The Abdominal Adiposity Index (A Body Shape Index) Predicts 10-Year All-Cause Mortality in Elderly Active Non-Obese Subjects

Background/Objectives: A Body Shape Index (ABSI), which accounts for waist circumference relative to mass and height, shows a robust association with mortality risk. The present study evaluates the effectiveness of ABSI as a predictor of 10-year all-cause mortality in physically active, non-obese elderly individuals. Methods: This prospective cohort study included 159 volunteers (94 women, aged 60-80 years), recruited in the frame of the "Physical Activity and Nutrition for Great Ageing" (PANGeA) Cross-border Cooperation Program Slovenia-Italy 2007-2013, and followed for 10 years. Baseline characteristics included anthropometric measurements, bioelectrical impedance analysis, and cardiovascular fitness tests (VO₂max). Statistical analyses (Cox regression, Kaplan-Meier survival) were conducted to examine the relationship between ABSI and mortality. Results: During the 10-year follow-up, 10 deaths (6.7%) were recorded. ABSI (adjusted for age, smoking, comorbidities, and therapy) was an independent predictor of mortality (hazard ratio = 4.65, p < 0.001). Higher ABSI scores were linked to reduced VO₂max (r = -0.190, p = 0.017) and increased systolic blood pressure (r = 0.262, p = 0.001). An ABSI-based predictive model showed strong discriminatory power (AUROC = 0.91). Conclusions: ABSI is a reliable predictor of 10-year mortality in active, non-obese elderly individuals and may improve risk stratification in clinical practice.