Cocoa intake, blood pressure, and cardiovascular mortality: the Zutphen Elderly Study

BACKGROUND: Small, short-term, intervention studies indicate that cocoa-containing foods improve endothelial function and reduce blood pressure. We studied whether habitual cocoa intake was cross-sectionally related to blood pressure and prospectively related with cardiovascular mortality. METHODS: Data used were of 470 elderly men participating in the Zutphen Elderly Study and free of chronic diseases at baseline. Blood pressure was measured at baseline and 5 years later, and causes of death were ascertained during 15 years of follow-up. Habitual food consumption was assessed by the cross-check dietary history method in 1985, 1990, and 1995. Cocoa intake was estimated from the consumption of cocoa-containing foods. RESULTS: One third of the men did not use cocoa at baseline. The median cocoa intake among users was 2.11 g/d. After adjustment, the mean systolic blood pressure in the highest tertile of cocoa intake was 3.7 mm Hg lower (95% confidence interval [CI], -7.1 to -0.3 mm Hg; P = .03 for trend) and the mean diastolic blood pressure was 2.1 mm Hg lower (95% CI, -4.0 to -0.2 mm Hg; P = .03 for trend) compared with the lowest tertile. During follow-up, 314 men died, 152 of cardiovascular diseases. Compared with the lowest tertile of cocoa intake, the adjusted relative risk for men in the highest tertile was 0.50 (95% CI, 0.32-0.78; P = .004 for trend) for cardiovascular mortality and 0.53 (95% CI, 0.39-0.72; P < .001) for all-cause mortality. CONCLUSION: In a cohort of elderly men, cocoa intake is inversely associated with blood pressure and 15-year cardiovascular and all-cause mortality.     

The effect of magnesium supplementation on blood pressure: a meta-analysis of randomized clinical trials

BACKGROUND: An increased intake of magnesium might lower blood pressure (BP), yet evidence from clinical trials is inconsistent, perhaps as a result of small sample size or heterogeneity in study design. METHODS: We performed a meta-analysis of randomized trials that tested the effects of magnesium supplementation on BP. Twenty trials meeting the inclusion criteria were identified. Random effects models and meta-regression methods were used to pool study results and to determine the dose-response relationship of magnesium to BP. RESULTS: The 20 studies included 14 of hypertensive and 6 of normotensive persons totaling 1220 participants. The doses of magnesium ranged from 10 to 40 mmol/day (median, 15.4 mmol/day). Magnesium supplementation resulted in only a small overall reduction in BP. The pooled net estimates of BP change (95% confidence interval [CI]) were -0.6 (-2.2 to 1.0) mm Hg for systolic BP and -0.8 (-1.9 to 0.4) mm Hg for diastolic BP. However, there was an apparent dose-dependent effect of magnesium, with reductions of 4.3 mm Hg systolic BP (95% CI 6.3 to 2.2; P < .001) and of 2.3 mm Hg diastolic BP (95% CI 4.9 to 0.0; P = .09) for each 10 mmol/day increase in magnesium dose. CONCLUSIONS: Our meta-analysis detected dose-dependent BP reductions from magnesium supplementation. However, adequately powered trials with sufficiently high doses of magnesium supplements need to be performed to confirm this relationship.     

The Effect of Vegan Diets on Blood Pressure in Adults: A Meta-Analysis of Randomized Controlled Trials

