Washington: Researchers have found link poor sleep quality with the development of cognitive decline over three to four years.
Results show that higher levels of fragmented sleep and lower sleep efficiency were associated with a 40 to 50 percent increase in the odds of clinically significant decline in executive function, which was similar in magnitude to the effect of a five-year increase in age. In contrast, sleep duration was not related to subsequent cognitive decline.
Lead author Terri Blackwell, MA, senior statistician at the California Pacific Medical Center Research Institute (CPMCRI) in San Francisco, California, said that it was the quality of sleep that predicted future cognitive decline in this study, not the quantity.
Blackwell said with the rate of cognitive impairment increasing and the high prevalence of sleep problems in the elderly, it is important to determine prospective associations with sleep and cognitive decline.
The study involved 2,822 community-dwelling older men at six clinical centers in the U.S. Participants had a mean age of 76 years.
An average of five nights of objective sleep data were collected from each participant using a wrist actigraph. Cognitive function assessment included evaluation of attention and executive function using the Trails B test.
The study has been published online in the scientific journal Sleep.