Fitbit-measured physical activity is inversely associated with incident atrial fibrillation among All of Us participants

ABSTRACT Background and Aims Individuals who report meeting weekly moderate to vigorous physical activity (MVPA) guidelines have lower risk of atrial fibrillation (AF). However existing studies have relied on subjective questionnaires or short-duration (<1 week) objective assessments using accelerometry. The objective of this research was to investigate an association between moderate to vigorous physical activity (MVPA) levels and the incidence of atrial fibrillation (AF), utilizing long-term, free-living accelerometry data. Methods 1-year Fitbit data, in addition to survey and electronic health record (EHR) data, were extracted from the NIH All of Us (AoU) research database. Cox proportional hazards regression was used to model the association of average MVPA (both continuous and categorized as 300 minutes/week) and incident AF over a five-year follow-up period. Results 6086 AoU participants were included (51±16 years, 70% female, 83% White, BMI 28.5±4.9 kg/m 2 , 41±12 complete weeks of Fitbit wear). 55 individuals (0.9%) experienced incident AF in the five-year follow-up period. More time spent in MVPA was associated with lower AF risk (HR = 0.89 [0.81,0.98], p=0.02), with a step-wise reduction for 151-300 mins (p=0.07) and >300 mins (p=0.04) of weekly MVPA, respectively. In a subset of 3847 participants with genomic data, this association persisted after adjustment for AF genetic risk score. Conclusions Higher amounts of objectively measured MVPA, measured using free-living, long-term accelerometry data, were inversely associated with risk of incident AF, independent of clinical and genetic risk factors.