Blood Pressure Distribution Research Articles

High blood pressure in adults with disabilities: Influence of gender, body weight and health behaviors

The aims of this study were to explore the mean and distribution of systolic and diastolic blood pressure, and to examine the influence of gender, body weight and health behaviors on hypertension in adults with disabilities. We analyzed the 2010 annual community health examination chart of adults with disabilities in east Taiwan. The study samples included 833 adults with disabilities whose age 30 years and over participated in the analyses. The mean value of diastolic and systolic blood pressure (mmHg) of the study participants was 76.51 ± 12.65 (range = 40-155) and 127.39 ± 20.32 (range = 77-221). Fifteen percent and 23.4% of the participants have high diastolic (>/=90 mmHg) and systolic (>/= 140 mmHg) blood pressure. There were 27.4% of the participants who had hypertension, high diastolic or/and systolic blood pressure. Finally, we found that the factors of older age (OR = 2.45, 95% CI = 1.22-4.93), overweight or obese in BMI (OR = 6.72, 95% CI = 1.90-23.78; OR = 6.76, 95% CI = 1.84-24.84), waist circumference (OR = 1.64, 95% CI = 1.03-2.61) and vegetable/fruit intake (OR = 0.61, 95% CI = 0.39-0.94) were variables that could significantly predict the hypertension condition of the subjects after controlling factors of marital status, type and level of disability. To improve the healthcare for people who suffer with and prevention for hypertension, the study highlights the health authorities should pay much attention to blood pressure condition and their determinants for people with disabilities in the communities.

Mathematical analysis for internal filtration of convection-enhanced high-flux hemodialyzer

Structural modifications using a conventional hemodialyzer improved the internal filtration and clearance of middle molecular weight wastes by enhanced convection effect. In this study, we employed a mathematical model describing the internal filtration rate as well as the hemodynamic and hematologic parameters in highflux dialyzer to interpret the previous reported experimental results. Conventional high-flux hemodialysis and convection-enhanced high-flux hemodialysis were configured in the mathematical forms and integrated into the iterative numerical method to predict the internal filtration phenomena inside the dialyzers during dialysis. The distributions of blood pressure, dialysate pressure, oncotic pressure, blood flow rates, dialysate flow rates, local ultrafiltration, hematocrit, protein concentration and blood viscosity along the axial length of dialyzer were calculated in order to estimate the internal filtration volume. The results show that the filtration volumes by internal filtration is two times higher in a convection-enhanced high-flux hemodialyzer than in a conventional high-flux hemodialzer and explains the experimental result of improved clearance of middle molecular size waste in convection-enhanced high-flux hemodialyzer.

Red blood cell partitioning and blood flux redistribution in microvascular bifurcation

This paper studies red blood cell (RBC) partitioning and blood flux redistribution in microvascular bifurcation by immersed boundary and lattice Boltzmann method. The effects of the initial position of RBC at low Reynolds number regime on the RBC deformation, RBC partitioning, blood flux redistribution and pressure distribution are discussed in detail. It is shown that the blood flux in the daughter branches and the initial position of RBC are important for RBC partitioning. RBC tends to enter the higher-flux-rate branch if the initial position of RBC is near the center of the mother vessel. The RBC may enter the lower-flux-rate branch if it is located near the wall of mother vessel on the lower-flux-rate branch side. Moreover, the blood flux is redistributed when an RBC presents in the daughter branch. Such redistribution is caused by the pressure distribution and reduces the superiority of RBC entering the same branch. The results obtained in the present work may provide a physical insight into the understanding of RBC partitioning and blood flux redistribution in microvascular bifurcation.

