A Randomized Trial of Rosiglitazone Therapy in Patients With Inadequately Controlled Insulin-Treated Type 2 Diabetes

Abstract

OBJECTIVE—To determine the efficacy and safety of rosiglitazone (RSG) when added to insulin in the treatment of type 2 diabetic patients who are inadequately controlled on insulin monotherapy. RESEARCH DESIGN AND METHODS—After 8 weeks of insulin standardization and placebo (PBO) run-in, 319 type 2 diabetic patients with mean baseline HbA_1c ≥7.5% (8.9 ± 1.1 to 9.1 ± 1.3) on twice-daily insulin therapy (total daily dose ≥30 U) were randomized to 26 weeks of additional treatment with RSG (4 or 8 mg daily) or PBO. Insulin dose could be down- titrated only for safety reasons. The primary end point was reduction of HbA_1c from baseline. RESULTS—RSG 4 and 8 mg daily significantly improved glycemic control, which was unchanged on PBO. By intent-to-treat analysis, treatment with RSG 8 mg plus insulin resulted in a mean reduction from baseline in HbA_1c of 1.2% (P < 0.0001), despite a 12% mean reduction of insulin dosage. Over 50% of subjects treated daily with RSG 8 mg plus insulin had a reduction of HbA_1c ≥1.0%. Neither total:HDL cholesterol nor LDL:HDL cholesterol ratios significantly changed with RSG treatment. Serious adverse events did not differ among groups. CONCLUSIONS—The addition of RSG to insulin treatment results in significant improvement in glycemic control and is generally well tolerated.