RESUMO
Purpose: Baroreflex emerges as a therapeutic target of hypertension. We investigated blood pressure (BP) lowering effect of the combined passive head-up and -down movement with device-guided slow breathing in untreated mild hypertension or high-normal BP. Methods: In a randomized, cross-over trial, untreated subjects with an ambulatory systolic/diastolic BP of 125-140/80-90 mmHg and a clinic BP of 130-150/80-90 mmHg were randomized to intervention treatment with head movement and slow breathing or sham control, and then crossed over. Both treatments consisted of 1-week preparation, 2-week treatment, and 1-week recovery. During the 2-week treatment, subjects were treated for a session of 20 min/day. BP, pulse rate and respiration were measured before and after each treatment session. Ambulatory BP monitoring was performed at baseline and the end of the 2-week treatments' period, and home BP monitoring in the morning and evening for the whole 8-week follow-up period. Results: 14 subjects completed the study. The intervention treatment, compared to control, reduced respiration rate by -2.1 breaths/min (95% CI -2.9 to -1.2, p = .0001), but not clinic BP and pulse rate (p ≥ .67). The intervention treatment, compared to control, significantly reduced nighttime systolic/diastolic blood pressure by -5.63/-3.82 mm Hg (p ≤ .01) but not 24-h or daytime ambulatory blood pressure (p ≥ .69). Home BP decreased with the intervention treatment, but the between-treatment difference was not statistically significant (p ≥ .27). Conclusions: The combined head movement with slow breathing did not influence 24-h BP, but reduced nighttime BP in untreated mild hypertension or high-normal BP.