Platelet aggregation in young men with contrasting predisposition to high blood pressure

In essential hypertension, abnormal platelet function may induce vasospasm and predispose to thrombotic vascular occlusion. We studied in vitro aggregability in platelets from young men with contrasting predisposition to hypertension, defined by their own blood pressure and blood pressures of their parents. Among offspring of parents with low blood pressure, higher blood pressure was associated with impaired aggregation in response to epinephrine (2 × 10⁻⁸ to 5 × 10⁻⁶ mol/L), which was unaffected by endothelin-1 (10⁻⁹ mol/L). By contrast, among offspring of parents with high blood pressure, higher blood pressure was associated with normal aggregation to epinephrine and potentiation of the primary phase of aggregation by endothelin-1. We conclude that enhanced platelet sensitivity to endothelin-1 appears to be a feature of the familial predisposition to hypertension, rather than a nonspecific consequence of high blood pressure.     

Risk factors associated with newly diagnosed high blood pressure in men and women

BACKGROUND: Hypertension is a major risk factor for cardiovascular diseases. Early diagnosis and prevention of hypertension are of great importance in reducing overall mortality. The objective was to determine which potential risk factors are associated with newly diagnosed high blood pressure in women and men. METHODS: This study is part of a population-based, cross-sectional study including 4,228 women and men aged 60 years in Stockholm County, Sweden. Newly diagnosed high blood pressure was defined as systolic and/or diastolic blood pressure exceeding 140/90 measured on one occasion. Subjects with known hypertension were excluded, leaving 3,156 individuals. RESULTS: Waist circumference > or =95 cm (quintiles 3-5) in men and > or =88.5 cm (quintiles 4-5) in women was associated with newly diagnosed high blood pressure. Secondary school was a protective factor in men (odds ratio (OR), men = 0.73, 95% confidence interval (CI) = 0.54-0.99) and university education was protective in both men (OR = 0.66, 95% CI = 0.52-0.85) and women (OR = 0.45, 95% CI = 0.34-0.59). Regular physical activity was negatively associated in women (OR = 0.77, 95% CI = 0.61-0.99), and high alcohol consumption (>30 g/day) was positively associated in men (OR = 1.60, 95% CI = 1.22-2.09). Women were negatively associated with newly diagnosed high blood pressure (OR = 0.50, 95% CI = 0.41-0.61). An interaction between college/university and gender was found in multivariate analysis (OR = 0.67, 95% CI = 0.47-0.97). CONCLUSION: Gender differences in risk profile for newly diagnosed high blood pressure might explain part of the differences in hypertension found between men and women. These findings should be considered when planning preventive actions against hypertension at the community level.     

Sodium intake and cardiac sympatho-vagal balance in young men with high blood pressure.

We have previously reported that a high sodium intake increases sleep-time blood pressure (BP) in young men. However, there are cases in which this relation does not apply. To account for them, we investigated the relation between sodium intake and cardiac sympatho-vagal balance (SVB) in young men with high BP. Sodium intake was estimated from the amount of urinary sodium excretion over 1 week. Twenty-four-hour (24-h) urinary sodium excretion (Salt24), 24-h ambulatory BP and ECG were obtained on the last day of the observation period. As an index of sodium intake, the expression In(Salt24/Cr24) (Cr24, 24-h urinary creatinine excretion) was used. From power-spectral analysis of ECG-RR intervals during sleep, we obtained the LF/HF ratio between the low-frequency component (LF) and the high frequency component (HF) and used it as an index of SVB. The subjects were male medical students divided into a normal BP group (N-group; n=103) and a high BP group (H-group; n=26, 24-h BP>125/75 mmHg). Mean In(Salt24/Cr24) and LF/HF in the H-group were significantly higher than those in the N-group (LF/HF: 1.86+/-0.44 [SD] vs. 1.37+/-0.30, p<0.001). The calculated discriminant function (D) for the H-group and N-group was D=1.6x + 5y - 11, where x is In(Salt24/Cr24) and y is LF/HF. This formula (D) resulted in high discriminant predictive accuracy (82%) between the groups. If D=0 (the value of the cut-off line determining separation of the groups), the relation y=-0.32x + 2.2 (negative relation between y and x) was obtained. These results suggest that excessive sodium intake in combination with accentuated SVB (LF/HF) increases BP in young men.     

