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Chlorthalidone (CTD) reduces 24-hour blood pressure more effectively than hydrochlorothiazide (HCTZ), but whether this influences electrocardiographic left ventricular hypertrophy is uncertain. One source of comparative data is the Multiple Risk Factor Intervention Trial, which randomly assigned 8012 hypertensive men to special intervention (SI) or usual care. SI participants could use CTD or HCTZ initially; previous analyses have grouped clinics by their main diuretic used (C-clinics: CTD; H-clinics: HCTZ). After 48 months, SI participants receiving HCTZ were recommended to switch to CTD, in part because higher mortality was observed for SI compared with usual care participants in H-clinics, whereas the opposite was found in C-clinics. In this analysis, we examined change in continuous measures of electrocardiographic left ventricular hypertrophy using both an ecological analysis by previously reported C- or H-clinic groupings and an individual participant analysis where use of CTD or HCTZ by SI participants was considered and updated annually. Through 48 months, differences between SI and usual care in left ventricular hypertrophy were larger for C-clinics compared with H-clinics (Sokolow-Lyon: -93.9 versus -54.9 μV, P=0.049; Cornell voltage: -68.1 versus -35.9 μV, P=0.019; Cornell voltage product: -4.6 versus -2.2 μV/ms, P=0.071; left ventricular mass: -4.4 versus -2.8 g, P=0.002). At the individual participant level, Sokolow-Lyon and left ventricular mass were significantly lower for SI men receiving CTD compared with HCTZ through 48 months and 84 months of follow-up. Our findings on left ventricular hypertrophy support the idea that greater blood pressure reduction with CTD than HCTZ may have led to differences in mortality observed in the Multiple Risk Factor Intervention Trial.

Case studies and small trials suggest that acupuncture may effectively treat hypertension, but no large randomized trials have been reported. The Stop Hypertension with the Acupuncture Research Program pilot trial enrolled 192 participants with untreated blood pressure (BP) in the range of 140/90 to 179/109 mm Hg. The design of the trial combined rigorous methodology and adherence to principles of traditional Chinese medicine. Participants were weaned off antihypertensives before enrollment and were then randomly assigned to 3 treatments: individualized traditional Chinese acupuncture, standardized acupuncture at preselected points, or invasive sham acupuncture. Participants received < or = 12 acupuncture treatments over 6 to 8 weeks. During the first 10 weeks after random assignment, BP was monitored every 14 days, and antihypertensives were prescribed if BP exceeded 180/110 mm Hg. The mean BP decrease from baseline to 10 weeks, the primary end point, did not differ significantly between participants randomly assigned to active (individualized and standardized) versus sham acupuncture (systolic BP: -3.56 versus -3.84 mm Hg, respectively; 95% CI for the difference: -4.0 to 4.6 mm Hg; P=0.90; diastolic BP: -4.32 versus -2.81 mm Hg, 95% CI for the difference: -3.6 to 0.6 mm Hg; P=0.16). Categorizing participants by age, race, gender, baseline BP, history of antihypertensive use, obesity, or primary traditional Chinese medicine diagnosis did not reveal any subgroups for which the benefits of active acupuncture differed significantly from sham acupuncture. Active acupuncture provided no greater benefit than invasive sham acupuncture in reducing systolic or diastolic BP.

The association of insulin resistance and body mass index (BMI) at age 13 years and change in insulin resistance and BMI from ages 13 to 19 years with systolic blood pressure, triglycerides, and high-density lipoprotein cholesterol at age 19 years was studied in black and non-Hispanic white children. Insulin clamps were conducted at mean ages 13 (N=357), 15 (N=309), and 19 (N=224) years with insulin resistance adjusted for lean body mass. A repeated-measures multiple regression model was used to predict the 3 risk factors and the clustering of the factors with fasting insulin (the insulin resistance [metabolic] syndrome score) at age 19 years from levels of insulin resistance and BMI at age 13 and their changes from ages 13 to 19 years. The tracking correlation between ages 13 and 19 was 0.85 for BMI and 0.42 for insulin resistance. It was 0.18 for fasting insulin (P=0.01) and P=0.11 after adjustment for BMI. In a multiple regression analysis, BMI at 13 years did not predict any of the risk factors at age 19; change in BMI predicted all 3 of the factors and score; insulin resistance at 13 years predicted systolic blood pressure, triglycerides, and score; change in insulin resistance predicted triglycerides and score. These results show an effect for insulin resistance that is independent of BMI, consistent with the hypothesis that reducing insulin resistance, in addition to weight, may be needed to reduce the prevalence of cardiovascular risk.

