Sleep Duration Polygenic Risk and Phenotype: Associations with Biomarkers of Accelerated Aging in the Baltimore Longitudinal Study of Aging.

We sought to explore whether genetic risk for, and self-reported, short sleep are associated with biological aging and whether age and sex moderate these associations. Participants were a subset of individuals from the Baltimore Longitudinal Study of Aging who had complete data on self-reported sleep (n = 567) or genotype (n = 367). Outcomes included: Intrinsic Horvath age, Hannum age, PhenoAge, GrimAge, and DNAm-based estimates of plasminogen activator inhibitor-1 (PAI-1) and granulocyte count. Results demonstrated that polygenic risk for short sleep was positively associated with granulocyte count; compared to those reporting <6 hr sleep, those reporting >7 hr demonstrated faster PhenoAge and GrimAge acceleration and higher estimated PAI-1. Polygenic risk for short sleep and self-reported sleep duration interacted with age and sex in their associations with some of the outcomes. Findings highlight that polygenic risk for short sleep and self-reported long sleep is associated with variation in the epigenetic landscape and subsequently aging.

24 h Rest/Activity Rhythms in Older Adults with Memory Impairment: Associations with Cognitive Performance and Depressive Symptomatology.

Little is known about links of circadian rhythm alterations with neuropsychiatric symptoms and cognition in memory impaired older adults. Associations of actigraphic rest/activity rhythms (RAR) with depressive symptoms and cognition are examined using function-on-scalar regression (FOSR). Forty-four older adults with memory impairment (mean: 76.84 ± 8.15 years; 40.9% female) completed 6.37 ± 0.93 days of actigraphy, the Beck depression inventory-II (BDI-II), mini-mental state examination (MMSE) and consortium to establish a registry for Alzheimer's disease (CERAD) delayed word recall. FOSR models with BDI-II, MMSE, or CERAD as individual predictors adjusted for demographics (Models A1-A3) and all three predictors and demographics (Model B). In Model B, higher BDI-II scores are associated with greater activity from 12:00-11:50 a.m., 2:10-5:50 p.m., 8:40-9:40 p.m., 11:20-12:00 a.m., higher CERAD scores with greater activity from 9:20-10:00 p.m., and higher MMSE scores with greater activity from 5:50-10:50 a.m. and 12:40-5:00 p.m. Greater depressive symptomatology is associated with greater activity in midafternoon, evening, and overnight into midday; better delayed recall with greater late evening activity; and higher global cognitive performance with greater morning and afternoon activity (Model B). Time-of-day specific RAR alterations may affect mood and cognitive performance in this population.

Sleep Duration and Cognition in a Nationally Representative Sample of U.S. Older Adults.

OBJECTIVE: Excessive and insufficient sleep have been associated with cognitive dysfunction in older adults in U.S. and non-U.S. STUDIES: However, the U.S. studies were not in nationally representative samples. The authors investigated the association between sleep duration and cognitive performance in a nationally representative sample of U.S. older adults. PARTICIPANTS: The authors studied 1,496 survey participants aged 60 years or older from the National Health and Nutrition Examination Survey 2013-2014 dataset. MEASUREMENTS: Our primary predictor was weekday (or workday) nighttime sleep duration, categorized as 2-4, 5, 6, 7 (reference), 8, 9, and 10 hours or more. The authors studied five cognitive outcomes: Consortium to Establish a Registry for Alzheimer's Disease Word Learning (CERAD-WL) immediate recall, CERAD-WL delayed recall, Animal Fluency Test (AFT), Digital Symbol Substitution Test (DSST), and subjective cognitive problems (SCP). RESULTS: After adjusting for age, sex, race, education, depressive symptoms, and sedative-hypnotic use, sleep duration of 10 hours or more was significantly associated with lower scores on CERAD-WL immediate recall, CERAD-WL delayed recall, AFT, and DSST, and greater odds of SCP; sleep duration of 8 hours or more was associated with lower CERAD-WL delayed recall scores: 8, 9, and 10 hours or more. After adjustment, there were no significant associations of shorter sleep duration with cognition. CONCLUSION: In U.S. adults aged 60 years or older, long nighttime weekday or workday sleep duration is associated with poorer verbal memory, semantic fluency, working memory, and processing speed in addition to greater odds of self-reported cognitive problems. Long sleep duration may be a marker of fragmented sleep or neurodegeneration in U.S. older adults.

Caregivers' assessments of preference-based quality of life in Alzheimer's disease.

BACKGROUND: This study was designed to evaluate the feasibility, reliability, and validity of use of caregivers' ratings of two health preference measures as outcomes for cost-effectiveness analyses in persons with very mild to moderate Alzheimer's disease (AD). METHODS: Caregivers completed ratings of preference for AD patients' health by use of the EuroQol-5D system (EQ-5D) and the Health Utilities Index Mark 2 (HUI2). They also rated patients' cognition, mood, burden, AD-specific and generic health-related quality of life (QOL), and activities of daily living. RESULTS: Caregivers' HUI2 scores were reliable. Neither the caregiver ratings of the patients' health by use of the EQ-5D nor the HUI2 had a relationship with severity of cognitive impairment. Both the EQ-5D and the HUI2 had expected relationships with caregivers' assessments of patients' function, AD-specific QOL, and physical and mental health and selected subscales of the measures of AD-specific QOL and overall health. In addition, caregiver scores showed relationships with patient self-rated function, mood, and physical health but not AD-specific QOL. Caregiver burden was associated with caregivers' scores. CONCLUSIONS: Caregiver-completed ratings of preference for patients' health made by use of the EQ-5D and the HUI2 have many of the characteristics of valid preference measures. However, the lack of association with patient Mini-Mental Status Exam scores and patient self-rated AD-specific QOL and the associations with caregiver subjective burden might present limitations to their use as proxy measures for cost-effectiveness analyses.