Subjective cognitive decline and self‐reported sleep at a memory clinic: The SCIENCe project

Abstract

AbstractBackgroundsleep problems have been associated with Alzheimer’s disease (AD) pathology and they have been suggested to occur early in the disease process. Sleep problems have also been associated with subjective cognitive decline (SCD), although in many subjects with SCD, no AD biomarker evidence is found for the experienced cognitive decline. Our aim was to investigate whether frequency and type of sleep problems in memory clinic patients with SCD are associated with cognition, mental health, MRI measures, and AD CSF biomarkers.Method308 subjects (65±8yrs, 44% female, MMSE 29±1) from the Subjective Cognitive Impairment Cohort (SCIENCe) project with available information on sleep were included. Sleep was evaluated by the Berlin Questionnaire (3 categories; ≥2 high risk sleep apnea) and Pittsburgh Sleep Quality Index (range 0‐21; ≥5 poor sleep quality). All underwent a standardized memory clinic work‐up. Subjects were classified as having sleep problems when ≥1 sleep questionnaire was above the cut‐off. Sociodemographics, cognitive performance (attention, memory, language, and executive functioning), depressive symptoms, anxiety, self‐reported cognitive decline (Cognitive Change Index; CCI), medial temporal lobe atrophy, global cortical atrophy, white matter hyperintensities, and CSF levels of Aβ42, t‐tau, p‐tau were compared between subjects with and without sleep problems.Result198/308 (64%) subjects reported sleep problems, based on 107 (35%) sleep apnea and 162 (53%) poor sleep quality. Subjects with sleep problems tended to be younger (63.8±8.1 vs 65.7±8.5), more often female (47% vs 39%) and more often APOE ε4 carrier (40% vs 28%), but these differences did not reach statistical significance (all p>.05, Table 1). They reported more depressive symptoms (CES‐D median(IQR): 10(5‐16) vs 4(2‐7)), anxiety (HADS‐A: 5(2‐10) vs 2(0.25‐4)) and cognitive decline (CCI: 43(31‐56) vs 35(25‐47)), all p≤.001. Sociodemographics, cognitive performance, MRI measures and AD CSF biomarker levels did not differ between groups.Conclusionsleep problems are common in subjects with SCD and are associated with higher levels of anxiety, depressive symptoms and self‐reported cognitive decline, but not AD biomarkers. Our results suggest that poor sleep quality and hygiene are a potentially reversible cause of the subjective experience of cognitive decline and potential leads for treatment in many subjects with SCD.