Belly Fat Is Culprit in Stroke Gender Gap

Middle-Aged Women 3 Times as Likely to Have Had a Stroke Than Men

he midlife gender gap in stroke rates continues to widen, with women aged 45 to 54 now three times more likely than men in that age group to report having had a stroke.

Several years ago, the same researchers reported that between 1999 and 2004, women aged 45 to 54 were more than twice as likely as their male counterparts to have had a stroke.

The findings created a stir in the medical community as middle-aged women before menopause have long been thought to be protected against heart disease.

So what's driving this disturbing trend? Then, like now, tummy fat appears to be to blame, says Amytis Towfighi, MD, an assistant professor of neurology at the University of Southern California in Los Angeles.

In the current analysis, stroke risk factors were worse in men than in women -- all, that is, except weight gain around the waist, she says.

"Our hypothesis is abdominal obesity increases the risk of other risk factors --diabetes, high blood pressure, high cholesterol. Together, they drive up the risk of stroke," Towfighi tells WebMD.

The study was presented at the American Stroke Association's (ASA) International Stroke Conference.

Middle-Aged Stroke Gap Real

The new analysis was conducted to determine if the gender gap observed in the earlier study was a real phenomenon or a fluke, Towfighi says. So she and colleagues analyzed data on 2,136 men and women aged 35 to 64 who participated in the National Health and Nutrition Examination Survey done from 2005 to 2006.

It was real, Towfighi says. Nearly 3% of women in that age group reported having suffered a stroke, compared with only 1% of men.

The disparity appeared to be driven mainly by differences in the 45 to 54 age group, where women had 3.12 times the odds of having a stroke compared to men, she says. 

Seeking to find out why, the researchers then looked at a host of factors that can affect risk, including smoking, high blood pressure, and high cholesterol.

"We found that in general, men were more likely to have conventional cardiovascular risk factors," Towfighi says.

But 62% of women suffered from abdominal obesity vs. 50% of men. In women, abdominal obesity is defined as a waist circumference of 35 inches or more; in men, it's 40 inches or more.

Towfighi notes that the absolute risk of a middle-aged woman having had a stroke is still quite low -- only about a three-in-100 risk.

Still, the findings reinforce advice to exercise at  least 30 minutes a day, eat five or more serving of fruits and vegetables daily, and cut down on high-fat foods, she says.

American Stroke Association spokeswoman Cheryl Bushnell, MD, MHS, associate professor of neurology at Wake Forest University in Winston-Salem, N.C., says, "This is really important work, as this is an age group where we would not expect to see [higher stroke rates in women than in men]."

The findings of the earlier analysis led her to embark on her own study in which she is measuring the thickness of arteries leading to the brain -- a known predictor of stroke later in life -- in middle-aged women and men. Results are expected in about two years.