Abstract Body (Do not enter title and authors here): Introduction: Obesity increases coronary artery disease (CAD) risk and is highly associated with diabetes. Although body mass index (BMI) is more frequently used as an objective assessment of obesity, abdominal circumference (AC) is often overlooked as a risk factor, especially in nonobese individuals. We examined the association between AC and coronary artery calcium score (CAC), a marker of subclinical CAD.

Methods: We analyzed data from 2184 asymptomatic nonobese individuals (BMI 18 - 30 kg/m²) without prior cardiovascular disease (CVD) from the ELSA-Brasil cohort. The association of standardized AC and CAC incidence was examined by multivariable logistic regression models. Models were adjusted for age, sex, race, premature family history of CVD, tobacco use, physical activity, hypertension, triglycerides, LDL, statin use, diabetes, and interaction between diabetes and AC. CAC incidence was defined by initial CAC = 0 and repeated CAC > 0 and were performed between 2010-2018.

Results: The mean age was 48±8, 60% were female, and 67.2% were white. CAC incidence was 15% (327/2184) and the mean CAC interval in years was 5.2±1. AC was significantly associated with CAC incidence across all models (Model 1 OR = 1.53, 95% CI: 1.24-1.89, p<0.001; Model 2 OR = 1.49, 95% CI: 1.20-1.85, p<0.001; Model 3 OR = 1.46, 95% CI: 1.16-1.83, p=0.001). Diabetes mellitus status did not significantly alter the risk estimates.

Conclusions: Abdominal circumference is an independent risk factor for the incidence of subclinical CAD assessed by CAC in nonobese asymptomatic individuals without prior CVD, after adjusting for classical risk factors. This finding suggests that AC may serve as a subtle clinical marker of residual risk factors, potentially indicating the importance of visceral fat in this population.