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

Abstract

Objectives: What is the impact of prolonged use of device or non-device guided slow breathing compared to usual care, on the BP values of hypertensive patients? Design: Systematic review and meta-analysis of randomized clinical trials. Participants: Hypertensive patients, with or without comorbidity, over 18 years old, of both sexes, with or without hypertensive medication. Intervention: The selected studies showed comparisons between groups that performed device-guided and/or non-device-guided slow breathing with control conditions. Outcome measures: The primary outcome was the value of systolic blood pressure (SBP) and diastolic blood pressure (DBP) after the interventions. The secondary outcome was the reduction in the quantity/dosage of drugs administered to control hypertension. Results: Twenty-two studies involving 17,214 participants were included in the quantitative analysis. Considerable heterogeneity was revealed between studies. Using random effect model, it was found that device-guided slow breathing did not significantly reduce SBP and DBP compared to usual care, both in terms BP values and in relation to their variations (SBP, MD -2.13 mmHg, [95% CI -12.71 to 8.44], 288 individuals; I2 = 93%, high heterogenity : DBP, MD -0.90, 95% CI -3.97 to 2.11, 288 individuals; I2 = 63%,substantial heterogenity . SBP variations MD - 2.42, 95% CI -7.24 to 2.40, 443 individuals; I2 = 85% high heterogenity / DBP variations MD -1.67, 95% CI -4.57 to 1.24, 443 individuals; I2 = 80%, high heterogenity ). Conclusion: Based on these results it appears that device-guided slow breathing did not reduce blood pressure in hypertensive patients. Registration: PROSPERO CRD42020147554