Dec. 19, 2013 at 4:07 PM ET
It may not be the best time to point this out, what with the looming stress of the holidays, but new research finds that all that anxiety you feel now and the rest of the year — well, it just might give you a stroke.
Sorry, but it’s true, at least according to the first-ever study that looks at how anxiety influences the risk of stroke separate from depression and other factors.
In fact, people with the highest levels of anxiety, those in the top third of anxiety sufferers, had a 33 percent greater chance of having a future stroke than those at the lowest levels, according to psychiatric researchers at the University of Pittsburgh School of Medicine.
“Everyone has some anxiety now and then, but when it’s elevated and chronic, it may have an effect on your vasculature years down the road,” said Maya Lambiase, the study author and a behavioral medicine researcher. The study is published Thursday in the journal Stroke.
The results are significant in a country where stroke is the fourth-leading cause of death and a leading cause of disability. Nearly 800,000 people in the U.S. have strokes every year and it kills about 130,000 of them, according to the Centers for Disease Control and Prevention. At the same time, nearly 20 percent of Americans adults and a quarter of children and teens suffer from anxiety disorders, according to the National Institute of Mental Health.
Lambiase and her colleagues examined 22 years of records from more than 6,000 participants aged 25 to 74 in a federal database, the first National Health and Nutrition Examination Survey, or NHANES 1.
That’s a nationally representative sample of folks who agreed to in-person interviews, medical exams, questionnaires and blood draws — and also agreed to be followed for decades.
They answered questions included in a recognized tool that measures whether a person is anxious or tense, the General Well-Being Schedule, or GWB-A.
Queries focused on the past month and asked things like: “Have you been anxious, worried or upset?” “Have you been under or felt you’ve been under any strain, stress or pressure?” “Have you been bothered by nervousness or your nerves?”
Most of the questions were rated on a scale where 0 indicated highest levels of anxiety and 5 indicated the lowest. So researchers flipped the responses so that higher numbers corresponded with higher anxiety levels.
During the study period, nearly 7 percent of those patients, some 419 people, had strokes.
When the researchers tallied the anxiety symptoms and correlated them with the risk of stroke, they discovered something surprising. For every single standard deviation increase in anxiety, there was a 17 percent increase in stroke risk. At the same time, people with higher anxiety levels were more likely to smoke and not get enough exercise, which also could elevate their risk.
The analysis provides valuable insight into factors that contribute to stroke, said Dr. Shazam Hussain, head of the Cleveland Clinic’s Stroke Center, who was not involved in the research.
Scientists have known that anxiety contributes to heart disease, but the link with stroke hasn’t been as clear, he said. “We’re always looking for things besides the standard risk factors.”
The problem, experts say, is that chronic anxiety can lead to a set of biochemical reactions that flood the body with a stress hormone, cortisol, and activate what’s known as the hypothalamic-pituitary-adrenal or HPA axis. That’s the system of feedback involving the hypothalamus, pituitary gland and the adrenal glands, which work together to regulate stress and other bodily functions.
When that activation is intense or prolonged, it can impair the vascular system, including the blood vessels in the brain, increasing likelihood of a stroke.
It’s still not clear whether or how reducing anxiety would curb stroke risks, though it’s an interesting topic for further research, Lambiase said.
But Hussain said the findings should influence people to take a look at anxiety and stress in their lives and find ways now to reduce them.
“You don’t have to wait for a health crisis to do these things,” he said.
JoNel Aleccia is a senior health reporter at NBC News. Reach her on Twitter at @JoNel_Aleccia or send her an email.