PIOGLITAZONE can reduce conversion to type 2 diabetes but at a cost of weight gain and oedema, a trial has shown.

US researchers studied the effects of 30 mg pioglitazone per day compared with placebo in 600 patients with impaired glucose tolerance and baseline mean BMI of 34.5.

Pioglitazone reduced the risk of converting from impaired glucose tolerance to type 2 diabetes by 72% over 2.4 years (48% pioglitazone vs 28% placebo), the manufacturer-supported study found. Treatment of 18 participants for a year prevented one case of diabetes.

However, weight gain in the pioglitazone group was 3.6 kg compared with only 0.77 kg in the placebo group, and oedema was double with pioglitazone (12.9% vs 6.4%). 

HbA1c decreased by 0.04% in people who received pioglitazone, and increased by 0.20% in the placebo group, the US researchers found.

The pioglitazone group also had improved fasting and two-hour glucose, diastolic blood pressure and carotid intima-media thickening.

NEJM 2011; 364:1104-15