By Robert Preidt
It included 487,200 people in China, average age 51, with no history of stroke or heart disease. They were asked if they had any of these problems three or more times a week: trouble falling asleep or staying asleep; waking up too early; or trouble staying focused during the day due to poor sleep.
Eleven percent said they had trouble falling asleep or staying asleep; 10% reported waking up too early; and 2% struggled to focus during the day.
During an average 10-year follow-up, there were just over 130,000 cases of stroke, heart attack and similar diseases.
Compared to those with no insomnia symptoms, people with all three were 18% more likely to develop these diseases.
"The link between insomnia symptoms and these diseases was even stronger in younger adults and people who did not have high blood pressure at the start of the study, so future research should look especially at early detection and interventions aimed at these groups," said study author Dr. Liming Li, from Peking University in Beijing.
Of people who had trouble falling asleep or staying asleep, 32% had a stroke or heart problem, compared to 26% of others.
The risk of these diseases was 7% higher among people who woke too early and could not get back to sleep, and 13% higher for those who had trouble staying focused.
The findings were published online Nov. 6 in the journal Neurology.
The study does not prove insomnia symptoms cause heart attack and stroke, only that there is an association between them. Li said the findings merit further investigation.
"These results suggest that if we can target people who are having trouble sleeping with behavioral therapies, it's possible that we could reduce the number of cases of stroke, heart attack and other diseases later down the line," he said in a journal news release.