Pioglitazone, used to treat type 2 diabetes, may reduce the risk of recurrent stroke and heart attacks by 24% in people who are insulin resistant but do not have diabetes, according to findings from the Insulin Resistance Intervention after Stroke (IRIS) trial. The study, supported by the National Institute of Neurological Disorders and Stroke, is the first to provide evidence that suggests a drug targeting cell metabolism may be protective against recurrent vascular events even before diabetes develops.
In the IRIS study, ≥ 3,000 patients who had had an ischemic stroke or transient ischemic attack were randomly assigned to receive pioglitazone or placebo for up to 5 years, in addition to standard care. Nine percent of those on the drug had another stroke or heart attack, compared with 12% of those on placebo.
Pioglitazone also reduced the risk of diabetes by 52%. However, the study offered further evidence of a known adverse effect, increased risk of bone fractures.
Although previous research had suggested that insulin resistance increases the risk of stroke, IRIS was the first to test the pioglitazone treatment. However, pioglitazone is not FDA-approved for the uses studied in the trial.