People with insomnia may be more likely to have a stroke than people who don't have trouble sleeping, according to a new study.
Study participants who had insomnia had a 54 per cent higher risk of stroke over four years than the people who were not diagnosed with the sleep disorder.
They also found that, among people with insomnia, stroke was eight times more common in people ages 18 to 34 than in those older than 34.
"Our results add support to the prior findings on the link between insomnia and a wide range of health risks," said study author Ya-Wen Hsu, an assistant professor at Chia Nan University of Pharmacy and Science in Taiwan.
"Though insomnia is the most common sleep complaint, it should be perceived more as a symptom of another disease," Hsu told Live Science. People with insomnia should be treated early to prevent other conditions, he said.
Although the number of deaths from stroke in the United States declined by 22.8 per cent between 2000 and 2010, about 795,000 people have a stroke each year, according to the American Heart Association. In 2010, stroke was responsible for one out of every 19 deaths in the US.
In the study, the researchers followed a group of 21,438 people with insomnia and 64,314 healthy people for four years. During the study, 583 (2.7 per cent) of those with insomnia were admitted to a hospital for stroke, whereas 962 (1.5 per cent) of those without insomnia were admitted for stroke.
The link was strongest in people who'd had trouble sleeping for up to six months, according to the study.
The researchers said they don't know how or why insomnia may be linked with an increased risk of stroke.
However, they speculated that the sleeping disorder may contribute to inflammation, increase blood pressure and deregulate metabolism and, therefore, affect people's cardiovascular health, Hsu said.
"We feel strongly that individuals with chronic insomnia, particularly younger persons, see their physician to have stroke risk factors assessed and, when indicated, treated appropriately," Hsu said in a statement.