The effectiveness of lifestyle interventions on type 2 diabetes and gestational diabetes incidence and cardiometabolic outcomes: A systematic review and meta-analysis of evidence from low- and middle-income countries.

Abstract

SummaryBackgroundAs lifestyle modification offers a unique strategy to prevent diabetes, we evaluated the effectiveness of lifestyle interventions in the prevention of type 2 diabetes and gestational diabetes in low- and middle-income countries (LMICs).MethodsWe did a systematic literature review and meta-analysis. We searched MEDLINE, Embase, Web of Science, and Cochrane Library for randomised controlled trials published in English, Spanish, French, and Portuguese between 1 January 2000 and 15 June 2022, evaluating multi-target and multi-component lifestyle interventions in at-risk populations conducted in LMICs. The main outcomes were incidence of type 2 diabetes and gestational diabetes, and indicators of glycaemic control. We assessed the methodological quality of the studies using the Cochrane risk of bias tool. Inverse-variance random-effects meta-analyses estimated the overall effect sizes. Sources of heterogeneity and study bias were evaluated. The study protocol was registered in PROSPERO (CRD42021279174).FindingsFrom 14 330 abstracts, 48 (0·3%) studies with 50 interventions were eligible of which 56% were conducted in lower-middle-income countries, 44% in upper-middle, and none in low-income. 54% of the studies were assessed as moderate risk of bias and 14% as high risk. A median of 246 (IQR 137-511) individuals participated in the interventions with a median duration of 6 (3-12) months. Lifestyle interventions decreased the incidence risk ratio of type 2 diabetes by 25% (0·75 [95% CI 0·61 to 0·91]), and reduced the levels of HbA1c by 0·15% [−0·25 to −0·05], fasting plasma glucose by 3·44 mg/dL [−4·72 to −2·17], and 2-hr glucose tolerance by 4·18 mg/dL [−7·35 to −1·02]. No publication bias was suggested for these outcomes. High levels of heterogeneity (I²≥ 81%) were found in most meta-analyses. Exploration using meta-regressions could not identify any explanatory variable, except for fasting glucose for which the quality score of the articles seems to be an effect modifier decreasing slightly the heterogeneity (72%) in the low risk of bias pooled estimate. The effect on gestational diabetes could not be evaluated due to the scarcity of available studies.InterpretationComprehensive lifestyle interventions are effective strategies to prevent type 2 diabetes among at-risk populations in LMICs. The heterogeneity identified in our results should be considered when using these interventions to address the onset of type 2 diabetes.FundingNone.