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Alihanoglu, Yusuf I., Mehmet Kayrak, Mehmet S. Ulgen, Mehmet Yazici, Mehmet Yazici, Remzi Yilmaz, Kenan Demir et al. « The Impact of Central Blood Pressure Levels on the Relationship Between Oscillometric and Central Blood Pressure Measurements : A Multicenter Invasive Study ». Journal of Clinical Hypertension 15, no 9 (16 juillet 2013) : 681–86. http://dx.doi.org/10.1111/jch.12166.
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Beenken, Andrew, et Andrew S. Bomback. « Aldosterone breakthrough does not alter central hemodynamics ». Journal of the Renin-Angiotensin-Aldosterone System 18, no 4 (octobre 2017) : 147032031773500. http://dx.doi.org/10.1177/1470320317735002.
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Introduction: Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are widely used in congestive heart failure and chronic kidney disease, but up to 40% of patients will experience aldosterone breakthrough, with aldosterone levels rising above pre-treatment levels after 6–12 months of renin-angiotensin-aldosterone system blockade. Aldosterone breakthrough has been associated with worsening congestive heart failure and chronic kidney disease, yet the pathophysiology remains unclear. Breakthrough has not been associated with elevated peripheral blood pressure, but no studies have assessed its effect on central blood pressure. Methods: Nineteen subjects with well-controlled peripheral blood pressure on stable doses of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker had aldosterone levels checked and central blood pressure parameters measured using the SphygmoCor system. The central blood pressure parameters of subjects with or without breakthrough, defined as serum aldosterone >15 ng/dl, were compared. Results: Of the 19 subjects, six had breakthrough with a mean aldosterone level of 33.8 ng/dl, and 13 were without breakthrough with a mean level of 7.1 ng/dl. There was no significant difference between the two groups in any central blood pressure parameter. Conclusions: We found no correlation between aldosterone breakthrough and central blood pressure. The clinical impact of aldosterone breakthrough likely depends on its non-genomic, pro-fibrotic, pro-inflammatory effects rather than its regulation of extracellular volume.
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Seo, Jeong-Hwa, Chul-Woo Jung et Jae-Hyon Bahk. « Uppermost Blood Levels of the Right and Left Atria in the Supine Position ». Anesthesiology 107, no 2 (1 août 2007) : 260–63. http://dx.doi.org/10.1097/01.anes.0000270720.67307.fa.
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Background To eliminate the influence of hydrostatic pressure, proper transducer positions for central venous pressure and pulmonary artery wedge pressure are at the uppermost blood levels of right atrium (RA) and left atrium (LA). This study was performed to investigate accurate reference levels of central venous pressure and pulmonary artery wedge pressure in the supine position. Methods Chest computed tomography images of 96 patients without history of cardiothoracic surgery, heart disease, or cardiothoracic anatomical abnormality were retrospectively reviewed. The anteroposterior (AP) diameter of the thorax and the vertical distances from the skin on the back to the most anterior portion of RA (RA height) and LA (LA height) were measured. Their ratios were abbreviated, respectively, as RA height/AP diameter and LA height/AP diameter. Data are expressed as mean +/- SD (range). Results There was a significant difference [4.6 +/- 1.0 (1.6-6.4) cm; P < 0.001] between RA and LA heights. AP diameter was positively correlated with RA and LA heights (R = 0.839 and 0.700, respectively; P < 0.001). There was also a significant difference between RA height/AP diameter [0.83 +/- 0.03 (0.71-0.91)] and LA height/AP diameter [0.62 +/- 0.04 (0.52-0.72)] (P < 0.001). Conclusion In the supine position, a central venous pressure transducer should be positioned approximately 4.6 cm higher than a pulmonary artery wedge pressure transducer. The external reference level for central venous pressure seems to be at approximately four fifths of the AP diameter of the thorax from the back, and that for pulmonary artery wedge pressure seems to be at approximately three fifths of the AP diameter.
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Vadziuk, Stepan, Petro Tabas, Vitaliy Kulchytskyi et Ihor Pankiv. « Cardiovascular System Response to Cold Stress in Individuals with Different Levels of Blood Pressure ». Problems of Cryobiology and Cryomedicine 32, no 2 (30 juin 2022) : 134–43. http://dx.doi.org/10.15407/cryo32.02.134.
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The study determines the peculiarities of the response of the central and peripheral links of to a cold stimulus in people with different levels of blood pressure (BP). The dynamics of blood pressure, heart rate, rheographic index and cardiorhythmography before and after the cold pressor test were evaluated. A significantly higher increase in systolic and diastolic BP in response to the cold pressor test was found in the persons with a normal high level of initial blood pressure (130/85–139/89 mm Hg) (p < 0.05). During the examination, a higher percentage of those with a hyperreactive blood pressure response was found (25%). In the experiment participants with initial blood pressure > 130/85 mm Hg a significant influence of the sympathetic nervous system on the cardiovascular system central and peripheral links in response to cold stress was observed. The individuals with normal (120/80– 129/84 mm Hg) and normal low (110/70-120/80 mm Hg) blood pressure showed a satisfactory response of the cardiovascular system to cold stress, so they should expect less health risks when working at low ambient temperatures.
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Guidoboni, Giovanna, Fabrizia Salerni, Rodolfo Repetto, Marcela Szopos et Alon Harris. « Relationship between intraocular, blood and cerebrospinal fluid pressures : a theoretical approach ». Modeling and Artificial Intelligence in Ophthalmology 2, no 3 (11 juin 2019) : 9–13. http://dx.doi.org/10.35119/maio.v2i3.93.
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Intraocular pressure (IOP), arterial blood pressure (PA), and cerebrospinal fluid (CSF) pressure have been identified as major players in several ocular pathologies, including glaucoma, central vein occlusion, and papilledema, to name a few. IOP, PA, and CSF pressures are not independent from each other. For example, aqueous humor and CSF flows, whose mechanics contribute to establish IOP and CSF pressure levels, originate from blood flow, which is driven by PA. As a consequence, it is difficult to experimentally isolate IOP, PA, and CSF pressure and to disentangle their effect in pathological conditions. Here we utilize a theoretical approach to address this issue.
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Mironova, S. A., Yu S. Yudina, M. A. Ionov, N. G. Avdonina, I. V. Emelyanov, E. Yu Vasil`eva, E. A. Kitaeva, N. E. Zvartau et A. O. Konradi. « Novel biomarkers of kidney injury and fibrosis in patients with different severity of hypertension : relation to vascular reactivity and stiffness ». Russian Journal of Cardiology, no 1 (9 février 2019) : 44–51. http://dx.doi.org/10.15829/1560-4071-2019-1-44-51.
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Aim. To compare the relationships between conventional and new potentially more early investigational biomarkers (urine and ultrasound) of kidney injury and central aortic blood pressure, vascular stiffness and reactivity, endothelial dysfunction in patients with different severity of hypertension.Material and methods. Urine levels NGAL, KIM-1, L-FABP, albuminuria and serum levels of сystatin C and creatinine were measured in 92 hypertensive patients with mild and severe hypertension, 46 male (mean age 50,7±12,2 years). Glomerular filtration rate was estimated by the level of serum creatinine and cystatin C by MDRD and CKD-EPI formulas. Instrumental examination included measuring office blood pressure, 24-hour ambulatory blood pressure monitoring (SpaceLabs 90207), applanation tonometry (SphygmoCor, Artcor Medical) with the calculation of central aortic blood pressure, pulse wave velocity and augmentation index and Doppler ultrasonography with assessment of intraparenchymal renal arterial resistance indices — resistive index and pulsatility index (Vivid 7 dimension). Endothelial function was assessed by reactive hyperemia index with EndoPAT device (Itamar Medicals).Results. There were no differences in conventional levels of biomarkers between patients, however, cystatin C level increased and serum cystatin C estimated GFR and serum creatinine and cystatin C estimated GFR (CKD EPI formula) (sCr,Cys-estimated GFR) levels decreased with the severity of hypertension. These novel biomarkers were associated with increased central aortic blood pressure, arterial stiffness and intraparenchymal renal arterial resistance indices. Decreased sCr,Cys-estimated GFR levels were associated with lower reactive hyperemia index. There were no differences in NGAL, KIM-1 and L-FABP levels in patients with hypertension. However, NGAL levels were associated with increased augmentation index, resistive index in intralobular and pulsatility index in arcuate arteries, KIM-1 and L-FABP levels were associated with increased systolic and diastolic central aortic blood pressure, pulse wave velocity only in patients with severe and resistant hypertension.Conclusion. Serum cystatin C, NGAL, KIM-1 and L-FABP levels seem to be biomarkers of increased systemic and intrarenal vascular stiffness in patients with different severity of hypertension.
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Convertino, V. A., G. W. Mack et E. R. Nadel. « Elevated central venous pressure : a consequence of exercise training-induced hypervolemia ? » American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 260, no 2 (1 février 1991) : R273—R277. http://dx.doi.org/10.1152/ajpregu.1991.260.2.r273.
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Resting blood volumes and arterial and central venous pressures (CVP) were measured in 14 men before and after exercise training to determine whether training-induced hypervolemia is accompanied by a change in total vascular capacitance. In addition, resting levels of plasma arginine vasopressin (AVP), atrial natriuretic peptide (ANP), aldosterone (Ald), and norepinephrine (NE) were measured. The same measurements were conducted in seven subjects who did not undergo exercise and acted as controls. Exercise training consisted of 10 wk of controlled cycle exercise for 30 min/day, 4 days/wk at 75-80% of maximal O2 uptake (VO2max). A training effect was verified by a 20% increase in VO2max, a resting bradycardia, and a 9% increase in blood volume. Mean arterial blood pressure was unaltered by exercise training, but resting CVP increased by 16% (P less than 0.05). The percent change in blood volume from before to after training was linearly related to the percent change in CVP (r = 0.903, P less than 0.05). As a consequence of elevations in both blood volume and CVP, the volume-to-pressure ratio was unchanged after exercise training. Plasma AVP, ANP, Ald, and NE were unaltered. Our results indicate that elevated CVP is a consequence of training-induced hypervolemia without alteration in total effective venous capacitance.
