Effect of Feedback Signal on Blood Pressure Self-regulation Capability in Individuals With Prehypertension or Stage I Hypertension: A Randomized Controlled Study. Issue 2 (March 2016) - Wang, Mei-Yeh
Abstract : Objectives: We aimed to determine the efficacy of an 8-week direct blood pressure (BP) biofeedback training program for prehypertensive or stage I hypertensive patients with a particular focus on the impact of the authenticity of feedback signals on the efficacy of BP regulation. Designs: This study has a randomized, double-blind, parallel-group design. Participants and Methods: Fifty-nine individuals with ages from 18 to 64 years and who met the criteria for the diagnosis of prehypertenion or stage 1 hypertension participated in this study. The participants were referrals from physicians or community-dwelling volunteers. No participants had taken antihypertensive medication within the previous 2 months prior to enrollment. The participants were randomly assigned to the biofeedback group (n = 31) trained with real-time BP feedback signals or the control group (n = 28) trained with pseudofeedback signals. The primary outcome measures were systolic BP (SBP) and diastolic BP (DBP). Systolic BP and DBP were assessed at baseline, 1 week after training (week 9), and 8 weeks after training (week 16) in both groups. Only 54 participants had week 16 data. Results: The changes in SBP and DBP from baseline to week 9, from baseline to week 16, and from week 9 to week 16 were not significantly different between the groups (All P > 0.05). Both groups were able to significantly decrease BP after completing the training. A percentage of 45.2% of the participants in the biofeedback group and 63.0% of the participants in the control group lowered their SBP by 5 mm Hg or more at week 9. The SBP-lowering effects were also maintained for at least 8 weeks after the completion of training. Conclusions: The equivalent magnitude of BP reduction between the 2 study groups suggests that repeated practice in BP self-regulation was more likely responsible for the efficacy of direct BP biofeedback training than was the type of feedback signals.