Pioglitazone may reduce the risk of MI and stroke in people who are insulin resistant and have had a recent TIA or stroke, researchers report.

Published in the NEJM the study randomised almost 4,000 patients who had a recent TIA or stroke to either pioglitzone (45mg daily) or placebo.

Patients included in the study did not have diabetes but had a  score of more than 3.0 on the homeostasis model assessment of insulin resistance (HOMA-IR) index.

Over an almost five year follow up period the research team found a 24% lower risk of stroke or MI in the treatment group compared to the placebo group

Overall, 175 of the 1939 patients (9%) taking pioglitazone had an event over nearly five years, compared with 228 of the 1937 patients (11.8%) taking placebo (HR 0.76; 95% CI 0.62 to 0.93 P=0.007).

Furthermore, taking pioglitazone was also associated with a halving of the risk of developing diabetes (3.8% in the pioglitazone group and 7.7% in the placebo group (0.48 (0.33 to 0.69); P<0.001).

However, patients taking pioglitazone had a higher rate of weight gain, oedema, and fractures compared to the placebo group.

The researchers led by Walter Kernan, a professor of medicine at Yale School of Medicine in New Haven, Connecticut, USA calculated that treating 100 patients similar to those in the trial with pioglitazone for about five years would prevent three patients from having a stroke or MI.

But the treatment would be expected to result in bone fractures requiring surgery or hospitalisation in two patients, they said.

“Pioglitazone . . . can prevent cardiovascular events among patients who have insulin resistance along with cerebrovascular disease,” they concluded.