A high body mass index (BMI) in middle-aged men is associated with an increased likelihood of having a stroke over the next two or three decades - even after taking into account other risk factors such as high blood pressure and diabetes -Swedish investigators have found.

Obesity is recognized as a risk factor for heart disease but its role in stroke is less clear, Dr. Katarina Jood and colleagues note in the American Heart Association’s medical journal Stroke.

To look into that question, the team followed men enrolled in the Multifactor Primary Prevention Study.

The 7400 apparently healthy men were between the ages of 47 and 55 when the study began in 1970. During the next 28 years, there were 873 strokes.

The average BMI at screening was 25.5, ranging from 14.9 to 47.9, report Dr. Jood and her colleagues at Sahlgrenska University Hospital in Goteborg. A BMI below 20 is considered underweight, and above 25 is classified as overweight.

After accounting for smoking, exercise, psychological stress, occupational class and parental history of stroke, the investigators found that men with a BMI greater 30 had almost double the risk of stroke as men with a BMI in the low-normal 20-23 range.

After further adjustment for high blood pressure, diabetes and cholesterol level, the risk for stroke still remained significantly increased for subjects with a BMI above 30.

The researchers conclude that mid-life obesity among men is a risk factor for stroke later in life. These findings underline the “importance of reducing obesity for stroke prevention.”

SOURCE: Stroke, rapid access October 28, 2004.