The risk of stroke may be much higher in people who have insomnia, especially young adults, according to a new study.

Researchers in Taiwan reviewed randomly selected health records of 21,000 people with insomnia and 64,000 without and found after four years of follow-up that:

  • Stroke incidence was eight times higher for 18-34 year-olds with insomnia. After age 35, the risk decreased.
  • Insomnia raised the likelihood of stroke hospitalization by 54 percent.
  • 583 insomniacs and 962 non-insomniacs were hospitalized for stroke.
  •  Diabetes also appeared to increase stroke risk in insomniacs.
  • The three-year cumulative incidence of stroke was higher for those with persistent insomnia versus those in remission.

“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,” said Ya-Wen Hsu, Ph.D., study author. “Our findings also highlight the clinical importance of screening for insomnia at younger ages. Treating insomnia is also very important, whether by medication or cognitive 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 been diagnosed previously with stroke or sleep apnea — by types of insomnia:

  • Difficulty initiating or maintaining sleep
  • Chronic or persistent insomnia for one to six months
  • Relapse insomnia, insomnia returning after more than six months
  • Remission, a non-insomnia diagnosis in someone previously diagnosed.

The link between insomnia and stroke is not fully understood, but evidence shows that insomnia may change cardiovascular health via systematic inflammation, impaired glucose tolerance, increased blood pressure or sympathetic hyperactivity. Physical activity, diet, alcohol use, smoking and stress may also be factors, researchers said.

“Individuals should not simply accept insomnia as a benign, although difficult, condition that carries no major health risks,” said Hsu, also an assistant professor at Chia Nan University of Pharmacy and Science and the Department of Medical Research at Chi-Mei Medical Center in Taiwan. “They should seek medical evaluation of other possible risk factors that might contribute to stroke.”

The article appeared in Stroke, an American Heart Association journal.

Photo courtesy of Alexson Calahan.

For more information: