Periodic Limb Movements in Sleep are Associated with Greater Cognitive Decline in Older Men without Dementia

Study Objectives: To examine the association between periodic limb movements in sleep (PLMS) and change in selected aspects of cognition in community-dwelling older men. Methods: We studied 2,636 older men without dementia who underwent in-home polysomnography with measurement of the periodic limb movement index (PLMI) and periodic limb movement arousal index (PLMAI) using piezoelectric sensors. Random-effects models and logistic regression were used to examine the association between PLMI, PLMAI, and 3- to 4-y change in cognition. Results: After multivariable adjustment, men with a high PLMI had greater decline on the Trail Making Test - Part B (P trend = 0.02); those with a PLMI >= 30 were 48% more likely (odds ratio = 1.48, 95% confidence interval = 1.05-2.07) to experience the development of significant cognitive impairment (>= 1 SD above mean change). Further adjustment for sleep efficiency, nocturnal hypoxemia, or dopaminergic medication use and analysis among men without Parkinson disease (n = 2,607) showed similar findings. No significant association was found for PLMAI or for Modified Mini-Mental State Examination scores. Conclusions: Among older men without dementia, higher PLMS frequency was associated with greater decline in cognition, particularly in executive function.