Abstract 4144170: Association of loneliness and social isolation with incident atrial fibrillation: a population-based cohort study using the UK Biobank

Background: The role of socio-psychological factors, such as loneliness and social isolation has gained increasing attention, especially in a post-COVID world. However, their related evidence on atrial fibrillation (AF) is scarce. Aims: We sought to assess whether loneliness and social isolation are associated with the risk of incident AF, and which behavioral factors serve as the mediators in such association. Methods: Using data from the UK Biobank, we included the participants free of AF at baseline, and categorized them into three-level loneliness and social isolation scales by self-reported questionnaires, respectively. After adjusting for potential confounders, the hazard ratios (HRs) with 95% confidence interval (CI) of incident AF were estimated by Cox proportional hazard models. The mediating effects of behavioral factors (including current smoking, excess alcohol use, insufficient physical activity, unhealthy diet, sleep deprivation, and obesity) were assessed using a 2-stage regression method for survival data. Results: Among 459,282 participants (mean age of 56.4 years, 55.0% female), 25,406 incident AF cases were documented during a median follow-up period of 12.1 years. In the fully adjusted models, compared with participants with the lowest loneliness scale (zero), participants with the highest loneliness scale of 2 had a significantly higher risk of incident AF (HR 1.21 [95% CI 1.15-1.27]. However, those with social isolation scale of ≥2 had only mild additional risk, with marginal significance (HR 1.06 [95% CI 1.02-1.10]. The association between loneliness and risk of AF was significantly modified by sex (P for interaction=0.029), with female participants suffering from the more detrimental effect of loneliness. Obesity, current smoking, and sleep deprivation were the top three mediators, with a mediated proportion of 20.3%, 8.4%, and 7.6%, respectively. Conclusions: Loneliness was independently associated with a higher risk of incident AF, which was mediated by unhealthy behaviors.