Women in midlife -- those aged 45 to 54 -- are more than twice as likely as men their age to have strokes, according to a new study released Wednesday.
While the exact reasons for the imbalance aren't clear, the research team at the University of California at Los Angeles speculated from the study of more than 17,000 people over age 18 that increasing waistlines may be at least partly to blame for the increased stroke risk in middle-aged women.
The study, published in the journal Neurology, showed that such differences did not exist in people aged 35 to 44, nor in those aged 55 to 64 -- a fact that could further point to midlife obesity in women as a potential cause.
"Women have more complications from obesity than men, in general," said lead study author Dr. Amytis Towfighi. "So this widening in stroke rates might reflect the impact of this growing obesity epidemic in the U.S."
Another thing the researchers discovered is that women aged 35 to 64 tended to experience a high rate of increase in their blood pressure and cholesterol. Similarly steep increases were not observed for men in the study, suggesting that these factors may be special warning flags for women.
"Heart disease is correlated with increased abdominal girth," said Dr. Lynne Perry Bottinger, a cardiologist at New York Presbyterian Hospital, on ABC's "Good Morning America" Thursday. "Look at the ratio of your waist to hips… Women with bigger waist sizes have a greater risk of heart disease. It's been known for years that it increases cardiovascular disease overall."
A stroke -- sometimes known as a "brain attack" -- happens when a blood vessel leading to the brain is either blocked by a clot or ruptures. When this happens, blood flow is cut off to the brain, leading to brain damage.
Depending on where this damage occurs, different abilities such as speech, movement and memory may be affected.
Though the fact remains that strokes most often occur in women age 65 and over, increasing girth may put additional stress on a woman's system, leading to earlier problems.
"Heart disease traditionally has thought to be prevalent 65 or older," Bottinger said. "About 10 years after menopause. In particular, these women have a risk factor of being overweight."
And it's not just any weight. The extra pounds in women at risk take the form of deep abdominal fat -- otherwise known as visceral fat -- which increases the risk of diabetes and cholesterol.
This fat resides in the waist, leading to the "apple-shaped" body type known to be more prone to stroke and heart problems.
"Large waist size has been shown to be a predictor of stroke under 65 in the past," Towfighi said, adding that women may also face other risk factors that increase their chances of stroke.
"Women have unique risk factors such as pregnancy, birth control and hormone replacement," she said.
But even in the face of this increased risk, many women younger than 65 may not even be aware that they are in danger.
"Most women think of stroke as an old woman's disease and breast cancer as a young woman's disease," Bottinger said. "Two times as many women die of stroke than breast cancer. Still, 10 times as many women will die of cardiovascular disease than breast cancer. Most of that is due to poor detection."