Excess mortality associated with increased pulse pressure among middle-aged men and women is explained by high systolic blood pressure

OBJECTIVE: To assess the risk of death from coronary heart disease, stroke, all cardiovascular diseases and all-cause mortality associated with pulse pressure among the middle-aged population. METHODS AND DESIGN: A prospective 15-year follow-up cohort study was conducted of two independent cross-sectional random samples of the population who participated in baseline surveys in 1972 or 1977. Each survey included a self-administered questionnaire with questions on smoking and antihypertensive drug treatment, measurements of height, weight and blood pressure and the determination of the serum cholesterol concentration. Multivariate analyses were performed by using Cox proportional hazard models. SETTING: The provinces of North Karelia and Kuopio in eastern Finland PARTICIPANTS: Men and women aged 45-64 years with no history of myocardial infarction or stroke at the time of the baseline survey were selected. In total 4333 men and 5270 women took part in this follow-up study. RESULTS: The relative risk of coronary heart disease, stroke, cardiovascular disease and all-cause mortality increased with the increasing pulse pressure in individuals aged 45-64 years independent of the diastolic blood pressure level. Only in women with diastolic blood pressure > or = 95 mmHg was the relative risk of fatal stroke not statistically significant. After adjustment for systolic blood pressure, the positive association between mortality and increasing pulse pressure disappeared. CONCLUSION: Increasing pulse pressure is a predictor of death from coronary heart disease, stroke, cardiovascular disease and all causes in men and women aged 45-64 years, but the increase in risk is entirely associated with the increase in systolic blood pressure.     

Association of serum high molecular weight adiponectin and blood pressure among non-diabetic community-dwelling men

Adiponectin is one of the important molecules in the development of metabolic syndrome, and its concentration is decreased in obesity, type-2 diabetes, and cardiovascular disease. We aim to determine whether serum high-molecular weight (HMW) adiponectin, which is thought to represent the biological active form, was associated with a risk for the prevalence of prehypertension and hypertension. The cross-sectional study was carried out in 2002. A total of 614 men, aged 58 ± 14 (range, 20-89) years, and 779 women, aged 62 ± 12 (range, 21-88) years without medications for hypertension, diabetes, or dyslipidemia were recruited from a single community at the time of their annual health examination. In men, nonadjusted and age-adjusted mean serum HMW adiponectin were significantly lower in subjects with prehypertension and hypertension than those with normotension. In women, only nonadjusted values were higher in subjects with hypertension than those with normotension. Multiple linear regression analysis using systolic blood pressure (SBP) and diastolic blood pressure (DBP) as an objective variable, adjusted for risk factors as explanatory variables, showed that only in men, log serum HMW adiponectin were significantly and independently associated with SBP and DBP. In men, lower serum HMW adiponectin categories were positively associated with prehypertension and hypertension in an age-adjusted model, and hypertension in an age- and BMI-adjusted model. Serum HMW adiponectin concentrations were inversely associated with blood pressure (BP) in the general male population.     

Insulin resistance and blood pressure in young black men

Insulin resistance, independent of obesity or non-insulin-dependent diabetes mellitus, has been demonstrated to be associated with high blood pressure. To determine if insulin resistance could be an antecedent to hypertension in a high-risk population, we studied normotensive (112 +/- 12/70 +/- 10 mm Hg) and borderline hypertensive (135 +/- 8/85 +/- 5 mm Hg) lean young black men (22-26 years old) with the euglycemic hyperinsulinemic clamp technique. All subjects had clinically normal oral glucose tolerance. Body mass index and percent adipose mass were the same in both groups. Fasting plasma insulin concentration was significantly higher in the borderline hypertensive group (p less than 0.01). Insulin-directed exogenous glucose metabolism at the same degree of steady-state hyperinsulinemia was significantly lower in the borderline hypertensive group (5.98 +/- 2.22 versus 8.22 +/- 1.96 mg/kg/min; p less than 0.01). For the total population, a significant inverse correlation existed between the glucose infusion rate and systolic blood pressure (p less than 0.01). These data indicate that there is a relation between insulin-mediated glucose uptake and blood pressure. Furthermore, in this high-risk population insulin resistance may precede the onset of established essential hypertension.     

