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Summary: Hippocampal atrophy is a prominent neurodegenerative feature of Alzheimer's disease and related dementias. Alterations in circadian rhythms can exacerbate cognitive aging and neurodegeneration. This study aimed to examine how dim light melatonin onset and melatonin levels are associated with hippocampal volume in cognitively healthy individuals. We studied data from 52 later‐life adults (mean age ± SD = 70.0 ± 6.3 years). T1‐weighted anatomical images from 3.0 T magnetic resonance imaging data were collected and processed using the BRAINSTools toolbox. Dim light melatonin onset was used to assess circadian timing. The area under the curve was calculated to quantify melatonin concentration levels 6 hr before bedtime, and 14‐day wrist actigraphy data were used to assess habitual bedtime. Multiple linear regression modelling with hippocampal volume as the dependent variable was used to analyse the data adjusting for age and sex. The average dim light melatonin onset was 19:45 hours (SD = 84 min), and area under the curve of melatonin levels 6 hr before habitual bedtime was 38.4 pg ml−1 × hr (SD = 29.3). We found that later dim light melatonin onset time (b = 0.16, p = 0.005) and greater area under the curve of melatonin levels 6 hr before habitual bedtime (b = 0.05, p = 0.046) were associated with greater adjusted hippocampal volume. The time between dim light melatonin onset and the midpoint of sleep timing was not associated with hippocampal volume. The findings suggest that earlier circadian timing (dim light melatonin onset) and reduced melatonin may be associated with reduced hippocampal volume in older adults. Future research will help researchers utilize circadian rhythm information to delay brain aging. [ABSTRACT FROM AUTHOR]

Summary: Sleep behaviour is an important contributing factor in healthy human ageing and cognitive function. Previous studies have linked sleep deficiency with cognitive decline in older adults. However, there is need for more prospective investigations that focus on specific domains of cognitive function. The present study analysed cross‐sectional and prospective associations between self‐reported sleep and cognitive function in the Midlife in the United States (MIDUS) study. Weekday and weekend sleep duration and habitual sleep quality were obtained via questionnaire data. Brief Test of Adult Cognition by Telephone was conducted to assess overall cognitive function, as well as episodic memory and executive function. We found significant trend for both long weekday and weekend sleep (>8 hr) and lower episodic memory scores in the overall sample. Sex‐specific cross‐sectional analysis demonstrated men with longer weekend sleep duration have lower overall cognitive function scores, and a negative association between weekend sleep and episodic memory scores. Women demonstrated a positive association between weekend sleep duration and executive function scores. There was no prospective significance for overall or sex‐specific analysis. Our present results suggest that sleep duration may contribute to cognitive function, and future studies should include objective sleep measurements and focus on the potential cognitive benefits of improving sleep to further elucidate this association. [ABSTRACT FROM AUTHOR]

Objectives: Alzheimer's disease (AD) and related dementias contribute to one in three senior deaths. Lifestyle factors, including sleep, may contribute to AD risk and mortality; however, current evidence on sleep and AD mortality is mixed. Methods: We used data from the NIH-AARP Diet and Health Study. Sleep duration and napping were self-reported and AD death were ascertained via linkage to the National Death Index. Results: Long sleep and napping were both associated with increased AD mortality. Specifically, 9+ hr of sleep was associated with 50% increase (hazard ratio = 1.50, 95% CI = [1.17, 1.92]) in AD mortality when compared 7 to 8 hr, while napping for 1+ hr was associated with 29% increase (1.29 [1.08, 1.55]) when compared with no napping. Results appeared to be stronger in men and remained after removing AD deaths within first 5 years after baseline. Discussion: Long sleep and napping may predict higher AD mortality in the older population. [ABSTRACT FROM AUTHOR]

