Flu increases risk of stroke by 40%, research warns
CATCHING the flu can increase your risk of having a stroke by up to 40 per cent, new research has revealed.
In one study researchers found that, after contracting a flu-like illness, the odds of suffering a stroke increase by nearly 40% over the next 15 days.
The findings showed that the risk of a stroke remained higher than normal for up to a whole year following the illness.
Suffering from a flu-like illness has also been linked to a heightened risk of stroke and neck artery tears. The findings come from two new studies due to be presented at the American Stroke Association’s International Stroke Conference in Hawaii next week.
Researchers estimated the chance of a patient being hospitalised by an ischemic stroke, where circulation to the brain is obstructed by a blood clot, after they had been in hospital for a flu-like illness.
They identified more than 30,000 patients who suffered an ischemic stroke in 2014 in the state of New York – 49% male, 20% black, 84% urban and with an average age of 71.9 years.
Researchers discovered the link between flu and stroke when comparing each patient’s health records, from the previous two years, with their health records produced in the time preceding stroke, known as the “case window”.
The analyses were divided by urban and rural status based on post code, sex and race.
Study lead author Dr Amelia Boehme, assistant professor of epidemiology in neurology at Columbia University in New York City, said the findings were unexpected.
She said: “We were expecting to see differences in the flu-stroke association between rural and urban areas. Instead we found the association between flu-like illness and stroke was similar between people living in rural and urban areas, as well as for men and women, and among racial groups.”
There are many theories behind the flu-stroke link, but no definite explanation has been found for the association. Researchers suspect it could be due to inflammation caused by the infection.
In a second study from the same institution, researchers found an increased risk of tearing neck arteries within one month of battling a flu-like illness.