Carotid baroreflex function in young men with borderline blood pressure elevation.

Carotid baroreflex function was assessed in 10 normotensive young men and 20 age-matched subjects with borderline hypertension (successive blood pressures above and below 140/90 mm Hg) by measuring sinus node responses to brief neck suction. Subjects with borderline hypertension were divided into two equal groups according to their average systolic arterial pressures. Baroreflex responses were reset to function at higher pressure levels than normal in subjects with mild borderline hypertension, but reflex sensitivity was normal. Responses were also reset in subjects with more severe borderline hypertension, but reflex was subnormal. The results suggest that a gradation of baroreflex responsiveness exists among patients classified as having borderline hypertension: Subnormal responsiveness was found in those subjects whose resting average systolic arterial pressure was greater than or equal to 140 mm Hg.     

Hemodynamic significance of high brachial pulse pressure in young men

This study investigates whether an increased brachial pulse pressure (PP) in young healthy men constitutes a representative measure of the central hemodynamic forces, or the mere expression of an exaggerated upper limb amplification. Thirty two healthy men between 17 and 28 years old underwent noninvasive evaluation of systemic hemodynamics (impedance cardiography) and pulse wave analysis (SphygmoCor). Subjects were divided into 3 predefined groups of brachial PP: < 50, 50-64, and > or = 65 mmHg. The brachial-central PP difference increased with increasing brachial PP (17 +/- 4, 22 +/- 4, and 29 +/- 4 mmHg, respectively P < 0.001). In contrast, peripheral amplification (as measured by the brachial:central PP ratio) remained constant among the tree groups, at the expense of a concomitant widening of aortic PP (P < 0.001) without difference in augmentation index. In the entire sample, central and brachial PP, and the difference between the two measures, correlated positively with cardiac output (P < 0.001) and stroke volume (P < 0.01), and negatively with systemic vascular resistance (P < 0.001), without significant relationship with heart rate. In conclusion, despite the different amplitude, central and brachial PP shared common hemodynamic determinants. A high PP among young men underlied a high output-low resistance circulatory pattern, independently of the site of measurement.     

Polymorphisms in candidate genes for blood pressure regulation in young men with normal or elevated screening blood pressure

We have previously shown correlations between cardiovascular risk factors such as blood pressure (BP), sympathetic nervous system activity, lipids and insulin resistance in young men with elevated screening BP. In the present study we aimed to: (1) compare the genotype distribution and allele frequencies of 11 polymorphisms in seven candidate genes for BP regulation in healthy 21-year-old Caucasian men, between 18 men with normal and 67 men with high screening BP, and (2) evaluate the effect of these polymorphisms in candidate genes on casual BP, BP responses to mental stress or catecholamines and metabolic parameters including insulin sensitivity. There were no differences in genotype distributions or allele frequencies between the subjects with normal and those with high screening BP. Insulin sensitivity was significantly higher in GG homozygotes in the G-261A polymorphism at the alpha 2A-adrenergic receptor (alpha(2A)AR) locus compared to GA heterozygotes (p = 0.007). Subjects who were homozygous both GG in the G-261A polymorphism at the alpha(2A)AR locus and GlyGly in the Arg16Gly polymorphism at the beta2-adrenergic (beta2AR) receptor loci had significantly higher insulin sensitivity and lower catecholamine levels during mental stress than subjects with other genotypes. Subjects who were II homozygous at the angiotensin converting enzyme (ACE) locus and AA homozygous at the angiotensin type I receptor (AT1R) locus had lower BP and a better lipid profile than the rest of the group. Thus, in this explorative study, we report an association between insulin sensitivity and a polymorphism at the alpha(2A)AR locus. We suggest the presence of gene-gene interactions in the renin-angiotensin system and the sympathetic nervous system.     