Dysregulation of the autonomic nervous system has been implicated in the development of hypertension. Heart rate variability is a noninvasive tool to quantitatively estimate cardiac autonomic activity and has been used to document decreased cardiac autonomic activity in hypertension. The ability of decreased heart rate variability to predict incident hypertension has not been well studied, and there are no studies of whether hypertension leads to changes in heart rate variability. We investigated the temporal sequence linking hypertension, blood pressure, and heart rate variability in a population-based cohort of 11 061 individuals aged 45 to 54 years at baseline. Individuals with hypertension had decreased heart rate variability at baseline, and this association was present across the full blood pressure range. Among 7099 individuals without hypertension at baseline, low heart rate variability predicted greater risk of incident hypertension over 9 years of follow-up. The hazard ratio (95% confidence interval [CI]) for the lowest compared with the highest quartile of the standard deviation of normal-to-normal R-R intervals was 1.24 (95% CI, 1.10-1.40), for the root mean square of successive differences in normal-to-normal R-R intervals was 1.36 (95% CI, 1.21-1.54), and for R-R interval was 1.44 (95% CI, 1.27-1.63). Over 9 years, there was no measurable difference in the rate of change in heart rate variability among those with and without hypertension, although the differences in heart rate variability at follow-up were smaller than those at baseline. These findings thus support the thesis that the autonomic nervous system is involved in the development of hypertension, yet suggest that differences in the autonomic profile of hypertensives and normotensives do not increase with time.

This study was intended to clarify the relation between fasting insulin, lipids, and blood pressure in adolescents before the onset of hypertension and to examine the association of these data with similar data obtained in their parents. The participants in this study were 183 adolescents 14 to 18 years old (96 girls) completing a 4-year intervention trial and their parents (164 mothers, 122 fathers). Blood pressure was measured twice on the right arm in a seated position using a random-zero sphygmomanometer. Fasting blood samples were obtained for lipid and insulin analyses. Fasting insulin was significantly correlated with systolic blood pressure in the adolescents and also in the parents before and after adjustment for body mass index. Fasting insulin was correlated significantly with levels of cholesterol, triglycerides, and HDL and LDL cholesterol in the adolescents. It was correlated only with triglycerides and HDL-cholesterol in mothers and fathers. After adjustment for body mass index, the correlations between fasting insulin and lipids in the children were not significant. A significant relation was shown between children's systolic blood pressure and mothers' fasting insulin and systolic blood pressure. Significant correlations were found between the children's and fathers' triglycerides and HDL-cholesterol, whereas significant correlations were found for fasting insulin and all lipids between mothers and children, and these remained significant after adjustment for body mass index. These results show (1) a significant relation between fasting insulin and both lipids and systolic blood pressure in adolescents and (2) a significant relation for these factors between adolescents and their parents. Although weight appears to play an important role in this relation during adolescence, genetic and environmental factors other than those mediated via weight may control insulin metabolism within families. The data support a role for studies during early biological development to address these issues.

Problems with sexual function have been a long-standing concern in the treatment of hypertension and may influence the choice of treatment regimens and decisions to discontinue drugs. The Treatment of Mild Hypertension Study (TOMHS) provides an excellent opportunity for examination of sexual function and effects of treatment on sexual function in men and women with stage I diastolic hypertension because of the number of drug classes studied, the double-blind study design, and the long-term follow-up. TOMHS was a double-blind, randomized controlled trial of 902 hypertensive individuals (557 men, 345 women), aged 45 to 69 years, treated with placebo or one of five active drugs (acebutolol, amlodipine maleate, chlorthalidone, doxazosin maleate, or enalapril maleate). All participants received intensive lifestyle counseling regarding weight loss, dietary sodium reduction, alcohol reduction (for current drinkers), and increased physical activity. Sexual function was ascertained by physician interviews at baseline and annually during follow-up. At baseline, 14.4% of men and 4.9% of women reported a problems with sexual function. In men, 12.2% had problems obtaining and/or maintaining an erection; 2.0% of women reported a problem having an orgasm. Erection problems in men at baseline were positively related to age, systolic pressure, and previous antihypertensive drug use. The incidences of erection dysfunction during follow-up in men were 9.5% and 14.7% through 24 and 48 months, respectively, and were related to type of antihypertensive therapy. Participants randomized to chlorthalidone reported a significantly higher incidence of erection problems through 24 months than participants randomized to placebo (17.1% versus 8.1%, P = .025). Incidence rates through 48 months were more similar among treatment groups than at 24 months, with nonsignificant differences between the chlorthalidone and placebo groups. Incidence was lowest in the doxazosin group but was not significantly different from the placebo group. Incidence for acebutolol, amlodipine, and enalapril groups was similar to that in the placebo group. In many cases, erection dysfunction did not require withdrawal of medication. Disappearance of erection problems among men with problems at baseline was common in all groups but greatest in the doxazosin group. Incidence of reported sexual problems in women was low in all treatment groups. In conclusion, long-term incidence of erection problems in treated hypertensive men is relatively low but is higher with chlorthalidone treatment. Effects of erection dysfunction with chlorthalidone appear relatively early and are often tolerable, and new occurrences after 2 years are unlikely. The rate of reported sexual problems in hypertensive women is low and does not appear to differ by type of drug. Similar incidence rates of erection dysfunction in placebo and most active drug groups caution against routine attribution of erection problems to antihypertensive medication.

