to a fish, fish oil, or control group and the children were accordingly provided a lightly grilled oily fish, a re-esterified triacylglycerol fish oil capsule, or no fish for 12 weeks. Baseline body weight, height and body mass index were assessed and a non-fasting blood sample collected at baseline and after 12 weeks of intervention. Data on food intake were gathered using a 24-hour recall questionnaire; also collected were data on weight, height, blood pressure, triglycerides and fasting glucose. In addition, teachers completed the National Initiative for Children’s Health Quality Vanderbilt Assessment Scales-Teacher Assessment Scale to assess the prevalence and sub-types of ADHD. Results: At baseline, a significant number of the children had low levels of vitamin D, and omega-3 fatty acids. The low levels of vitamin D and omega-3 fatty acids were ameliorated significantly by fish consumption and fish oil supplementation. In terms of weight, the prevalence of overweight or obesity for the total sample was 28.2% (10%, 46%) and 22.6% (8%, 38%). That is, about one fourth of the study subjects were overweight or obese. With regards to ADHD, the prevalence rate of PIS, PHIS and ADHDCIH among Omani school children was 7.3%, 3% and 8.8%, respectively. After 12 weeks intervention, the children who received fish oil (54.1±17.5 nmol/L; p < 0.001) and fish (49.2±17.4 nmol/L; p < 0.05) had elevated levels of vitamin D than those who did not (42.3±17.5 nmol/L). The fish oil (1.2±0.70 μmol/L) and fish (1.20±0.7 μmol/L) groups also had higher concentrations of beta carotene than the placebo group (0.85±0.43 μmol/L; p < 0.0001). Systolic and diastolic blood pressure (p=0.0001) and plasma triglycerides (p < 0.05) but not HDL, LDL and total cholesterol (p > 0.05) were lower in the fish oil group compared with those who were fed oily fish. Conclusions: This study provides important and underreported data on nutrient intake levels by school children in Arab world. For the first time, these data will be available as a benchmark for future research and health programs in the region. A large number of boys and girls had diets that failed to provide the recommended levels of daily nutrients. This study also indicates that ADHD is relatively common among Omani school children; additional studies are needed to assess the generalisability of these findings. Vitamin D deficiency is prevalent in Omani school children, but can be mitigated with omega-3 fatty acid supplementation. This study also provides evidence that Omani pre-adolescents have a low level n-3 fatty acid index that can be ameliorated by fish oil supplementation or consumption of oily fish. Hence, there is a need for a child-focused program of food fortification, school feeding programmes, targeted intervention with n-3 fatty acid enriched food products, family nutrition education and outdoor activities to alleviate the problem.

Gli stili APA, Harvard, Vancouver, ISO e altri

48

Ormarsdóttir, Sif. "Osteoporosis in chronic liver disease". Doctoral thesis, Uppsala University, Department of Medical Sciences, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-660.

Testo completo

Abstract (sommario):

Ormarsdóttir, S. 2001. Osteoporosis in Chronic Liver Disease. Acta Universitatis Upsaliensis. Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1037. 60 pp. Uppsala. ISBN 91-554-5021-0.

Osteoporosis is a well-known and frequently reported complication of chronic liver disease (CLD) with a high fracture rate contributing to significant morbidity after liver transplantation. The pathogenesis is unknown and controversy exists about many risk factors for osteoporosis in CLD.

In the present thesis, bone mineral density (BMD) was found to be significantly lower at the lumbar spine (p<0.01) in a cohort of patients with CLD compared with age- and gender -matched individuals. Osteoporosis was found in 30% of the patients and 15% of the controls, respectively. Low body mass index (BMI), corticosteroid treatment, prothrombin time, age and female gender were independent risk factors for osteoporosis in the patients.

In a follow-up study, 43 of 72 patients were available for a second BMD measurement 25 months (median) after the first. Bone loss at the femoral neck was 1.5 ± 2.4% in females and 2.9 ± 2.0% in males with a significant decrease in BMD Z-score over time (p=0.005 and p=0.02 for females and males, respectively), indicating increased bone loss at this site. Hyperbilirubinaemia and low circulating levels of 25-hydroxy vitamin D₃ predicted increased bone loss at the femoral neck. These findings suggest that cortical bone, in addition to trabecular bone, may be affected in CLD and bilirubin and vitamin D₃ may be involved in the pathophysiology of osteoporosis in CLD.

In order to elucidate the suggested role of insulin-like growth factors (IGFs) and leptin in the pathophysiology of osteoporosis in CLD, we studied the relationship between these factors and BMD. Levels of IGFs were extremely low (p<0.0001 compared with the controls) and related to liver function but no correlation was found between the IGFs and BMD. Serum leptin adjusted for BMI correlated negatively with BMD in female patients (p=0.003 and p=0.04 at the lumbar spine and the femoral neck, respectively) and in male patients at the femoral neck (p=0.04). Thus, the IGFs appear not to be involved in the pathophysiology of osteoporosis in CLD but a role of circulating leptin is possible.

