An inspiratory load enhances the antihypertensive effects of home-based training with slow deep breathing: a randomised trial.

QUESTION Can adding an inspiratory load enhance the antihypertensive effects of slow breathing training performed at home? DESIGN Randomised trial with concealed allocation. PARTICIPANTS Thirty patients with essential hypertension Stage I or II. INTERVENTION Experimental groups performed slow deep breathing at home, either unloaded or breathing against a load of 20 cmH(2)O using a threshold-loaded breathing device. Participants trained for 30 min, twice daily for 8 weeks. A control group continued with normal activities. OUTCOME MEASURES Resting blood pressure and heart rate were measured at home and in the laboratory before and after the training period. RESULTS Compared to the control group, systolic and diastolic blood pressure decreased significantly with unloaded breathing by means of 13.5 mmHg (95% CI 11.3 to 15.7) and 7.0 mmHg (95% CI 5.5 to 8.5), [corrected] respectively (laboratory measures). With loaded breathing, the reductions were greater at 18.8 mmHg (95% CI 16.1 to 21.5) and 8.6 mmHg (95% CI 6.8 to 10.4), respectively. The improvement in systolic blood pressure was 5.3 mmHg (95% CI 1.0 to 9.6) greater than with loaded compared to unloaded [corrected] breathing. Heart rate declined by 8 beats/min (95% CI 6.5 to 10.3) with unloaded breathing, and 9 beats/min (95% CI 5.6 to 12.2) with loaded breathing. Very similar measures of blood pressure and heart rate were obtained by the patients at home. CONCLUSION Home-based training with a simple device is well tolerated by patients and produces clinically valuable reductions in blood pressure. Adding an inspiratory load of 20 cmH(2)O enhanced the decrease in systolic blood pressure. TRIAL REGISTRATION NCT007919689.