Device and non-device-guided slow breathing to reduce blood pressure: A systematic review and meta-analysis

Objectives: Interest is increasing in nonpharmacological interventions to treat blood pressure in hypertensive and prehypertensive patients at low cardiac risk. This meta-analysis of randomized controlled trials assesses the impact of device-guided and non-device-guided (pranayama) slow breathing on blood pressure reduction in these patient populations.

Methods: We searched PubMed, EMBASE, CINAHL, Cochrane CENTRAL, Cochrane Database of Systematic Reviews, Web of Science, BIOSIS (Biological Abstracts) Citation Index and Alt HealthWatch for studies meeting these inclusion criteria: randomized controlled trial or first phase of a randomized cross-over study; subjects with hypertension, prehypertension or on antihypertensive medication; intervention consisting of slow breathing at ≤10 breaths/minute for ≥5 min on ≥3 days/week; total intervention duration of ≥4 weeks; follow-up for ≥4 weeks; and a control group. Data were extracted by two authors independently, the Cochrane Risk of Bias Tool assessed bias risk, and data were pooled using the DerSimonian and Laird random effects model. Main outcomes included changes in systolic (SBP) and/or diastolic blood pressure (DBP), heart rate (HR), and/or decreased antihypertensive medication.

Results: Of 103 citations eligible for full-text review, 17 studies were included in the meta-analysis. Overall, slow breathing decreased SBP by -5.62 mmHg [-7.86, -3.38] and DBP by -2.97 mmHg [-4.28, -1.66]. Heterogeneity was high for all analyses.

Conclusions: Slow breathing showed a modest reduction in blood pressure. It may be a reasonable first treatment for low-risk hypertensive and prehypertensive patients who are reluctant to start medication.