Blood pressure-lowering effects of biofeedback treatment in hypertension.
Meta-analysis at Teikyo University Medical School in Tokyo reveals that biofeedback significantly reduces hypertension, but only when combined with other relaxation and imagery technique
The Department of Hygiene and Public Health (EBM Center) at the School of Medicine,Teikyo University, in Tokyo, Japan published a meta-analysis of 22 randomized, controlled studies investigating the efficacy of biofeedback for reducing hypertension. The 22 studies were published between 1966 and 2001, and involved a total of 905 hypertensive patients.Compared with non-intervention controls, biofeedback intervention resulted in systolic and diastolic blood pressure reductions that were greater by 7.3 mmHg (for systole; 95% confidence interval: 2.6 to 12.0) and 5.8 mmHg (for diastole; 95% confidence interval: 2.9 to 8.6).
When compared with placebo or non-specific behavioral intervention controls, the net reductions in systolic and diastolic blood pressures by biofeedback intervention were 3.9 (95% confidence interval: -0.3 to 8.2) and 3.5 (-0.1 to 7.0) mmHg, respectively.
Results from multiple regression analysis also indicated that biofeedback intervention decreased systolic and diastolic blood pressures more than non-intervention controls (p < 0.001), but not more than placebo or non-specific behavioral intervention controls (p > 0.05), when controlling for the effects of initial blood pressures.
When biofeedback intervention types were classified into two types - simple biofeedback and relaxation-assisted (imagery) biofeedback - only the relaxation-assisted biofeedback significantly decreased both systolic and diastolic blood pressures (p < 0.05) compared with those in placebo or non-specific behavioral intervention controls. The treatment was only found to be superior when combined with other relaxation techniques. Further studies will be needed to determine whether biofeedback itself has an anti-hypertensive effect beyond the general relaxation response.
Citation: Nakao M, Yano E, Nomura S, Kuboki T. Blood pressure-lowering effects of biofeedback treatment in hypertension: a meta-analysis of randomized controlled trials. Hypertension Research. 2003 Jan; 26(1): pages 37-46. [email protected]