Misappraisal of sleep quality is associated with lower cognitive functioning

Abstract

AbstractBackgroundSelf‐reported sleep quality often does not strongly correlate with objective measurements of sleep, and thus, other factors such as cognitive ability might contribute in the self‐awareness of one’s own sleep. Although sleep disturbances are increasingly recognized as risk factor for dementia, individuals with lower cognitive performance might present with an impaired ability to appropriately report their sleep, reducing the importance of self‐reported data. The purpose of this study was to evaluate whether misappraisal of sleep consolidation and quality was associated with poorer cognitive performance.MethodWe studied 265 participants (58.0±8.9 years, 50.2 % men) in the Framingham Heart Study Offspring Cohort who had an overnight in‐home polysomnography and neuropsychological testing 3.5 years later on average. Self‐reported sleep quality regarding the night of the polysomnography was compared to objective sleep efficiency (cut‐off at 85%). Four groups were created representing those with consistent appraisal of good sleep (n=75, good self‐reported and objective sleep); consistent appraisal of poor sleep (n=72, poor self‐reported and objective sleep); misappraisal of poor sleep (n=41, good self‐reported sleep but poor objective sleep); misappraisal of good sleep (n=77, poor self‐reported sleep but good objective sleep). We evaluated global cognition (composite score), verbal memory (Logical Memory immediate and delayed recall), executive function (Trail Making Test B minus A) and visual organization (Hooper Visual Organization Test). Models were adjusted for age, sex, education, time between polysomnography and neuropsychology, APOE4 allele status, body mass index, sleeping pills, depression, and stroke risk.ResultParticipants that misappraised poor sleep, i.e., reported good sleep quality but had lower sleep efficiency, had lower global cognitive performance (β±SE=‐0.34±0.17; p=0.047), worse immediate verbal memory recall (‐1.39±0.67; p=0.039) and poorer executive functioning (‐0.16±0.05; p=0.003) compared to participants with consistent appraisal of good sleep. No other between‐group differences were observed.ConclusionIndividuals with misappraisal of poor sleep had poorer cognitive performance than individuals with consistent appraisal of good sleep. This type of sleep misappraisal could be occurring when cognitive functions are declining and self‐awareness is impaired. Further studies comparing self‐report to objective measures of sleep are required in patients in preclinical stages of dementia and with cognitive impairment.