Abstract 4113188: Increased Physical Activity Intensity Associated with Reduced Risk of Atrial Fibrillation among Older Adults in South Korea: A Retrospective Cohort Study

Introduction: Physical activity (PA) may be associated with a lower risk of atrial fibrillation (AF), but this relationship remains controversial. In particular, further research is needed on the association between changes in PA intensity and AF risk among older adults. Hypothesis: We hypothesized that an increase in PA intensity would be associated with a reduced risk of AF among older adults aged 65 years and older in South Korea. Aim: This cohort study aimed to evaluate the association between changes in metabolic equivalent tasks (METs)-min/week and the risk of AF in the elderly using a nationally representative database. Methods: We conducted a retrospective cohort study using the Korea National Health Insurance Service (KNHIS) database. This cohort included 1,726,697 individuals aged 65 years and older without a history of cardiovascular disease diagnosis who underwent two consecutive health screening examinations from 2009 to 2012. PA was defined as MET-min/week derived from two consecutive health examinations during 2009-2010 (1st period) and 2011-2012 (2nd period), respectively. The primary outcome was an AF diagnosis during the follow-up period from 2013 to 2021. We estimated the sub-distribution hazard ratio (sHR) and 95% confidence interval (CI) for the association of changes in PA intensity with AF using Fine-Gray sub-distribution hazard models after adjustment for covariates. Results: This study included 1,726,697 participants (mean age 71.08; 46.78% male). An increase in PA intensity was associated with a reduced risk of AF (P for trend<0.001). Compared to persisting in physical inactivity, a change in PA intensity from physically inactive to ≥1000 MET–min/week was associated with a lower risk of AF (sHR, 0.83, 95% CI, 0.81-0.85). In contrast, a change in PA intensity from ≥1000 MET–min/week to being physically inactive was associated with a higher risk of AF (sHR, 1.30, 95% CI, 1.27-1.33) as compared to persistence in ≥1000 MET–min/week of PA intensity. Conclusions: An increase in MET-min/week may be associated with a reduced risk of AF among adults aged 65 years and older. Therefore, interventions encouraging PA should be recommended to maximize the health benefits of AF prevention in the elderly.