Altered Circadian Rhythms Are Associated with Dementia

Aging is associated with decreases in daily peak activity (“amplitude”), earlier onset of sleepiness, and earlier morning waking. These researchers examined the relation between alterations in circadian rhythm and onset of dementia or mild cognitive impairment (MCI) in 1282 healthy women (mean age, 83). The women underwent wrist actigraphy for at least 72 hours and, 5 years later, comprehensive cognitive assessments, when 15% were diagnosed with dementia and 24% with MCI.

Women in the lowest quartile of amplitude (i.e., least peak activity) were more likely than those in the highest quartile to be older; to have a high body-mass index (BMI), more problems in instrumental activities of daily living (ADLs), more medical conditions, hypertensio…