Medline ® Abstracts for References 1,9,10

PURPOSE: Physical activity has been associated with reduced blood pressure in observational epidemiologic studies and individual clinical trials. This meta-analysis of randomized, controlled trials was conducted to determine the effect of aerobic exercise on blood pressure.

DATA SOURCES: English-language articles published before September 2001.

STUDY SELECTION: 54 randomized, controlled trials (2419 participants) whose intervention and control groups differed only in aerobic exercise.

DATA EXTRACTION: Using a standardized protocol and data extraction form, three of the investigators independently abstracted data on study design, sample size, participant characteristics, type of intervention, follow-up duration, and treatment outcomes.

DATA SYNTHESIS: In a random-effects model, data from each trial were pooled and weighted by the inverse of the total variance. Aerobic exercise was associated with a significant reduction in mean systolic and diastolic blood pressure (-3.84 mm Hg [95% CI, -4.97 to -2.72 mm Hg]and -2.58 mm Hg [CI, -3.35 to -1.81 mm Hg], respectively). A reduction in blood pressure was associated with aerobic exercise in hypertensive participants and normotensive participants and in overweight participants and normal-weight participants.

CONCLUSIONS: Aerobic exercise reduces blood pressure in both hypertensive and normotensive persons. An increase in aerobic physical activity should be considered an important component of lifestyle modification for prevention and treatment of high blood pressure.

PURPOSE: To quantify effectiveness of lifestyle interventions for hypertension.

DATA SOURCES: Electronic bibliographic databases from 1998 onwards, existing guidelines, systematic reviews.

STUDY SELECTION AND DATA ABSTRACTION: We included randomized, controlled trials with at least 8 weeks' follow-up, comparing lifestyle with control interventions, enrolling adults with blood pressure at least 140/85 mmHg. Primary outcome measures were systolic and diastolic blood pressure. Two independent reviewers selected trials and abstracted data; differences were resolved by discussion.

RESULTS: We categorized trials by type of intervention and used random effects meta-analysis to combine mean differences between endpoint blood pressure in treatment and control groups in 105 trials randomizing 6805 participants. Robust statistically significant effects were found for improved diet, aerobic exercise, alcohol and sodium restriction, and fish oil supplements: mean reductions in systolic blood pressure of 5.0 mmHg [95% confidence interval (CI): 3.1-7.0], 4.6 mmHg (95% CI: 2.0-7.1), 3.8 mmHg (95% CI: 1.4-6.1), 3.6 mmHg (95% CI: 2.5-4.6) and 2.3 mmHg (95% CI: 0.2-4.3), respectively, with corresponding reductions in diastolic blood pressure. Relaxation significantly reduced blood pressure only when compared with non-intervention controls. We found no robust evidence of any important effect on blood pressure of potassium, magnesium or calcium supplements.

CONCLUSIONS: Patients with elevated blood pressure should follow a weight-reducing diet, take regular exercise, and restrict alcohol and salt intake. Available evidence does not support relaxation therapies, calcium, magnesium or potassium supplements to reduce blood pressure.

Exercise is widely recommended as one of the key preventive lifestyle changes to reduce the risk of hypertension and to manage high blood pressure (BP), but individual studies investigating the effect of exercise on ambulatory BP have remained inconclusive. Therefore, the primary purpose of this systematic review and meta-analysis was to determine the effect of aerobic endurance training on daytime and night-time BP in healthy adults. A systematic literature search was conducted using PubMed and Cochrane Controlled Clinical trial registry from their inception to May 2012. Randomized controlled trials of at least 4 weeks investigating the effects of aerobic endurance training on ambulatory BP in healthy adults were included. Inverse weighted random effects models were used for analyses, with data reported as weighted means and 95% confidence limits. We included 15 randomized controlled trials, involving 17 study groups and 633 participants (394 exercise participants and 239 control participants). Overall, endurance training induced a significant reduction in daytime SBP [-3.2 mmHg, 95% confidence interval (CI), -5.0 to-1.3]and daytime DBP (-2.7 mmHg, 95% CI, -3.9 to -1.5). No effect was observed on night-time BP. Thefindings from this meta-analysis suggest that aerobic endurance exercise significantly decreases daytime, but not night-time, ambulatory BP.