Association Between Sleep Quantity and Quality in Early Adulthood With Cognitive Function in Midlife

Area of Science:

• Neuroscience
• Sleep Medicine
• Cognitive Health

Background:

• Growing evidence links sleep quality to dementia risk.
• Midlife cognition is crucial for understanding the sleep-dementia association.
• Objective sleep measures in midlife and their cognitive impact remain understudied.

Purpose of the Study:

• To examine the association between objectively measured sleep duration and quality in midlife and subsequent cognitive performance.
• To investigate if sleep parameters in midlife predict cognitive function 11 years later.
• To analyze these associations in a diverse cohort of Black and White adults.

Main Methods:

• Utilized wrist actigraphy and the Pittsburgh Sleep Quality Index (PSQI) for objective and subjective sleep assessment in midlife.
• Assessed midlife cognition using multiple tests including DSST, Stroop, RAVLT, MoCA, and fluency tests.
• Employed multivariable logistic regression to analyze the relationship between sleep parameters and poor cognitive performance (defined as >1 SD below the mean).

Main Results:

• High sleep fragmentation, measured objectively, was associated with significantly increased odds of poor cognitive performance on DSST, fluency, and MoCA tests.
• Participants in the highest tertile of sleep fragmentation had over twice the odds of poor cognitive performance compared to the lowest tertile.
• Neither objective sleep duration nor subjective sleep quality (PSQI score) showed a significant association with midlife cognitive performance.

Conclusions:

• Actigraphy-measured sleep fragmentation, not duration, is linked to worse cognitive outcomes in middle age.
• Sleep quality is a critical factor for cognitive health preservation starting in midlife.
• These findings underscore the importance of addressing sleep fragmentation for long-term brain health.