The effect of exercise on adiponectin and leptin levels in overweight or obese subjects: a meta-analysis of randomized controlled trials

Introduction The obesity-induced dysregulated expression of adipokines plays a critical role in the onset of obesity-related diseases. A great number of randomized controlled trails demonstrated that exercise could influence the secretion of adipokines. However, the results have been inconsistent. The aim of the study was to explore the effect of exercise on adipokines’ levels in overweight or obese subjects. Methods PubMed, EMBASE and other databases were searched up to January 2016. A total of 21 studies, including 1218 participants, were included in the meta-analysis. Results Exercise was statistically associated with an increase in the adiponectin level (WMD 0.67, P < 0.001) and a reduction in the leptin level (WMD −1.06, P < 0.001). Subgroup analyses indicated that a larger change for the adiponectin level was found in Asian subjects (WMD 1.49, P < 0.001) and those with diet co-intervention (WMD 0.81, P = 0.003), combinative exercise (WMD 0.81, P = 0.003) and a training duration >8 weeks (WMD 0.79, P = 0.014). For leptin, exercise was more effective in subjects with diet co-intervention (WMD −3.09, P < 0.001), aerobic exercise (WMD −3.57, P < 0.001), a training duration >8 weeks (WMD −1.55, P < 0.001) and a training time ≥60 min per week (WMD −1.14, P = 0.005). Conclusions These results suggest that an exercise program, with diet co-intervention, can show beneficial effects to ameliorate adipokines dysregulation.