Yoga for metabolic syndrome: A systematic review and meta-analysis

Background Metabolic syndrome is the most important risk factor for developing cardiovascular disease and type 2 diabetes. The aim of this review was to systematically assess and perform a meta-analysis of the effects of yoga on the parameters of metabolic syndrome. Methods MEDLINE/PubMed, Scopus, the Cochrane Central Register of Controlled Trials and IndMED were searched and screened from their inception through to 8 March 2016 for randomised controlled trials on yoga for patients with metabolic syndrome. Risk of bias was assessed using the Cochrane risk of bias tool. Results Seven trials with a total of 794 participants were included. No effects of yoga on resolution of metabolic syndrome, diastolic blood pressure, triglycerides, high-density lipoprotein cholesterol and fasting plasma glucose were found, but yoga was superior to usual care for waist circumference (standardised mean difference (SMD)=-0.35; 95% confidence interval (CI)=-0.57 to -0.13; p<0.01) and systolic blood pressure (SMD=-0.29; 95% CI=-0.51 to -0.07; p=0.01). However, these effects were not robust against selection bias. No intervention-related adverse events were reported. Conclusion Based on the results of this meta-analysis, no recommendation can be made for or against yoga in order to influence the parameters of metabolic syndrome. Despite methodological drawbacks, and until further research is undertaken, yoga can be preliminarily considered as a safe and effective intervention for reducing waist circumference and systolic blood pressure in individuals with metabolic syndrome who are not adhering to conventional forms of exercise.