Effects of guided breathing on blood pressure and heart rate variability in hypertensive diabetic patients

Objective: Our aim was to investigate medium-term effects of device-guided breathing on blood pressure (BP) and its capacity to improve the cardiovascular autonomic balance in hypertensive diabetic patients. This feasibility study was conceived as a proof-of-concept trial under real life conditions for justification of further investigations. Methods:A randomized, controlled study (RCT) of the effects of device-guided slow breathing on top of usual care against usual care alone (including non-pharmacological and pharmacological treatment). The intervention included 12-min sessions of guided breathing performed daily for 8 weeks. Treatment effects were assessed with ambulatory blood pressure monitoring (24 h ABPM) and with spectral analysis of short-term heart rate variability (HRV) obtained during standardized modified orthostatic load. Thirty-two subjects with diabetes and antihypertensive therapy were randomly assigned to both study groups. Results: After 8 weeks of guided breathing, significant reductions were demonstrated in 24 h systolic BP (x +/- SEM: 126.1 +/- 3.0 vs 123.2 +/- 2.7 mm Hg, p = 0.01), and in 24 h pulse pressure (PP, 53.6 +/- 2.6 vs. 51.3 +/- 2.5 mm Hg, p = 0.01), whereas no significant impact in the control group was shown. The differences in treatment effects (delta mm Hg, RESPeRATE(R) vs control) were significant only for PP (-2.3 +/- 0.8 vs +0.2 +/- 1.2 mm Hg, p < 0.05). Strong baseline dependence of treatment effects (delta systolic BP) was observed (p < 0.01). Guided breathing showed a stronger treatment effect in terms of an increase in HRV, predominantly in low frequency band (p < 0.03 vs. usual care). Conclusion: Even in well controlled hypertensive diabetic patients, guided breathing induced relevant effects on BP and HRV, finding which should be investigated further. (C) 2013 Elsevier B.V. All rights reserved.