Pattern of Blood Pressure Distribution among University Students in Ajman, United Arab Emirates

Background Elevated blood pressure has been identified as a silent killer contributing to mortality and morbidity worldwide, hence it is essential to identify the high risk individuals at an early age to prevent the progress of the disease and its co-morbid conditions. Objective The objective of the present cross-sectional study was to assess the pattern of blood pressure distribution among students of medical and allied health professions at Gulf Medical University (GMU) Ajman, United Arab Emirates (UAE). Methods The study was conducted from November 2009 to February 2010. GMU has academic programmes such as Bachelor of Medicine, Physical therapy, Pharm D and Dental Medicine with a multiethnic student population. A pretested structured instrument used for data collection and blood pressure was measured using mercury sphygmomanometer. Descriptive statistics such as means and standard deviation were used to summarize the quantitative variables. The association of age, gender and nationality with systolic and diastolic blood pressure was determined by Pearson's correlation coefficient and a p-value ≤ 0.05 was considered statistically significant. Results The systolic and diastolic blood pressures were evenly distributed across all students irrespective of their age. A significantly higher systolic blood pressure in males was observed when compared to females, but the difference was not significant in diastolic blood pressure. In the present study among medical and allied health science students, the distribution of blood pressure was not associated with age. The mean systolic blood pressure and diastolic blood pressure were seen to be higher among Arabs when compared to Non-Arabs though not statistically significant. Family history of metabolic diseases did not show any association with the mean blood pressure. Conclusion There was a strong association for developing hypertension among male when compared to female gender. Key Words: University students; Age; Gender; Nationality; Systolic blood pressure; Diastolic blood pressureDOI: http://dx.doi.org/10.3126/nje.v1i3.5572 Nepal Journal of Epidemiology 2011;1(3) 86-89

Carotid Stiffness in Young Adults: A Life-Course Analysis of its Early Determinants

Cardiovascular risk factors affecting arterial stiffness in adulthood may develop at different critical periods earlier in life. We examined whether the trajectories, from adolescence to young adulthood, of blood pressure, body fatness and fat distribution, blood lipids, cardiorespiratory fitness, and heart rate determined levels of arterial stiffness in young adults. We investigated 373 apparently healthy adults in whom cardiovascular risk factors were repeatedly examined between the ages of 13 and 36 years and carotid stiffness estimates were obtained at the age of 36 years. Differences in the mean levels and the trajectories of risk factors throughout the 24-year longitudinal period between subjects with different levels of carotid stiffness at age 36 years were analyzed with generalized estimating equations. Compared with individuals with less stiff carotid arteries, those with stiffer carotid arteries at the age of 36 years were characterized from ages 13 to 36 years by greater levels of and steeper increases in blood pressure and central fatness, independently of each other and other risk factors. These increases were already present in adolescence, preceded the development of poorer levels of blood lipids, cardiorespiratory fitness, and heart rate, which were evident during adulthood only, and explained to a great extent the deleterious association between these risk factors and carotid stiffness at the age of 36 years. Multiple and intertwined mechanisms involved in the pathogenesis of arterial stiffness have their origins in early life. Blood pressure and central fatness have a pivotal role herein and should be specifically targeted to prevent arterial stiffening and its cardiovascular sequelae.

EDHF: spreading the influence of the endothelium.

Our view of the endothelium was transformed around 30 years ago, from one of an inert barrier to that of a key endocrine organ central to cardiovascular function. This dramatic change followed the discoveries that endothelial cells (ECs) elaborate the vasodilators prostacyclin and nitric oxide. The key to these discoveries was the use of the quintessentially pharmacological technique of bioassay. Bioassay also revealed endothelium-derived hyperpolarizing factor (EDHF), particularly important in small arteries and influencing blood pressure and flow distribution. The basic idea of EDHF as a diffusible factor causing smooth muscle hyperpolarization (and thus vasodilatation) has evolved into one of a complex pathway activated by endothelial Ca(2+) opening two Ca(2+) -sensitive K(+) -channels, K(Ca)2.3 and K(Ca)3.1. Combined application of apamin and charybdotoxin blocked EDHF responses, revealing the critical role of these channels as iberiotoxin was unable to substitute for charybdotoxin. We showed these channels are arranged in endothelial microdomains, particularly within projections towards the adjacent smooth muscle, and close to interendothelial gap junctions. Activation of K(Ca) channels hyperpolarizes ECs, and K(+) efflux through them can act as a diffusible 'EDHF' stimulating Na(+) /K(+) -ATPase and inwardly rectifying K-channels. In parallel, hyperpolarizing current can spread from the endothelium to the smooth muscle through myoendothelial gap junctions upon endothelial projections. The resulting radial hyperpolarization mobilized by EDHF is complemented by spread of hyperpolarization along arteries and arterioles, effecting distant dilatation dependent on the endothelium. So the complexity of the endothelium still continues to amaze and, as knowledge evolves, provides considerable potential for novel approaches to modulate blood pressure.

