Clinical Trial Aims to Prevent Recurrent Strokes

Story by: L. Wylie Shepard 

According to the Centers for Disease Control and Prevention, stroke is the third leading cause of death in the United States. Despite existing treatments, 25 percent of stroke survivors will experience a recurrent stroke or associated heart attack within four years of their initial episode.

A decade-long clinical trial known as IRIS, Insulin Resistance Intervention after Stroke, is testing a new approach to preventing recurrent strokes and heart attacks. IRIS began after research validated evidence linking insulin resistance, a common medical condition, to stroke.

“Now that this connection has been made we can only continue to move forward,” said Ann Toctt, a study coordinator at the University of Utah’s Stroke Center, “Every new piece of information opens doors to create connections and save lives.”

Stroke is a disease caused by blockages in blood vessels that supply the brain with oxygen. Researchers believe that insulin resistance is responsible for these blockages. Nearly half of all stroke patients are found to have insulin resistance following their initial stroke.

IRIS intends to prove that Pioglitazone, or PIO, a small white pill commonly prescribed to treat type 2 diabetes, is effective in the prevention of recurrent strokes and heart attacks. Researchers hypothesize that Pioglitazone could reduce this risk by 20 percent in non-diabetic patients. PIO functions by maintaining healthy insulin and blood sugar levels that support smooth flow through blood vessels, therefore helping to prevent blockages that cause strokes.

A patient who recently completed the second phase of the trial explained, “there were very few possible side effects,”—minimal weight gain and leg swelling are listed on the trial’s website—“so I had no reason not to take a chance and now its been almost six years since my last stroke.”

Recent clinical studies found that Pioglitazone reduced strokes and heart attacks in diabetics who received PIO instead of a placebo. Scientists anticipate that non-diabetic patients who have insulin resistance will experience similar effects.

According to the IRIS Trial website, between 2005 and 2015, IRIS will enroll 3000 patients from health organizations worldwide. Participants are currently being accepted into the third and final phase of the trial.

Eligible participants are:

  • 40 years or older
  • Non-diabetic
  • Recovering from a stroke within the last 6 months
  • Insulin resistant (determined by blood test)
  • Able to take PIO daily for up to 4 years


Once enrolled, each participant is randomly assigned to Pioglitazone or a placebo, neither the patient or their healthcare provider is aware of which medication was administered until after the conclusion of the study.

Patients will stay on their medication for approximately four years. Once a year, participants will need to schedule a follow-up appointment and a blood test to continually monitor levels of insulin resistance.

“The third phase is the last phase but it’s no different than the first two. It’s an opportunity for anyone who has recently suffered a stroke to never experience one again,” said Jennifer Majersik, M.D., the principal investigator at Utah’s Stroke Center.

The University of Utah’s Clinical Neurosciences Center is the only IRIS provider in the greater Salt Lake area and is currently accepting eligible participants. For more information, contact the CNC at (801) 585-7575 or visit [554]