The optimal dose of metformin to control conversion to diabetes in patients with prediabetes: A meta-analysis.

Aim: This study aims to investigate the optimal dose of metformin for controlling the transition to diabetes in patients diagnosed with prediabetes.

Methods: We systematically searched randomized controlled trials (RCTs) in CNKI, Wanfang, VIP, SinoMed, Scopus, PubMed, Embase, Cochrane Library, Web of Science, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) from inception to February 2024. Meta-analysis was conducted using RevMan 5.4 software.

Results: We included 25 randomized controlled trials comprising 2437 patients. The results of the meta-analysis revealed that compared to dose groups of 500 mg/d, 850 mg/d, 1000 mg/d, 1500 mg/d, 1700 mg/d, and 2000 mg/d, a dosage of 750 mg/d of metformin significantly reduced the incidence of diabetes in patients (risk ratio [RR] = 0.21, 95 % confidence interval [CI]: 0.11, 0.41; p < 0.00001), lowered Postprandial Blood Glucose (PBG) (mean difference[MD] = -2.60, 95 % CI: -4.34, -0.86; p = 0.003), and promoted the normalization of blood glucose levels (RR = 2.13, 95 % CI: 1.68, 2.71; p < 0.00001). Regarding safety evaluation, no significant differences were identified among the various dose groups. In contrast, the cohort receiving a daily dosage of 750 mg demonstrated the most pronounced decrease in the incidence of adverse reactions.

Conclusion: Based on the efficacy and safety evaluation results, our findings suggest that a daily dosage of 750 mg of metformin may represent the optimal dose for controlling the progression from pre-diabetes to diabetes.

Registration: PROSPERO registration ID: CRD42024538322.