The Relationship Between Systemic Blood Pressure and Intraocular Pressure in a Hospital Sample of Ghanaian Adults

Some studies in the Caucasian subject showed that systemic blood pressure is related to in-traocular pressure (IOP) and that hypertensive patients are prone to develop raised IOP (glaucoma) but there are few records from black Africans where systemic hypertension is com-mon. We have thus examined IOP in 113 hypertensive patients and compared their IOP with IOP in 74 normotensive patients. The results showed that mean IOP was higher in hypertensive than normotensive subjects (p< 0.001) and there was a significant correlation between blood pressure distribution and IOP in the combined population. Therefore patients with high blood pressure should be screened for open angle glaucoma as a preventive measure.

Prevalence of Hypertension in 9- to 10-Year-Old Icelandic School Children

The purpose of the study was to investigate blood pressure (BP) distribution, prevalence of hypertension, and correlation between BP and body mass index (BMI) in 9- to 10-year-old Icelandic children. Two manual and two automated BP measurements were performed in 1071 Icelandic children. Children with elevated BP underwent a second BP screening, and a third screening was performed if the BP was elevated at the second visit. Hypertension was defined as BP ≥95th percentile at all three visits. White-coat hypertension was diagnosed in hypertensive children with normal 24-hour ambulatory BP. Of 970 children with complete data, 489 were girls (50.4%). The mean BP was 111/63 mm Hg in girls and 112/64 mm Hg in boys (P<.001). The prevalence of elevated BP was 13.1%, 6.0%, and 3.1% after the first, second, and third screen, respectively. The prevalence of sustained hypertension was 2.5% and an additional 0.6% had white-coat hypertension. A significant correlation between BMI and BP was observed (r=0.338, P<.001) and 8.6% of the obese children had hypertension. The prevalence of hypertension in 9- to 10-year-old Icelandic children is lower than indicated in recent reports and is associated with obesity.

Monitoring and Evaluation of Blood Pressure Changes With a Home Healthcare System

We investigated changes in blood pressure with exercise, including walking and ergometer training, sleep, and body weight. Blood pressure was monitored over a period of about 1 year in 61 subjects in Osaka, Japan. The morning systolic blood pressures were analyzed using multivariate regression analysis, and the correlations between systolic blood pressure and the above parameters were determined. The systolic blood pressure distribution was classified into improved, stable, and ingravescence groups. In the improved group, exercise intensity and total calories were important factors controlling the systolic blood pressure. More than 300 kcal per day was needed to improve the systolic blood pressure. In the stable and ingravescence groups, body weight control was also an important factor in maintaining blood pressure. An increase of 1 kg in body weight was associated with systolic blood pressure increases of 3 and 6 mm Hg in the stable and ingravescence groups, respectively. The long-term repeated use of home blood pressure testing may be a good self-care strategy for monitoring daily health.

Direct and reflex effects of nitroglycerin on the blood volume distribution, evaluated by regional weighing in the cat.

The effects of nitroglycerin on the blood volume distribution were studied with a method of regional weighing in the anaesthetized cat. An i.v. bolus injection of nitroglycerin produced a dose-dependent decrease in arterial pressure accompanying a decrease in the thoracic blood volume. The latter change was associated with blood volume increases principally in the abdomen, and slightly in the hindquarters. Elimination of the cardiovascular reflex effects by carotid sinus denervation and cervical vagotomy signficantly enhanced and prolonged the following changes: the hypotension, the decrease in thoracic blood volume and the volume pooling in the abdomen. The magnitude of increase in hindquarters blood volume was not significantly affected by the denervation procedures, but the duration was much prolonged. The results indicate that the major site of nitroglycerin-induced venous pooling is in the splanchnic circulation. The peripheral venous pooling is produced at the expense of a decrease in the central or pulmonary blood volume. The secondary reflex adjustments tend to minimize the direct effects of nitroglycerin on the blood pressure and blood volume distribution.

