Clinical effect of combination therapy of pioglitazone and an α-glucosidase inhibitor

This study evaluated the efficacy of adding pioglitazone 30 mg to the therapy of patients with type 2 diabetes mellitus whose glycaemic control was poor on an alpha-glucosidase inhibitor (alpha-GI) alone or in combination with a sulphonylurea (SU). The patients (n = 20) had a HbA(1c) level between 7.0 and 12.0% and the fasting plasma glucose was 7.8 mmol/l or higher. They were treated with 30 mg pioglitazone once daily for 16 weeks. The decrease in HbA(1c) at week 16 of treatment was 0.8% (7.8% at baseline dropping to 7.1% at week 16; p less than or equal to 0.01). An increase in leptin was observed 4 weeks after starting the post-study period (p less than or equal to 0.05). Tumour necrosis factor-alpha (TNF-alpha) and body fat percentage did not show significant alterations. Correlations between the decrease in HbA(1c) at week 16 and characteristic variables of patients were examined. A correlation with leptin (p = -0.5632, p less than or equal to 0.05) levels was found. Five patients experienced adverse drug reactions, such as oedema, hypoglycaemia and increased creatine phosphokinase (CK), all of which were mild in severity. The addition of pioglitazone in diabetics whose glycaemic control was poor on a alpha-GI alone or with a alpha-GI and SU combination resulted in a significant decrease in HbA(1c), and the treatment was well-tolerated. Our findings also suggest that leptin levels could be useful for assessing responders to pioglitazone.