Mediators between body mass index and atrial fibrillation: a Mendelian randomization study

Although obesity is a recognized risk factor of atrial fibrillation (AF), the mechanisms are not fully understood. We aimed to identify the potential mediators between body mass index (BMI) and AF. We conducted a two-sample Mendelian randomization (MR) analysis using publicly available summary-level data from genome-wide association studies. Univariable MR analyses were applied to identify potential mediators, and then the multivariable MR analyses were conducted to explore the mediated roles of circulating biomarkers, metabolic markers and comorbidities in the association between BMI and AF. This MR study found a significant causal association between BMI and AF (OR = 1.41, 95% CI = 1.33-1.50;