People who have trouble falling asleep, struggle to stay asleep, or wake up too early are at greater risk of having a stroke compared with those who have a good night’s rest, research suggests.
Scientists in the US have found people with one or more self-reported symptoms of insomnia have a 16% increased risk of developing the serious medical condition, compared with those without symptoms.
They said the link was stronger in participants under 50 years of age, where those with five to eight symptoms had nearly four times the risk of having a stroke.
The team said its findings, published in the journal Neurology, suggest that improving sleep quality through therapies could help reduce this risk.
Study author Dr Wendemi Sawadogo, of Virginia Commonwealth University in Richmond and member of the American Academy of Neurology, said: “There are many therapies that can help people improve the quality of their sleep, so determining which sleep problems lead to an increased risk of stroke may allow for earlier treatments or behavioural therapies for people who are having trouble sleeping and possibly reducing their risk of stroke later in life.”
The research involved more than 31,000 participants, with an average age of 61, who had no history of stroke at the beginning of the study and were followed for an average of nine years.
Participants were asked how often they found falling asleep difficult, whether they woke up during the night regularly, whether they had trouble with waking up too early and not being able to go back to sleep, and how often they felt rested in the morning.
Scores ranged from zero to eight, with a higher number meaning more severe symptoms.
The researchers said they adjusted for factors that could affect the risk of stroke, such as alcohol use, smoking, and level of physical activity.
Over the course of nearly a decade, there were 2,101 cases of stroke: 1,300 with one to four symptoms, 436 with five to eight symptoms and 365 with no symptoms.
People with five to eight symptoms of insomnia had a 51% increased risk of stroke, the researchers said.
And participants under 50 who experienced five to eight symptoms had nearly four times the risk of stroke compared with people with no symptoms, they added.
Meanwhile, people aged 50 or older with the same number of symptoms were found to have a 38% increased risk of stroke compared with those without symptoms.
This association was even greater for people with diabetes, high blood pressure, heart disease and depression, the team said.
Dr Sawadogo said: “This difference in risk between these two age groups may be explained by the higher occurrence of stroke at an older age.
“The list of stroke risk factors such as high blood pressure and diabetes can grow as people age, making insomnia symptoms one of many possible factors.
“This striking difference suggests that managing insomnia symptoms at a younger age may be an effective strategy for stroke prevention.
“Future research should explore the reduction of stroke risk through management of sleeping problems.”