The risk of sleep‐related cognitive impairment increases in middle‐age to older adulthood

Abstract

AbstractBackgroundThe association between sleep quality and cognition is widely established but the role of aging in this relationship has been unclear due to inconsistent findings with heterogeneous methods and a lack of studies in wide age ranges. The current study examined how age impacts the sleep‐cognition relationship using a large‐scale dataset with adults from young adulthood to older adulthood. Furthermore, we tested non‐linear effect of age to investigate the presence of age ranges in which the association between sleep and cognition is modified.MethodSample included 711 individuals (ages 36.00‐89.83, 59.66 ± 14.91, 55.7% female) from the Human Connectome Project‐Aging (HCP‐A). Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI), and cognitive outcome measures included the NIH Toolbox fluid cognition (Dimensional change Card Sort Test, List Sorting Working Memory Test, Picture Sequence Memory Test, Pattern comparison Processing Speed Test, Flanker Inhibitory Control and Attention Test) and crystallized cognition composite scores (Oral Reading Recognition Test and Picture Vocabulary Test), the Trail Making Test (TMT) A and B, and the Rey Auditory Verbal Learning Test (RAVLT). The association between sleep quality and cognitive performance was measured using linear regression models, with sex, race, use of sleep medication, and years of education as covariates. Age moderation was tested via the interaction between sleep and age on cognition, with age as linear and non‐linear (quadratic) terms.ResultThere was a significant interaction term between the PSQI and non‐linear age term (age2) on TMT‐B (p = 0.02) and NIH Toolbox crystallized cognition (p = 0.02), indicating that the association between poor sleep quality and cognitive performance was moderated by age. Further analyses indicated that there were “critical age ranges” in which the sleep‐cognition association was more salient (ages 50‐75 for TMT‐B and 66‐70 for crystallized cognition).ConclusionThe association between sleep quality and cognitive performance may be modified by age. Individuals of the middle‐age to early older adulthood may be more vulnerable to sleep‐related cognitive impairment, indicating the clinical importance of detection and treatment of sleep disturbance in this particular age group.