Effect of acupuncture for type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials

Background Previous studies suggest acupuncture may be effective for various chronic conditions, but its impact on type 2 diabetes (T2DM) remains debated. Objective To evaluate the effect of acupuncture on blood glucose-related outcome indicators in T2DM. Methods We searched four databases (PubMed, Embase, Web of Science, and Cochrane Library) from inception to 3 July 2025 to identify randomised controlled trials that enrolled patients with T2DM and compared acupuncture and non-acupuncture. The analysis employed standardized mean differences with 95% confidence intervals and incorporated Prediction Intervals (PI) for each outcome. Subgroup analysis, meta-regression, sensitivity analysis, and publication bias evaluation were also performed. Results Twenty RCTs involved 1479 patients were included. The results demonstrated that the acupuncture group had significant reduction in FBG (SMD: -0.52; 95% CI:-0.91 to -0.13; P = 0.009), HbA1c (SMD:-0.76; 95% CI:-1.24 to -0.27; P = 0.002), 2hPG (SMD:-0.69; 95% CI:-1.00 to -0.39; P < 0.00001) and HOMA-IR (SMD:-1.72; 95% CI: -2.57 to -0.86; P < 0.0001), but not reveal statistically significant difference in insulin level (SMD:-1.16; 95% CI:-2.36 to 0.04; P = 0.06). The Hartung-Knapp adjustment showed consistent results, with the PI indicating potential variability in future studies. Conclusions Acupuncture effectively reduces FBG, HbA1c, 2hPG, and HOMA-IR in patients with T2DM, but does not significantly affect insulin levels. Our study suggests that acupuncture may serve as a valuable complementary treatment for glycemic control in T2DM. Future research should focus on optimizing acupuncture protocols, assessing its long-term effects, and investigating the biological mechanisms behind its impact.