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Gomez-Sanchez, E. P., et C. E. Gomez-Sanchez. « Effect of central amiloride infusion on mineralocorticoid hypertension ». American Journal of Physiology-Endocrinology and Metabolism 267, no 5 (1 novembre 1994) : E754—E758. http://dx.doi.org/10.1152/ajpendo.1994.267.5.e754.
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There is strong evidence from different types of studies, including the discrete infusion of agonists and antagonists and ablation of specific brain areas or transmitter-type neurons, that mineralocorticoids, in excess, act in the brain to elevate blood pressure. Aldosterone enhances the entry of Na+ through amiloride-sensitive Na+ channels in some mineralocorticoid-sensitive transport epithelial cells. To define possible cellular mechanisms involved in central mineralocorticoid action, benzamil, an amiloride analogue with selective affinity for the Na+ channel, was continuously infused intracerebroventricularly in three mineralocorticoid-dependent hypertension models in Sprague-Dawley rats, the continuous subcutaneous infusion of aldosterone, the intracerebroventricular infusion of aldosterone, and the ingestion of carbenoxolone, a synthetic licorice analogue. The intracerebroventricular infusion of 0.3 and 0.5 micrograms/h of benzamil, doses that did not have an adverse effect on growth and that had no effect on the blood pressure when infused subcutaneously, prevented the increase in blood pressure in these models. The infusion of these levels of benzamil had no effect on urine volume even in those animals in which it prevented an increase in blood pressure. These data suggest that the central effects of mineralocorticoids on blood pressure are mediated, at least in part, by the effects of mineralocorticoids on amiloride-sensitive sodium transport.
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Шитя, A. Shitya, Тамбовцева, R. Tambovtseva, Орел, V. Orel, Гацунаев et A. Gatsunaev. « Central Hemodynamic and Vascular Resistances in the Archers in the Simulation of the Draw ». Journal of New Medical Technologies 22, no 3 (15 septembre 2015) : 102–7. http://dx.doi.org/10.12737/13309.
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The integrated studies of central hemodynamics and vascular load of the heart in athletes of various specializations and skill levels are carried out over the last 30 years at RSUPE. However, data on the central hemodynamics and vascular load of the heart in highly skilled archers in the conditions of the draw are virtually absent. Determination of the vascular resistances (peripheral and elastic) during the draw is difficult because of the need of blood pressure measuring [4], it is virtually impossible since a typical way to draw both arms stiff. To simulate the draw, the authors have used the expander, one end of which is rigidly fixed, and stretching expander at the other end with one hand simulates the draw thus the second hand is free to measure blood pressure. It is shown that in the course of research the vascular resistances change in wide limits - from optimal normal levels to prehypertonic and hypertonic levels of their values. Thus, the systolic and diastolic pressures remain normal before stretching expander, and during the tensioning and recovery. With the increase in vascular resistance the values of the stroke and minute blood volumes are significantly reduced.
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PUCCIO, V. F., et M. SOLIANI. « Blood Pressure and Intraventricular Hemorrhage in Premature Infants ». Pediatrics 86, no 6 (1 décembre 1990) : 1006. http://dx.doi.org/10.1542/peds.86.6.1006.
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To the Editor.— We have read with great interest the recently published article by Perry et al.1 The need to define "safe" blood pressure levels in the critically ill premature infants is a central topic in the prevention of intracranial hemorrhage. However, in Perry's paper maximum systolic blood pressure and maximum mean blood pressure values are much higher than those reported by previously published articles.2-4 High blood pressure values were reported by Lou and Friis-Hansen5 in nine newborns.
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Bakogiannis, Constantinos, Konstantinos Stavropoulos, Christodoulos Papadopoulos et Vasilios Papademetriou. « The Impact of Various Blood Pressure Measurements on Cardiovascular Outcomes ». Current Vascular Pharmacology 19, no 3 (31 décembre 2020) : 313–22. http://dx.doi.org/10.2174/1570161118666200330155905.
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: Hypertension is a potent risk factor for cardiovascular morbidity and mortality. High blood pressure (BP) correlates closely with all-cause and cardiovascular mortality. Although the gold standard remains office BP (auscultatory or automated), other methods (central or out-of-office) are gaining popularity as better predictors of CV events. In this review, we investigated the prognostic value of each method of BP measurement and explored their advantages and pitfalls. Unattended automated office BP is a novel technique of BP measurement with promising data. Ambulatory BP monitoring, and to a lesser extent, home BP measurements, seem to predict cardiovascular events and mortality outcomes better, while at the same time, they can help distinguish hypertensive phenotypes. Data on the association of central BP levels with cardiovascular and mortality outcomes, are conflicting. Future extensive cross-sectional and longitudinal studies are needed to evaluate head-to-head the corresponding levels and results of each method of BP measurement, as well as to highlight disparities in their prognostic utility.
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Bordin Pelazza, Bruno, et Sebastião Rodrigues Ferreira Filho. « Comparison between Central and Brachial Blood Pressure in Hypertensive Elderly Women and Men ». International Journal of Hypertension 2017 (2017) : 1–5. http://dx.doi.org/10.1155/2017/6265823.
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Aim. To compare the values of central and brachial systemic blood pressure (SBP) between women and men over 60 years of age with systemic arterial hypertension. Methods. This study was a quantitative, descriptive, cross-sectional study with elderly patients admitted to and selected from spontaneous and scheduled demand at basic health units in Uberlândia, Minas Gerais, Brazil, between March 2013 and March 2014. We included 69 study participants and compared central and brachial SBP using a Sphygmocor® XCEL device (AtCor Medical, Sydney, Australia). Results. Significant differences were found in the blood pressure values of the whole population in the central versus brachial systolic blood pressure (SP) [140(21) versus 153(23) mmHg] and in the central versus brachial pulse pressure (PP) [55(18) versus 70(18) mmHg]. Additionally, females exhibited higher blood pressure levels than males [central SP 144(23) versus 134(16) mmHg and brachial SP 161(26) versus 148(18) mmHg and central PP 62(17) versus 45(14) mmHg and brachial PP 80(21) versus 63(15) mmHg, resp.]. Conclusion. Elderly women exhibited higher blood pressure values than elderly hypertensive men.
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Rickards, Caroline A., Blair D. Johnson, Ronée E. Harvey, Victor A. Convertino, Michael J. Joyner et Jill N. Barnes. « Cerebral blood velocity regulation during progressive blood loss compared with lower body negative pressure in humans ». Journal of Applied Physiology 119, no 6 (15 septembre 2015) : 677–85. http://dx.doi.org/10.1152/japplphysiol.00127.2015.
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Lower body negative pressure (LBNP) is often used to simulate blood loss in humans. It is unknown if cerebral blood flow responses to actual blood loss are analogous to simulated blood loss during LBNP. Nine healthy men were studied at baseline, during three levels of LBNP (5 min at −15, −30, and −45 mmHg), and during three levels of blood loss (333, 667, and 1,000 ml). LBNP and blood loss conditions were randomized. Intra-arterial mean arterial pressure (MAP) during LBNP was similar to that during blood loss ( P ≥ 0.42). Central venous pressure (2.8 ± 0.7 vs. 4.0 ± 0.8, 1.2 ± 0.6 vs. 3.5 ± 0.8, and 0.2 ± 0.9 vs. 2.1 ± 0.9 mmHg for levels 1, 2, and 3, respectively, P ≤ 0.003) and stroke volume (71 ± 4 vs. 80 ± 3, 60 ± 3 vs. 74 ± 3, and 51 ± 2 vs. 68 ± 4 ml for levels 1, 2, and 3, respectively, P ≤ 0.002) were lower during LBNP than blood loss. Despite differences in central venous pressure, middle cerebral artery velocity (MCAv) and cerebrovascular conductance were similar between LBNP and blood loss at each level (MCAv at level 3: 62 ± 6 vs. 66 ± 5 cm/s, P = 0.37; cerebrovascular conductance at level 3: 0.72 ± 0.05 vs. 0.73 ± 0.05 cm·s−1·mmHg−1, P = 0.53). While the slope of the MAP-MCAv relationship was slightly different between LBNP and blood loss (0.41 ± 0.03 and 0.66 ± 0.04 cm·s−1·mmHg−1, respectively, P = 0.05), time domain gain between MAP and MCAv at maximal LBNP/blood loss ( P = 0.23) and low-frequency MAP-mean MCAv transfer function coherence, gain, and phase were similar ( P ≥ 0.10). Our results suggest that cerebral hemodynamic responses to LBNP to −45 mmHg and blood loss up to 1,000 ml follow a similar trajectory, and the arterial pressure-cerebral blood velocity relationship is not altered from baseline under these conditions.
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Karmia, Hudila Rifa, Afriwardi Afriwardi, Hirowati Ali, Johanes Cornelius Mose et Yusrawati Yusrawati. « The Correlation of L-citrulline Levels with Blood Pressure in Severe Preeclampsia ». Indonesian Biomedical Journal 12, no 1 (19 mars 2020) : 15–8. http://dx.doi.org/10.18585/inabj.v12i1.964.
