Weaker, More Fragmented Circadian Rhythms May Increase Dementia Risk

MONDAY, Jan. 5, 2026 (HealthDay News) — Circadian rhythms that are weaker and more fragmented are associated with an increased risk for dementia, according to a study published online Dec. 29 in Neurology.

Wendy Wang, M.D., from UT Southwestern Medical Center in Dallas, and colleagues conducted a retrospective examination of data from the Atherosclerosis Risk in Communities (ARIC) study conducted at four U.S. centers to examine the association between circadian rest-activity rhythms and incident dementia. A total of 2,183 ARIC participants who wore the Zio XT long-term continuous monitoring patch for three or more days in 2016 to 2017 were included; participants were followed for a median of three years.

The researchers found that each one-standard deviation (SD) decrement in relative amplitude and one-SD increment in intradaily variability were associated with a 54 and 19 percent greater risk for dementia, respectively, after multivariable adjustment. Associations were seen for amplitude and mesor with elevated dementia risk after multivariable adjustment (hazard ratio per one-SD decrement, 1.43 and 1.33, respectively). Compared with a normal acrophase, a later acrophase was associated with a 1.45 times increased risk for dementia.

“Disruptions in circadian rhythms may alter body processes like inflammation, and may interfere with sleep, possibly increasing amyloid plaques linked to dementia, or reducing amyloid clearance from the brain,” Wang said in a statement. “Future studies should examine the potential role of circadian rhythm interventions, such as light therapy or lifestyle changes, to determine if they may help lower a person”s risk of dementia.”

One author disclosed ties to the pharmaceutical, publishing, and health technology industries.

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