Controlled evaluation of thermal biofeedback in treatment of elevated blood pressure in unmedicated mild hypertension

In the first of two studies, 42 unmedicated mild hypertensives completed either 16 sessions of thermal biofeedback (TBF) training for hand (7 sessions) and foot (9 sessions) warming or 8 weeks of monitoring BPs at home. There was a trend (p<.10) for more of those treated (57.1%) to have DBPs lower than 90 mm Hg than for those only monitoring BPs at home (33%). Analyses of clinic BP values from random zero sphygmomanometer measurements, from 24-hour ambulatory BP monitoring, and from home BP measurements made by the patient showed no advantage for treatment versus BP monitoring. Sixteen of the 21 patients in BP monitoring were later treated. Analyses of treatment effects across all treated subjects by gender revealed a significant (p=.02) decrease in DBP for treated female subjects (n=13) but not for males (n=24). In the second study the 22 initial treatment successes, that is, those whose DBP was below 90 mm Hg at posttreatment (59.4% of those who completed treatment), were randomized to an intensive follow-up (monthly visits for 6 months, then visits every two months) emphasizing regular home practice with an electronic TBF device or regular follow-up (visits every 3 months). Twelve of the 22 were still normotensive at 12 months. There were no differences at any point during the follow-up between the two conditions in success rate or BPs despite a numerical advantage in reported frequency of home practice by those in the intensive follow-up condition.This research was supported by a grant from NHLBI, HL-31189.