Acute effects of transcendental meditation on hemodynamic functioning in middle-aged adults

Objective: Increased peripheral vasoconstriction (ie, total peripheral resi stance, or TPR) has been implicated as playing an important role in the ear ly development of essential hypertension. Some studies have demonstrated th at Transcendental Meditation (TM) reduces high blood pressure, but the hemo dynamic adjustments behind these blood pressure reductions have not been el ucidated. The aim of this study was to provide a preliminary investigation of the acute effects of TM on TPR. Methods: Subjects were 32 healthy adults (16 women and 16 men; 30 white and two African American; mean age, 46.4 +/ - 3.9 years). Subjects were divided into a TM group of long-term TM practit ioners (eight white women, nine white men, and one African American man; me an years of twice-daily TM practice, 22.4 +/- 6.7) and a control group (eig ht white women, five white men, and one African American man). Hemodynamic functioning was assessed immediately before and during three conditions: 20 minutes of rest with eyes open (all subjects), 20 minutes of TM (TM group) , and 20 minutes of eyes-closed relaxation (control group). Results: During eyes-open rest, the TM group had decreases in systolic blood pressure (SBP ) and TPR, compared with increases in the control group (SBP: -2.5 vs. +2.4 mm Hg, p < .01; TPR: -0.7 vs. +0.5 mm Hg/liter per minute, p < .004). Duri ng TM, there was a greater decrease in SEP due to a concomitantly greater d ecrease in TPR compared with the control group during eyes-closed relaxatio n (SBP: -3.0 vs. +2.1 mm Hg, p < .04; TPR: -1.0 vs. +0.3 mm Hg/liter per mi nute, p < .03). Conclusions: TPR decreased significantly during TM. Decreas es in vasoconstrictive tone during TM may be the hemodynamic mechanism resp onsible for reduction of high blood pressure over time. The results of this study provide a preliminary contribution to the understanding of the under lying hemodynamic mechanisms responsible for the beneficial influence of TM on cardiovascular risk factors.