BackgroundVegan diets are increasing in popularity and have beneficial effects on glycemia and blood lipids, but the evidence is inconclusive regarding their effect on blood pressure. The purpose of this study was to review the effect of vegan diets on blood pressure in adults.MethodsWe searched MEDLINE, EMBASE, CENTRAL, and ClinicalTrials.gov for records that compared a vegan diet with any less restrictive diet and reported pre- and postintervention systolic and diastolic blood pressures. Two reviewers independently screened abstracts for randomized, controlled clinical trials in individuals ≥ 18 years of age and older. We used the PRISMA guidelines to select 11 clinical trials from 1673 records. Data synthesis was performed through a random-effects model.ResultsThe pooled data included 983 participants. Compared with less restrictive diets, a vegan diet did not result in a significant change in systolic (? 1.33 mm Hg; 95% confidence interval [CI], ? 3.50-0.84; P = .230) or diastolic (? 1.21 mm Hg; 95% CI, ? 3.06-0.65; P = .203) blood pressure. A prespecified subgroup analysis of studies with baseline systolic blood pressure ≥ 130 mm Hg revealed that a vegan diet resulted in a mean decrease in the systolic (? 4.10 mm Hg; 95% CI, ? 8.14 to ? 0.06; P = .047) and diastolic (? 4.01 mm Hg; 95% CI, ? 5.97 to ? 2.05; P = 0.000) blood pressures.ConclusionThe changes in blood pressure induced by a vegan diet without caloric restrictions are comparable with those induced by dietary approaches recommended by medical societies and portion-controlled diets.     

Influence of weight reduction on blood pressure: a meta-analysis of randomized controlled trials

Increased body weight is a strong risk factor for hypertension. A meta-analysis of randomized controlled trials was performed to estimate the effect of weight reduction on blood pressure overall and in population subgroups. Twenty-five randomized, controlled trials (comprising 34 strata) published between 1966 and 2002 with a total of 4874 participants were included. A random-effects model was used to account for heterogeneity among trials. A net weight reduction of -5.1 kg (95% confidence interval [CI], -6.03 to -4.25) by means of energy restriction, increased physical activity, or both reduced systolic blood pressure by -4.44 mm Hg (95% CI, -5.93 to -2.95) and diastolic blood pressure by -3.57 mm Hg (95% CI, -4.88 to -2.25). Blood pressure reductions were -1.05 mm Hg (95% CI, -1.43 to -0.66) systolic and -0.92 mm Hg (95% CI, -1.28 to -0.55) diastolic when expressed per kilogram of weight loss. As expected, significantly larger blood pressure reductions were observed in populations with an average weight loss >5 kg than in populations with less weight loss, both for systolic (-6.63 mm Hg [95% CI, -8.43 to -4.82] vs -2.70 mm Hg [95% CI, -4.59 to -0.81]) and diastolic (-5.12 mm Hg [95% CI, -6.48 to -3.75] vs -2.01 mm Hg [95% CI, -3.47 to -0.54]) blood pressure. The effect on diastolic blood pressure was significantly larger in populations taking antihypertensive drugs than in untreated populations (-5.31 mm Hg [95% CI, -6.64 to -3.99] vs -2.91 mm Hg [95% CI, -3.66 to -2.16]). This meta-analysis clearly shows that weight loss is important for the prevention and treatment of hypertension.     

Literature Alert

The beneficial effects of flavonoid consumption on cardiovascular risk are supported by mechanistic and epidemiologic evidence. We aimed to systematically review the effectiveness of different flavonoid subclasses and flavonoid-rich food sources on cardiovascular disease (CVD) and risk factors—ie, lipoproteins, blood pressure, and flow-mediated dilatation (FMD). Methods included a structured search strategy on MEDLINE, EMBASE, and Cochrane databases; formal inclusion or exclusion, data extraction, and validity assessment; and meta-analysis. One hundred thirty-three trials were included. No randomized controlled trial studied effects on CVD morbidity or mortality. Significant heterogeneity confirmed differential effects between flavonoid subclasses and foods. Chocolate increased FMD after acute (3.99%; 95% CI: 2.86, 5.12; 6 studies) and chronic (1.45%; 0.62, 2.28; 2 studies) intake and reduced systolic (−5.88 mm Hg; −9.55, −2.21; 5 studies) and diastolic (−3.30 mm Hg; −5.77, −0.83; 4 studies) blood pressure. Soy protein isolate (but not other soy products or components) significantly reduced diastolic blood pressure (−1.99 mm Hg; −2.86, −1.12; 9 studies) and LDL cholesterol (−0.19 mmol/L; −0.24, −0.14; 39 studies). Acute black tea consumption increased systolic (5.69 mm Hg; 1.52, 9.86; 4 studies) and diastolic (2.56 mm Hg; 1.03, 4.10; 4 studies) blood pressure. Green tea reduced LDL (−0.23 mmol/L; −0.34, −0.12; 4 studies). For many of the other flavonoids, there was insufficient evidence to draw conclusions about efficacy. To date, the effects of flavonoids from soy and cocoa have been the main focus of attention. Future studies should focus on other commonly consumed subclasses (eg, anthocyanins and flavanones), examine dose-response effects, and be of long enough duration to allow assessment of clinically relevant endpoints.     

