Daytime sleepiness associated with cognitive issues, slow gait speed
Older adults with poor sleep were more likely to develop motoric cognitive risk syndrome, a predementia syndrome characterized by slow gait speed and cognitive symptoms, with depression appearing to explain some of the association.
Overall poor sleep quality was associated with incident motoric cognitive risk syndrome (MCR), a study found.
To examine the association of sleep disturbances with incident and prevalent MCR in older adults, researchers used an existing prospective cohort study at a single location of community-residing adults ages 65 years and older without dementia. MCR was defined as cognitive symptoms reported on standardized questionnaires and slow gait speed as recorded on an electronic treadmill. Participants were divided into “good” sleepers and “poor” sleepers based on an established sleep score. Depression and global cognitive scores were used to examine the association between baseline sleep disturbances and MCR. Results were published Nov. 6 by Neurology.
A total of 445 participants were included in the study (56.9% women; mean age, 75.9 years). Among the 403 who were free of MCR at baseline, 36 developed incident MCR over a mean follow-up of 2.9 years. Poor sleepers had a higher risk of incident MCR (hazard ratio [HR], 2.7; 95% CI, 1.2 to 5.2) than good sleepers, but this association was not significant after adjustment for depressive symptoms (adjusted HR, 1.6; 95% CI, 0.7 to 3.4). Among the seven components of the sleep score, only sleep-related daytime dysfunction (excessive sleepiness and lower enthusiasm) showed a significant association with incident MCR in fully adjusted models (aHR, 3.3; 95% CI, 1.5 to 7.4). Prevalent MCR was not associated with poor sleep quality (odds ratio, 1.1; 95% CI, 0.5 to 2.3).
The authors wrote that sleep dysfunction is associated with increased risk for incident MCR, noting that patients characterized as poor sleepers had a twofold increased rate compared to good sleepers. Among the seven measurements of the sleep score, worse subjective sleep quality, short sleep duration, and frequent daytime dysfunction predicted incident MCR.
“Excessive day sleepiness is associated with greater risk of incident MCR and needs to be further examined as a potentially modifiable risk factor,” the authors wrote. “Our findings also emphasize the need for an early screening of sleep disturbances as a potential preventive intervention for cognitive decline, whether depressive symptoms are present.”