Pioglitazone and reductions in post-challenge glucose levels in patients with type 2 diabetes.

Aim: Pioglitazone (PIO) has been shown to decrease insulin resistance in patients with type 2 diabetes, resulting in lowered blood glucose concentrations, lowered plasma insulin levels and lowered haemoglobin A1C (A1C) values. Postprandial glucose control has been recently recognized as an important target for reducing overall glycemic burden in patients with type 2 diabetes. Some authors assert that reductions in postprandial glucose levels may lead to a decrease in cardiovascular risk, one of the major complications associated with diabetes.

Methods: Data were analysed from a 26-week PIO monotherapy study of 88 patients who underwent a 3-h oral glucose tolerance test (75 g dose) at baseline and last measurement. Change from baseline in area under the curve (AUC) values and hourly glucose concentrations were calculated and analysed at both time points for four medication groups: placebo group and PIO 15, 30 and 45 mg groups. Changes from baseline in fasting plasma glucose (FPG) and A1C also were reported.

Results: Glucose AUC was significantly (p < 0.05) different from baseline at 15, 30 and 45 mg doses of PIO. In addition, when compared to placebo, PIO (15, 30 and 45 mg) significantly decreased post-challenge blood glucose AUC (p < 0.05). The mean hourly blood glucose levels at last measurement for PIO 15, 30 and 45 mg all were significantly lower (p < 0.05) than placebo at all four time points. In addition, PIO significantly (p < 0.05) reduced FPG and A1C from baseline to last measurement in a dose-related fashion.

Conclusions: PIO significantly reduced post-challenge glucose levels following an oral glucose challenge, leading to improvements in overall glycemic control. Postprandial glucose lowering is one of several metabolic effects of PIO in addition to decreasing insulin resistance and improving some lipids components. Whether these combined metabolic effects can lead to cardiovascular risk reductions may be confirmed by the pending results of cardiovascular outcomes studies with PIO.