Determinants of blood pressure distribution in school children

Hypertension (potential risk for cardiovascular diseases) is a major health problem in developed and developing countries affecting approximately one billion individuals worldwide. Many of the risk factors associated with development of hypertension are preventable. Early identification of children at risk for hypertension is important to prevent serious complications. The present study aimed at determining the percentile of systolic blood and diastolic blood pressure and to investigate distribution of blood pressure and its association with anthropometric variables. A cross-sectional study among 701 school children (in the age group of 12-16 years), selected by stratified random sampling was conducted in Aligarh. Personal data were collected through a pre-tested questionnaire. Blood pressure, weight and height were measured through standardized techniques and quetelet index was used to determine BMI. The distributions of blood pressure by anthropometric characteristics were examined. Mean, standard deviation, chi square and correlation coefficient were used for statistical analysis using SPSS 12 software. High blood pressure was defined as systolic and/or diastolic blood pressure over the 95th percentile. Out of 363 boys, 34 (9.36%) and out of 338 girls, 32 (9.46%) had hypertension with overall prevalence of 66 (9.4%) children. Mean systolic blood and diastolic blood pressure were higher as the range of weight, height and BMI increased and blood pressure of children showed positive correlation with anthropometrics characteristics. It is therefore recommended that the children must be screened regularly for blood pressure to detect the prevalence so that remedial measure may be initiated as early as possible.

Impact of Diastolic and Systolic Blood Pressure on Mortality: Implications for the Definition of “Normal”

The National Heart, Lung and Blood Institute currently defines a blood pressure under 120/80 as "normal." To examine the independent effects of diastolic (DBP) and systolic blood pressure (SBP) on mortality and to estimate the number of Americans affected by accounting for these effects in the definition of "normal." DESIGN, PARTICIPANTS AND MEASURES: Data on adults (age 25-75) collected in the early 1970s in the first National Health and Nutrition Examination Survey were linked to vital status data through 1992 (N = 13,792) to model the relationship between blood pressure and mortality rate adjusting for age, sex, race, smoking status, BMI, cholesterol, education and income. To estimate the number of Americans in each blood pressure category, nationally representative data collected in the early 1960s (as a proxy for the underlying distribution of untreated blood pressure) were combined with 2008 population estimates from the US Census. The mortality rate for individuals over age 50 began to increase in a stepwise fashion with increasing DBP levels of over 90. However, adjusting for SBP made the relationship disappear. For individuals over 50, the mortality rate began to significantly increase at a SBP ≥ 140 independent of DBP. In individuals ≤ 50 years of age, the situation was reversed; DBP was the more important predictor of mortality. Using these data to redefine a normal blood pressure as one that does not confer an increased mortality risk would reduce the number of American adults currently labeled as abnormal by about 100 million. DBP provides relatively little independent mortality risk information in adults over 50, but is an important predictor of mortality in younger adults. Conversely, SBP is more important in older adults than in younger adults. Accounting for these relationships in the definition of normal would avoid unnecessarily labeling millions of Americans as abnormal.

Population blood pressure and low to moderate alcohol intake in an untreated population followed over 20 years. Copenhagen City heart study

The aim of this study is to evaluate whether a changing population alcohol intake is capable of setting off a shift in the blood pressure distribution in the untreated part of a population. The focus is on subjects with an alcohol intake well below the limits of alcoholism because these subjects make out the majority of the population. The Copenhagen City Heart Study is a prospective longitudinal epidemiological study. The untreated study population was followed over 20 years. Specially trained technicians using a blinded sphygmomanometer measured BP once with the subject in the sitting position. The BP measurement was fully standardised and the measurement method was unchanged throughout the observation period. A questionnaire concerning drinking habits was completed by the participants and double-checked by the technicians. The results were a decreasing population systolic BP and an increasing self-reported alcohol intake. The population increase was based on an increasing proportion of light to moderate drinkers. There was no effect of a moderately increasing alcohol intake as a covariate in a multivariate analysis of population systolic BP. Conclusion: A moderately increasing population alcohol intake cannot explain the observed changes in population systolic blood pressure.

