Objective: To assess the efficacy of pioglitazone treatment in comparison with that of acarbose treatment in patients with type 2 diabetes mellitus.
Participants and methods: In this randomized, parallel-group, open-label study patients were assigned to treatment with either pioglitazone (n = 129) or acarbose (n = 136). During a 1-week run-in patients commenced an individualized dietary regimen which was maintained throughout the study. Patients received the assigned study medication for 26 weeks. Serum glycosylated hemoglobin (HbA1c) levels, insulin resistance and lipid profiles were determined at baseline and at endpoint.
Results: Mean HbA1c was reduced from 8.98+/-1.20% to 7.82+/-1.95% with pioglitazone treatment and from 9.03+/-1.32% to 8.55+/-1.96% with acarbose treatment during the 26-week study. The change from baseline to endpoint was significantly greater for pioglitazone compared with acarbose when analyzed for all patients (p < 0.001) and for those who had (p = 0.009) or had not (p < 0.001) received previous medication for diabetes mellitus. Compared with acarbose, pioglitazone produced a significantly greater decrease in fasting glucose, insulin and insulin resistance (p < 0.001 for each). Triglycerides were decreased by 71.1+/-184.1 mg/dl with pioglitazone compared with 38.1+/-171.3 mg/dl with acarbose (p = 0.001 for difference between groups). High density lipoprotein (HDL)-cholesterol level was increased by 7.8+/-10.2 mg/dl with pioglitazone compared with a decrease of 0.8+/-24.1 mg/dl with acarbose (p < 0.001). While serum low density lipoprotein (LDL)-cholesterol levels remained unchanged with both treatment regimens, the decrease from baseline in very low density lipoprotein (VLDL)-cholesterol was significantly greater with pioglitazone than with acarbose (p < 0.04). Pioglitazone decreased systolic blood pressure by 5.6+/-17.7mm Hg compared with a 0.4+/-18.4mm Hg increase during acarbose treatment (p < 0.001). Pioglitazone caused a significantly greater decrease compared with acarbose in serum levels of gamma-glutamyl aminotransferase (p < 0.001) and alanine aminotransferase (p = 0.004).
Conclusions: Six months of pioglitazone treatment decreased insulin resistance and improved glycemic control to a significantly greater extent than acarbose treatment. Pioglitazone was also associated with a significantly improved lipid profile, suggesting a reduction in risk of coronary heart disease.