Relationship Identified in Sleep Quality, Sleep Apnea, and Cognitive Function

Matthew Pase, PhD

Credit: Monash University

A recent study conducted by the Sleep and Dementia Consortium identified a relationship between sleep architecture, respiratory-related sleep disturbances, and cognitive function in middle-aged and older adults.¹

Obstructive sleep apnea has been shown to inhibit cognitive functioning, such as reduced executive functioning, attention, and memory.²

The research, based on data collected from 5 independent community-based cohorts, aimed to understand the impact of sleep on cognitive health and dementia risk. Results revealed insights into the importance of sleep consolidation and the absence of sleep apnea for optimizing cognitive function with aging.¹

Data were curated from population-based cohorts across the US involving 5946 participants without a history of stroke or dementia, who underwent overnight, home-based type II polysomnography (PSG) sleep studies and neuropsychological assessments over a 5-year follow-up period.

The cohorts included the Atherosclerosis Risk in Communities study, Cardiovascular Health Study, Framingham Heart Study (FHS), Osteoporotic Fractures in Men Study, and Study of Osteoporotic Fractures. Sleep metrics were collated centrally and analyzed using linear regression.

After adjusting for various factors including demographic variables, the time between PSG and neuropsychological assessment, body mass index, antidepressant use, and sedative use, investigators found better sleep consolidation and the absence of sleep apnea were significantly associated with better global cognition.

However, individual sleep stage percentages failed to show a notable correlation with cognitive function. The analysis demonstrated a link between higher sleep maintenance efficiency, lower wake after sleep onset, and improved global cognition.

Although, it also observed participants with moderate to severe obstructive sleep apnea (OSA) had poorer global cognition compared with those with an apnea-hypopnea index (AHI) of < 5.

"The lack of an association between sleep architecture and verbal learning and memory in our study was interesting given the role of sleep in memory consolidation," investigators wrote. "However, it should be noted that we did not examine sleep-dependent learning specifically (ie, the presentation of stimuli and the recall of that stimuli were not separated by an overnight sleep period)."

Sleep quality and the absence of sleep apnea may play a crucial role in preserving cognitive function over time, emphasizing the significance of addressing sleep disturbances for overall brain health.

The results were consistent across the different cohorts involved in the study with results indicating a need for interventions aimed at improving sleep consolidation and addressing sleep apnea. Investigators stated this approach could be valuable in optimizing cognitive health as individuals age.

References:

1. Pase MP, Harrison S, Misialek JR, et al. Sleep Architecture, Obstructive Sleep Apnea, and Cognitive Function in Adults. JAMA Netw Open. 2023;6(7):e2325152. doi:10.1001/jamanetworkopen.2023.25152
2. Krysta K, Bratek A, Zawada K, Stepańczak R. Cognitive deficits in adults with obstructive sleep apnea compared to children and adolescents. J Neural Transm. 2017;124(S1):187-201.