Aging
Mediating Effects of DNA Methylation on the Association Between Health-Related Behaviors and Cognition Using Data From the Health and Retirement Study Junyub Lim* Junyub Lim Lim Lim Edson College of Nursing and Health Innovation, Arizona State University, Phoenix, AZ, United States
[SER 2026 Poster Presentation Abstract]
Title: Mediating Effects of DNA Methylation on the Association Between Health-Related Behaviors and Cognition Using Data From the Health and Retirement Study
Junyub Lim, M.A. 1; Ross Andel, Ph.D.1; Judith Rijnhart, MSc, PhD2
1 Edson College of Nursing and Health Innovation, Arizona State University, Phoenix, AZ, United States
2 Department of Epidemiology, College of Public Health, University of South Florida, Tampa, FL, United States
Objectives: Biological mechanisms linking health-related behaviors to cognitive aging remain unclear. We examined whether DNA methylation–derived pace of biological aging, measured by the DunedinPoAm38, mediates associations between smoking, alcohol consumption, physical activity, sleep disturbance, and cognitive function in a nationally representative U.S. sample. Methods: Using Health and Retirement Study data (2014–2020), we analyzed data from 3,761 participants from the 2016 Venous Blood Study who were dementia-free at baseline (2014) and had complete data. Causal mediation analyses assessed whether the pace of biological aging mediated associations between health-related behaviors and cognition score, adjusting for sociodemographic factors. Results: Participants had a mean age of 67.2 years (SD = 9.6), and 58.5% were women. Current smoking and sleep disturbance were significantly associated with poorer cognition score (total effects = -0.148, 95% CI [-0.246, -0.055] and -0.073 [-0.099, -0.047], respectively), whereas vigorous physical activity and heavy alcohol consumption were significantly associated with better cognition score (total effects = 0.145 [0.086, 0.211] and 0.139 [0.030, 0.254], respectively). The pace of biological aging significantly mediated associations between four health-related behaviors and cognition score. Among current smokers, the pace of biological aging accounted for 45.2% of the association (indirect effect = -0.067 [-0.123, -0.012]); for vigorous physical activity, 11.4% (indirect effect = 0.016 [0.006, 0.028]); and for sleep disturbance, 2.8% (indirect effect = -0.002 [-0.004, 0.000]). Heavy alcohol consumption showed a significant negative indirect effect through the pace of biological aging (-0.014 [-0.028, -0.003]), indicating inconsistent mediation. Discussion: Findings suggest that the pace of biological aging mediated the associations between smoking, alcohol consumption, physical activity, sleep disturbance, and cognition.
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