Sodium-Glucose Co-Transporter 2 Inhibitors Compared with Sulfonylureas in Patients with Type 2 Diabetes Inadequately Controlled on Metformin: A Meta-Analysis of Randomized Controlled Trials

Background and ObjectiveWhen metformin is insufficient for patients with type 2 diabetes mellitus (T2DM), the optimal adjunctive therapy is unclear. This meta-analysis was to compare the efficacy and safety of sodium-glucose co-transporter 2 (SGLT2) inhibitors with sulfonylureas (SUs) as second-line therapy in patients with T2DM inadequately controlled on metformin.MethodsWe systematically searched PubMed, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov for randomized controlled trials comparing SGLT2 inhibitors with SUs as add-on to metformin. Our primary endpoints were glycemic control, hypoglycemia, and change in weight. We assessed pooled data using a random-effects model.ResultsFive trials involving 4300 participants were included in our meta-analysis. Compared with SUs, SGLT2 inhibitors led to no significant reduction in changes in HbA1c (mean difference [MD] -0.06; 95% confidence interval [CI] [-0.12, 0.08]), but less hypoglycemia as add-on to metformin (odds ratio [OR] 0.12; 95% CI [0.07, 0.21]). SGLT2 inhibitors led to a reduction in weight by about 3.5kg; however, SUs caused a gain in weight by about 1kg (MD -4.39; 95% CI [-4.64, -4.14]). SGLT2 inhibitors also showed a reduction in blood pressure, but increased the incidence of genital tract infections compared with SUs. Interestingly, subgroup analysis by duration of interventions showed that reduction of HbA1c from baseline was similar between the two groups at 12-52weeks, but SGLT2 inhibitors led to a greater reduction in HbA1c at 104-208weeks.ConclusionsDespite similar glycemic efficacy in a relatively short term, SGLT2 inhibitors are more effective in the longer term than SUs as add-on to metformin. In addition, SGLT2 inhibitors produce less hypoglycemic events and lead to greater reductions in weight and blood pressure compared with SUs.