Excessive alcohol intake increases the risk of arterial stiffening in men with normal blood pressure.

Excessive alcohol intake is a known atherosclerotic cardiovascular risk factor. However, the relation between excessive alcohol intake and atherosclerotic cardiovascular risk in subjects with normal blood pressure has not been fully elucidated. This cross-sectional study investigated the relationship between alcohol intake and arterial stiffness, as assessed using brachial-ankle pulse wave velocity, in men with normal blood pressure. Middle-aged male workers who were found to have a normal blood pressure during an annual health check-up performed in May-July 2000 (n=1,682) were enrolled in the study. The subjects' laboratory data were analyzed, and information on drinking and smoking habits was obtained by a self-administered questionnaire. The brachial-ankle pulse wave velocity was measured using volume plethysmography. The mean brachial-ankle pulse wave velocities of men with an alcohol intake of 40-59 g/day and > or =60 g/day were larger than those of non-drinkers and men with an alcohol intake of <20 g/day. A multivariate general linear model was used to identify the association between alcohol intake and brachial-ankle pulse wave velocity after controlling for other risk factors using a multivariate analysis. An alcohol intake of more than 60 g of ethanol/day was significantly associated with an elevated brachial-ankle pulse wave velocity, after controlling for conventional atherosclerotic cardiovascular risk factors. In conclusion, the present results suggest that excessive alcohol intake increases the atherosclerotic cardiovascular risk associated with arterial stiffening in men with normal blood pressure.     

Heterosexual anal intercourse increases risk of HIV infection among young South African men

Data from a nationally representative household survey of South African youth aged 15-24 years found that sexually active men reporting anal intercourse were nearly twice as likely to be HIV infected as men reporting only vaginal sex (OR 1.7, 95% CI 1.0-3.0). The associated risk was more pronounced among men aged 15-19 years (OR 4.3, 95% CI 1.5-12.1). The association among women was not significant (OR 1.2, 95% CI 0.7-2.0).     

Attenuated increases in blood pressure by dynamic resistance exercise in middle-aged men

The present study was performed to test the hypothesis that the blood pressure (BP) response to resistance exercise in middle-aged men with stiffening arteries is greater than that in young men with compliant arteries. The BP responses to acute dynamic resistance exercise (leg press) at individual relative (low, moderate and high) and absolute intensities were investigated in both young and middle-aged men. A total of 21 sedentary healthy normotensive men, 21-25 years of age (young) and 41-59 years of age (middle-aged), were included in the study. At rest, the arterial compliance (simultaneous ultrasound and applanation tonometry) and muscle strength (leg press) were lower, and indices of arterial stiffness and BP were higher in the middle-aged men than in the young men (p < 0.05). There were no significant differences in height, body mass, or heart rate between the two groups. During exercise, the systolic BP of the middle-aged men at 80% one-repetition maximum (1RM) was significantly lower than that of the young men for the last half of the exercise period (p < 0.05). The amounts of change in systolic and diastolic BP from baseline to the end of resistance exercise were lower in the middle-aged men than in the young men at individual relative intensities (p < 0.05) and at individual absolute intensity. In contrast to our hypothesis, these findings indicated that the BP response during dynamic resistance exercise using large muscle groups may be attenuated in middle-aged men relative to young men.     

Size at birth, obesity and blood pressure at age five

Background: The fetal origins hypothesis indicates that morphometric evidence of fetal nutritional deprivation is predictive of excessive weight gain/obesity, insulin resistance, and cardiovascular disease after birth. However, it is unclear whether these effects are present in offspring with "normal" birth weights in contemporary Western society, whether they are population specific, and how early in life they appear. This study was designed to examine these questions in a select populace of morphometrically diverse offspring to test the null hypothesis that morphometric evidence of nutritional restriction in utero has no effect on the presence of either obesity or increased blood pressure at ages 5 and 6. Methods: We present a prospective study of 101 offspring born of well-nourished, middle and upper socioeconomic-class women who participated in studies of diet and exercise during pregnancy. At birth and age 5 to 6 the offspring underwent morphometric evaluation with the additional measurement of blood pressure at age 5 to 6. Results: There were no significant negative correlations between neonatal morphometrics and either blood pressure or obesity at age 5 to 6. There were, however, direct positive correlations between birth weight and both weight and BMI at age 5 to 6 (p < 0.0001). Conclusions: In this specific populace, morphometrics at age 5 to 6 correlated with size at birth. However, there was no relationship between mophometric evidence of in utero nutritional deprivation at birth and either blood pressure or obesity at age 5 to 6.     

