Effectiveness of a three-month yoga protocol on glycemic control in type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials.

Background: Type 2 diabetes mellitus (T2DM) is a major global health challenge, characterized by insulin resistance, progressive β-cell dysfunction, and persistent hyperglycemia. Yoga is a mind-body practice that has been studied as a potential complementary therapy for T2DM. However, no systematic review has specifically synthesized evidence on the effects of a three-month yoga intervention on glycemic control. Methods: A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted in accordance with PRISMA guidelines (PROSPERO: CRD42024599832). Three electronic databases (PubMed, Science Direct, Cochrane Library) were searched from inception to October 2024. Eligible studies included participants with T2DM who had undergone yoga for three months. The primary outcome was glycated hemoglobin (HbA1c), secondary outcomes were fasting blood glucose (FBG) and postprandial blood glucose (PPBG). Results: Fourteen RCTs comprising 1876 participants with T2DM met the eligibility criteria. Pooled analysis showed a significant reduction in HbA1c (Mean difference [MD] = - 0.55; 95% Confidence interval [CI]: - 1.02 to - 0.08; I² = 97%), FBG (MD = - 24.72 mg/dL; 95% CI: - 34.10 to - 15.34; I² = 80%), and PPBG (MD = - 26.01 mg/dL; 95% CI: - 40.91 to - 11.12; I² = 51%) after three months of yoga. Most trials had a high overall risk of bias. Conclusion: A three-month yoga practice significantly reduces HbA1c, FBG, and PPBG in participants with T2DM without adverse effects, supporting its role as a safe, low-cost adjunct to standard care. However, high heterogeneity restricts certainty. High-quality, multicenter RCTs with standardized yoga protocols are warranted to confirm these findings.