Poor sleep quality may be associated with incidental, but not prevalent, motoric cognitive risk syndrome (MCR), a predementia syndrome characterized by slow gait speed and cognitive complaints, according to a study published online Nov. 6 in Neurology.

Victoire Leroy, M.D., Ph.D., from the Albert Einstein College of Medicine in Bronx, New York, and colleagues examined the association of sleep disturbances with incident and prevalent MCR in older adults. MCR was defined as cognitive complaints reported on standardized questionnaires and slow gait speed as recorded on an electronic treadmill.

The 445 participants were categorized as good or poor sleepers based on an estimated Pittsburgh Sleep Quality Index (PSQI) cut score.

The researchers found that 36 of the 403 participants without MCR at baseline developed incident MCR during a mean follow-up of 2.9 years. The risk for incident MCR was higher for poor sleepers than good sleepers (adjusted hazard ratio, 1.6; 95 percent confidence interval, 0.7 to 3.4).

Of the seven components of the PSQI, only sleep-related daytime dysfunction (excessive sleepiness and lower enthusiasm) was significantly associated with MCR in fully adjusted models (adjusted hazard ratio, 3.3; 95 percent confidence interval, 1.5 to 7.4). There was no association seen for prevalent MCR with poor sleep quality.

"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 write.