Atrial Fibrillation and the Risk of Subsequent Fracture

There is conflicting evidence regarding the association between atrial fibrillation and the risk of subsequent fractures. We included participants aged 45 years or older from the Framingham Heart Study Offspring, Third-Generation, New Offspring Spouse, Omni 1, and Omni 2 cohorts. We prespecified analyzing index age 65 years as our primary analysis; we repeated analyses for index ages 45, 55, and 75 years. The primary outcome was any incident bone fracture, except finger, toe, foot, skull, and facial fractures. We assessed the association between time-varying atrial fibrillation and subsequent fractures by an illness-death model that accounted for the competing risk of death. We estimated hazard ratios (HR) adjusted for age, sex, body mass index, smoking, diabetes, alcohol intake, and prior fracture. We included 3403 participants (mean age of 68 years, 53.3% female) in the analysis at index age 65 years and above. In all, 525 (15%) participants suffered incident fractures during follow-up (median 12.5 years). The HR between atrial fibrillation and subsequent fracture was 1.37; 95% confidence interval (CI), 1.06-1.79. There was no evidence of effect modification by sex (HR 1.55; 95% CI, 1.06-2.26 in men; HR 1.22; 95% CI, 0.84-1.77 in women; interaction P value .27). Results were consistent at other index ages. Atrial fibrillation was associated with increased risk of incident fracture in the community-based Framingham Heart Study.