Objective Previous cross-sectional studies have observed alterations in activity rhythms in dementia patients but the direction of causation is unclear. We determined whether circadian activity rhythms measured in community-dwelling older women are prospectively associated with incident dementia or mild cognitive impairment (MCI). Method Activity rhythm data were collected from 1,282 healthy community-dwelling women from the Study of Osteoporotic Fractures cohort (mean age 83 years) with wrist actigraphy for a minimum of three 24-hour periods. Each participant completed a neuropsychological test battery and had clinical cognitive status (dementia, MCI, normal) adjudicated by an expert panel approximately 5 years later. All analyses were adjusted for demographics, BMI, functional status, depression, medications, alcohol, caffeine, smoking, health status, and co-morbidities. Results After 4.9 years of follow-up, 195 (15%) women had developed dementia and 302 (24%) had developed MCI. Older women with decreased activity rhythms had a higher likelihood of developing dementia or MCI when comparing those in the lowest quartiles of amplitude (Odds ratio[OR]=1.57,95% CI,1.09–2.25) or rhythm robustness (OR=1.57,95%CI,1.10–2.26) to women in the highest quartiles. An increased risk of dementia or MCI (OR=1.83,95% CI,1.29–2.61) was found for women whose timing of peak activity occurred later in the day (after 3:51PM) when compared to those with average timing (1:34PM–3:51PM). Interpretation Older, healthy women with decreased circadian activity rhythm amplitude and robustness, and delayed rhythms have increased odds of developing dementia and MCI. If confirmed, future studies should examine whether interventions (physical activity, bright light exposure) that influence activity rhythms will reduce the risk of cognitive deterioration in the elderly.

Objective To test the hypothesis that non-frail older men with poorer sleep at baseline are at increased risk for frailty and death at follow-up. Methods In this prospective cohort study, subjective (questionnaires) and objective sleep parameters (actigraphy and in-home overnight polysomnography) were measured at baseline in 2,505 non-frail men aged ≥67 years. Repeat frailty status assessment was performed an average of 3.4 years later; vital status was assessed every four months. Sleep parameters were expressed as dichotomized predictors using clinical cut-points. Statuses at follow-up exam were classified as robust, intermediate (pre-frail) stage, frail, or died in interim. Results None of the sleep disturbances were associated with the odds of being intermediate/frail/dead (vs. robust) at follow-up. Poor subjective sleep quality (multivariable odds ratio [MOR] 1.26, 95%CI 1.01–1.58), greater nighttime wakefulness (MOR 1.31, 95% CI 1.04–1.66), and greater nocturnal hypoxemia (MOR 1.47, 95% CI 1.02–2.10) were associated with a higher odds of frailty/death at follow-up (vs. robust/intermediate). Excessive daytime sleepiness (MOR 1.60, 95% CI 1.03–2.47), greater nighttime wakefulness (MOR 1.57, 95% CI 1.12–2.20), severe sleep apnea (MOR 1.74, 95% CI 1.04–2.89), and nocturnal hypoxemia (MOR 2.28, 95% CI 1.45–3.58) were associated with higher odds of death (vs. robust/intermediate/frail at follow-up). The association between poor sleep efficiency and mortality nearly reached significance (MOR 1.48, 95% CI 0.99–2.22). Short sleep duration and prolonged sleep latency were not associated with frailty/death or death at follow-up. Conclusions Among non-frail older men, poor subjective sleep quality, greater nighttime wakefulness, and greater nocturnal hypoxemia were independently associated with a higher odds of frailty or death at follow-up, while excessive daytime sleepiness, greater nighttime wakefulness, severe sleep apnea, and greater nocturnal hypoxemia were independently associated with an increased risk of mortality.

Objective: To The prevalence of 25 hydroxyvitamin D [25(OH)D] deficiency, defined as 25(OH)D level less than 20 ng/mL, is high, especially among the elderly, with 25% to 65% affected. [1][2][3][4][5][6] While much research has focused on the adverse effect of 25(OH)D deficiency on bone health, 5,7 associations between 25(OH)D deficiency and non-bone health outcomes, including hypertension, 8 cardiovascular morbidity, 9 diabetes, 10,11 and cancer, 12,13 have also been reported. In addition, there is a growing body of literature to support the role of vitamin D in brain function and development.14 -25 Despite the experimental and animal evidence supporting an important role for vitamin D in mood and cognition, epidemiologic studies testing this hye-Pub ahead of print on November 25, 2009, at www.neurology.org.

Low 25(OH)D levels among older women were associated with a higher odds of global cognitive impairment and a higher risk of global cognitive decline.

Objectives Test the hypothesis that sleep disturbances are independently associated with greater evidence of frailty in older men. Design Cross-sectional analysis of prospective cohort study Setting Six U.S. centers Participants 3133 men ≥67 years Measurements Self reported sleep parameters (questionnaire); objective parameters of sleep wake patterns (actigraphy data collected for an average of 5.2 nights); and objective parameters of sleep disordered breathing, nocturnal hypoxemia, and periodic leg movements with arousals (PLMA) (in-home overnight polysomnography). Frailty status classified as robust, intermediate stage or frail using criteria similar to those used in the Cardiovascular Health Study frailty index. Results The prevalence of sleep disturbances including poor sleep quality, excessive daytime sleepiness, short sleep duration, reduced sleep efficiency, prolonged sleep latency, sleep fragmentation (greater nighttime wakefulness and frequent long wake episodes), sleep disordered breathing, nocturnal hypoxemia and frequent PLMA was lowest among robust men, intermediate among men in the intermediate stage group, and highest among frail men (p-for-trend ≤0.002 for all sleep parameters). After adjusting for multiple potential confounders, self-reported poor sleep quality (Pittsburgh Sleep Quality Index <5, multivariable odds ratio (MOR) 1.28, 95%CI 1.09–1.50), sleep efficiency <70% (MOR 1.37, 95% CI 1.12–1.67), sleep latency ≥60 minutes (MOR 1.42, 95% CI 1.10–1.82), and sleep disordered breathing (respiratory disturbance index ≥15, MOR 1.38, 95% CI 1.15–1.65) were each independently associated with an increased odds of greater frailty status. Conclusion Sleep disturbances including poor self-reported sleep quality, reduced sleep efficiency, prolonged sleep latency and sleep disordered breathing are independently associated with greater evidence of frailty.