Beyond body mass index: visceral adiposity and metabolic alterations as early markers of atrial dysfunction and atrial fibrillation in midlife

Background: Atrial fibrillation (AF) develops along the cardiometabolic continuum, where visceral adiposity and early atrial dysfunction may precede overt disease. We aimed to identify independent predictors of new- onset and recurrent AF in middle-aged individuals with cardiometabolic risk. Methods: This observational cohort included 240 outpatients (40-60 years; 71 controls, 77 new-onset AF, 92 recurrent AF). Conventional anthropometric parameters (body mass index, body roundness index) and biochemical markers (fasting glucose, uric acid, creatinine clearance, inflammatory markers and high-sensitivity troponin I- hsTnI) were assessed. A comprehensive echocardiographic assessment including left atrial reservoir strain (LASr), electromechanical delay (EMD), and epicardial adipose tissue (EAT) were analyzed. Binary logistic regression and ROC analyses were performed. Results: New-onset AF was independently associated with fasting glucose (OR 3.604; 95% CI 1.338-9.704; p=0.011), EAT thickness (OR 1.479; p=0.006), electromechanical delay (OR 1.043; p=0.001), uric acid (OR 1.006; p=0.026), and lower LASr (OR 0.944; p=0.045). Among the evaluated parameters, EAT demonstrated the highest discriminatory ability for new-onset AF (AUC 0.664; p