Association between sleep inertia and cognitive performance among older adults in the Wisconsin Sleep Cohort study

Since sleep inertia and hypersomnolence, broadly, have not been adequately studied in the context of neurocognitive performance, this investigation examined associations between sleep inertia severity, other measures of hypersomnolence, and outcomes from a standardized, cognitive testing battery in a well-characterized community-based sample of older adults.

Wisconsin Sleep Cohort participants completed the Sleep Inertia Questionnaire (SIQ), Epworth Sleepiness Scale (ESS), Hypersomnia Severity Index (HSI) and six widely used cognitive tests. Linear regression examined relationships between hypersomnolence measures (SIQ, ESS, and HSI) and cognitive outcomes. Secondary analyses assessed relationships between SIQ subscales (physiological, cognitive, emotional, and responses) and cognitive outcomes. Adjusted models included covariates capturing demographic, psychosocial, sleep, and testing characteristics.

The sample (N = 461) was predominantly non-Hispanic white older adults (average age = 73.84 ± 6.66 years), with majority being male (55.8%). In unadjusted analyses, SIQ total score was associated with Grooved Pegboard (GPB), Trail Making Test-Part B (TMT-B), and Symbol Digits Modalities Test, while neither ESS nor HSI was associated with cognitive outcomes. Significant associations between SIQ and GPB and TMT-B remained in fully adjusted analyses. Physiological, cognitive, and emotional SIQ subscales were also associated with cognitive tests, particularly GPB and TMT-B.

This study suggests that sleep inertia may be an important, specific symptom that is associated with cognitive performance in older adults. Future research is indicated to clarify the role of sleep inertia in aging, while exploring its potential value as a risk factor for cognitive impairment and target for intervention to support cognitive health.

Sleep inertia is a common sleep-related symptom, yet it remains insufficiently studied, particularly regarding neurocognitive performance. The Sleep Inertia Questionnaire (SIQ) is a validated measure of sleep inertia, but has not been studied in older populations at risk for cognitive impairment. Clarifying relationships between SIQ scores and neurocognitive outcomes may identify those at greater risk for cognitive impairment.

Sleep inertia is a common sleep-related symptom, yet it remains insufficiently studied, particularly regarding neurocognitive performance. The Sleep Inertia Questionnaire (SIQ) is a validated measure of sleep inertia, but has not been studied in older populations at risk for cognitive impairment. Clarifying relationships between SIQ scores and neurocognitive outcomes may identify those at greater risk for cognitive impairment.