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BACKGROUND: Based on 'vascular disorder of pregnancy' terminology, preeclampsia primarily was not a hypertensive disorder, but a vascular disorder (general vasospasm) in pregnancy due to idiopathic etiology. The overall incidence of preeclampsia was 5-14% of all pregnancies. One of the substances responsible for regulating vascular tone is nitric oxide (NO), which produced in endothelial blood vessels. NO and L-citrulline are produced altogether by the reaction between L-arginine and oxygen. L-citrulline levels reflected NO production. This study was aimed to assess the correlation between the L-citrulline level and blood pressure in severe preeclampsia.METHODS: This cross-sectional study was done in Dr. M. Djamil Central General Hospital, Padang, Indonesia The sample size was 36 samples of pregnant women with severe preeclampsia and had yet been given antihypertensive therapy. Sampling was done by consecutive sampling from Obstetrics and Gynecology Division. After maternal examination and measurements L-citrulline levels of cubital venous blood by using enzyme-linked immunosorbent assay (ELISA) method, Pearson correlation was performed to assess the relationship between variables for normally distributed data and Spearman's correlation for abnormal distribution data with significance level p<0.05.RESULTS: Means of L-citrulline levels, systolic blood pressure, diastolic blood pressure, and arterial pressure (MAP) were 87.21 nmol/mL, 179.4 mmHg, 108.3mmHg, and 132.1 mmHg, respectively. Correlation of the L-citrulline level with systolic blood pressure, diastolic blood pressure, and MAP were -0.08, -0.175, and -0.136 (p>0.05), respectively.CONCLUSION: L-citrulline levels had no correlation with blood pressure in severe preeclampsia.KEYWORDS: L-citrulline levels, blood pressure, severe preeclampsia
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Sitanggang, Ervina Julien. « Korelasi Lingkar Pinggang dengan Kadar Gula Darah Puasa, Kadar Trigliserida, dan Tekanan Darah pada Mahasiswa Fakultas Kedokteran Universitas HKBP Nommensen ». Health and Medical Journal 3, no 2 (1 juillet 2021) : 08–13. http://dx.doi.org/10.33854/heme.v3i2.583.
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Introduction: Cardiovascular disease is the number one cause of death globally with an incidence of adolescents and young adults in Indonesia as many as 153.705 cases. Central obesity is associated with the risk of cardiovascular disease due to increase in fasting blood glucose levels, cholesterol and triglyceride levels, and blood pressure. Aims: to determine the correlation between waist circumference and fasting blood glucose levels, triglyceride levels, and blood pressure in young adults. Method: This analytic study with a cross-sectional approach involved 53 young adult subjects (18-25 years old). Waist circumference is measured using a tape measure. Blood sugar and triglyceride levels were measured using Cobas® 6000 analyzer machine from blood samples of subjects after fasting for 8-12 hours. Blood pressure data are obtained by measurement using aneroid sphygmomanometer. Results: In this study, the mean waist circumference of the research subjects was 77,4 cm. No correlation was found between waist circumference and fasting blood sugar levels (p = 0,159). However, a positive correlation was found between waist circumference and triglyceride levels (p = 0,008; r = 0,332), between waist circumference and systolic blood pressure (p = 0,049; r = 0,230), and between waist circumference and diastolic blood pressure (p = 0,017; r = 0,293). Conclusion: waist circumference is positively correlated with triglyceride levels and blood pressure, but does not correlate with fasting blood sugar levels.
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Stella, A., R. Golin, S. Genovesi et A. Zanchetti. « Renal reflexes in the regulation of blood pressure and sodium excretion ». Canadian Journal of Physiology and Pharmacology 65, no 8 (1 août 1987) : 1536–39. http://dx.doi.org/10.1139/y87-242.
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The rich innervation of the kidney is distributed to all structures of renal parenchyma thus providing important anatomical support to the functional evidence that the renal nerves can control kidney functions and send signals on the kidney environment to the central nervous system. Efferent renal nerve fibres are known to influence renal haemodynamics by modifying arteriolar vascular tone, renin release by a direct action on juxtaglomerular cells, and the excretion of sodium and water by changing tubular reabsorption of sodium and water at the different tubular levels. Mechano- and chemo-receptors have been shown in the kidney. Afferent fibres connected with renal receptors convey signals to the central nervous system both at spinal and supraspinal levels. The central areas receiving inputs from the kidney are those involved in the control of cardiovascular homeostasis and fluid balance. Activation of renal receptors by the electrical stimulation of renal afferent fibres were found to elicit both excitatory and inhibitory sympathetic responses. Although the existence of excitatory renorenal reflexes has been suggested, electrophysiological and functional data demonstrate that neural renorenal reflexes exert a tonic inhibitory influence on the tubular sodium and water reabsorption and on the secretion of renin from the juxtaglomerular cells.
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Ivanenko, V. V., O. P. Rotar et A. Konradi. « Association of arterial wall stiffness with cardiovascular risk factors ». "Arterial’naya Gipertenziya" ("Arterial Hypertension") 15, no 3 (28 juin 2009) : 290–95. http://dx.doi.org/10.18705/1607-419x-2009-15-3-290-295.
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Objective. To assess relation between central blood pressure and arterial stiffness with cardiovascular risk factors. Design and methods. 116 subjects considering themselves healthy were examined. 63 showed blood pressure elevation. Anthropometry was performed and fasting blood specimens were obtained from all patients. Plasma glucose and lipids levels were measured. Pulse wave velocity (PWV) and augmentation index (AI) were measured by Sphygmocor Px device (Australia). Results. Parameters of arterial stiffness were strongly associated with hypertension, increased waist circumference, age, cholesterol level, and metaboloc syndrome. Females had higher AI as compared to males. Conclusion. Central blood pressure and arterial stiffness are determined not only by age and peripheral blood pressure but by cholesterol level and anthropometric parameters as well.
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Gkaliagkousi, Eugenia, Eleni Gavriilaki, Barbara Nikolaidou, Fani Chatzopoulou, Panagiota Anyfanti, Areti Triantafyllou, Konstantinos Petidis, Chrysanthos Zamboulis et Stella Douma. « Association Between Cardiotrophin 1 Levels and Central Blood Pressure in Untreated Patients With Essential Hypertension ». American Journal of Hypertension 27, no 5 (8 janvier 2014) : 651–55. http://dx.doi.org/10.1093/ajh/hpt238.
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Ruitenbeek, Astrid G., Tischa J. M. van der Cammen, Anton H. van den Meiracker et Francesco U. S. Mattace-Raso. « Age and Blood Pressure Levels Modify the Functional Properties of Central but Not Peripheral Arteries ». Angiology 59, no 3 (13 mai 2008) : 290–95. http://dx.doi.org/10.1177/0003319707305692.
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Hsu, Pai-Feng, Shao-Yuan Chuang, Hao-Min Cheng, Shih-Hsien Sung, Chih-Tai Ting, Edward G. Lakatta, Frank C. P. Yin, Pesus Chou et Chen-Huan Chen. « Associations of serum uric acid levels with arterial wave reflections and central systolic blood pressure ». International Journal of Cardiology 168, no 3 (octobre 2013) : 2057–63. http://dx.doi.org/10.1016/j.ijcard.2013.01.164.
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Xu, Hong, Ivan Cabezas-Rodriguez, Abdul Rashid Qureshi, Olof Heimburger, Peter Barany, Sunna Snaedal, Björn Anderstam et al. « Increased Levels of Modified Advanced Oxidation Protein Products are Associated with Central and Peripheral Blood Pressure in Peritoneal Dialysis Patients ». Peritoneal Dialysis International : Journal of the International Society for Peritoneal Dialysis 35, no 4 (juillet 2015) : 460–70. http://dx.doi.org/10.3747/pdi.2013.00064.
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♦Background and Aims Oxidative stress plays an important role in the pathogenesis of cardiovascular disease (CVD). Central blood pressure (BP) is thought to be more relevant than peripheral BP for the pathogenesis of CVD. Advanced oxidation protein products (AOPP) are markers of oxidative stress. This study investigated the relationship between AOPP and central BP in peritoneal dialysis (PD) patients. ♦Methods In a cross-sectional study of 75 PD patients (67% men), we analyzed two oxidative stress markers, AOPP (modified assay, mAOPP, correcting for the impact of triglycerides) and pentosidine, three inflammation markers, interleukin-6 (IL-6), tumor necrosis factor (TNF), and high-sensitivity C-reactive protein (hs-CRP). All patients underwent measurement of central systolic blood pressure (SBP) and diastolic blood pressure (DBP) by applanation tonometry. ♦Results Patients with mAOPP levels above the median had a higher central SBP and DBP than those below the median values. In univariate analysis, the levels of mAOPP associated with central SBP and central DBP. Multiple regression analysis, adjusting for age, gender, diabetes, CVD, protein-energy wasting (PEW), hs-CRP and extracellular water by multi-frequency bioimpedance or N-terminal prohormone of brain natriuretic peptide (NT-proBNP), confirmed independent associations between mAOPP and central SBP and central DBP respectively. ♦Conclusions The mAOPP level is independently associated with the central SBP and DBP in PD patients. This finding suggests that oxidative stress may be involved in the pathogenesis of hypertension or that hypertension itself or factors associated with hypertension such as fluid overload may have an additional effect on oxidative stress in PD patients.
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Takemoto, Yumi. « Amino Acids That Centrally Influence Blood Pressure and Regional Blood Flow in Conscious Rats ». Journal of Amino Acids 2012 (29 mai 2012) : 1–14. http://dx.doi.org/10.1155/2012/831759.
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Functional roles of amino acids have increasingly become the focus of research. This paper summarizes amino acids that influence cardiovascular system via the brain of conscious rats. This paper firstly describes why amino acids are selected and outlines how the brain regulates blood pressure and regional blood flow. This section includes a concise history of amino acid neurotransmitters in cardiovascular research and summarizes brain areas where chemical stimulations produce blood pressure changes mainly in anesthetized animals. This is followed by comments about findings regarding several newly examined amino acids with intracisternal stimulation in conscious rats that produce changes in blood pressure. The same pressor or depressor response to central amino acid stimulations can be produced by distinct mechanisms at central and peripheral levels, which will be briefly explained. Thereafter, cardiovascular actions of some of amino acids at the mechanism level will be discussed based upon findings of pharmacological and regional blood flow measurements. Several examined amino acids in addition to the established neurotransmitter amino acids appear to differentially activate brain structures to produce changes in blood pressure and regional blood flows. They may have physiological roles in the healthy brain, but pathological roles in the brain with cerebral vascular diseases such as stroke where the blood-brain barrier is broken.
