The risk of stroke may be much higher in people with
insomnia1 compared to those who don't have trouble sleeping, according to new research in the American Heart Association journal Stroke. The risk also seems to be far greater when insomnia occurs as a young adult compared to those who are older, said researchers who reviewed the randomly-selected health records of more than 21,000 people with insomnia and 64,000 non-insomniacs in Taiwan.
They found: Insomnia raised the likelihood of subsequent hospitalization for stroke by 54 percent over four years. The incidence of stroke was eight times higher among those diagnosed with insomnia between 18-34 years old. Beyond age 35, the risk continually decreased.
Diabetes2 also appeared to increase the risk of stroke in insomniacs.
"We feel strongly that individuals with
chronic3 insomnia, particularly younger persons, see their physician to have stroke risk factors assessed and, when indicated, treated appropriately," said Ya-Wen Hsu, Ph.D., study author and an assistant professor at Chia Nan University of
Pharmacy4 and Science and the Department of Medical Research at Chi-Mei Medical Center in Taiwan. "Our findings also highlight the clinical importance of screening for insomnia at younger ages. Treating insomnia is also very important, whether by medication or
cognitive5 therapy."
The study is the first to try to quantify the risk in a large population group and the first to assess if the risk of stroke differs by insomnia subtypes, Hsu said.
Researchers divided participants -- none of whom had a previous
diagnosis6 of stroke or sleep
apnea(窒息) -- into different types of insomnia. In general, insomnia included difficulty
initiating7 or maintaining sleep; chronic or
persistent8 insomnia lasted one to six months; relapse insomnia was a return of insomnia after being diagnosed free of disease for more than six months at any
assessment9 point during the four-year study; and remission was a change from a diagnosis of insomnia to non-insomnia at the subsequent time point.
During the four-year follow-up, 583 insomniacs and 962 non-insomniacs were admitted for stroke. Persistent insomniacs had a higher three-year
cumulative10 incidence of stroke compared to the other participants in the remission group.
The
mechanism11 linking insomnia to stroke is not
fully12 understood, but evidence shows that insomnia may alter cardiovascular health via
systematic13 inflammation,
impaired14 glucose15 tolerance16, increased blood pressure or sympathetic hyperactivity. Some behavioral factors (e.g., physical activity, diet, alcohol use and smoking) and psychological factors like stress might affect the observed relationship.
The researchers said it's unclear if the findings also apply to people in other nations, but studies in other countries have also
pointed17 to a relationship between insomnia and stroke.
"Individuals should not simply accept insomnia as a
benign18, although difficult, condition that carries no major health risks," Hsu said. "They should seek medical
evaluation19 of other possible risk factors that might contribute to stroke."