Obesity and the Pill May Raise Risk of Rare Stroke
But, overall risk is still low, experts say
By Karen Pallarito
MONDAY, March 14, 2016 (HealthDay News) -- Obese women who take oral contraceptives may have a higher risk for a rare type of stroke, a new study suggests.
Dutch researchers found that obese women on birth control pills were nearly 30 times more likely to develop this rare type of stroke, known as cerebral venous thrombosis (CVT), compared with women of normal weight who didn't take birth control pills.
But the chances of having this type of stroke in one's lifetime remain very low, the researchers added. And the study wasn't designed to prove a cause-and-effect relationship.
CVT affects just over one person per 100,000 each year, said study author Dr. Jonathan Coutinho. He's a stroke neurologist at the Academic Medical Center at University of Amsterdam.
In the United States, that's about 4,200 new patients annually, he said.
Coutinho added that CVT tends to occur mostly in children and young to middle-aged adults.
Dr. Carolyn Westhoff, a professor of obstetrics and gynecology, and epidemiology at Columbia University in New York City, said the findings, while not that surprising, provide "an extra supporting piece of the puzzle."
Obese women have a higher risk of clots, as do oral contraceptive users, she explained.
"When you put those two risk factors together, you get even higher risk of clots," said Westhoff. She's also editor-in-chief of the journal Contraception.
Overall, CVT is less disabling than other types of stroke caused by a blocked blood vessel (ischemic), as more than five of six patients have good long-term recovery and outcomes, said Dr. Chirantan Banerjee, an assistant professor of neurology at the Medical University of South Carolina in Charleston.
"The challenge is that it is harder to diagnose sometimes, because patients can have nonspecific and variable symptoms that are not usually attributed to stroke, like headache, confusion, blurry vision or seizures," he said.
The study was published online March 14 in the journal JAMA Neurology.
The study included 186 adult CVT patients, including men and women. Their strokes occurred from the mid-2000s through Dec. 31, 2014.