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Kahkashan, Nudrath, Mehnaaz Sameera Arifuddin, Mohammed Abdul Hannan Hazari, Safia Sultana, Farah Fatima et Syyeda Anees. « Variation in carotid-femoral pulse wave velocity, augmentation pressure and augmentation index during different phases of menstrual cycle ». Annals of Medical Physiology 2, no 3 (28 novembre 2018) : 27–32. http://dx.doi.org/10.23921/amp.2018v2i3.10454.
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Physiological variation of estrogen and progesterone during menstrual cycle is well known. They not only have an effect on blood pressure control, but also seem to have a role in regulating arterial compliance. This study was done to find out whether there are any changes in central arterial parameters during different phases of menstrual cycle. Thirty female subjects in the age group of 18-22 years with normal, regular menstrual cycles participated in this prospective observational study at our teaching hospital. Anthropometric parameters were recorded. Blood pressure in all 4 limbs was recorded using cardiovascular risk analyzer-Periscope™ on Day 3rd to 5th (follicular phase), Day 12th to 14th (ovulation phase), Day 22nd to 24th (luteal phase) of their menstrual cycle. We collected blood samples during these three phases for estimation of estradiol and progesterone by ELISA technique. Analysis of variance and correlation statistics were done using SPSS 17.0 statistical software. No significant statistical changes were observed in systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse pressure, aortic systolic pressure, aortic diastolic pressure, aortic augmentation pressure, aortic index and pulse wave velocity during the three recorded phases of the menstrual cycle. There are many studies which correlate changes in peripheral artery blood pressure with different phases of menstrual cycle. But there is scarcity in data available which correlates central arterial pressures and arterial stiffness with natural hormonal variations in different phases of menstrual cycle. However, our results show that although there are subtle changes in blood pressure parameters along with estrogen and progesterone levels throughout the menstrual cycle, yet these were not statistically significant.
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Hinojosa-Laborde, Carmen, Robert E. Shade, Gary W. Muniz, Cassondra Bauer, Kathleen A. Goei, Heather F. Pidcoke, Kevin K. Chung, Andrew P. Cap et Victor A. Convertino. « Validation of lower body negative pressure as an experimental model of hemorrhage ». Journal of Applied Physiology 116, no 4 (15 février 2014) : 406–15. http://dx.doi.org/10.1152/japplphysiol.00640.2013.
Texte intégralRésumé :
Lower body negative pressure (LBNP), a model of hemorrhage (Hem), shifts blood to the legs and elicits central hypovolemia. This study compared responses to LBNP and actual Hem in sedated baboons. Arterial pressure, pulse pressure (PP), central venous pressure (CVP), heart rate, stroke volume (SV), and +dP/d t were measured. Hem steps were 6.25%, 12.5%, 18.75%, and 25% of total estimated blood volume. Shed blood was returned, and 4 wk after Hem, the same animals were subjected to four LBNP levels which elicited equivalent changes in PP and CVP observed during Hem. Blood gases, hematocrit (Hct), hemoglobin (Hb), plasma renin activity (PRA), vasopressin (AVP), epinephrine (EPI), and norepinephrine (NE) were measured at baseline and maximum Hem or LBNP. LBNP levels matched with 6.25%, 12.5%, 18.75%, and 25% hemorrhage were −22 ± 6, −41 ± 7, −54 ± 10, and −71 ± 7 mmHg, respectively (mean ± SD). Hemodynamic responses to Hem and LBNP were similar. SV decreased linearly such that 25% Hem and matching LBNP caused a 50% reduction in SV. Hem caused a decrease in Hct, Hb, and central venous oxygen saturation (ScvO2). In contrast, LBNP increased Hct and Hb, while ScvO2 remained unchanged. Hem caused greater elevations in AVP and NE than LBNP, while PRA, EPI, and other hematologic indexes did not differ between studies. These results indicate that while LBNP does not elicit the same effect on blood cell loss as Hem, LBNP mimics the integrative cardiovascular response to Hem, and validates the use of LBNP as an experimental model of central hypovolemia associated with Hem.
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Cui, Jian, Sylvain Durand, Benjamin D. Levine et Craig G. Crandall. « Effect of skin surface cooling on central venous pressure during orthostatic challenge ». American Journal of Physiology-Heart and Circulatory Physiology 289, no 6 (décembre 2005) : H2429—H2433. http://dx.doi.org/10.1152/ajpheart.00383.2005.
Texte intégralRésumé :
Orthostatic stress leads to a reduction in central venous pressure (CVP), which is an index of cardiac preload. Skin surface cooling has been shown to improve orthostatic tolerance, although the mechanism resulting in this outcome is unclear. One possible mechanism may be that skin surface cooling attenuates the drop in CVP during an orthostatic challenge, thereby preserving cardiac filling. To test this hypothesis, CVP, arterial blood pressure, heart rate, and skin blood flow, as well as skin and sublingual temperatures, were recorded in nine healthy subjects during lower body negative pressure (LBNP) in both normothermic and skin surface cooling conditions. Cardiac output was also measured via acetylene rebreathing. Progressive LBNP was applied at −10, −15, −20, and −40 mmHg at 5 min/stage. Before LBNP, skin surface cooling lowered mean skin temperature, increased CVP, and increased mean arterial blood pressure (all P < 0.001) but did not change mean heart rate ( P = 0.38). Compared with normothermic conditions, arterial blood pressure remained elevated throughout progressive LBNP. Although progressive LBNP decreased CVP under both thermal conditions, during cooling CVP at each stage of LBNP was significantly greater relative to normothermia. Moreover, at higher levels of LBNP with skin cooling, stroke volume was significantly greater relative to normothermic conditions. These data indicate that skin surface cooling induced an upward shift in CVP throughout LBNP, which may be a key factor for preserving preload, stroke volume, and blood pressure and improving orthostatic tolerance.
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TRANG, Ha, Arlette GIRARD, Dominique LAUDE et Jean-Luc ELGHOZI. « Short-term blood pressure and heart rate variability in congenital central hypoventilation syndrome (Ondine's curse) ». Clinical Science 108, no 3 (18 février 2005) : 225–30. http://dx.doi.org/10.1042/cs20040282.
Texte intégralRésumé :
The effect of CCHS (congenital central hypoventilation syndrome, or Ondine's curse) on short-term BP (blood pressure) and HR (heart rate) variability was evaluated in 16-year-old subjects presenting a form of CCHS requiring night ventilatory assistance. The 12 patients were compared with 12 age- and gender-matched healthy volunteers. Recordings were obtained during daytime while the subjects were breathing spontaneously. Continuous BP was measured with a Finapres® device in the supine, head-up tilt and standing positions. The manoeuvre of actively standing was also analysed. HR levels were elevated in CCHS subjects at supine rest (+23%) with a reduced HR overall variability (−88%). The low- and high-frequency components of HR variability were affected. BP levels were preserved at rest, but the manoeuvres demonstrated a limited capacity to elevate BP. There was no overshoot in BP during the manoeuvre of actively standing, and steady standing BP levels in patients were not higher than supine BP levels as usually observed in healthy controls. The spontaneous baroreflex sensitivity estimated using the sequence technique or the cross-spectral analysis fell in the patients to approx. one-third of the sensitivity estimated in the healthy controls whatever the position. This cardiovascular profile suggests a predominant vagal dysfunction with signs of vagal withdrawal and baroreflex failure, and relative preservation of the cardiac and vascular sympathetic function. It is likely that the impaired ontogeny of the visceral reflexes, considered now to cause CCHS syndrome, includes the baroreceptive pathway and mainly its vagal component.
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Antropova, O. N., et I. V. Osipova. « New Targets in Blood Pressure Control : Arguments Pro and Contra ». Kardiologiia 59, no 5 (25 mai 2019) : 87–91. http://dx.doi.org/10.18087/cardio.2019.5.2510.
Texte intégralRésumé :
The review contains results of analysis of clinical studies on the problem of defining the target level of the blood pressure (BP). The rationale for selection the target systolic BP level below120 mmHg was obtained in the SPRINT study comparing the target levels <120 mmHg and <140 mmHg. A considerably lower number of cardiovascular complications and deaths was seen in the group of a stricter BP control. Nevertheless, this study had some limitations related to certain patient populations, and methods of BP measurement. More ambitious target of BP lowering was associated with elevated risk of iatrogenic hypotension and fainting. Moreover, the ACCORD study, exploring the same target levels failed to demonstrate similar risk reduction. Taking into account various literature data, the authors find it reasonable to use personalized approach to determining BP targets, and utilize assessment of central aortic pressure and state of vessels for more accurate risk stratification and selection of treatment.
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Sayk, Friedhelm, Alexander Vietheer, Bernhard Schaaf, Peter Wellhoener, Gunther Weitz, Hendrik Lehnert et Christoph Dodt. « Endotoxemia causes central downregulation of sympathetic vasomotor tone in healthy humans ». American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 295, no 3 (septembre 2008) : R891—R898. http://dx.doi.org/10.1152/ajpregu.90444.2008.
Texte intégralRésumé :
Experimental endotoxemia as a model of the initial septic response affects the autonomic nervous system with profound cardiovascular sequelae. Whether the postsynaptic sympathoneural activity to the muscle vascular bed is altered in the early septic phase remains to be determined. The present study aimed to elucidate the early effects of LPS on muscle sympathetic nerve activity (MSNA) and cardiovascular regulation in healthy humans. Young, healthy volunteers randomly received either an LPS bolus (4 ng/kg body wt, n = 11) or placebo (saline; n = 7). Experimental baroreflex assessment (baseline measurements followed by infusion of vasoactive drugs nitroprusside/phenylephrine) was done prior to and 90 min following LPS or placebo challenge. MSNA, heart rate, blood pressure, and blood levels of catecholamines, TNF-α and IL-6 were measured sequentially. Endotoxin but not placebo-induced flu-like symptoms and elevated cytokine levels. In contrast to placebo, LPS significantly suppressed MSNA burst frequency 90 min after injection [mean ± SE: 12.1 ± 2.9 vs. 27.5 ± 3.3 burst/min (post- vs. pre-LPS); P < 0.005] but increased heart rate [78.4 ± 3.1 vs. 60.6 ± 2.0 beats/min (post- vs. pre-LPS); P < 0.001]. Baseline blood pressure was not altered, but baroreflex testing demonstrated a blunted MSNA response and uncoupling of heart rate modulation to blood pressure changes in the endotoxin group. We conclude that endotoxin challenge in healthy humans has rapid suppressive effects on postsynaptic sympathetic nerve activity to the muscle vascular bed and alters baroreflex function which may contribute to the untoward cardiovascular effects of sepsis.
