Approximately half of older people report sleep disturbances, which are associated with various health conditions, including neurodegenerative disease and dementia. Indeed, 60 to 70% of people with cognitive impairment or dementia have sleep disturbances, which are linked to poorer disease prognosis. Sleep disturbances in people with dementia have long been recognized and studied; however, in the past 10 years, researchers have begun to study disturbed sleep, including sleep fragmentation, abnormal sleep duration, and sleep disorders, as risk factors for dementia. In this review the authors summarize evidence linking sleep disturbance and dementia. They describe how specific aspects of sleep (e.g., quality, duration) and the prevalence of clinical sleep disorders (e.g., sleep-disordered breathing, rapid eye movement sleep behavior disorder) change with age; how sleep parameters and sleep disorders are associated with the risk of dementia; how sleep can be disturbed in dementia; and how disturbed sleep affects dementia prognosis. These findings highlight the potential importance of identifying and treating sleep problems and disorders in middle-aged and older adults as a strategy to prevent cognitive decline and dementia. The authors also review recent evidence linking sleep disturbances to the pathophysiology underlying dementing conditions, and briefly summarize available treatments for sleep disorders in people with dementia.

Background: Previous studies reported that slower gait speed might predict cognitive impairment and dementing illnesses, supporting the role of gait speed as a possible subclinical marker of cognitive impairment. However, the predictive value of other gait parameters for cognitive decline is unclear. Objective: To investigate and compare the association with, and prediction of, specific gait parameters for cognition in a population-based sample. Methods: The analysis included 3,426 cognitively normal participants enrolled in the Mayo Clinic Study of Aging. At baseline and every 15 months (mean follow-up = 1.93 years), participants had a study coordinator evaluation, neurological examination, and a neuropsychological assessment using nine tests that covered four domains. Gait parameters were assessed with the GAITRite ^® instrument. General linear mixed effects models were used to compute the annualized rate of change in cognitive domain z-scores, controlling for age, sex, education, depression, comorbidities, body mass index, APOE ɛ 4 allele, and visit number, and excluding individuals with a history of stroke, alcoholism, Parkinson’s disease, subdural hematoma, and normal pressure hydrocephalus. Results: Spatial (stride length), temporal (ambulatory time, gait speed, step count, cadence, double support time), and spatiotemporal (cadence) gait parameters, and greater intraindividual variability in stride length, swing time, and stance time were associated with a significant decline in global cognition and in specific domains including memory, executive function, visuospatial, and language. Conclusions: Spatial, temporal, and spatiotemporal measures of gait and greater variability of gait parameters were associated with and predictive of both global- and domain-specific cognitive decline.

Background: Adiponectin, a protein involved in inflammatory pathways, may impact the development and progression of Alzheimer’s disease (AD). Adiponectin levels have been associated with mild cognitive impairment (MCI) and AD; however, its associatio

Background: We determined the association between neighborhood socio-environmental factors and insomnia symptoms in a nationally representative sample of US adults aged >50 years. Methods: Data were analyzed from two waves (2006 and 2010) of the Health and Retirement Study using 7,231 community-dwelling participants (3,054 men and 4,177 women) in the United States. Primary predictors were neighborhood physical disorder (e.g. vandalism/graffiti, feeling safe alone after dark, and cleanliness) and social cohesion (e.g. friendliness of people, availability of help when needed, etc.); outcomes were insomnia symptoms (trouble falling asleep, night awakenings, waking too early, and feeling unrested). Results: After adjustment for age, income, race, education, sex, chronic diseases, body mass index, depressive symptoms, smoking, and alcohol consumption, each one-unit increase in neighborhood physical disorder was associated with a greater odds of trouble falling asleep (odds ratio (OR) = 1.09, 95% confidence interval (CI): 1.04–1.14), waking too early (OR = 1.05, 95% CI: 1.00–1.10), and, in adults aged ≥69 years (adjusting for all variables above except age), feeling unrested in the morning (OR = 1.11, 95% CI: 1.02–1.22 in 2006). Each one-unit increase in lower social cohesion was associated with a greater odds of trouble falling asleep (OR = 1.06, 95% CI: 1.01–1.11) and feeling unrested (OR = 1.09, 95% CI: 1.04–1.15). Conclusions: Neighborhood-level factors of physical disorder and social cohesion are associated with insomnia symptoms in middle-aged and older adults. Neighborhood-level factors may affect sleep, and consequently health, in our aging population.