Research Brief
Irregular circadian rhythms – the body’s internal clocks – are associated with an increased risk of dementia, according to a study published in Neurology. The authors say the study opens new possibilities for detecting and treating neurodegenerative disease.
Researchers from UT Southwestern Medical Center documented health outcomes of nearly 2,200 people using wearable heart monitors to track their circadian rhythms. They found more of them developed dementia if their circadian rhythms peaked later in the day or if the rhythms were weak and fragmented.
“Disruptions in our circadian rhythms may interfere with our sleep-wake cycle and alter body processes such as inflammation,” said Dr. Wendy Wang, a UT Southwestern epidemiologist who led the study. “Over time, these disruptions could influence the buildup or clearance of amyloid plaques in the brain linked to dementia.”
The research, published in Neurology, detailed health outcomes of elderly participants who did not have dementia when the study began. After an avearage of three years of follow-up, Dr. Wang’s team found that people with weaker body clocks had nearly 2.5 times greater chance of developing dementia. People with circadian rhythms that peaked later in the day – 2:15 pm or later – had a 45% increased risk of dementia.
Dr. Wang said the findings do not prove irregular circadian rhythms cause dementia, but they do show an association that merits further research.
“There are important public health implications of this study,” Dr. Wang said. “Future work should examine whether interventions, such as light therapy or lifestyle modifications, can strengthen circadian rhythms and lower dementia risk.”
