Mega Doctor News
By UT Southwestern Medical Center
Newswise — DALLAS – Disruptions in patterns of daily activity and rest may provide early clues to heightened dementia risk, a study co-led by a UT Southwestern Medical Center scientist found. The research, published in Neurology, suggests data from a widely used heart monitor could help identify circadian rhythm changes associated with dementia in older adults.
“Circadian rhythm is the body’s internal clock that regulates physiological functions over a 24-hour cycle,” said Wendy Wang, Ph.D., M.P.H., Assistant Professor of Epidemiology in the Peter O’Donnell Jr. School of Public Health and of Internal Medicine at UT Southwestern. Dr. Wang co-led the study with Lin Yee Chen, M.B.B.S., M.S., Professor of Medicine at the University of Minnesota.
“Among community-based adults, altered rest-activity rhythms, which are markers of circadian rhythms, may be a risk factor for dementia,” Dr. Wang said. “A key aspect of our study was the novelty of using accelerometer data from an ambulatory monitor to measure rest-activity rhythms. To the best of our knowledge, this study is the first to use rest-activity rhythm measures obtained from chest-worn electrocardiogram (ECG) monitors to assess dementia risk.”
The researchers analyzed data from the Atherosclerosis Risk in Communities (ARIC) Study, a long-running, community-based cohort. The analysis included more than 2,000 participants who had not been diagnosed with dementia and wore a chest-mounted ambulatory ECG monitor for up to two weeks between 2016 and 2017.
Using the monitor’s built-in accelerometer, the team assessed several features of the participants’ daily activity patterns, including the strength of activity cycles, fragmentation of activity and rest across day and night, and timing of peak activity.
Over an average follow-up of about three years, 176 participants developed dementia. After adjusting for age, education, cardiovascular risk factors, and genetic susceptibility (APOE ε4), the analysis showed that weaker daily rhythms, greater fragmentation, and later peak activity times were each associated with a higher likelihood of developing dementia.
“Disruptions in circadian rhythms may alter various processes, such as the regulation of oxidative stress or inflammation, which may ultimately lead to dementia,” Dr. Wang said.
The study participants included a racially diverse group of older adults, with an average age of 79 and nearly one-quarter identifying as Black. As a result, the findings help clarify how dementia risk relates to circadian patterns in populations that have been underrepresented in prior research and in late adulthood, when disease-related changes are already emerging.
Because ambulatory heart monitors are commonly used in clinical care, information collected during routine monitoring could eventually complement existing approaches to assessing dementia risk, the researchers said. They cautioned, however, that additional studies are needed before such data could be applied clinically.
“Future work assessing circadian rhythms earlier in life is warranted, especially given the long preclinical stage of dementia,” Dr. Wang said.
The findings also help lay the groundwork for future studies to explore whether interventions such as light therapy or lifestyle modifications can strengthen circadian rhythms and potentially reduce dementia risk.
Dr. Wang is an Investigator in the Peter O’Donnell Jr. Brain Institute.
The study was funded by the National Heart, Lung, and Blood Institute (T32HL007779, R01HL126637, R01HL141288, R01HL158022, K24HL155813), the National Institutes of Health, the U.S. Department of Health and Human Services (75N92022D00001, 75N92022D00002, 75N92022D00003, 75N92022D00004, 75N92022D00005), the National Institute of Neurological Disorders and Stroke (RF1NS127266, RF1NS135615), and the National Institute on Aging (R01AG075883, K01AG076967, K01AG080122).
