Efficacy of pioglitazone on glycemic control and carotid intima-media thickness in type 2 diabetes patients with inadequate insulin therapy

Abstract

Aims/Introduction: The present study was designed to determine the effects of pioglitazone on glycemic control and atherosclerosis in patients with poorly controlled type 2 diabetes on insulin therapy.

Materials and methods: The study was a prospective, randomized controlled trial involving 48 patients with inadequately controlled type 2 diabetes treated with insulin. We assigned patients to oral pioglitazone titrated from 15-30 mg (n = 22) or no pioglitazone (n = 26), to be taken in addition to their glucose-lowering drugs and other medications. Daily insulin doses and numbers were recorded during the study period.

Results: The adjusted mean glycosylated hemoglobin (HbA1c) values decreased significantly by 1.13 ± 1.50% and 0.55 ± 0.76% in the pioglitazone and control groups, respectively. Significant decrease of HbA1c level was observed in the pioglitazone group compared with the control group (P < 0.05). The insulin dose lowered by 0.04 ± 0.10 units/kg/day in the pioglitazone group and increased by 0.03 ± 0.10 units/kg/day in the control group (P < 0.05). The number of insulin injections decreased by 0.1 ± 0.6 times/day in the pioglitazone group and increased by 0.2 ± 0.4 times/day in the control group (P < 0.05). The carotid intima-media thickness estimated by B-mode echography was carried out in both groups and decreased significantly at the end-point only in the pioglitazone group, relative to the baseline.

Conclusions: These findings show that pioglitazone is useful in improving glycemic control and preventing the progression of atherosclerosis in poorly-controlled type 2 diabetics on insulin therapy. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00064.x, 2010).

Keywords: Atherosclerosis; Insulin therapy; Pioglitazone.

Figure 1

Schematic diagram of the study protocol.

Figure 2

Comparison of changes in mean (±SD) HbA_1c of patients with pioglitazone (open circles) and non‐pioglitazone‐treated control group (closed circles). ^#P < 0.01 vs 0 week, *P < 0.05, between the pioglitazone and control groups.

Figure 3

Changes in (a) total daily dose of insulin and (b) number of daily insulin injections in the pioglitazone (open squares) and control (closed squares) groups. Data are mean ± SD. *P < 0.05, between the pioglitazone and control groups.