Differential effect of nonpharmacological interventions according to prediabetes phenotype: Systematic review and meta-analysis of randomized clinical trials

Background and Aims: Impaired glucose intolerance (IGT) and impaired fasting glucose (IFG) are totally different. Lifestyle modification is effective in moving from prediabetes to normoglycaemia. There is a lack of information showing the effect of lifestyle modification according to each prediabetes and assessing its effect on the degree of reversibility to normoglycaemia and on cardiometabolic markers. Methods and Results: We searched for randomized controlled trials (RCT) that enrolled individuals with IGT or IFG. Meta-analysis was performed to compare the proportion of subjects progressing to type 2 diabetes mellitus (T2DM); proportion reversing to normoglycaemia and mean differences in glucose level and cardiometabolic parameters. Thirty-six RCTs were included. The proportion of subjects progressing from impaired glycaemia to T2DM was higher among those with IGT (16.3% vs. 10.9%), whereas reversion to normoglycaemia was higher in subjects with IFG (27.2% vs. 24.8%). The effect of lifestyle modification on glucose level was significant on those with IFG (mean difference [MD] = −1.56 mg/dL, 95% CI: −2.71, −0.40), but not on those with IGT of (MD = 1.47 mg/dL, 95% CI: −1.33, 4.28). Conclusion: Diverse lifestyle modification interventions improved glucose levels in people with IFG, but not in those with IGT. Our findings imply that different non-pharmacological interventions are warranted for IGT and IFG.