Improved Glycemic Control with Insulin Glargine Versus Pioglitazone as Add-On Therapy to Sulfonylurea or Metformin in Patients with Uncontrolled Type 2 Diabetes Mellitus

Abstract

To compare glycemic control with add-on insulin glargine versus pioglitazone treatment in patients with type 2 diabetes. This 48-week, multicenter, parallel-group, open-label study randomized 389 adults with poorly controlled type 2 diabetes (glycated hemoglobin A1c [A1C], 8.0% to 12.0%), despite > or =3 months of sulfonylurea or metformin monotherapy, to receive add-on therapy with insulin glargine or pioglitazone. Outcomes included A1C change from baseline to end point (primary), percentage of patients achieving A1C levels < or =7.0%, and changes from baseline in fasting plasma glucose, body mass index, weight, and serum lipids. The safety analysis included incidence of adverse events and rates of hypoglycemia. At end point, insulin glargine yielded a significantly greater reduction in A1C in comparison with pioglitazone (-2.48% versus -1.86%, respectively; 95% confidence interval, -0.93 to -0.31; P = .0001, 48-week modified intent-to-treat population). Insulin glargine also yielded significantly greater reductions in fasting plasma glucose at all time points (end point difference, -34.9 mg/dL; 95% confidence interval, -47.6 to -22.2; P<.0001). In comparison with pioglitazone, insulin glargine resulted in a lower overall incidence of possibly related treatment-emergent adverse events (12.0% versus 20.7%) and fewer study discontinuations (2.2% versus 9.1%), but a higher rate (per patient-year) of confirmed clinically relevant hypoglycemic episodes (blood glucose <70 mg/dL and all severe hypoglycemia) (4.97 versus 1.04; P<.0001) and severe hypoglycemia (0.07 versus 0.01; P = .0309). Weight and body mass index changes were similar between the 2 treatment groups. The addition of insulin glargine early in the diabetes treatment paradigm in patients for whom sulfonylurea or metformin monotherapy had failed resulted in significantly greater improvements in glycemic control in comparison with the addition of pioglitazone. Although severe hypoglycemia was more frequent in patients with insulin glargine therapy, hypoglycemic events occurred in <5% of patients in the insulin glargine treatment group.