Effects of lifestyle interventions on glucose regulation and diabetes risk in adults with impaired glucose tolerance or prediabetes: a meta-analysis

The prevalence of diabetes mellitus is increasing and is related to sedentary lifestyles and obesity. Many studies were published on the effect of lifestyle interventions on glucose regulation and delay the onset of diabetes in adults with impaired glucose tolerance (IGT) or prediabetes. This study aimed to investigate the role of lifestyle interventions in individuals with IGT or prediabetes using a meta-analytic approach. PubMed, Embase, and the Cochrane Central Register of Controlled Trials databases were searched from their inception up to January 2020 to select eligible randomized controlled trials (RCTs). The weighted mean difference (WMD; for fasting plasma glucose (FPG) and 2-hour plasma glucose (2hPPG)) or relative risk (RR; for the risk of diabetes) with 95% confidence interval (CI) were calculated for pooled effect estimates using the random-effects model. Thirteen RCTs involving 3376 individuals with IGT or prediabetes were selected for this meta-analysis. The results showed that lifestyle interventions were associated with lower FPG (WMD: -0.14; 95% CI: -0.24 to -0.05 mmol/L; p=0.004) and 2hPPG (WMD: -0.66; 95% CI: -1.12 to -0.20 mmol/L; p=0.005) in adults with IGT or prediabetes. Moreover, the risk of diabetes was significantly reduced in individuals who received lifestyle interventions (RR: 0.75; 95% CI: 0.60-0.95; p=0.015). Lifestyle interventions could help improve glucose dysregulation and prevent the progression of diabetes in adults with IGT or prediabetes. Further large-scale RCTs should be conducted to assess the effects of long-term lifestyle interventions on diabetic complications in adults with IGT or prediabetes.