Sleep Stage Distribution Linked to Cognitive Decline

Sleep stage distribution of increased time in stage N1 sleep and less time in REM sleep is associated with declining cognitive function in older men, according to a study of 2,601 community-dwelling men ages 67 years and older.

Investigators assessed cognitive outcomes using the Trail Making Test Part B and Modified Mini-Mental State (3MS) at the initial visit, which also included in-home polysomnography, and 2 follow-up visits. Subjects were stratified by quartiles of percentage of sleep time spent in different sleep stages, which resulted in:

• the highest quartile of stage N1 sleep had double the risk of cognitive decline compared with those in the lowest quartile

• the lowest quartile of REM stage had more cognitive decline on the 3MS than those in the highest quartile

Citation: Song Y, Blackwell T, Yaffe K, Ancoli-Israel S, Redline S, Stone KL; Osteoporotic Fractures in Men (MrOS) Study Group. Relationships between sleep stages and changes in cognitive function in older men: The MrOS Sleep Study. Sleep. 2015;38(3):411-421. doi: 10.5665/sleep.4500.