The trend of hypertension and its relationship to the weight status among Taiwanese young adolescents

This study evaluates prevalence of hypertension in 1996 and 2006, and examines the relationship between hypertension and weight of Taiwanese young adolescents. Two cross-sectional surveys, administered in 1996 and 2006, to junior-high school in Taipei were included. Anthropometric and blood pressure were measured using standard methods, and structured questionnaire was used to collect personal history and lifestyle characteristics. Overweight and obesity are defined based on Taiwan's Department of Health criteria and bases pre-hypertension and hypertension on the 90th and 95th percentile distribution of blood pressure of the population of both surveys. The prevalence of pre-hypertension in Taiwan between 1996 and 2006 increased from 12.0 to 14.4% for boys and decreased from 9.5 to 9.4% for girls. Hypertension increased from 22.8-29.7% and 12.5-20.7% for both boys and girls, respectively. In 1996, compared with normal young adolescents, the risk of hypertension for overweight was 1.8 times higher for boys and 3.4 times for girls. However, the risk of hypertension for overweight in 2006 was 1.7 times higher for boys and 1.5 times higher for girls compared with normal. Every unit increment of body mass index and waist circumference was associated with 17-27% and 6-11% risk of hypertension in both genders in 1996, and was associated with 9-13% and 4% risk of hypertension among young adolescents in 2006, respectively. The prevalence of hypertension has increased significantly in young adolescents, especially for overweight. It is necessary to enrol young adolescents in weight management programs to prevent hypertension-related co-morbidities.

Blood pressure distribution and its relation to anthropometric measurements among school children in Aligarh

A cross-sectional study among 701 school children (12-16 years) was conducted in Aligarh to find out the prevalence of hypertension and to correlate school going adolescent's blood pressure with age, sex, height and weight. The weight was taken by a standardized weighing machine while height was measured using a standard stediometer. Blood pressure measurements were taken by a mercury sphygmomanometer. The distribution of blood pressure by anthropometric characteristics were studied. Mean, standard deviation and correlation coefficient were used for statistical analysis. The overall prevalence of hypertension was found to be 9.4%. Blood pressure of both gender appear to have positive correlation with anthropometric characteristics. Study recommends that children must be screened regularly for blood pressure so that remedial measure can be initiated as early as possible.

Measured Blood Pressure and Hypertension among Young Adults: A Comparison between Two Nationally Representative Samples

Measurement and distribution of systolic and diastolic blood pressure and related health risk factors in the National Longitudinal Study of Adolescent Health (Add Health) were compared with data from the National Health and Nutrition Examination Survey (NHANES) 2007–2008. Sociodemographic patterns of blood pressure, prevalence of hypertension, and measurement characteristics in Add Health were also examined. Prevalence of hypertension (20.88%) in Add Health was significantly higher than that in NHANES (4.60%). This difference was only partially explained by body mass index and waist circumference and could reflect different measurement techniques, sample composition differences, or masked hypertension.

A survey of blood pressure in Lebanese children and adolescence.

Background:Blood pressure varies between populations due to ethnic and environmental factors. Therefore, normal blood pressure values should be determined for different populations.Aims:The aim of this survey was to produce blood pressure nomograms for Lebanese children in order to establish distribution curves of blood pressure by age and sex.Subjects and Methods:We conducted a survey of blood pressure in 5710 Lebanese schoolchildren aged 5 to 15 years (2918 boys and 2792 girls), and studied the distribution of systolic and diastolic blood pressure in these children and adolescents. Blood pressure was measured with a mercury sphygmomanometer using a standardized technique.Results:Both systolic and diastolic blood pressure had a positive correlation with weight, height, age, and body mass index (r= 0.648, 0.643, 0.582, and 0.44, respectively) (P < .001). There was no significant difference in the systolic and diastolic blood pressure in boys compared to girls of corresponding ages. However, the average annual increase in systolic blood pressure was 2.86 mm Hg in boys and 2.63 mm Hg in girls, whereas the annual increase in diastolic blood pressure was 1.72 mm Hg in boys and 1.48 mm Hg in girls. The prevalence of high and high-normal blood pressure at the upper limit of normal (between the 90th and 95th percentile, at risk of future hypertension if not managed adequately), was 10.5% in boys and 6.9% in girls, with similar distributions among the two sexes.Conclusions:We present the first age-specific reference values for blood pressure of Lebanese children aged 5 to 15 years based on a good representative sample. The use of these reference values should help pediatricians identify children with normal, high-normal and high blood pressure.

