Network Meta-analysis of the Therapeutic Effects of Hypoglycemic Drugs and Intensive Lifestyle Modification on Impaired Glucose Tolerance

Purpose In the Guidelines for the Prevention and Control of Type 2 Diabetes in China (2017 edition), intensive lifestyle interventions are recommended for preventing the progression of impaired glucose tolerance (IGT) to type 2 diabetes mellitus. Acarbose and metformin can also be considered if intensive lifestyle modification has been ineffective for 6 months. But the effects of intensive lifestyle modification and glucose-lowering drug interventions that work best in the population with IGT are unclear. This network meta-analysis assessed the effectiveness of intensive lifestyle modification, acarbose, and metformin in treating populations with IGT. Methods We systematically searched both Chinese- and English-language databases, including China Knowledge, the Cochrane Library, Embase, PubMed, VIP, and Wanfang, for articles published between database inception and September 2019. Randomized, controlled clinical trials in patients with IGT treated with acarbose, metformin, and intensive lifestyle modification were assessed for eligibility. The data from all included studies were evaluated by 2 reviewers independently in accordance with the Cochrane Handbook for Systematic Reviews of Intervention version 6.0. A network meta-analysis was performed by using R software version 3.6.1. Findings The data from 53 randomized controlled trials were included in the review, with a sample size of 21,208 patients. Compared with the control group, the use of acarbose, metformin, and/or intensive lifestyle modification was associated with reduced rates of progression to diabetes (relative risks [RRs] [95% credible intervals]: acarbose, 0.37 [0.29–0.47]; metformin, 0.39 [0.30–0.50]; intensive lifestyle modification, 0.61 [0.50–0.73]). The surface under the cumulative ranking (SUCRA) value of acarbose was 88.35%, supporting that acarbose was more effective in reducing the rate of progression to diabetes compared with controls. With acarbose, metformin, and intensive lifestyle modification, the rates of achieving a normal glucose level were increased by RR = 2.1, 1.7, and 1.2, respectively when compared with control group. The SUCRA value of acarbose was 99.69%, supporting the optimal effect of acarbose in achieving a normal blood glucose level. Implications In this meta-analysis in patients with IGT, compared with controls, acarbose and metformin were associated with decreased rates of progression to diabetes and increased rates of achieving a normal glucose level. Acarbose use was associated with an increased rate of achieving a normal glucose level, while intensive lifestyle modification was not.