降压治疗预防脑卒中或短暂性脑缺血发作患者脑卒中再发的荟萃分析

目的了解降压治疗预防脑卒中或短暂性脑缺血发作(TIA)患者脑卒中再发的作用。方法检索PubMed数据库、EMbase、Cochrane图书馆、中国生物医学文献数据库、中国期刊全文数据库(CNKI)、中文科技期刊全文数据库(VIP)等数据库,搜索2000-01-2009-01研究降压治疗预防脑卒中再发的随机对照临床试验的文献,按照Downs&Black评分系统评价纳入研究的质量,并进行荟萃分析。对以利尿剂和以肾素血管紧张素醛固酮系统(RAAS)阻断剂为主要治疗药物的试验进行了亚组分析。结果共纳入10个随机对照临床试验,入选对象累计38227例。总的降压治疗预防脑卒中再发的OR为0.78(95%CI0.68～0.90;P=0.007),其中含利尿剂的试验为0.63(95%CI0.54～0.73,P<0.01),含RAAS阻断剂的试验为0.93(95%CI0.87～1.01,P=0.086)。含利尿剂的试验与包含RAAS阻断剂的试验间存在异质性(P<0.01)。总的OR值也存在异质性(P<0.01)。所有试验汇总的结果,收缩压/舒张压平均下降5.1/2.5mmHg,含利尿剂的试验下降8.5/3.6mmHg,含RAAS阻断剂的试验下降4.0/2.1mmHg。加权回归分析显示,脑卒中再发OR值和收缩压下降明显相关。结论降压治疗可降低脑卒中再发风险。     

Control of hypertension in adults with chronic kidney disease in the United States

Although improved control of hypertension is known to attenuate progression of chronic kidney disease (CKD), little is known about the adequacy of hypertension treatment in adults with CKD in the United States. Using data from the Fourth National Health and Nutrition Survey, we assessed adherence to national hypertension guideline targets for patients with CKD (blood pressure <130/80 mm Hg), we assessed control of systolic (<130 mm Hg) and diastolic (<80 mm Hg) blood pressure, and we evaluated determinants of adequate blood pressure control. Presence of CKD was defined as glomerular filtration rate <60 mL/min per 1.73 m2 or presence of albuminuria (albumin:creatinine ratio >30 microg/mg). Multivariable logistic regression with appropriate weights was used to determine predictors of inadequate hypertension control and related outcomes. Among 3213 participants with CKD, 37% had blood pressure <130/80 mm Hg (95% confidence interval [CI], 34.5% to 41.8%). Of those with inadequate blood pressure control, 59% (95% CI, 54% to 64%) had systolic >130 mm Hg, with diastolic < or =80 mm Hg, whereas only 7% (95% CI, 3.9 to 9.8%) had a diastolic pressure >80 mm Hg, with systolic blood pressure < or =130 mm Hg. Non-Hispanic black race (odds ratio [OR], 2.4; 95% CI, 1.5 to 3.9), age >75 years (OR, 4.7; 95% CI, 2.7 to 8.2), and albuminuria (OR, 2.4; 95% CI, 1.4 to 4.1) were independently associated with inadequate blood pressure control. We conclude that control of hypertension is poor in participants with CKD and that lack of control is primarily attributable to systolic hypertension. Future guidelines and antihypertensive therapies for patients with CKD should target isolated systolic hypertension.     

