Published articles reported controversial results about the association between leisure-time physical activity (LTPA) and risk of type 2 diabetes. A meta-analysis of prospective cohort studies was conducted to explore the effect of LTPA on the incidence of type 2 diabetes. PubMed and Embase databases were searched from its inception to June 13, 2014. Fixed or random effects models were used to calculate the pooled effect sizes based on between-study heterogeneity that was examined by the Q test and I (2) statistic. A total of eight studies, including 296,395 participants and 10,815 incident cases, were included in this study. Both high-level LTPA [high vs. low: hazard ratio (HR) 0.69, 95 % confidence interval (CI) 0.61-0.78] and moderate-level LTPA (moderate vs. low: HR 0.79, 95 % CI 0.70-0.89) were associated with decreased incidence of type 2 diabetes. In conclusion, LTPA was significantly associated with decreased risk of diabetes; high-level LTPA is more beneficial in decreasing the incidence of type 2 diabetes than moderate-level LTPA.
Keywords: Cohort studies; Meta-analysis; Physical activity; Type 2 diabetes.