The effect of a six-week program of yoga and meditation on brachial artery reactivity: Do psychosocial interventions affect vascular tone?

Background: Chronic stress is estimated to increase the risk of cardiovascular (CV) events two-fold. Although stress reduction has been linked to a reduction in CV events, little is known regarding its exact mechanism of benefit. Hypothesis: Yoga and meditation will improve parameters of endothelial function. Methods: We examined the effects of yoga and meditation on hemodynamic and laboratory parameters as well as on endothelial function in a 6-week pilot study. Systolic and diastolic blood pressures, heart rate, body mass index (BMI), fasting glucose, lipids, hs C-reactive protein (CRP), and endothelial function (as assessed by brachial artery reactivity) were all studied at baseline and after 6 weeks of yoga practice. Results: A course in yoga and meditation was given to the subjects for 1.5 h three times weekly for 6 weeks and subjects were instructed to continue their efforts at home. This prospective cohort study included 33 subjects (mean age 55 11 years) both with (30%) and without (70%) established coronary artery disease (CAD). There were significant reductions in blood pressure, heart rate, and BMI in the total cohort with yoga. None of the laboratory parameters changed significantly with yoga. For the total cohort there was no significant improvement in endothelial-dependent vasodilatation with yoga training and meditation compared with baseline (16.7% relative improvement from 7.2-8.4%; p = 0.3). In the group with CAD, endothelial-dependent vasodilatation improved 69% with yoga training (6.38-10.78%; p = 0.09). Conclusion: Yoga and meditation appear to improve endothelial function in subjects with CAD.