Indices of obesity and blood pressure in young men followed 32 years

In order to assess the effects of baseline indices of obesity, lean body mass, blood pressure, and weight change on future blood pressure, 112 former college men were rexamined 20 and 32 years after initial examination at age 20.5 (±2) yr. Baseline body weight, relative body weight, body mass index and body density all showed similar significant correlations with baseline systolic blood pressure (r = 0.35, 0.31, 0.30, – 0.31) but not baseline diastolic blood pressure (r = 0.13, 0.07, 0.10, – 0.11) or follow-up blood pressure. Changes in body weight, relative body weight, body mass index and sum of skinfolds were significantly correlated with change in both systolic and diastolic blood pressure. Baseline systolic blood pressure was the most powerful predictor of 20- and 32-yr follow-up systolic (r = 0.57, 0.42), but baseline diastolic was a much weaker correlate of follow-up diastolic blood pressure (r = 0.24, 0.18).     

Prognostic significance of systolic blood pressure increases in men during exercise stress testing

Our aim was to investigate whether exercise-induced increase in systolic blood pressure (BP) measured during exercise stress testing (EST) adds prognostic information to cardiovascular (CV) mortality. EST is ideally suited to evaluate the prognostic power of systolic BP; it not only measures systolic BP response to exercise but also provides information about exercise capacity and other EST variables, which may affect the peak systolic BP. The study population consisted of 6,145 consecutive patients who underwent symptom-limited EST. Using the median value of change in systolic BP from baseline, patients were grouped according to exercise-induced increases in systolic BPor=44 mm Hg (group B, n=3,083). Multivariate analysis was used to adjust for baseline differences between the 2 groups with CV mortality as the end point for follow-up. Six thousand one hundred forty-five men underwent EST with a mean follow-up of 6.6 years. During follow-up, 676 patients died of CV causes with an average annual CV mortality of 1.6%. CV mortality was significantly higher in group A than in group B (13.7% vs 8.2%, p<0.001). After adjusting for baseline differences in the 2 groups using multivariate analysis, an increase in systolic BP of or=44 mm Hg during EST was associated with a 23% improvement in survival over a mean follow-up of >6 years.     

Behavioural and psychosocial correlates of nondipping blood pressure pattern among middle-aged men and women at work

The underlying pathogenetic mechanisms of nondipping blood pressure (BP) pattern are not completely understood. Especially the role of psychosocial correlates remains unclear. The aim was to assess the association between nondipping BP pattern, behavioural and psychosocial factors in a sample of working men and women. The study sample included 167 working men and women aged 40-64 years from the BELSTRESS cohort. Socio-demographic, behavioural and psychosocial factors were assessed by self-administered questionnaires. Participants were medically examined and underwent an ambulatory BP monitoring during 24 h. Nondipping was defined when the average nocturnal decline in BP was <10%. The prevalence of nondipping for both systolic and diastolic BP was 7.8%. Nondipping was not significantly related to smoking, alcohol consumption and leisure time physical activity. A crude significant association was observed between nondipping and sleep problems. After adjusting for gender, education and body mass index, the risk for nondipping was associated with job strain, living alone, being unsatisfied about the contact with one's children, depressive symptoms and vital exhaustion. Nondipping BP pattern was consistently related to psychosocial factors in this study: positive associations were observed with measures of job strain, poor private life support (living alone and being unsatisfied about the contact with one's children) and mental health problems (depressive symptoms and vital exhaustion).