Associations of socioeconomic status and chronic stress with incident atrial fibrillation among older adults: A prospective cohort study from the UK biobank

Background: This study aimed to assess the relationship between socioeconomic status (SES) and chronic stress on the incidence of atrial fibrillation (AF) in older adults, and the potential role of chronic stress in the association. Methods: This study included 122,494 UK Biobank participants aged >= 60 years without AF at baseline. Latent class analysis was used to define the SES of participants. Chronic stress was measured using allostatic load (AL), and participants were categorized into low, medium and high AL groups. The Cox proportional hazards model, mediation, and interaction analyses were conducted to investigate the associations between SES, AL, and AF risk. Results: Low SES (hazard ratio [HR]: 1.10; 95 % confidence interval [CI]: 1.04-1.15) and high AL (HR: 1.37; 95 % CI: 1.30-1.45) were associated with an increased risk of AF, respectively. Individuals in the low SES and high AL groups exhibited the highest risk of AF compared to those in the high SES and low AL groups (HR: 1.46; 95 % CI: 1.32-1.61). We identified additive and multiplicative interactions in the low SES and high AL groups (relative risk due to interaction: 0.12 (95 % CI: 0.02-0.22); P for interaction = 0.0385). AL also exerted a partial mediating effect on the association between SES and the incidence of AF (mediation proportion: 17.3 %; 95 % CI: 5.9-28.7 %). Conclusions: Our study revealed significant associations between SES, chronic stress, and the incidence of AF in older adults. Chronic stress was also shown to partially mediate the association.