A Systematic Review and Meta-Analysis of RCTs Assessing Efficacy of Lifestyle Interventions on Glycemic Control in...

The rising prevalence of Type 2 Diabetes Mellitus (T2DM), coupled with sedentary behavior and an increase in obesity rates in South Asian countries, calls for effective management strategies. We aimed to assess the efficacy of lifestyle interventions on glycemic control among adults with T2DM in South Asian countries.

A systematic review and meta-analysis of randomized controlled trials (RCTs) were conducted to assess the effectiveness of lifestyle interventions on glycemic control in adults diagnosed with T2DM in South Asia. We conducted a comprehensive search in CINAHL, Embase, PubMed, Cochrane Library, Web of Science (WoS), and Scopus to identify related studies published from 2000 to 13 June 2024. We assessed the risk of bias using the ROB 2.0 tool and calculated the pooled mean differences in HbA1c and FBG levels under a random-effects model. We conducted subgroup and leave-one-out sensitivity analyses to assess and explore sources of heterogeneity. PROSPERO Registration: CRD42024552286.

We included 16 RCTs with a total of 1499 participants. Lifestyle interventions reduced HbA1c levels by 0.86% (95% CI: -1.30 to -0.42, p < 0.01) and FBG levels by 22.49 mg/dL (95% CI: -32.88 to -12.10, p < 0.01). We observed substantial heterogeneity (I² = 98% for HbA1c and I² = 87% for FBG). Subgroup analyses indicated larger HbA1c reductions in long-term (-1.44%) than short-term trials (-0.62%), and greater FBG decreases in long-term (-23.7 mg/dL) versus short-term studies (-22.5 mg/dL). Physical activity interventions had the largest improvements (HbA1c -0.99%; FBG -26.1 mg/dL), followed by dietary (HbA1c -0.59%; FBG -15.8 mg/dL) and combined programs (HbA1c -0.55%). Participants aged >50 years achieved greater glycemic improvements (HbA1c -0.92%; FBG -24.0 mg/dL) compared to younger adults (HbA1c -0.60%; FBG -21.3 mg/dL). Despite high heterogeneity, sensitivity analyses confirmed the robustness of the overall findings.

Lifestyle modifications yielded a clinically significant reduction in HbA1c and FBG in adults with T2DM in South Asia. Although heterogeneity of the included studies was substantial, the direction of the effects was uniformly consistent across subgroups. To further validate these findings and assess their long-term effects, large-scale and standardized RCTs conducted for longer durations are necessary.