Altered sleep architecture following consecutive nights of pre-sleep alcohol.

STUDY OBJECTIVES: Alcohol consumption before sleep decreases sleep latency, explaining the common use of alcohol as a sleep aid. The full impact of alcohol on sleep architecture is not well understood, particularly the potential cumulative effects of pre-sleep alcohol consumption across consecutive nights. Here, we describe the effects of pre-sleep alcohol on sleep architecture across three consecutive nights.

METHODS: Thirty adult participants took part in a crossover, within-subjects study consisting of two sets of three consecutive nights of in-lab polysomnography. For each series of nights, participants drank one of two beverages: a mixer only or a mixer plus alcohol (targeting a BrAC of 0.08 mg/L), ending 1 hour before lights out. Polysomnography (PSG) was used to stage sleep, and standard sleep variables were extracted. Linear mixed-effect (LME) analysis and generalized additive modeling were used to examine the effect of alcohol on sleep architecture.

RESULTS: Alcohol before sleep increased the rate of slow-wave-sleep (SWS) accumulation across all three nights and decreased the rate of REM sleep accumulation at the start of each night. Alcohol also decreased the total amount of REM sleep but did not affect the total amount of SWS each night.

CONCLUSIONS: These data indicate that drinking alcohol before sleep substantially affects sleep architecture, including changes to the rate of accumulation of SWS and REM sleep. We show that alcohol disrupts normal sleep architecture, leading to a significant decrease in REM sleep; thus, the use of alcohol as a sleep aid remains a public health concern.