An approach of hypertension prevalence in a sample of 5381 Portuguese children and adolescents. The AVELEIRA registry. “Hypertension in Children”

Introduction. The distribution of blood pressure (BP) in children and adolescents remains relatively unknown. Thus, it is imperative to ascertain BP distribution at a young age, which constitutes the main objective of this registry. Methods. Cross-sectional assessment of BP in 5381 Portuguese children and adolescents, mean age 12.50±3.23 years (4–18 years), body mass index (BMI) 19.65±4.00 kg/m2 (9.37–60.30 kg/m2), mostly male (4519), mean age 12.70±3.16 years, and with 862 females, mean age 11.44±3.34 years. BP and heart rate were measured three times after a 10-min resting period, with a validated automatic blood pressure monitor (OMRON 705IT) and an appropriately sized cuff over the brachial artery. About 30% of the youngsters were amateur registered athletes and 70% were beginning their sportive activity at the time of evaluation. Results. BP distribution was 12.8% stage 1 hypertension, 21.6% high-normal, and 65.6% normal (similar between genders). Registered athletes and subjects beginning their sports activity revealed different hypertension prevalence (9.8% vs 14.3%, respectively; p < 0.0001). Overweight was found in 7.8%. Hypertension and high-normal BP increased with increasing BMI. Body weight classification was independently associated with hypertension and high-normal BP. Registered sportive practice was independently associated with a reduction in hypertension prevalence. Conclusions. The proportion of children with BP above the 90th percentile was high, with an overall prevalence of hypertension of 12.8%, independent of gender and related to overweight. The implications of these observations are even more important when we consider the epidemiology of hypertension in Portugal and its link with stroke as the leading cause of death and disability.

Is periodontal inflammation associated with raised blood pressure? Evidence from a National US survey

There is incomplete and inconclusive evidence for the association between periodontal disease markers and arterial blood pressure, particularly from large national epidemiological studies. This study assessed the relationship between different markers of periodontal inflammation and disease with arterial blood pressure in people aged 17 years and over in USA. We analysed data from the Third National Health and Nutrition Examination Survey on 6617 men and 7377 women who received a periodontal examination. Blood pressure was analysed in both a continuous format and a binary variable for case definition of hypertension. Periodontal disease markers (extent of gingival bleeding, pocket depth, and loss of attachment, and a case definition of periodontitis) were associated on the arterial blood pressure outcomes through a series of regression models, incrementally adjusting for confounders (demographic, inflammation markers, chronic conditions, smoking, BMI, socio-economic status). All periodontal measures had significant crude associations with SBP and hypertension. Gingival bleeding, a marker of current periodontal inflammation, was the only measure consistently and significantly associated with raised SBP and an increased odds of hypertension in the US adult population throughout the adjustment process. For a 10% greater extent of gingival bleeding, the average SBP was higher by 0.5 (0.3, 0.6) mmHg in the fully adjusted model. By referring to the general population and the whole distribution of blood pressure, not only to those at higher risk for hypertension, this association might have some important implications for clinical practice and public health strategies.

Genome-Wide Association Studies Will Unlock the Genetic Basis of Hypertension

This brief commentary is based on the debate that took part in May 2010 in New York. We describe the initial difficulties experienced in early genome-wide association studies of blood pressure and hypertension, as well as strategic developments, including large meta-analyses and sampling from the extremes of blood pressure distribution. The reasons for negative attitudes toward the genome-wide association studies include their nonhypothesis-driven character and the need for very large sample sizes. Nevertheless, we describe published successes, which include 13 single nucleotide polymorphisms/loci associated with blood pressure and hypertension at P < 5 x 10⁻⁸, which fulfill the criteria of genome-wide significance. We conclude by suggesting a way forward, which will include resequencing to aid fine mapping and the identification of causal variants, even bigger meta-analyses, and, most importantly, appropriate functional studies leading to clinically useful applications.