Effects of lifestyle interventions on the prevention of type 2 diabetes and reversion to normoglycemia by prediabetes phenotype: A systematic review and meta-analysis of randomized controlled trials

Objective: To explore the effects of lifestyle interventions on the prevention of type 2 diabetes (T2D) and reversion to normoglycemia by prediabetes phenotype.

Methods: We searched MEDLINE, Embase, and the Cochrane Library for randomized controlled trials (RCTs) that evaluated the effects of lifestyle interventions in adults with prediabetes for a minimum duration of one year. Two reviewers independently screened articles, extracted data, and performed quality assessment. The relative effects were analyzed using a random-effects model, subgroup analysis was employed to explore the potential effects among subpopulations.

Results: A total of 31 RCTs involving 23684 participants were analyzed. Compared with usual care, lifestyle interventions reduced the incident T2D by 41 % (RR 0.59 [95 % CI 0.52-0.68]) and increased the probability of reverting to normoglycemia by 44 % (RR 1.44 [95 % CI 1.15-1.81]) in adults with prediabetes. No significant difference was observed between the impaired fasting glucose (IFG_5.6)/impaired glucose tolerance (IGT) and IFG_6.1/IGT (P = 0.752). IGT + IFG benefited more than isolated IGT in prevention of T2D (RR_{IGT + IFG} 0.47 [95 % CI 0.41-0.55]; RR_isolatedIGT 0.77 [95 % CI 0.64-0.93]), whereas no benefit was found in isolated IFG (RR 0.77 [95 % CI 0.51-1.16]) or elevated HbA1c (RR 0.89 [95 % CI 0.74-1.07]).

Conclusions: Lifestyle intervention could help prevent T2D and revert to normoglycemia in adults with prediabetes, with significant benefit in people with IGT but not in those with isolated IFG or elevated HbA1c.