Coenzyme Q10 in the treatment of hypertension: a meta-analysis of the clinical trials

Our objective was to review all published trials of coenzyme Q10 for hypertension, assess overall efficacy and consistency of therapeutic action and side effect incidence. Meta-analysis was performed in 12 clinical trials (362 patients) comprising three randomized controlled trials, one crossover study and eight open label studies. In the randomized controlled trials (n=120), systolic blood pressure in the treatment group was 167.7 (95% confidence interval, CI: 163.7-171.1) mm Hg before, and 151.1 (147.1-155.1) mm Hg after treatment, a decrease of 16.6 (12.6-20.6, P<0.001) mm Hg, with no significant change in the placebo group. Diastolic blood pressure in the treatment group was 103 (101-105) mm Hg before, and 94.8 (92.8-96.8) mm Hg after treatment, a decrease of 8.2 (6.2-10.2, P<0.001) mm Hg, with no significant change in the placebo group. In the crossover study (n=18), systolic blood pressure decreased by 11 mm Hg and diastolic blood pressure by 8 mm Hg (P<0.001) with no significant change with placebo. In the open label studies (n=214), mean systolic blood pressure was 162 (158.4-165.7) mm Hg before, and 148.6 (145-152.2) mm Hg after treatment, a decrease of 13.5 (9.8-17.1, P<0.001) mm Hg. Mean diastolic blood pressure was 97.1 (95.2-99.1) mm Hg before, and 86.8 (84.9-88.8) mm Hg after treatment, a decrease of 10.3 (8.4-12.3, P<0.001) mm Hg. We conclude that coenzyme Q10 has the potential in hypertensive patients to lower systolic blood pressure by up to 17 mm Hg and diastolic blood pressure by up to 10 mm Hg without significant side effects.     

Potassium depletion exacerbates essential hypertension

OBJECTIVE: To determine the effect of potassium depletion on blood pressure in patients with essential hypertension. DESIGN: Double-blind, randomized, crossover study, with each patient serving as his or her own control. SETTING: Clinical research center at a university hospital. PATIENTS: Twelve patients with hypertension. INTERVENTIONS: Patients were placed on 10-day isocaloric diets providing a daily potassium intake of either 16 mmol or 96 mmol. The intake of sodium (120 mmol/d) and other minerals was kept constant. On day 11 each patient received a 2-litre isotonic saline infusion over 4 hours. MEASUREMENTS: Blood pressure; urinary excretion rates for sodium, potassium, calcium, and phosphorous; glomerular filtration rate; renal plasma flow; and plasma levels of vasoactive hormones. MAIN RESULTS: With low potassium intake, systolic blood pressure increased (P = 0.01) by 7 mm Hg (95% CI, 3 mm Hg to 11 mm Hg) and diastolic pressure increased (P = 0.04) by 6 mm Hg (CI, 1 mm Hg to 11 mm Hg), whereas plasma potassium concentration decreased (P less than 0.001) by 0.8 mmol/L (CI, 0.4 to 1.0 mmol/L). In response to a 2-litre isotonic saline infusion, the mean arterial pressure increased similarly on both diets but reached higher levels on low potassium intake (115 +/- 2 mm Hg compared with 109 +/- 2 mm Hg, P = 0.03). Potassium depletion was associated with a decrease in sodium excretion (83 +/- 6 mmol/d compared with 110 +/- 5 mmol/d, P less than 0.001). Plasma renin activity and plasma aldosterone concentrations also decreased in patients during low potassium intake, but concentrations of arginine vasopressin and atrial natriuretic peptide, glomerular filtration rate, and renal plasma flow were unchanged. Further, low potassium intake increased urinary excretion of calcium and phosphorus and of plasma immunoreactive parathyroid hormone levels. CONCLUSION: Dietary potassium restriction increases blood pressure in patients with essential hypertension. Both sodium retention and calcium depletion may contribute to the increase in blood pressure during potassium depletion.     