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Wood, Charles E., et Haiyan Tong. « Central nervous system regulation of reflex responses to hypotension during fetal life ». American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 277, no 6 (1 décembre 1999) : R1541—R1552. http://dx.doi.org/10.1152/ajpregu.1999.277.6.r1541.
Texte intégralRésumé :
The ability of the fetus to survive, grow, and successfully complete the transition from fetal to neonatal life is critically dependent on the appropriate regulation of fetal blood pressure, blood volume, and fluid dynamics. This is a short review of the physiological mechanisms controlling the fetal cardiovascular system, focusing mainly on the neural and endocrine elements in the schema of cardiovascular function and control. The fetal cardiovascular system is arranged anatomically to provide for perfusion of the umbilical-placental circulation, the organ of gas exchange of the fetus, and to largely bypass the lungs. Fetal blood volume and pressure, maintained at levels that are appropriate for this function, are influenced by neural and endocrine control mechanisms, which are similar to, but quantitatively different from, the adult animal. Baroreceptors and chemoreceptors located in the carotid sinuses and aortic arch sense changes in blood pressure and blood gases and comprise the afferent limb of the major reflexes that maintain normal fetal blood pressure and volume. Fetal hypotension stimulates reflex decreases in fetal heart rate, which are apparently mediated by chemoreceptor input. Arginine vasopressin responses to hypotension are most likely mediated by baroreceptor input. Recent evidence suggests that the reflex responses to hypotension in the fetus are modulated by paracrine or endocrine factors. For example, baroreceptor or chemoreceptor reflex pathways are modulated by the endogenous production of prostanoids and by the preparturient changes in fetal plasma estrogen concentration.
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Hess, Kari L., Thad E. Wilson, Charity L. Sauder, Zhaohui Gao, Chester A. Ray et Kevin D. Monahan. « Aging affects the cardiovascular responses to cold stress in humans ». Journal of Applied Physiology 107, no 4 (octobre 2009) : 1076–82. http://dx.doi.org/10.1152/japplphysiol.00605.2009.
Texte intégralRésumé :
Cardiovascular-related mortality peaks during cold winter months, particularly in older adults. Acute physiological responses, such as increases in blood pressure, in response to cold exposure may contribute to these associations. To determine whether the blood pressure-raising effect (pressor response) of non-internal body temperature-reducing cold stress is greater with age, we measured physiological responses to 20 min of superficial skin cooling, via water-perfused suit, in 12 younger [25 ± 1 (SE) yr old] and 12 older (65 ± 2 yr old) adults. We found that superficial skin cooling elicited an increase in blood pressure from resting levels (pressor response; P < 0.05) in younger and older adults. However, the magnitude of this pressor response (systolic and mean blood pressure) was more than twofold higher in older adults ( P < 0.05 vs. younger adults). The magnitude of the pressor response was similar at peripheral (brachial) and central (estimated in the aorta) measurement sites. Regression analysis revealed that aortic pulse wave velocity, a measure of central arterial stiffness obtained before cooling, was the best predictor of the increased pressor response to superficial skin cooling in older adults, explaining ∼63% of its variability. These results indicate that there is a greater pressor response to non-internal body temperature-reducing cold stress with age in humans that may be mediated by increased levels of central arterial stiffness.
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Jin, Qing-Hua, Yuto Ueda, Yuta Ishizuka, Takato Kunitake et Hiroshi Kannan. « Cardiovascular changes induced by central hypertonic saline are accompanied by glutamate release in awake rats ». American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 281, no 4 (1 octobre 2001) : R1224—R1231. http://dx.doi.org/10.1152/ajpregu.2001.281.4.r1224.
Texte intégralRésumé :
To elucidate neurochemical mechanisms responsible for cardiovascular responses induced by central salt loading, we directly perfused the paraventricular nucleus (PVN) of the hypothalamus region with hypertonic saline (0.3 or 0.45 M) by using an in vivo brain microdialysis technique. We then measured the extracellular concentrations of glutamate in the PVN region in conscious rats along with the blood pressure and heart rate. Blood pressure, heart rate, and glutamate levels were increased by perfusion of 0.45 M saline; however, they did not change by perfusion of 0.3 M saline. Next, we examined the possible involvement of glutamate in the cardiovascular responses induced by hypertonic saline. Dizocilpine, a noncompetitive antagonist of the N-methyl-d-aspartate (NMDA) receptor, attenuated the increases of blood pressure and heart rate, although 6-cyano-7-nitroquinoxaline-2,3-dione, an antagonist of the non-NMDA receptor, did not affect the blood pressure and heart rate. Our results show that local perfusion of the hypothalamic PVN region with hypertonic saline elicits a local release of glutamate, which may act via NMDA-type glutamate receptors to produce cardiovascular responses.
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Rentziou, Gianna, Katerina Saltiki, Efstathios Manios, Kimon Stamatelopoulos, Eleni Koroboki, Anastasia Vemmou, Emily Mantzou, Nikolaos Zakopoulos et Maria Alevizaki. « Effects of Recombinant Human Thyrotropin Administration on 24-Hour Arterial Pressure in Female Undergoing Evaluation for Differentiated Thyroid Cancer ». International Journal of Endocrinology 2014 (2014) : 1–8. http://dx.doi.org/10.1155/2014/270213.
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Objective.Thyroid-stimulating-hormone (TSH) receptors are expressed in endothelial cells. We investigated whether elevated TSH levels after acute recombinant TSH (rhTSH) administration may result in alterations in blood pressure (BP) in premenopausal women with well-differentiated thyroid carcinoma (DTC).Designs.Thirty euthyroid DTC female patients were evaluated by rhTSH stimulation test (mean age40.4±8.6years). A 24 h ambulatory systolic and diastolic blood pressure (SBP, DBP) monitoring (24 hr ABPM) was performed on days 2-3(D2-3). TSH was measured on day 1(D1), day 3(D3), and day 5(D5). Central blood pressure was evaluated on D3. Twenty-three patients were studied 1–4 weeks earlier (basal measurements).Results.TSH levels were D1: median 0.2 mU/L, D3: median 115.0 mU/L, and D5: median 14.6 mU/L. There were no significant associations between TSH on D1 and D3 and any BP measurements. Median D5 office-SBP and 24 h SBP, DBP, and central SBP were correlated with D5-TSH (P<0.04). In those where a basal 24 h ABPM had been performed median pulse pressure was higher after rhTSH-test (P=0.02).Conclusions.TSH, when acutely elevated, may slightly increase SBP, DBP, and central SBP. This agrees with previous reports showing positive associations of BP with TSH.
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Van Huysse, J. W., et S. L. Bealer. « Hypertension and alterations in central catecholamines after preoptic recess lesions ». American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 256, no 2 (1 février 1989) : R487—R493. http://dx.doi.org/10.1152/ajpregu.1989.256.2.r487.
Texte intégralRésumé :
Catecholamine concentrations were measured in brain regions of rats with lesions of the anteroventral third ventricle (AV3V-X rats) or parietal cortex (CORT-X) and of control-operated (CONT) rats. Three hours after surgery, total norepinephrine (NE) concentrations in all brain regions measured of AV3V-X rats were less than those of CONT or CORT-X rats. Epinephrine (EPI) concentrations were decreased in the medulla and hypothalamus, but dopamine levels were unchanged. Also, extracellular NE concentration, estimated by in vivo microdialysis techniques, was increased in the anterior hypothalamic nucleus (AHNE) and dorsomedial medulla (DMMNE) of AV3V-X rats compared with CONT rats. Increased DMMNE paralleled blood pressure increases. DMMNE did not change after blood pressure was increased by intravenous angiotensin II infusion (60 ng/min) in CONT rats. Thus 1) AV3V lesions result in decreased NE and EPI concentrations in multiple brain regions; 2) acute reductions in central NE in AV3V-X rats are associated with increased extracellular NE in the AH and DMM, suggesting increased NE release; and 3) although increased DMMNE is temporally related to increased blood pressure following AV3V lesions, increased DMMNE is not a response to the hypertension per se.
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Perry, S. F., R. Fritsche, T. M. Hoagland, D. W. Duff et K. R. Olson. « The control of blood pressure during external hypercapnia in the rainbow trout (Oncorhynchus mykiss) ». Journal of Experimental Biology 202, no 16 (15 août 1999) : 2177–90. http://dx.doi.org/10.1242/jeb.202.16.2177.
