Importance: Biofeedback with device-guided lowering of breathing frequency could be an alternate nonpharmacologic treatment option for hypertension. Evidence from trials with high methodologic quality is lacking.
Objective: To evaluate the effects of device-guided lowering of breathing frequency on blood pressure in patients with type 2 diabetes mellitus and hypertension.
Design: Single-center, double-blind, sham-controlled trial.
Setting: A large nonacademic teaching hospital in the Netherlands.
Participants: Patients with type 2 diabetes mellitus and hypertension.
Intervention: Fifteen-minute sessions with either the device that guides breathing through musical tones to a lower breathing frequency (aiming at <10 breaths/min) or a sham device (music without aiming at lowering of breathing frequency) for an 8-week study period.
Main outcomes and measures: Systolic and diastolic blood pressure measured in the physician's office.
Results: Forty-eight patients were randomized; 21 patients (88%) in the intervention group and 24 patients (100%) in the control group completed the study. There were no significant changes in systolic and diastolic blood pressure, with a difference in systolic blood pressure of 2.35 mm Hg (95% CI, -6.50 to 11.20) in favor of the control group and a difference in diastolic blood pressure of 2.25 mm Hg (95% CI, -2.16 to 6.67) in favor of the intervention group. Three patients in the intervention group experienced adverse events.
Conclusions and relevance: This high methodologic quality study shows no significant effect of device-guided lowering of breathing frequency on office-measured blood pressure in patients with type 2 diabetes. On the basis of this study, together with results from all but one previous trial, device-guided lowering of breathing frequency does not appear to be a viable nonpharmacologic option for hypertension treatment.