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

This rigorous meta-analysis examined the effect of acupuncture in the treatment of type 2 diabetes mellitus (T2DM), a chronic condition characterized by elevated blood glucose levels due to insulin resistance and impaired insulin secretion. The study included 20 randomized controlled trials with 1,479 patients, representing the most comprehensive analysis available on this topic to date. The research was conducted following rigorous protocols, including a search across four major databases and advanced statistical analysis with prediction intervals and the Hartung-Knapp adjustment to correct for between-study heterogeneity. The results demonstrated that acupuncture produced significant improvements in multiple markers of glycemic control.

Fasting blood glucose showed a significant reduction (SMD: -0.52; 95% CI: -0.91 to -0.13; P=0.009), as did glycated hemoglobin HbA1c (SMD: -0.76; 95% CI: -1.24 to -0.27; P=0.002), which is considered the gold standard for evaluating long-term glycemic control. The 2-hour postprandial blood glucose also showed substantial improvement (SMD: -0.69; 95% CI: -1.00 to -0.39; P<0.00001). Particularly impressive was the reduction in the HOMA-IR index (SMD: -1.72; 95% CI: -2.57 to -0.86; P<0.0001), indicating significant improvement in insulin resistance, a central aspect of T2DM pathophysiology. Interestingly, insulin levels did not show significant changes, suggesting that acupuncture acts primarily by improving insulin sensitivity rather than increasing its production.

The acupuncture techniques used included traditional Chinese acupuncture, electroacupuncture, and acupoint catgut embedding, with points located primarily on the head, trunk, and limbs. Protocols ranged from 15 days to 15 weeks of treatment, with sessions of 20 to 30 minutes. Subgroup analysis did not identify specific sources of heterogeneity, suggesting that the benefits are consistent regardless of the specific protocols used. From a clinical standpoint, these findings are highly relevant, as conventional T2DM treatment faces significant challenges, including medication side effects, difficulties in achieving personalized glycemic targets, and concerns about the long-term sustainability of pharmacological treatment.

Acupuncture emerges as a promising complementary therapy, offering benefits without the significant adverse effects associated with many medications. The safety of acupuncture, as reported in the included studies, was excellent, with only mild adverse events reported. This reinforces its potential as a noninvasive and cost-effective therapeutic option. The proposed mechanisms for the effects of acupuncture include modulation of vagus nerve activity, improvement in glucose uptake by the liver and skeletal muscles, and reduction of inflammatory responses.

Experimental studies suggest that stimulation of acupoints can activate cellular signaling pathways that improve glucose metabolism and reduce insulin resistance.