Purpose: To compare the efficacy of adding pioglitazone or bedtime isophane (NPH) insulin to maximal doses of metformin and an insulin secretagogue in patients with poor glucose control.
Methods: We conducted a nonblinded, open-label, randomized controlled trial involving 62 patients with type 2 diabetes and glycosylated hemoglobin (HbA1C) levels >8.0%. Patients received either pioglitazone or bedtime NPH insulin in addition to their usual diabetes medication for 16 weeks. Outcome measurements of glycemic control, hypoglycemia, blood pressure, lipid levels, microalbuminuria, and quality of life were assessed at baseline and at 16 weeks.
Results: HbA1C levels were lowered to a similar degree in each treatment arm (pioglitazone: -1.9% +/- 1.5%; insulin: -2.3% +/- 1.5%; P = 0.32), but hypoglycemia was less common among patients who received pioglitazone than those who received insulin (37% [11/30] vs. 68% [19/28], P=0.02). Pioglitazone, but not insulin, resulted in an increase in high-density lipoprotein (HDL) cholesterol levels. Both treatments had similar effects on weight, other lipid values, blood pressure, and urine microalbumin levels.
Conclusion: Adding pioglitazone or bedtime insulin for 16 weeks improved glycemic control in type 2 diabetic patients with secondary oral agent failure. Pioglitazone was associated with less hypoglycemia and improved HDL cholesterol levels.