Texte intégralRésumé :
Adult freshwater rainbow trout (Oncorhynchus mykiss) were exposed acutely (approximately 20 min) in a stepwise manner to increasing levels of environmental carbon dioxide ranging between 1.7 and 9.0 mmHg (0.23-1.2 kPa). Experiments were performed to examine, for the first time, the influence of hypercapnic acidosis on aspects of cardiovascular physiology including blood pressure, cardiac output and vascular resistance. Fish displayed dose (water CO(2) partial pressure) -dependent increases in ventral aortic (13–39 %) and dorsal aortic (17–54 %) blood pressures that reflected marked increases in systemic vascular resistance (16–78 %); branchial vascular resistance was unaffected by hypercapnia. At the highest level of hypercapnia (9.0 mmHg), central venous pressure was significantly elevated by 54 %. Although cardiac output remained constant, heart rate was significantly lowered by 4–7 beats min(−)(1) at the two highest levels of hypercapnia. To determine whether the cardiovascular responses to hypercapnia were being blunted by the stepwise increase in external P(CO2), a separate group of fish was exposed directly to a single step of hypercapnia (water P(CO2) 8.0 mmHg). The cardiovascular responses were similar to those exhibited by the more gradually exposed fish except that central venous pressure did not increase and the extent of the bradycardia was greater (13 beats min(−)(1)). After confirming the effectiveness of yohimbine in blocking the vasoconstrictory (α)-adrenoreceptors of the systemic vasculature, this antagonist was used as a tool to assess the importance of (α)-adrenoreceptor stimulation in promoting the cardiovascular responses during hypercapnia. Prior treatment of fish with yohimbine prevented the increased blood pressures and systemic vascular resistance during hypercapnia but did not influence the CO(2)-induced bradycardia. Plasma levels of catecholamines did not change during hypercapnia, and therefore the stimulation of the systemic (α)-adrenoreceptors presumably reflected increased sympathetic nerve activity. To determine whether the cardiovascular changes elicited by hypercapnia were related to acidosis-induced hypoxaemia, fish were exposed to hypoxia in a stepwise manner (water P(O2) 65–151 mmHg). The cardiovascular responses to hypoxia were markedly different from those to hypercapnia and consisted of pronounced increases in systemic and branchial vascular resistance, but only at the most severe level of hypoxia; ventral and dorsal aortic pressures were unaffected. The differences between the responses to hypercapnia and hypoxia, coupled with the smaller reductions in blood oxygen content during hypercapnia, support the hypothesis that the cardiovascular responses to CO(2) are direct and are unrelated to hypoxaemia.
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Ebert, T. J., L. Groban, M. Muzi, M. Hanson et A. W. Cowley. « ANP-mediated volume depletion attenuates renal responses in humans ». American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 263, no 6 (1 décembre 1992) : R1303—R1308. http://dx.doi.org/10.1152/ajpregu.1992.263.6.r1303.
Texte intégralRésumé :
Brief low-dose infusions of atrial natriuretic peptide (ANP) that emulate physiological plasma concentrations in humans have little if any effect on renal excretory function. This study explored the possibility that ANP-mediated reductions in cardiac filling pressures (through ANP's rapid effect on capillary dynamics) could attenuate its purported renal effects. Protocol A consisted of 16 healthy subjects (ages 19-27 yr old) who underwent three consecutive 45-min experimental sequences: 1) placebo, 2) ANP (10 ng.kg-1 x min-1), and 3) ANP alone (n = 8) or ANP with simultaneous lower body positive pressure (LBPP, n = 8). Electrocardiogram and direct measures of arterial and central venous pressures were continuously monitored. Blood was sampled at the end of each 45-min sequence before subjects stood to void. Compared with control (placebo), ANP produced a hemoconcentration and increased plasma norepinephrine, but did not change heart rate, blood pressure, plasma levels of renin, aldosterone, or vasopressin, or renal excretion of volume or sodium. In subjects receiving LBPP to maintain central venous pressure during the last 45 min of ANP infusion, norepinephrine did not increase and urine volume and sodium excretion increased (P < 0.05). In a second study (protocol B), five healthy subjects received a placebo infusion for 45 min followed by two consecutive 45-min infusions of ANP (10 ng.kg-1 x min-1). Central venous pressure was maintained (LBPP) at placebo baseline throughout the two ANP infusion periods. Urine volume and sodium excretion rates increased progressively and significantly during both ANP infusion periods (P < 0.05) without significant changes in creatinine clearance, blood pressure, or heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)
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Hornstrup, Bodil G., Jeppe B. Rosenbaek, Nikolai Hoffmann-Petersen, Pia H. Gjoerup, Jost Wessels, Thomas G. Lauridsen, Erling B. Pedersen et Jesper N. Bech. « Nocturnal Blood Pressure Decrease in Hypertensive Patients and Normotensives- Association with Obstructive Sleep Apnoea and Renal Function ». Open Hypertension Journal 10, no 1 (17 octobre 2018) : 28–40. http://dx.doi.org/10.2174/1876526201810010028.
Texte intégralRésumé :
Background:Blunted nocturnal Blood Pressure (BP) decrease is seen in patients with hypertension and obstructive sleep apnoea (OSA). The influence of OSA and renal function on nocturnal BP decrease is not fully clarified.Objective:In this case control study of hypertensive patients and healthy controls, we aimed to analyse the relationship between nocturnal BP decrease on one hand and presence of OSA, renal function, plasma levels of syndecan and vasoactive hormones, and urinary sodium excretion on the other.Methods:In 75 hypertensive patients and 56 controls, we performed brachial and central 24h ambulatory BP measurement and cardio respiratory monitoring. We measured syndecan, renin, angiotensinII, aldosterone, vasopressin, and brain natriuretic peptide in plasma and 24h urinary excretion of sodium, aquaporin2, and a component of the epithelial sodium channel (u-ENaCγ).Results:Nocturnal BP decrease was lower in patients than controls, brachial (13% versus 17%,p=0.001) and central (8% versus 10%,p=0.019). Moderate-to-severe OSA was present in 13% of patients, 2% of controls (p<0.005). Neither brachial nor central nocturnal BP decrease was associated with OSA, renal function, plasma levels of vasoactive hormones, syndecan-1, or urinary sodium excretion. P-syndecan and u-ENaCɣ were higher in patients than controls.Conclusion:Both brachial and central nocturnal BP decrease was lower in patients than in controls. Neither brachial nor central nocturnal BP decrease was associated with the presence of OSA, renal function, or plasma levels of vasoactive hormones. Increased syndecan in plasma in hypertensive patients suggested damage to the endothelial glycocalyx.
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Chen, Wu, Yiqun Han, Yanwen Wang, Xi Chen, Xinghua Qiu, Weiju Li, Yifan Xu et Tong Zhu. « Glucose Metabolic Disorders Enhance Vascular Dysfunction Triggered by Particulate Air Pollution : a Panel Study ». Hypertension 79, no 5 (mai 2022) : 1079–90. http://dx.doi.org/10.1161/hypertensionaha.121.18889.
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Background: Vascular dysfunction is a biological pathway whereby particulate matter (PM) exerts deleterious cardiovascular effects. The effects of ambient PM on vascular function in prediabetic individuals are unclear. Methods: A panel study recruited 112 Beijing residents with and without prediabetes. Multiple vascular function indices were measured up to 7 times. The associations between vascular function indices and short-term exposure to ambient PM, including fine particulate matter (PM 2.5 ), ultrafine particles, accumulation mode particles, and black carbon, and the modification of these associations by glucose metabolic status were examined using linear mixed-effects models. Results: Increases in brachial artery pulse pressure, central aortic pulse pressure, and ejection duration, and decreases in subendocardial viability ratio and reactive hyperemia index were significantly associated with at least one PM pollutant in all participants, indicating increased vascular dysfunction. For example, for an interquartile range increment in 5-day moving average ultrafine particles, brachial artery pulse pressure, and central aortic pulse pressure increased 5.4% (0.8%–10.4%) and 6.2% (1.2%–11.5%), respectively. Additionally, PM-associated changes in vascular function differed according to glucose metabolic status. Among participants with high fasting blood glucose levels (≥6.1 mmol/L), PM exposure was significantly associated with increased brachial artery systolic blood pressure, central aortic systolic blood pressure, brachial artery pulse pressure, central aortic pulse pressure, and augmentation pressure normalized to a heart rate of 75 bpm and decreased subendocardial viability ratio and reactive hyperemia index. Weaker or null associations were observed in the low-fasting blood glucose group. Conclusions: Glucose metabolic disorders may exacerbate vascular dysfunction associated with short-term ambient PM exposure.
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Mozos, Ioana, Daniela Jianu, Cristina Gug et Dana Stoian. « Links between High-Sensitivity C-Reactive Protein and Pulse Wave Analysis in Middle-Aged Patients with Hypertension and High Normal Blood Pressure ». Disease Markers 2019 (17 juillet 2019) : 1–9. http://dx.doi.org/10.1155/2019/2568069.
Texte intégralRésumé :
Arterial stiffness and arterial age provide valuable prognostic cardiovascular information. The present study aimed at assessing the levels of vitamin D, high-sensitivity C-reactive protein (hsCRP), low-density lipoprotein cholesterol (LDL), and oxidized LDL (oxLDL) in a group of middle-aged hypertensive patients and their relationship with pulse wave velocity (PWV), central blood pressure, and early arterial aging (EAA), respectively. A total of 56 patients, aged 48±6 years, 57% males, with hypertension and high normal blood pressure (HNBP), were investigated using a Mobile-O-Graph, to assess central and peripheral blood pressure, PWV, and arterial age. Additionally, hsCRP, LDL, oxLDL, and 25-hydroxy vitamin D3 were assessed. PWV, 25-hydroxy vitamin D3, hsCRP, oxLDL, and LDL levels were 7.26±0.69 m/s, 25.99±11.17 microg/l, 0.48±0.44 mg/dl, 261.37±421 ng/ml, and 145.73±39.53 mg/dl, respectively. Significant correlations were obtained between oxLDL and pulse pressure amplification (rS=−0.347, p=0.028) and between hsCRP and LDL levels with PWV and EAA, respectively. ROC curve analysis revealed that hsCRP is a sensitive and specific predictor of EAA and increased PWV values. Concluding, vitamin D deficiency and increased hsCRP and LDL values are very common, and high oxidized LDL is related to pulse pressure amplification in patients with elevated blood pressure. Vitamin D level and high-sensitivity C-reactive protein and LDL provide valuable information in middle-aged hypertensive and HNBP patients related to arterial stiffness and early arterial aging, but only hsCRP is a sensitive predictor of EAA and PWV.
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Matsukawa, Toshiyoshi, et Takenori Miyamoto. « Angiotensin II-stimulated secretion of arginine vasopressin is inhibited by atrial natriuretic peptide in humans ». American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 300, no 3 (mars 2011) : R624—R629. http://dx.doi.org/10.1152/ajpregu.00324.2010.
