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

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 HbA1c $7.5 % (8.9 6 1.1 to 9.1 6 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 HbA1c 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 HbA1c 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 HbA1c $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 improve