People who have trouble falling asleep or difficulties staying asleep and waking up too early may be more likely to have a stroke, according to a new study.
The research, published on Wednesday in the journal Neurology, also found that this risk was particularly much higher in people under 50 years old.
However, scientists, including those from the Virginia Commonwealth University in Richmond, US, said the study does not prove a causal link between insomnia and stroke, and only shows an association.
“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,” study author Wendemi Sawadogo said.
Scientists assessed the health information of 31,126 people, with an average age of 61, who had no history of stroke at the beginning of the study.
The participants were asked four questions about how often they had trouble falling asleep, trouble with waking up during the night, trouble with waking up too early and not being able to return to sleep, and how often they felt rested in the morning.
Their response options included “most of the time”, “sometimes” or “rarely or never” and scores to these responses ranged from zero to eight, with a higher number meaning more severe symptoms.
Participants were then followed for an average of nine years, during which 2,101 cases of stroke were reported.
Considering other factors that could affect stroke risk, including alcohol use, smoking and level of physical activity, the analysis found people with one to four symptoms had a 16 per cent increased risk of stroke compared to those with no symptoms.
Of the 19,149 people with one to four symptoms, scientists found 1,300 had a stroke.
And of the 6,282 people who reported no symptoms, 365 had a stroke, according to the study.
People with five to eight symptoms of insomnia had an over 50 per cent increased risk while among those with five to eight symptoms (5,695 people), 436 had a stroke.
The association was stronger in participants under age 50, with those who experienced five to eight symptoms having nearly four times the risk compared to people with no symptoms.
“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,” Dr Sawadogo said.
“This striking difference suggests that managing insomnia symptoms at a younger age may be an effective strategy for stroke prevention,” he said.
The risk also further increased for people with diabetes, hypertension, heart disease and depression, scientists said.
Citing one main limitation of the study, scientists said the participants reported their own symptoms of insomnia, so the information may not have been accurate.
However, they said the new evidence is sufficient to conduct further research to explore the reduction of stroke risk through sleep management.
