A systematic review and meta-analysis of yoga for hypertension

Background: The aim of this systematic review and meta-analysis was to evaluate the quality of evidence and the strength of recommendation for yoga as a therapeutic means in the management of prehypertension and hypertension.

Methods: MEDLINE/Pubmed, Scopus, CENTRAL, and IndMED were screened through February 2014 for randomized controlled trials (RCTs) on the effects of yoga interventions (≥8 weeks) compared with usual care or any active control intervention on blood pressure in patients with prehypertension (120-139/80-89 mm Hg) or hypertension (≥140/≥90 mm Hg). Risk of bias was assessed using the Cochrane risk of bias tool; quality of evidence was assessed according to the GRADE recommendations.

Results: Seven RCTs with a total of 452 patients were included. Compared with usual care, very low-quality evidence was found for effects of yoga on systolic (6 RCTs, n = 278; mean difference (MD) = -9.65 mm Hg, 95% confidence interval (CI) = -17.23 to -2.06, P = 0.01; heterogeneity: I (2) = 90%, χ(2) = 48.21, P < 0.01) and diastolic blood pressure (6 RCTs, n = 278; MD = -7.22 mm Hg, 95% CI = -12.83 to -1.62, P = 0.01; heterogeneity: I (2) = 92%, χ(2) = 64.84, P < 0.01). Subgroup analyses revealed effects for RCTs that included hypertensive patients but not for RCTs that included both hypertensive and prehypertensive patients, as well as for RCTs that allowed antihypertensive comedication but not for those that did not. More adverse events occurred during yoga than during usual care. Compared with exercise, no evidence was found for effects of yoga on systolic or diastolic blood pressure.

Conclusions: Larger studies are required to confirm the emerging but low-quality evidence that yoga may be a useful adjunct intervention in the management of hypertension.