Effectiveness of interventions for the reversal of a metabolic syndrome diagnosis: An update of a meta-analysis of mixed treatment comparison studies.

Introduction: Identifying the most effective interventions to reverse the metabolic syndrome can be key in the design of clinical strategies to prevent progression to type 2 diabetes mellitus and cardiovascular disease. Objective: To estimate the effect size of the interventions used for the reversal of metabolic syndrome. Materials and methods: We searched in Embase and Medline databases for randomized clinical trials with an outcome defined as the reversal of the metabolic syndrome diagnosis. We classified the interventions in four dimensions: 1) lifestyle (diet and exercise); 2) pharmaceuticals; 3) a combination of both, and 4) control groups, and we conducted a mixed treatment comparison analysis. Results: Additional to the previous meta-analysis published by Dunkley, et al. in 2012, we dentified two other studies. Lifestyle interventions had 2.61 more chances to achieve the reversal of the metabolic syndrome than the control group, with a credible interval between 1.00 and 5.47. Pharmaceutical treatments showed a 3.39 higher chance of reversing the syndrome compared with the control group, but the credible interval was estimated from 0.81 to 9.99. Lifestyle interventions had 1.59 more chance of reversal than the pharmaceutical treatments. Conclusion: Diet and physical activity-based interventions had a higher probability of effectiveness to reverse a metabolic syndrome diagnosis.