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 7.0 mmHg (95% CI 5.5 to 8.5) and 13.5 mmHg (95% CI 11.3 to 15.7), 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 unloaded 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. [Jones CU, Sangthong B, Pachirat 0 (2010) An inspiratory load enhances the antihypertensive effects of home-based training with slow deep breathing: a randomised trial. Journal of Physiotherapy 56: 179-186]