Short Sleep May Signal Stroke Risk

Chronically sleeping less than 6 hours per night significantly increased the rate of stroke symptoms among middle-age to older individuals of normal weight who had low risk of sleep-disordered breathing.

People who habitually sleep less than 6 hours appear to be at risk of developing symptoms that may predict future stroke, researchers reported here at the annual meeting of the Associated Professional Sleep Societies.

Study participants with normal body mass indices (BMIs) who slept less than 6 hours a night had a 4.5-fold increased risk of having a stroke-like symptom compared with similar individuals who got 8 to 9 hours of sleep a night, Megan Ruiter, PhD, a postdoctoral fellow at the University of Alabama at Birmingham, said in an oral presentation.

“We think our study should alert physicians that they should screen their patients for sleep problems,” said Ruiter.

The research involved 5,666 patients who participated in the long-term Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. Participants were asked if they had experienced any stroke-like symptoms: painless hemibody weakness, painless hemibody numbness, loss of vision in one or both eyes, loss of hemifield vision, inability to understand or the inability to express oneself in words or in writing.

“All of these signs are significant independent predictors of future stroke events,” Ruiter said.

In all, 244 individuals reported at least one of the stroke symptoms during about a 2- to 3-year follow-up. In the initial univariate analysis, short sleep was observed as one risk factor for stroke symptoms, but significance of that disappeared in the multivariate analysis, she said.

The researchers did observe that body mass index remained as a significant factor in risk of stroke symptoms, but short sleep and body mass index were only risk factors in normal-BMI individuals. Ruiter said her research team could not find a relationship between BMI for overweight or obese individuals and a link to habitual sleep duration.

“In employed, middle-age to older adults relatively free of major risk factors for stroke such as obesity and sleep-disordered breathing, short sleep duration may exact its own negative influence on stroke development,” said Megan Ruiter. “We speculate that short sleep duration is a precursor to other traditional stroke risk factors, and once these traditional stroke risk factors are present, then perhaps they become stronger risk factors than sleep duration alone.”

She suggested that because normal-weight individuals are not at high risk of having sleep problems, physicians may not ask about sleep duration in this population.

“The factor that is missing from this analysis is whether the individuals are sleeping less because they have difficulty falling asleep or because they choose to sleep less,” Daniel Cohen, MD, a private practice neurologist from Norfolk, Va., who moderated the session, told MedPage Today. “That could make a difference in these outcomes.”

The participants that Ruiter and colleagues scrutinized had no baseline history of stroke, transient ischemic attack, or stroke symptoms, and did not have a high risk for obstructive sleep apnea at the start of the study. Researchers recorded the first stroke symptoms, along with demographic information, stroke risk factors, depression symptoms, and various health behaviors.

The average age of the participants was 61 years, about 44 percent of the cohort were men, and about 33 percent were African Americans. Most of the individuals in the study were employed.

“Sleep and sleep-related behaviors are highly modifiable with cognitive-behavioral therapy approaches and/or pharmaceutical interventions,” Ruiter said. “These results may serve as a preliminary basis for using sleep treatments to prevent the development of stroke.”

By Ed Susman