The effects of aerobic exercise and T'ai Chi on blood pressure in older people: results of a randomized trial

OBJECTIVE: To compare the effects on blood pressure of a 12-week moderate-intensity aerobic exercise program and a T'ai Chi program of light activity. DESIGN: A randomized clinical trial. SETTING: A suburban clinic in the Baltimore, MD, area. PARTICIPANTS: Sixty-two sedentary older adults (45% black, 79% women, aged > or = 60 years) with systolic blood pressure 130-159 mm Hg and diastolic blood pressure < 95 mm Hg (not on antihypertensive medication). INTERVENTION: Participants were randomized to a 12-week aerobic exercise program or a light intensity T'ai Chi program. The goal of each condition was to exercise 4 days per week, 30 minutes per day. MEASUREMENTS: Blood pressure was measured during three screening visits and every 2 weeks during the intervention. Estimated maximal oxygen uptake and measures of physical activity level were determined at baseline and at the end of the intervention period. RESULTS: Mean (SD) baseline systolic and diastolic blood pressures were 139.9 (9.3) mm Hg and 76.0 (7.3) mm Hg, respectively. For systolic blood pressure, adjusted mean (SE) changes during the 12-week intervention period were -8.4 (1.6) mm Hg and -7.0 (1.6) mm Hg in the aerobic exercise and T'ai Chi groups, respectively (each within-group P < .001; between-group P = .56). For diastolic blood pressure, corresponding changes were -3.2 (1.0) mm Hg in the aerobic exercise group and -2.4 (1.0) mm Hg in the T'ai Chi group (each within-group P < .001; between-group P = .54). Body weight did not change in either group. Estimated maximal aerobic capacity tended to increase in aerobic exercise (P = .06) but not in T'ai Chi (P = .24). CONCLUSIONS: Programs of moderate intensity aerobic exercise and light exercise may have similar effects on blood pressure in previously sedentary older individuals. If additional trials confirm these results, promoting light intensity activity could have substantial public health benefits as a means to reduce blood pressure in older aged persons.     

Immediate postnatal growth is associated with blood pressure in young adulthood: the Barry Caerphilly Growth Study

There is a consistent inverse association between birth weight and systolic blood pressure; however, few studies have been able to examine the immediate postnatal period. We have examined whether accelerated postnatal growth predicts adult systolic and diastolic blood pressure. We followed up participants from the Barry Caerphilly Growth Study. Blood pressure data were obtained on 679 of the original 951 subjects (73%) aged approximately 25 years. Both multivariable linear regression and spline models were used to examine the association among weight, length, and growth velocities with systolic blood pressure and diastolic blood pressure. Both statistical approaches showed that birth weight was inversely associated with systolic blood pressure. Only the spline models found that immediate (0 to 5 months) weight gain (beta coefficient: 1.29 mm Hg; 95% CI: 0.36 to 2.23; P=0.007) and weight gain between 1 year and 9 months to 5 years (beta coefficient: 1.44 mm Hg; 95% CI: 0.31 to 2.57; P=0.01) were independently associated with systolic blood pressure, whereas only immediate weight gain (beta coefficient: 0.74 mm Hg; 95% CI: 0.08 to 1.41; P=0.03) was associated with diastolic blood pressure. This is the first study to demonstrate that only immediate postnatal growth predicts diastolic blood pressure in term births, whereas it adds further evidence that both birth weight and postnatal growth are associated with systolic blood pressure in support of both the fetal origins and growth acceleration hypotheses.     

Blood pressure response to transcendental meditation: a meta-analysis

BACKGROUND: Prior clinical trials suggest that the Transcendental Meditation technique may decrease blood pressure of normotensive and hypertensive individuals but study-quality issues have been raised. This study was designed to assess effects of Transcendental Meditation on blood pressure using objective quality assessments and meta-analyses. METHODS: PubMed and Cochrane databases through December 2006 and collected publications on Transcendental Meditation were searched. Randomized, controlled trials comparing blood pressure responses to the Transcendental Meditation technique with a control group were evaluated. Primary outcome measures were changes in systolic and diastolic blood pressure after practicing Transcendental Meditation or following control procedures. A specific rating system (0-20 points) was used to evaluate studies and random-effects models were used for meta-analyses. RESULTS: Nine randomized, controlled trials met eligibility criteria. Study-quality scores ranged from low (score, 7) to high (16) with three studies of high quality (15 or 16) and three of acceptable quality (11 or 12). The random-effects meta-analysis model for systolic and diastolic blood pressure, respectively, indicated that Transcendental Meditation, compared to control, was associated with the following changes: -4.7 mm Hg (95% confidence interval (CI), -7.4 to -1.9 mm Hg) and -3.2 mm Hg (95% CI, -5.4 to -1.3 mm Hg). Subgroup analyses of hypertensive groups and high-quality studies showed similar reductions. CONCLUSIONS: The regular practice of Transcendental Meditation may have the potential to reduce systolic and diastolic blood pressure by approximately 4.7 and 3.2 mm Hg, respectively. These are clinically meaningful changes.     

Isolated diastolic hypotension and incident heart failure in older adults

Aging is often associated with increased systolic blood pressure and decreased diastolic blood pressure. Isolated systolic hypertension or an elevated systolic blood pressure without an elevated diastolic blood pressure is a known risk factor for incident heart failure in older adults. In the current study, we examined whether isolated diastolic hypotension, defined as a diastolic blood pressure <60 mm Hg and a systolic blood pressure ≥100 mm Hg, is associated with incident heart failure. Of the 5795 Medicare-eligible community-dwelling adults age ≥65 years in the Cardiovascular Health Study, 5521 were free of prevalent heart failure at baseline. After excluding 145 individuals with baseline systolic blood pressure <100 mm Hg, the final sample included 5376 participants, of whom 751 (14%) had isolated diastolic hypotension. Propensity scores for isolated diastolic hypotension were calculated for each of the 5376 participants and used to match 545 and 2348 participants with and without isolated diastolic hypotension, respectively, who were balanced on 58 baseline characteristics. During >12 years of median follow-up, centrally adjudicated incident heart failure developed in 25% and 20% of matched participants with and without isolated diastolic hypotension, respectively (hazard ratio associated with isolated diastolic hypotension: 1.33 [95% CI: 1.10-1.61]; P=0.004). Among the 5376 prematch individuals, multivariable-adjusted hazard ratio for incident heart failure associated with isolated diastolic hypotension was 1.29 (95% CI: 1.09-1.53; P=0.003). As in isolated systolic hypertension, among community-dwelling older adults without prevalent heart failure, isolated diastolic hypotension is also a significant independent risk factor for incident heart failure.     

The relationship between blood pressure and blood lead in NHANES III. National Health and Nutritional Examination Survey

There is no general agreement as to whether low-level lead exposure increases blood pressure. The present study examined the correlation between blood pressure and blood lead in the NHANES III database (1988-1994). Analyses were performed for all adults (> or =20 years), and reported separately for white males (n = 4685), white females (n= 5138), black males (n = 1761) and black females (n = 2197). Significant covariates of blood pressure were selected by stepwise regression. The change in blood pressure that would be associated with a doubling of blood lead was calculated from the adjusted regression coefficients. Mean systolic/diastolic blood pressure was 123/76 mm Hg in white males, 119/70 mm Hg in white females, 126/77 mm Hg in black males and 121/72 mm Hg in black females. Median blood lead was 174 nmol/L (3.6 microg/dL), 101 nmol/L (2.1 microg/dL), 203 nmol/L (4.2 microg/dL) and 111 nmol/L (2.3 microg/dL), respectively. For a doubling of blood lead, the changes in systolic blood pressure were 0.3 (95% confidence interval: -0.2 to 0.7, P= 0.29), 0.1 (-0.4 to 0.5, P = 0.80), 0.9 (0.04 to 1.8, P = 0.04) and 1.2 (0.4 to 2.0, P = 0.004) mm Hg, respectively and the changes in diastolic blood pressure were -0.6 (-0.9 to -0.3, P = 0.0003), -0.2 (-0.5 to -0.1, P = 0.13), 0.3 (-0.3 to 1.0, P = 0.28) and 0.5 (0.01 to 1.1, P = 0.047) mm Hg, respectively. In conclusion, there is no consistent relationship between blood pressure and blood lead in the NHANES III dataset.     