Texte intégralRésumé :
We investigated the effect of the intravenous infusion of atrial natriuretic peptide (ANP) on the response of plasma arginine vasopressin (AVP) levels to intravenous infusion of angiotensin II (ANG II) in healthy individuals. Intravenous infusion of ANP (10 ng·kg−1·min−1) slightly but significantly decreased plasma AVP levels, while intravenous infusion of ANG II (10 ng·kg−1·min−1) resulted in slightly increased plasma AVP levels. ANG II infused significant elevations in arterial blood pressure and central venous pressure (CVP). Because the elevation in blood pressure could have potentially inhibited AVP secretion via baroreceptor reflexes, the effect of ANG II on blood pressure was attenuated by the simultaneous infusion of nitroprusside. ANG II alone produced a remarkable increase in plasma AVP levels when infused with nitroprusside, whereas the simultaneous ANP intravenous infusion (10 ng·kg−1·min−1) abolished the increase in plasma AVP levels induced by ANG II when blood pressure elevation was attenuated by nitroprusside. Thus, ANG II increased AVP secretion and ANP inhibited not only basal AVP secretion but also ANG II-stimulated AVP secretion in humans. These findings support the hypothesis that circulating ANP modulates AVP secretion, in part, by antagonizing the action of circulating ANG II.
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Velmakin, S., E. Troitskaya et Zh Kobalava. « HYPERTENSIVE PATIENTS WITH RHEUMATOID ARTHRITIS ARE CHARACTERIZED BY HIGHER LEVELS OF THE OFFICE BLOOD PRESSURE AND WORSE CONTROL OF CENTRAL BLOOD PRESSURE COMPARED TO THE CONTROLS ». Journal of Hypertension 37 (juillet 2019) : e317. http://dx.doi.org/10.1097/01.hjh.0000573948.13946.b6.
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Algowhary, Magdy Ibrahim Aldesowky Mohammed, Nady A. Razik, Amr Ahmed Aly Youssef, Lateef Gerges Lateef Fouad et Ayman Khairy M. Hassan. « Relationship between noninvasive central blood pressure and brain natriuretic peptide levels in patients with hypertensive pulmonary edema ». Blood Pressure Monitoring 27, no 2 (29 novembre 2021) : 113–20. http://dx.doi.org/10.1097/mbp.0000000000000574.
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Hsu, Pai-Feng, Shao-Yuan Chuang, Hao-Min Cheng, Shih-Hsien Sung, Chih-Tai Ting, Edward G. Lakatta, Frank C. P. Yin, Pesus Chou et Chen-Huan Chen. « P-001 ASSOCIATIONS OF SERUM URIC ACID LEVELS WITH ARTERIAL WAVE REFLECTIONS AND CENTRAL SYSTOLIC BLOOD PRESSURE ». Journal of Hypertension 29 (novembre 2011) : e45. http://dx.doi.org/10.1097/01.hjh.0000408108.20212.2a.
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Loaiza-Betancur, Andrés F., et Iván Chulvi-Medrano. « Is Low-Intensity Isometric Handgrip Exercise an Efficient Alternative in Lifestyle Blood Pressure Management ? A Systematic Review ». Sports Health : A Multidisciplinary Approach 12, no 5 (10 août 2020) : 470–77. http://dx.doi.org/10.1177/1941738120943882.
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Context: High blood pressure is one of the leading preventable causes of cardiovascular death worldwide. In this regard, several studies have shown interest in the benefits of isometric exercise on blood pressure regulation. Objective: To assess whether low-intensity isometric handgrip exercise (LI-IHE) is an effective strategy to lower blood pressure levels in prehypertensive and hypertensive patients. Data Source: This study was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement and registered with PROSPERO. Potentially eligible studies were identified after a systematic search conducted on 4 international databases: PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), PEDro, and SPORTDiscus. Study Selection: We included randomized controlled trials that comprised patients who received LI-IHE. Study Design: Systematic review with meta-analysis. Level of Evidence: Level 3. Data Extraction: Data related to patient characteristics, exercise programs, risk-of-bias assessment, and outcomes of interest were systematically reviewed independently by 2 authors. Results: The following reductions (mean differences) were observed after LI-IHE: systolic blood pressure (SBP), (MD) = −5.43 mm Hg; (95% CI, −8.47 to −2.39; P = 0.0005); diastolic blood pressure (DBP), −2.41 mm Hg (95% CI, −4.33 to −0.48; P = 0.01); mean arterial pressure (MAP), −1.28 mm Hg (95% CI, −2.99 to 0.44; P = 0.14). Conclusion: LI-IHE seems to lower SBP, DBP, and MAP values in prehypertensive and hypertensive adults. It appears that LI-IHE reduces, in greater magnitude, blood pressure levels in hypertensive patients, specifically in patients aged <45 years, those who are overweight, and those on medications. Nevertheless, substantial heterogeneity in the main results and in the analyses by subgroups generated uncertainty about the real reduction magnitude that LI-IHE can produce on blood pressure.
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Prasetia, Toni, Firhat Esfandiari, Sandhy Arya Pratama et Mohamad Imam Istawa. « Hubungan Tekanan Darah Sistolik Dengan Kadar Trigliserida Pada Pasien Diabetes Melitus Tipe 2 Di Klinik Arafah Lampung Tengah ». MAHESA : Malahayati Health Student Journal 1, no 3 (5 septembre 2021) : 230–36. http://dx.doi.org/10.33024/mahesa.v1i3.3944.
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ABSTRACT: CORRELATION OF SYSTOLIC BLOOD PRESSURE WITH TRIGLYCERIDE LEVELS IN TYPE 2 DIABETES MELLITUS PATIENTS IN ARAFAH CLINIC, CENTRAL LAMPUNGBackground: Hypertension is the main risk factor for DM. Hypertension can make cells insensitive to insulin. Even though insulin plays a role in increasing glucose uptake in many cells and in this way also regulates carbohydrate metabolism, so that if insulin resistance occurs by cells, the blood sugar levels can also be disrupted. Dyslipidemia is a change in blood lipid profile, one of which is an increase in triglyceride levels. High triglyceride levels can cause thickening of the blood vessels and cause narrowing of the arteries.Objective: To determine the relationship between systolic blood pressure and triglyceride levels in patients with type 2 diabetes mellitus in Klniki Arafah Tengah Lampung.Methodology: This research uses a descriptive-analytic research method with a cross-sectional approach. The sampling technique is Total Sampling. . Respondents in this study were patients with Type 2 Diabetes Mellitus at the Arafah Clinic in Central Lampung in 2020.Results: It is known that in the sex frequency distribution, there were 16 men with 34.8% and 30 women with 65.2%. Distribution of frequency based on age, it was found that the age group 24-45 years numbered 7 patients (15.2%), the age group 46-65 years amounted to 32 patients (69.6%), and the group> 65 years amounted to 7 patients (15.2 %). It is known that the frequency distribution of systolic blood pressure in type II diabetes mellitus patients, it was found that type II diabetes mellitus patients with normal systolic blood pressure levels were 34 patients with 73.9%, while high systolic blood pressure levels were 12 patients with 26.1%. It is known that the frequency distribution of triglyceride levels in patients with type II diabetes mellitus, it was found that 8 patients with normal triglycerides had normal triglyceride levels, and 38 patients (82.6%) had high triglyceride levels. The results of the chi-square statistical test found no relationship with the results of p = 898 (p> 0.05).Conclusion: There is no correlation between systolic blood pressure and cholesterol triglycerides in type 2 diabetes mellitus patients at the Arafah Clinic, Central Lampung in 2020. Keywords: Type 2 Diabetes Mellitus, Systolic Blood Pressure Triglierida INTISARI: HUBUNGAN TEKANAN DARAH SISTOLIK DENGAN KADAR TRIGLISERIDA PADA PASIEN DIABETES MELITUS TIPE 2 DI KLINIK ARAFAH LAMPUNG TENGAHLatar Belakang: Hipertensi merupakan faktor risiko untama untuk terjadinya DM. Hipertensi dapat membuat sel tidak sensitif terhadap insulin. Padahal insulin berperan meningkatkan ambilan glukosa di banyak sel dan dengan cara ini juga mengatur metabolisme karbohidrat, sehingga jika terjadi resistensi insulin oleh sel, maka kadar gula di dalam darah juga dapat mengalami gangguan. Dislipidemia adalah perubahan dari profil lipid darah salah satunya adalah peningkatan kadar trigliserida. Kadar trigliserida yang tinggi dapat menyebabkan penebalan pembuluh darah dan menyebabkan penyempitan pembuluh darahTujuan : Untuk mengetahui hubungan tekanan darah sistolik dengan kadar trigliserida pada pasien diabetes melitus tipe 2 di klniki arafah lampung tengahMetode : Jenis penelitian ini menggunakan metode penelitian deskriptif analitik dengan pendekatan cross – sectional. Teknik pengambilan sampel berupa Total Sampling. . Responden dalam penelitian ini adalah pasien Diabetes Melitus tipe 2 di Klinik Arafah Lampung Tengah tahun 2020.Hasil : pada variabel trigliserida dan tekanan darah sistolik diperoleh nilai p Vale = 898 (p>0,05)Kesimpulan: Tidak terdapat Hubungan Antara Tekanan Darah Sistolik dengan Trigliserida Kolesterol pada pasien Diabetes Melitus tipe 2 di Klinik Arafah Lampung Tengah tahun 2020.Kata Kunci : Diabetes Melitus tipe 2, Tekanan Darah Sistolil Triglierid
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Tsvetkova, E. E., A. A. Kuznetsov, D. V. Denisova, Yu I. Ragino et M. I. Voevoda. « Comparison of the association of brachial arterial pressure and parameters of central aortic pressure with left ventricular hypertrophy in the general population of Novosibirsk ». Russian Journal of Cardiology, no 1 (9 février 2019) : 18–22. http://dx.doi.org/10.15829/1560-4071-2019-1-18-22.
