Comparison of Basal Insulin Added to Oral Agents Versus Twice-Daily Premixed Insulin as Initial Insulin Therapy for Type 2 Diabetes

Abstract

OBJECTIVE—To compare the efficacy and safety of adding once-daily basal insulin versus switching to twice-daily premixed insulin in type 2 diabetic patients insufficiently controlled by oral antidiabetic agents (OADs). RESEARCH DESIGN AND METHODS—In a 24-week, multinational, multicenter, open, parallel group clinical trial, 371 insulin-naïve patients with poor glycemic control (fasting blood glucose [FBG] ≥120 mg/dl, HbA1c 7.5–10.5%) on OADs (sulfonylurea plus metformin) were randomized to once-daily morning insulin glargine plus glimepiride and metformin (glargine plus OAD) or to 30% regular/70% human NPH insulin (70/30) twice daily without OADs. Insulin dosage was titrated to target FBG ≤100 mg/dl (both insulins) and predinner blood glucose ≤100 mg/dl (70/30 only) using a weekly forced-titration algorithm. RESULTS—Mean HbA1c decrease from baseline was significantly more pronounced (−1.64 vs. −1.31%, P = 0.0003), and more patients reached HbA1c ≤7.0% without confirmed nocturnal hypoglycemia (45.5 vs. 28.6%, P = 0.0013) with glargine plus OAD than with 70/30. Similarly, FBG decrease was greater with glargine plus OAD (adjusted mean difference −17 mg/dl [–0.9 mmol/l], P < 0.0001), and more patients reached target FBG ≤100 mg/dl with glargine plus OAD than with 70/30 (31.6 vs. 15.0%, P = 0.0001). Glargine plus OAD patients had fewer confirmed hypoglycemic episodes than 70/30 patients (mean 4.07 vs. 9.87/patient-year, P < 0.0001). CONCLUSIONS—Initiating insulin treatment by adding basal insulin glargine once daily to glimepiride plus metformin treatment was safer and more effective than beginning twice-daily injections of 70/30 and discontinuing OADs in type 2 diabetic patients inadequately controlled with OADs.