Abnormal sleep traits correlated with domain-specific cognitive impairments, with CRP partially mediating the snoring-reasoning association, accounting for 32.1% of the observed relationship.
Both short and long sleep duration were associated with poorer numeric memory performance.
Moderate sleep quality and work shift were linked to impaired reasoning, reaction time, visual memory, and prospective memory.
C-reactive protein (CRP) partially mediated the association between snoring and reasoning ability.
Subgroup analyses stratified by age, sex, and BMI further supported the associations between sleep traits and cognitive impairments.
Mendelian randomization confirmed a causal association between snoring, elevated CRP levels, and impaired reasoning ability.
The study employed multiple analytical approaches to characterize the sleep-cognition relationship and its inflammatory mechanisms.
This research suggests that different sleep problems affect different aspects of thinking and memory in distinct ways. Using data from the UK Biobank — a large health study of hundreds of thousands of people — researchers found that sleeping too little or too much was linked to worse number memory, while poor sleep quality and working night or rotating shifts were associated with impaired reasoning, reaction time, visual memory, and the ability to remember to do things in the future. These associations held up even when the researchers looked separately at different age groups, sexes, and body weight categories. The study also investigated why snoring might hurt a person's reasoning ability. It found that a blood marker of inflammation called C-reactive protein (CRP) partially explained this link — snoring appeared to raise CRP levels, which in turn was associated with poorer reasoning. This inflammatory pathway accounted for about a third (32.1%) of the connection between snoring and reasoning ability. Importantly, a statistical technique called Mendelian randomization — which uses genetic data to test for cause-and-effect relationships — supported the idea that this is a genuine causal chain rather than just a coincidental association. This research suggests that different sleep problems may harm the brain through different pathways, and that inflammation is one mechanism linking sleep disruption (specifically snoring) to cognitive decline. Understanding these specific pathways could eventually help identify which people are at greatest risk for cognitive problems and might point toward targeted strategies — such as addressing snoring or monitoring inflammation — as areas worthy of further investigation.
Upload your bloodwork. We'll cross-reference your results against this study and 4,700 others.
Upload Your LabsPeng C, Yang F, Li F, Zhu R, Li L, Zhang Z, et al.. (2026). Sleep Traits and Cognitive Function: A Prospective Cohort Study With Exploration of Inflammatory Biomarkers.. Brain and behavior. https://doi.org/10.1002/brb3.71514