The roots of essential hypertension extend back into the first two decades of life, suggesting that effective intervention during those years may lead to a reduction in the incidence of adult hypertension. Decreasing the dietary sodium/potassium ratio offers a potentially effective approach to blood pressure reduction. This study tested the feasibility of 3-year sodium reduction or potassium supplementation in adolescents and the effect of these interventions on the rate of rise of blood pressure during adolescence. After 19,452 5th to 8th grade students were screened, 210 from the upper 15 percentiles of blood pressure distribution (105 boys, 105 girls) were randomly assigned to one of three groups: low sodium diet (70 mmol sodium intake per day), potassium chloride supplementation (normal diet plus 1 mmol/kg potassium chloride per day), or placebo (normal diet plus placebo capsule). Capsules for the potassium chloride and placebo groups were administered in a double blind protocol. Blood pressure was measured every 3 months for 3 years. The effect of the intervention was determined by comparing the rate of rise (slope) of blood pressure among the groups using a random-coefficient growth curve model. The boys groups and the girls placebo group had similar positive blood pressure slopes that were significantly different from zero. The girls low sodium group had a slightly negative slope (significantly lower than the slope of the girls placebo group), and the girls potassium group had a slightly positive slope. Both of these slopes were not significantly different from zero and were significantly lower than the slopes of the respective boys groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies that examine the effect of altered body weight or dietary sodium on blood pressure level are reviewed. Emphasis is placed on studies that compare the effects of weight reduction or sodium restriction in separate comparison groups or analyze the independent effect of the two intervention modalities in multiple regression analysis. Additional analyses of the Hypertension Prevention Trial data are presented. Most studies, where comparison can be made, suggest a greater effect for weight reduction than for the achieved, moderate, or short-term reduction in sodium intake on subsequent lowering of blood pressure; the lowering effect on blood pressure of weight reduction is independent of the effect of dietary sodium restriction. However, long-term (over a year) substantial reductions (up to 70 meq/day) of dietary sodium have not been achieved in comparative trials, nor are the effects of combined weight and sodium reduction in the prevention and treatment of hypertension quantified. Future studies and potential problems are discussed.

Among 9977 public school children aged 6 to 9 years screened in late winter and spring of 1978 in Minnesota, systolic blood pressure (SBP) and diastolic fourth phase blood pressure (DBP4) were found to be unrelated to age when height and body mass index (kg/m2) were taken into account. Weight was the best single measure of body size for predicing blood pressure. Black and white children had small and inconsistent, although statistically significant, differences in blood pressure after adjusting for other variables. The same was true for boys and girls. The problems of establishing normal blood pressures for children are discussed. The current analyses suggest the use of blood pressure centiles by height.

Concentrations of serum total calcium and serum calcium fractions were compared between 28 hypertensive subjects and 28 race-sex-age-matched normotensive controls. Mean levels of serum total calcium were not different between the two groups. Hypertensive subjects had lower mean serum levels of ultrafilterable calcium (-0.32 mg/dl; p = 0.01), ionized calcium (-0.07 mg/dl; p = 0.09), and complexed calcium (-0.23 mg/dl; p = 0.04) and higher levels of protein-bound calcium (+0.36 mg/dl; p = 0.07). Estimated dietary calcium intake was similar in the two groups. These findings add to the evidence that essential hypertension is associated with perturbations in calcium metabolism.

To assess the effects of modifying dietary sodium intake, 80 school children with blood pressures above the 95th percentile for age and sex but below 130/90 mm Hg at school screening were randomized to a family intervention program or a control group. Twenty children aged 6 to 9 years and their families began a program to modify the family diet toward a goal of 70 mEq sodium per person per day. Adherence was assessed by 3-day food records and urine collections in children and adults. The sodium intakes and blood pressures of the intervention and control group were compared 1 year after randomization. Sodium intake was significantly lower in the intervention group only in the active participants as compared to dropouts and controls (87 vs 130 and 133 mmoles/24 hr). There were no significant differences between the groups in height, weight, or blood pressure.

In 307 Native American (NA), 1784 black (B), and 7777 white (W) children in grades 1, 2, and 3 in Minneapolis schools (99% overall response rate), blood pressure (BP) was measured supine in the right arm after 5 minutes' rest by trained technicians using a random zero BP device. In addition, height, weight, pulse rate, and triceps skinfold thickness were measured. Among children aged 6 through 9 years, NA children had slightly higher systolic BP (SBP) than B or W children overall (mean SBP: NA 106, B 104, W 105 mm Hg) and for nearly all age sex groups. In contrast, Phase 4 and 5 diastolic BP (DBP) were consistently lower in NA children ( mean DBP4: NA 64, B 69, W 67 mm Hg); NA children also had lower pulse rates, greater pulse pressures, similar or slightly lower mean BP, similar height, greater weight, body mass index, and triceps skinfold. Multiple regression analyses revealed that the slightly higher SBP in NA children was explained almost entirely by greater ponderosity. However, the lower DBP could not be explained statistically by any of the variables measured.