Importance of salt in determining blood pressure in children: meta-analysis of controlled trials

To assess the effect of reducing salt intake on blood pressure in children, we carried out a meta-analysis of controlled trials. Trials were included if participants were children (< or = 18 years), and duration of salt reduction must have been for > or = 2 weeks. Mean effect size was calculated using a fixed-effect model, because there was no significant heterogeneity. Ten trials of children and adolescents with 966 participants were included (median age: 13 years; range: 8 to 16 years; median duration: 4 weeks; range: 2 weeks to 3 years). Salt intake was reduced by 42% (interquartile range [IQR]: 7% to 58%). There were significant reductions in blood pressure: systolic: -1.17 mm Hg (95% CI: -1.78 to -0.56 mm Hg; P<0.001); diastolic: -1.29 mm Hg (95% CI: -1.94 to -0.65 mm Hg; P<0.0001). Three trials of infants with 551 participants were included (median duration: 20 weeks; range: 8 weeks to 6 months). Salt intake was reduced by 54% (IQR: 51% to 79%). There was a significant reduction in systolic blood pressure: -2.47 mm Hg (95% CI: -4.00 to -0.94 mm Hg; P<0.01). This is the first meta-analysis of salt reduction in children, and it demonstrates that a modest reduction in salt intake causes immediate falls in blood pressure and, if continued, may well lessen the subsequent rise in blood pressure with age. This would result in major reductions in cardiovascular disease. These results in conjunction with other evidence provide strong support for a reduction in salt intake in children.     

Progressive resistance exercise and resting blood pressure : A meta-analysis of randomized controlled trials

Hypertension is a major public health problem affecting an estimated 43 million civilian, noninstitutionalized adults in the United States (24% of this population). The purpose of this study was to use the meta-analytic approach to examine the effects of progressive resistance exercise on resting systolic and diastolic blood pressure in adult humans. Studies were retrieved via (1) computerized literature searches, (2) cross-referencing from original and review articles, and (3) review of the reference list by 2 experts on exercise and blood pressure. Inclusion criteria were as follows: (1) trials that included a randomized nonexercise control group; (2) progressive resistance exercise as the only intervention; (3) adult humans; (4) journal articles, dissertations, and masters theses published in the English-language literature; (5) studies published and indexed between January 1966 and December 1998; (6) resting systolic and/or diastolic blood pressure assessed; and (7) training studies lasting a minimum of 4 weeks. Across all designs and categories, fixed-effects modeling yielded decreases of approximately 2% and 4% for resting systolic and diastolic blood pressure, respectively (mean+/-SD systolic, -3+/-3 mm Hg; 95% bootstrap CI, -4 to -1 mm Hg; mean+/-SD diastolic, -3+/-2 mm Hg; 95% bootstrap CI, -4 to -1 mm Hg). It was concluded that progressive resistance exercise is efficacious for reducing resting systolic and diastolic blood pressure in adults. However, a need exists for additional studies that limit enrollment to hypertensive subjects as well as analysis of data with an intention-to-treat approach before the effectiveness of progressive resistance exercise as a nonpharmacological intervention can be determined.     

A meta-analysis of randomised controlled trials (RCT) among healthy normotensive and essential hypertensive elderly patients to determine the effect of high salt (NaCl) diet of blood pressure.

