Patients who have experienced ischaemic stroke or a transient ischaemic attack (TIA) are at risk of future cardiovascular events. Insulin resistance can contribute to this risk, suggesting that improving insulin sensitivity, with a drug such as pioglitazone, could improve outcomes.
For the Insulin Resistance Intervention after Stroke trial (IRIS), researchers assigned 3,876 patients within six months of an ischaemic stroke or TIA to either pioglitazone or placebo. All patients had insulin resistance but not diabetes.
After 4.8 years, patients in the pioglitazone group were 24% less likely to have a cardiovascular event and 52% less likely to develop diabetes.
However, the researchers, writing in the New England Journal of Medicine (online, 17 February 2016)
, say that the risk of side effects in the pioglitazone group, such as weight gain, oedema and bone fractures, should be weighed against the benefits of treatment.