Objective: To investigate the effects of different dosages of pioglitazone on glycemic control,
insulin sensitivity, and
insulin secretion in patients with type 2 diabetes. Methods: Thirty patients with type 2 diabetes were randomly and double-blindly assigned to receive 15 or 30 mg of
pioglitazone hydrochloride per day for 12 weeks. Before and after treatment, fasting plasma glucose and insulin, HbA1c, HOMA insulin resistance(HOMA-IR) index were determined. Results: (1) Patients treated with 15 or 30 mg/day of pioglitazone hydrochloride had no difference in the decrease of fasting plasma glucose and HbA1c. (2) There was no difference in fasting plasma insulin and HOMA-IR index before and after the treatment of 15 mg/day of pioglitazone hydrochloride. Patients treated with 30 mg/day of pioglitazone hydrochloride had significant decreases from baseline in fasting plasma insulin and HOMA-IR index. Conclusion: Two dosages of pioglitazone hydrochloride decrease effectively and safely the fasting plasma glocuse and HbA1c in patients with type 2 diabetes. There is a dose-dependent effect of pioglitazone hydrochloride on
insulin sensitivity.