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Aim.There is evidence that central aortic blood pressure (BP) is more associated with left ventricular myocardial hypertrophy than brachial BP. The purpose of this work is to compare the association of brachial and central aortic BP with electrocardiographic parameters of left ventricular hypertrophy in the general population of Novosibirsk.Material and methods. We examined 327 people: 155 men and 172 women aged 25-44 years from a representative sample from the general population of Novosibirsk. The study program included anthropometry, BP measurement, electrocardiography, biochemical blood analysis. Radial artery applanation tonometry and pulse wave analysis were performed using the SphygmoCor system. Left ventricular hypertrophy was determined by electrocardiographic parameters.Results.In the general population of Novosibirsk, central aortic BP is more associated with left ventricular myocardial hypertrophy than brachial BP. Central pulse pressure, in contrast to brachial BP, is significantly associated with the R+S index (p=0,0085), as well as RI (p=0,0038) and RaVL (p=0,0039) wave amplitude. Central systolic aortic BP, in contrast to brachial systolic BP, is significantly associated with RI (p=0,042) and RaVL (p=0,029) wave amplitudes. Amplification parameters of central aortic BP, regardless of brachial BP, are associated with indices of left ventricular hypertrophy. Pulse pressure amplification in groups with or without left ventricular hypertrophy, standardized for age, gender, height, waist circumference, heart rate, triglyceride levels, high density lipoprotein cholesterol, low density lipoprotein cholesterol, blood glucose, and brachial pulse pressure, was 13,3 mm Hg and 12,5 mm Hg, respectively (p=0,035).Conclusion.The results of this study substantiate the relevance of the practical use of central aortic BP parameters in addition to the office measurement of brachial BP.
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Orno, Theosobia Grace. « THE EARLY DETECTION OF METABOLIC SYNDROME USED NCEP ATP-III METHOD IN WAAI VILLAGE COMMUNITY CENTRAL MALUKU REGENCY ». Molucca Medica 15, no 1 (15 mai 2022) : 1–8. http://dx.doi.org/10.30598/molmed.2022.v15.i1.1.
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Metabolic syndrome is a metabolic disorder that complexly includes carbohydrate, lipid and protein metabolism disorders which are known to be the main cause of diabetes mellitus, hypertension and coronary heart disease. Waai Village, Central Maluku Regency is one of the villages affected by the earthquake for a long time so that social assistance in the form of fast food is consumed in the long term which is thought to be one of the causes of metabolic syndrome. The purpose of this research is to detect the presence of metabolic syndrome with the NCEP ATP-III criteria consists of measuring blood pressure, fasting blood glucose levels and serum triglyceride levels using the photometric method. This type of research is descriptive research with a cross sectional approach. The sampling technique used is purposive sampling, in accordance with the predetermined sample criteria. The results showed that 29 of 50 subjects (58%) had metabolic syndrome with an average blood pressure of 148/94 mmHg, an average fasting blood glucose level of 158 mg/dL, and an average triglyceride level of 198 mg/dL.
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Sayk, Friedhelm, Isabel Wobbe, Christoph Twesten, Moritz Meusel, Peter Wellhöner, Inge Derad et Christoph Dodt. « Prolonged blood pressure elevation following continuous infusion of angiotensin II—a baroreflex study in healthy humans ». American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 309, no 11 (1 décembre 2015) : R1406—R1414. http://dx.doi.org/10.1152/ajpregu.00111.2015.
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ANG II interacts with the sympathetic nervous system at central nervous blood pressure-regulating structures, including the baroreflex. It is unknown whether prolonged BP elevation mediated by high ANG II plasma levels could induce a persistent shift of the central nervous baroreflex setpoint, lasting beyond the short ANG II plasmatic half time of a few seconds, thereby consolidating elevated BP and/or increased SNA in healthy humans. In a blinded crossover design, ANG II or placebo (saline) was infused for a 6-h period in 12 resting normotensive students (6 males, 6 females) raising BP to borderline hypertensive levels. Between 60 and 120 min after the infusion period, muscle sympathetic nerve activity (MSNA) was assessed microneurographically and correlated with oscillometric BP measurements and heart rate at supine rest (baseline) and during pharmacologic baroreceptor challenge. Infusion of ANG II increased BP to borderline-hypertensive levels, as intended, whereas heart rate remained unaltered. At baroreflex assessment (i.e., 60–120 min after end of infusion period), systolic BP was significantly higher compared with placebo (Δ8.4 ± 3.1 mmHg; P < 0.05), whereas diastolic values were nearly equal between conditions. Baseline MSNA was neither decreased nor increased, and baroreflex sensitivity to vasoactive drug challenge was not altered. Our results show that elevation of ANG II plasma levels over 6 h was able to increase systolic, but not diastolic, BP far beyond blood-mediated ANG II effects. MSNA or heart rate did not counter-regulate this BP elevation, indicating that ANG II had sustainably reset the central nervous BP threshold of sympathetic baroreflex function to accept elevated BP input signals without counter-regulatory response.
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Bayu Yoni Setyo Nugroho, Vilda Ana Veria Setyawati et Slamet Isworo. « Assessing factors affecting professional bus drivers in Central Java, Indonesia ». GSC Biological and Pharmaceutical Sciences 14, no 3 (30 mars 2021) : 019–26. http://dx.doi.org/10.30574/gscbps.2021.14.3.0059.
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Public transportation is a key solution to a connecting city in Indonesia country. An important factor of driver behavior and driver fatigue is the potential for loss in this field. This study aims to identify traffic loss risk factors associated with demographic characteristics, fatigue levels, body mass index, driver experience blood pressure levels, and inappropriate driver attitudes on public transport as well as to find out the effects of fatigue levels. This research is a cross-sectional technique with descriptive analytics. The sample in this study was 67 professional bus drivers with licenses in Central Java Province, Indonesia. Data collection in the month 1-30 January 2021. Based on the results of the study showed that 67 respondents, 77.6% experienced severe level fatigue, 85.1% worked more than 8 hours, 73.1% had a smoking habit. For Body Mass Index 29.9% are overweight, 65.7% have prehypertensive blood pressure levels. The fatigue experienced by public transport drivers is categorical as heavy (77.6%). periodic checks are required regarding the level of fatigue so that the risk of traffic accidents does not occur. The policy regarding working hours must be carried out from an average of 13.82 hours per day to 8 hours, according to regulations and a bus driver's working period of more than 5 years is a record of future health problems. Professional bus drivers have a dangerous level of fatigue, so there needs to be a change in the work system in order to avoid the risk of traffic accidents related to public transportation.
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Groban, L., A. W. Cowley et T. J. Ebert. « Atrial natriuretic peptide augments forearm capillary filtration in humans ». American Journal of Physiology-Heart and Circulatory Physiology 259, no 1 (1 juillet 1990) : H258—H263. http://dx.doi.org/10.1152/ajpheart.1990.259.1.h258.
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Low-dose infusions of atrial natriuretic peptide (ANP) into humans reduce cardiac filling pressures without enhancing renal excretion or producing vasodilation. The present human study was undertaken to seek an effect of ANP on capillary filtration in humans and to determine its relationship to reductions in cardiac filling pressures. Heart rate (electrocardiogram), blood pressure (cuff method), and renal excretion of salt and water were determined, and central venous pressure (jugular vein cannulation, strain-gauge transducer) and forearm venous compliance and capillary filtration coefficient (strain-gauge plethysmography) were derived by computer. Forearm girth and venous pressure (peripheral vein catheter) measurements were obtained while the arm was elevated above heart level, and an upper arm blood pressure cuff was intermittently inflated to venous occluding pressures of 20, 30, and 40 mmHg. Forearm measurements, hematocrit, plasma proteins, albumin and plasma levels of ANP were determined from euvolemic volunteers before and during 60 min intravenous infusions of ANP (5 ng.kg-1.min-1, n = 9) or placebo (isotonic saline, n = 7). ANP infusions produced physiological increases (4- to 5-fold) in plasma ANP (from a base line 35 +/- 6 pg/ml) (P less than 0.05). Hemodynamic responses to ANP consisted of a reduction in central venous pressure (P less than 0.05) and no change in heart rate, mean arterial pressure, or renal excretory parameters. ANP increased forearm capillary filtration between 37 and 63% (P less than 0.05) from base line but did not significantly alter forearm compliance measurements.(ABSTRACT TRUNCATED AT 250 WORDS)
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Matsukawa, Kanji, Hidehiko Komine, Tomoko Nakamoto et Jun Murata. « Central command blunts sensitivity of arterial baroreceptor-heart rate reflex at onset of voluntary static exercise ». American Journal of Physiology-Heart and Circulatory Physiology 290, no 1 (janvier 2006) : H200—H208. http://dx.doi.org/10.1152/ajpheart.00013.2005.
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We have reported that baroreflex bradycardia by stimulation of the aortic depressor nerve is blunted at the onset of voluntary static exercise in conscious cats. Central command may contribute to the blunted bradycardia, because the most blunted bradycardia occurs immediately before exercise or when a forelimb is extended before force development. However, it remained unknown whether the blunted bradycardia is due to either reduced sensitivity of the baroreflex stimulus-response curve or resetting of the curve toward a higher blood pressure. To determine this, we examined the stimulus-response relationship between systolic (SAP) or mean arterial pressure (MAP) and heart rate (HR) at the onset of and during the later period of static exercise in seven cats ( n = 348 trials) by changing arterial pressure with infusion of nitroprusside and phenylephrine or norepinephrine. The slope of the MAP-HR curve decreased at the onset of exercise to 48% of the preexercise value (2.9 ± 0.4 beats·min−1·mmHg−1); the slope of the SAP-HR curve decreased to 59%. The threshold blood pressures of the stimulus-response curves, at which HR started to fall due to arterial baroreflex, were not affected. In contrast, the slopes of the stimulus-response curves during the later period of exercise returned near the preexercise levels, whereas the threshold blood pressures elevated 6–8 mmHg. The maximal plateau level of HR was not different before and during static exercise, denying an upward shift of the baroreflex stimulus-response curves. Thus central command is likely to attenuate sensitivity of the cardiac component of arterial baroreflex at the onset of voluntary static exercise without shifting the stimulus-response curve.