Sitagliptin 100 mg vs glimepiride 1–3 mg as an add-on to insulin and metformin in type 2 diabetes (SWIM)

OBJECTIVE To compare the effect of sitagliptin (100 mg) vs glimepiride (1-3 mg) as add-on therapy in Indian type 2 diabetes (T2DM) patients on treatment with insulin and metformin (SWIM study). RESEARCH DESIGN AND METHODS This 24-week, controlled, open-label study randomized T2DM patients (n = 440) receiving a stable dose of metformin and insulin combination therapy to sitagliptin (100 mg) or glimepiride (1-3 mg) as add-on therapy. Baseline HbA1c was ≥7.3% and ≤8.5%. After a 6-week titration period for glimepiride (dose titrated every 2 weeks by 1 mg up to a maximum of 3 mg daily), patients were continued for 18 weeks on their respective tolerable doses of glimepiride (ranging from 1 mg to 3 mg) or sitagliptin (100 mg) along with metformin and insulin. RESULTS Greater reductions in HbA1c and TDD of insulin were achieved with sitagliptin compared to glimepiride. HbA1c targets and reductions in TDD were achieved by more patients on sitagliptin than on glimepiride. Reductions in both body weight and BMI were also noted among patients on sitagliptin when compared to those on glimepiride, and more hypoglycemic events occurred with glimepiride treatment than with sitagliptin. CONCLUSIONS Sitagliptin (100 mg), when compared to glimepiride (1-3 mg), bestowed beneficial effects to T2DM patients in terms of achieving greater glycemic control and also brought significant reductions in total daily dose of insulin required, bodyweight, BMI and hypoglycemic events. Overall, the results suggest that sitagliptin (100 mg) is a superior agent over glimepiride (1-3 mg) as an add-on to insulin-metformin therapy among Asian Indians with T2DM.