Association of Body Shape Index with Mortality and CHD Hospitalization: A Cohort Study in an Israeli Nationwide Middle-Aged Sample

Introduction: Obesity is a known risk factor for cardiovascular disease (CVD) morbidity and mortality. A body shape index (ABSI) is a waist circumference (WC) measure of abdominal obesity independent of body mass index (BMI) that has been shown to predict mortality and numerous clinical outcomes.

Aims: To study the predictive value of ABSI in conjunction with BMI for all-cause mortality and coronary heart disease (CHD) hospitalization among adult participants.

Methods: Participants (n=2,225) were drawn from the First Israeli National Health and Nutrition Survey (1999-2001), constituting adults aged 25-64. Baseline anthropometrics were measured and expressed as their allometric indices: BMI (weight/height²) and ABSI [WC/(BMI^2/3*height^1/2)]. Follow-up lasted through 2021 for mortality and 2022 for hospitalizations. Cox regressions assessed the adjusted risk of all-cause mortality and CHD hospitalization.

Results: Baseline mean [SD] age was 43 [11] years, and 50% were women. Correlation between BMI and WC was 0.78, and 0.02 for BMI and ABSI. Over a median follow-up of 21 years, 247 (11.1%) deaths occurred. Multivariable-adjusted hazard ratios (HRs) for mortality per 1 SD increase in BMI and ABSI were 1.11 (95% CI: 0.97; 1.27) and 1.55 (95% CI: 1.33; 1.79), respectively (Table). ABSI exhibited a significant association with mortality across all standard BMI categories with adjusted HRs (95% CIs) per 1 SD increase of 1.38 (1.01; 1.88) for individuals with a BMI of 18.5-24.9, 1.70 (1.34; 2.16) for BMI 25.0-29.9, and 1.46 (1.13; 1.87) for BMI ≥30.0. Among CVD-free participants at baseline (n=2,146), 267 (12.4%) were hospitalized for CHD during follow-up. An increase in the adjusted HR was seen for both ABSI [1.34 (95% CI: 1.15; 1.55)] and BMI [1.16 (95% CI: 1.01; 1.33)] (Table).

Conclusion: In a 20-year prospective study of a middle-aged cohort, baseline ABSI was a stronger predictor of mortality than BMI and predicted CHD hospitalization independently of BMI.