RESUMO
Mind body therapies appear to reduce morbidity and mortality in patients with cardiovascular diseases, but there is limited understanding of the mechanisms that mediate this effect. Vascular endothelial dysfunction is a central feature of atherogenesis that is adversely impacted by mental stress. We conducted a systematic review and meta-analysis of the effect of mind body therapies on peripheral endothelial function in patients with and without established cardiovascular disease. The search included Medline, Cochrane Library, Scopus and Embase to identify studies up to November 2009. Eligible studies were randomized controlled trials that compared the effects of mind body therapies and placebo on endothelial function. Two reviewers extracted data on study characteristics, methods, and outcomes. Disagreement was resolved by consensus. Three eligible trials enrolled a total of 258 patients. Sixty one (24 percent) were women and 53 percent had established cardiovascular disease. The trials had good methodological quality. Meta-analysis using random-effects model showed a non significant improvement of endothelial function by mind body therapies (standardized mean difference 0.15; 95% CI, -0.36 to 0.67, P=0.56). The analysis was underpowered due to small sample size. Circumstantial evidence indicates that mind body therapies may have a therapeutic benefit on endothelial dysfunction, however, the aggregate data from the three small randomized trials to date do not support this hypothesis. This biologically plausible effect requires additional investigation in adequately powered studies.