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

Abstract

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.

Relaxation therapies for the management of primary hypertension in adults: a Cochrane review

“…Entry criteria varied between trials, and the average baseline SBP of participants ranged between trials from 130 to 164 mm Hg (median: 144, inter-quartile range: 139-150 mm Hg) and the corresponding DBP from 86 to 109 mm Hg (median: 92, inter-quartile range: 89-97 mm Hg). Thirteen trials enrolled a mixture of participants who were and were not being treated with antihypertensive medication; [30][31][32][33][34][35][36][37][38][39][40][41][42] nine trials enrolled only participants who were not receiving antihypertensive medication, [43][44][45][46][47][48][49][50][51] although two of these trials enrolled participants who had previously been on medication; 45,47 one trial enrolled only participants who were receiving antihypertensive medication 52 and two trials did not specify the medication status of participants. 53,54 One trial enrolled only participants with a 'Type A' personality: a tendency to anger and hostility.…”

“…Only six trials reported ethnicity and in these 84% of the participants were white. 35,38,39,42,45,52 Ten trials were conducted in the USA, three in the UK, two in Canada, two in Israel, two in Spain, one in the Netherlands, one in New Zealand, one in the USSR, one in Taiwan, one in India and one in Venezuela.…”

“…32,34,44 Several trials combined components from several types of relaxation therapies in one active treatment arm. Relaxation interventions included: progressive muscle relaxation (16 trials) 30,31,[34][35][36][37]39,40,42,43,46,47,48,[51][52][53] ; biofeedback (12 trials) 32,34,35,[37][38][39][40][41]45,46,48,52 ; autogenic training (6 trials) 33,35,38,39,49,51 and cognitive or behavioural therapy or meditation (11 trials). 32,36,37,40,42,44,46,[49][50][51]54 Within these categories, interventions were heterogeneous.…”

“…41 Cognitive and behavioural therapies included anger control, 32 40 Most trials which taught progressive muscle relaxation encouraged participants to practise at home, often with the help of taped instructions; 31,35,39,40,43,46,47,51,53 some trials also encouraged participants to practise these relaxation techniques in stressful situations. 36,40,47 Relaxation therapies were delivered to participants either in a group setting 32,35,39,40,[42][43][44][45][46][51][52][53] or individually; 30,31,36,37,41,[47][48][49] in five trials the delivery setting was unclear. 33,34,38,50,54 The median duration of treatment was 8 weeks (range: 5-26 weeks).…”

Biobehavioral approaches to the treatment of essential hypertension.

“…However, more recent studies are less encouraging. Blanchard et al (1996) reported that an 8-week thermal biofeedback-training program had no effect on either clinic or ABP measurements. Hunyor et al (1997) found that almost 50% of the hypertensive patients in their study were able to lower their BP in the laboratory using thermal biofeedback.…”