The purpose of this investigation is to examine differences in rest-activity patterns and sleep characteristics in older adults with heart failure (HF) and healthy older adults. The sample included older adults with HF (n = 20) and a reference group of healthy older adults (n = 20). Traditional cosinor analysis was used to assess three parameters of rest–activity from wrist actigraphy data: amplitude (range of activity), mesor (mean activity), and acrophase (time of peak activity). Traditional sleep characteristics were also determined from actigraphy data: total sleep time (TST), sleep latency (SL), sleep efficiency (SE), and wake after sleep onset (WASO). The HF group demonstrated significantly lower mesor and amplitude than the reference group (p < .01). The HF group had significantly greater TST (p < .01), but the groups had similar SE, SL, and WASO. Despite similar sleep characteristics to healthy older adults, overall rest–activity patterns were significantly dampened in those with HF. [ABSTRACT FROM AUTHOR]

Before completing a nursing PhD program, doctoral students are encouraged to seek out and apply for a position in one of many, often highly competitive postdoctoral programs. These programs include the more traditional National Institutes of Health (NIH) funded experiences, such as the T32, as well as the nontraditional institution funded positions, including the associate faculty role. Graduates often need guidance on which postdoctoral programs are available, the resources each program offers to promote development of the applicant's program of research, the disadvantages of each program, and what each program uses as benchmarks for success. This article summarizes both traditional and nontraditional postdoctoral positions including the T32, F32, F99/K00, T90/R90, research supplements, associate faculty, research associate, and hospital-affiliated postdoctoral positions. This article updates previous papers describing postdoctoral opportunities and offers a starting place to aide PhD students planning their postgraduate activities in seeking and evaluating these positions. [ABSTRACT FROM AUTHOR]

Background: Alzheimer's disease (AD) is the most common form of dementia afflicting more than 5.8 million older adults in the United States. In AD, cognitive decline and neuropsychiatric symptoms are more pronounced in those who have chronic conditions. These chronic conditions often co‐occur with other chronic conditions, known as multiple chronic conditions (MCCs). This study aimed to examine the longitudinal association between the number of chronic conditions with cognition and neuropsychiatric symptoms by cognitive status. Methods: Participants were 21,219 community dwelling individuals from the longitudinal National Alzheimer's Coordinating Center (NACC, U24 AG072122) database (mean age = 71.8 ± 9.8; 42.8% male). Participants completed a medical history interview, cognitive assessment, and the Neuropsychiatric Inventory (NPI), approximately every two years over a 15‐year period. Number of MCCs was characterized as the sum of clinician‐diagnosed chronic conditions (i.e., cardiovascular, metabolic, sleep, respiratory, and psychological conditions;range 0‐18). The analysis focused on memory (Craft Story 21 recall immediate and delayed), processing speed (Trails A), and executive function (Trails B, Coding, animal naming). We used mixed effect models to test whether the number of MCCs was associated with a change on each cognitive test and number neuropsychiatric symptoms by clinician diagnosed cognitive status (i.e., normal cognition, mild cognitive impairment (MCI) presumed AD etiology, MCI presumed without AD etiology, MCI with AD etiology, dementia with AD etiology, dementia with non‐AD etiology). Results: We found that the mean number of chronic conditions were, 2.2 ± 1.8 in cognitively normal individuals, 2.8 ± 2.0 in MCI with AD etiology, 2.8 ± 2.0 in MCI with non AD etiology, 2.7±1.9 in dementia with AD etiology, 3.0±2.1 in dementia with non‐AD etiology. Compared to cognitively normal adults, individuals with more severe cognitive impairment (i.e., groups with dementia) and a higher number of MCCs demonstrated greater decline in immediate and delayed memory recall, Trails A, animal naming, and coding (p <0.05), as well as the number of neuropsychiatric symptoms (p <0.05) over time accounting for age, sex, and education. Conclusion: The findings suggest that having a higher number of chronic conditions is associated with longitudinal decline in cognition and neuropsychiatric symptoms. [ABSTRACT FROM AUTHOR]