To examine the effect of chronic NaCl ingestion on blood pressure (BP) in the elderly, a meta-analysis was undertaken of 11 randomised controlled trials of which five included patients > or =60 years of age only and six included patients with a mean age close to 60 years. The following databases were used: Medline, Embase, Current Contents, The Cochrane Library, the AMI and IPA databases. Mean erect systolic and diastolic blood pressures (SBP/DBP) on chronic (> or =9 weeks) high and low NaCl diets were recorded, the pooled mean effect, the pooled standard error and 95% confidence intervals (Cl) were calculated and linear regression was used to evaluate the potential association between NaCl intake and BP. When all trials were pooled, a chronic high NaCl diet significantly increased mean SBP and DBP by 5.58 mm Hg (95%Cl 4.31-6.85) and 3.5 mm Hg (95%Cl 2.62-4.38) respectively. There was a significant association between the level of NaCl intake and SBP (P = 0.05, r2 = 0.37) but not DBP (P = 0.76, r2 = 0.01). When trials were pooled separately, a chronic high NaCl diet increased SBP by 5.46 mm Hg (95%Cl 3.56-7.36) and DBP by 2.63 mm Hg (95%Cl 1.18-4.08) in trials including patients > or =60 years of age only, and increased SBP by 3.27 mm Hg (95%Cl 1.23-5.31) and DBP by 2.69 mm Hg (95%Cl 1.44-3.94) in trials including patients with a mean age close to 60 years. These data suggest that a chronic high NaCl diet in elderly patients with essential hypertension is associated with an increase in SBP and DBP, the association is significant for both SBP and DBP but more marked for SBP than DBP, the effect is more pronounced the older the patient and NaCl dose strongly predicts SBP in older patients.     

Meta-analysis of cyclooxygenase-2 inhibitors and their effects on blood pressure

BACKGROUND: Nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed and are associated with blood pressure (BP) elevation. The development of selective cyclooxygenase-2 inhibitors (coxibs) raises the issue of the magnitude of BP response compared with nonselective NSAIDs. We therefore performed a meta-analysis comparing the effects of coxibs with placebo, nonselective NSAIDs, and each other on BP elevation and hypertension. METHODS: Nineteen randomized controlled trials involving coxibs were published before May 2004, with a total of 45 451 participants in which BP data were available. The Cohen method statistically combined weighted mean difference (WMD). The Der Simonian and Laird method pooled results concerning the relative risk (RR) of developing hypertension and the RR of clinically important BP elevations. RESULTS: Among the trials analyzed, coxibs caused a WMD point estimate increase in systolic and diastolic BP compared with placebo (3.85/1.06 mm Hg) and nonselective NSAIDs (2.83/1.34 mm Hg). Cyclooxygenase-2 inhibitors were associated with a nonsignificantly higher RR of causing hypertension compared with placebo (RR, 1.61; 95% confidence interval [CI], 0.91-2.84; P = .10) and nonselective NSAIDs (RR, 1.25; 95% CI, 0.87-1.78; P = .23). Rofecoxib induced a WMD point estimate increase in systolic BP (2.83 mm Hg) and a nonsignificantly higher risk of developing clinically important systolic BP elevation (RR, 1.50; 95% CI, 1.00-2.26; P = .05) compared with celecoxib. CONCLUSIONS: Cyclooxygenase-2 inhibitors were associated with a point-estimate BP elevation compared with placebo and nonselective NSAIDs. There was a nonsignificantly higher incidence of developing hypertension compared with nonselective NSAIDs, as was observed with rofecoxib compared with celecoxib. These BP elevations may be clinically significant in relation to increased cardiovascular risk.     

Stop Hypertension with the Acupuncture Research Program (SHARP): results of a randomized, controlled clinical 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.     

Aerobic exercise and resting blood pressure: a meta-analytic review of randomized, controlled trials

In this study the authors used the meta-analytic approach to examine the effects of aerobic exercise on resting systolic and diastolic blood pressure in adults. Forty-seven clinical trials representing a total of 72 effect sizes in 2543 subjects (1653 exercise, 890 control) met the criteria for inclusion. Statistically significant exercise-minus-control decreases were found for changes in resting systolic and diastolic blood pressure in both hypertensive (systolic, −6 mm Hg, 95% CI, −8 to −3; diastolic, −5 mm Hg, 95% CI, −7 to −3) and normotensive (systolic, −2 mm Hg, 95% CI, −3 to −1; diastolic, −1 mm Hg, 95% CI, −2 to −1) groups. The differences between groups were statistically significant (systolic, p =0.008; diastolic, p =0.000). Relative decreases were approximately 4% (systolic) and 5% (diastolic) in hypertensives, and 2% (systolic) and 1% (diastolic) in normotensives. It was concluded that aerobic exercise reduces resting systolic and diastolic blood pressure in adults.