NEW YORK (Reuters Health) - Poor quality sleep may lead to poorer physical function among otherwise healthy older men, study findings suggest.
"Men with poorer sleep quality, such as frequent awakening episodes, had weaker hand grip, slower walking speed, poorer walking balance, and were less likely to rise from a chair without using their hands," Dr. Thuy-Tien L. Dam told Reuters Health.
However, "we don't know what came first or what caused what," noted Dam, who is currently associated with Columbia University College of Physicians and Surgeons, in New York.
Dam, who was with the University of California, San Diego at the time of the study, and colleagues studied associations between sleep quality and measures of physical function among 2,862 healthy men living independently in the community.
The men ranged in age from 67 to 96 years, did not use mechanical sleep devices or report sleep problems, and could move around without assistance, the researchers report in the Journal of the American Geriatrics Society.
After allowing for age differences, the investigators identified poorer physical function among men who slept for less than 6 hours and more than 8 hours a night, awakened for 90 minutes or longer after initially falling asleep, showed signs of the nighttime breathing disorder sleep apnea, and spent a lower percentage of time in bed actually asleep, also referred to as "sleep efficiency."
On average, men meeting these criteria had a 2.9 percent weaker hand grip and a 4.3 percent slower walking speed than men with better quality sleep. Those with poorer sleep quality were also less able to rise from a sitting position without using their hands and walk on a line without balance difficulties.
When they allowed for other factors potentially associated with poor sleep quality, including increased body weight, use of antidepressants, high blood pressure, a history of arthritis, diabetes, or cardiovascular, chronic lung, or Parkinson's disease, physical activity, and smoking, the investigators found poorer physical function most associated with both awakening for 90 minutes or more after falling asleep and poorer sleep efficiency.
Taken together, the findings highlight the need for future studies that assess interactions between poor sleep quality and physical function.
SOURCE: Journal of the American Geriatrics Society, September 2008
