Physical Exercise and Health, 6: Sedentary Time, Independent of Health-Related Physical Activity, as a Risk Factor for Dementia in Older Adults

J Clin Psychiatry. 2024 Feb 7;85(1):24f15270. doi: 10.4088/JCP.24f15270.ABSTRACTSedentary behaviors are leisurely behaviors that occur during waking hours performed while lying down or seated; examples are relaxing, conversing, using a smartphone, watching television, traveling in private or public transport, and thinking or working at a desk. Sedentary behaviors are common in everyday life; the average person spends 9-10 h/d sedentary. Findings from meta-analyses show that higher levels of physical activity are associated with a reduced risk of dementia and that near-absence of moderate to vigorous physical activity is associated with an increased risk of dementia. Sedentariness is a clearly defined construct that is more than just low levels of physical activity. Sedentariness, therefore, merits independent study. In this context, a recent cohort study, conducted in elderly subjects (mean age, 67 years) who were followed for a mean of 6.7 years, found that sedentariness, independent of current levels of moderate to vigorous physical activity, was associated in a dose-dependent fashion with the risk of incident dementia; the finding held true when reverse causation was addressed through the exclusion of subjects who developed dementia within 4 years of follow-up. The adjusted 10-year risk of dementia rose from about 8% with sedentariness at 10 h/d to about 23% with sedentariness at 15 h/d; the difference is clinically meaningful. Limitations of studies in the field are that ...
Source: Journal of Clinical Psychiatry - Category: Psychiatry Authors: Source Type: research