Gli stili APA, Harvard, Vancouver, ISO e altri

49

Бокова, Світлана Іванівна, Светлана Ивановна Бокова, Svitlana Ivanivna Bokova e М. В. Волкова. "Проблема вітамінно-мінеральної недостатності у дітей України". Thesis, Сумський державний університет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/48034.

Testo completo

Abstract (sommario):

Питання забезпеченості сучасних дітей вітамінами та мінералами стає все актуальнішим протягом останніх років і не полишає інтерес лікарів та науковців. Загально відомо, що мікронутрієнти мають суттєвий вплив на ріст і розвиток дитячого організму, а їх кількісні варіації вносять корективи у функціонування органів та систем. Так, вітамінно-мінеральна недостатність (ВМН) порушує обмін речовин, що призводить до негативних наслідків і позначається на загальному стані організму, процесах росту та розвитку, імунній системі тощо. Зазвичай це має відповідні клінічні прояви, обтяжує перебіг соматичних захворювань.

Gli stili APA, Harvard, Vancouver, ISO e altri

50

Rodrigues, Beatriz Almeida [UNESP]. "Efeitos das antocianinas, ácidos hidroxinâmicos e vitamina C sobre a biometria, composição corporal e qualidade óssea de ratos Wistar". Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/137890.

Testo completo

Abstract (sommario):

Submitted by Beatriz Almeida Rodrigues null (beatrizalmeidarodrigues@hotmail.com) on 2016-04-11T11:13:52Z No. of bitstreams: 1 dissertação mestrado Bia .pdf: 890496 bytes, checksum: b8cfd0081be535752ecf08818cb57d99 (MD5)
Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-04-12T14:08:03Z (GMT) No. of bitstreams: 1 rodrigues_ba_me_jabo.pdf: 890496 bytes, checksum: b8cfd0081be535752ecf08818cb57d99 (MD5)
Made available in DSpace on 2016-04-12T14:08:03Z (GMT). No. of bitstreams: 1 rodrigues_ba_me_jabo.pdf: 890496 bytes, checksum: b8cfd0081be535752ecf08818cb57d99 (MD5) Previous issue date: 2016-02-24
A obesidade é um dos principais desafios para a saúde mundial e apresenta alta prevalência no homem e animais de companhia. Considerando a relevância dessa enfermidade, realizamos a presente pesquisa com o objetivo de avaliar o peso corporal, circunferência abdominal, índice de Lee, composição corporal, índice de Seedor, densidade mineral e resistência óssea de ratos Wistar tratados com dieta hipercalórica associada ou não à laranja vermelha, Citrus sinensis (L) Osbeck. O grupo que recebeu somente dieta hipercalórica apresentou menor massa magra em relação aos demais. Os animais tratados com fitoterápico associado à dieta hipercalórica apresentaram redução significativa na porcentagem de gordura em relação ao grupo tratado somente com dieta hipercalórica. Nos ensaios biomecânicos do úmero e fêmur não houve diferença na força máxima de ruptura, embora, no ensaio de compressão houve tendência de maior fragilidade óssea da cabeça do fêmur em ratos tratados somente com dieta hipercalórica. A associação de antocianinas, ácidos hidroxicinâmicos e vitamina C não interfere na densidade mineral óssea e na resistência biomecânica do úmero de ratos tratados com dieta padrão ou hipercalórica no período de cinco meses. Indivíduos resistentes à mudança de hábitos alimentares poderiam ser beneficiados pelo uso prolongado das antocianinas graças ao aumento da massa magra e redução da porcentagem de gordura após tratamento prolongado com laranja vermelha.
Obesity is a major challenge to global health and is highly prevalent in humans and pets. Considering the importance of this disease, we carried out this research in order to evaluate body weight, waist circumference, Lee index, body composition, Seedor index, mineral density and bone strength of Wistar rats treated with high calorie diet with or without orange red, Citrus sinensis (L) Osbeck. We note that the animal that received only calorie diet showed less lean mass than the others. In addition, animals treated with herbal associated with calorie diet showed significant reduction in body fat percentage compared to the group treated only with high calorie diet. In biomechanical testing of the humerus and femur there was no difference in maximum breaking strength, although the compression test tended increased bone fragility of the femoral head in rats treated only with high calorie diet. The association anthocyanins, hydroxycinnamic acids and vitamin C does not interfere with bone mineral density and biomechanical strength of the humerus rats treated with standard hypercaloric diet during five months of treatment. Resistant individuals to changing eating habits could benefit by prolonged use of anthocyanins through increased lean mass and decreased body fat percentage after prolonged treatment with red orange.

Gli stili APA, Harvard, Vancouver, ISO e altri

Tesi sul tema "Vitamin A in the body"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili