Abstract MP64: Body Mass Index and Waist Circumference are More Strongly Associated with Abdominal Adiposity Compared to a Body Shape Index in Middle-aged Adults: The Cardia Study

Abstract

Background: A Body Shape Index (ABSI) has been recently shown to better predict mortality when compared to BMI and waist circumference. Although individuals with higher abdominal adiposity generally exhibit greater mortality risk, the association between ABSI and imaging-based measures of abdominal adiposity has not been thoroughly explored. Objective: To quantify and compare associations between ABSI, BMI, and waist circumference with computed-tomography assessed measures of visceral (VAT), subcutaneous (SAT), and total (TAT) abdominal adipose tissue volumes in middle age adults according to race and sex. Methods: Coronary Artery Risk Development in Young Adults (CARDIA) is a community-based, prospective study of black and white men and women. Height (cm), weight (kg), and waist circumference (WC) were assessed during the year 25 exam (43-55 yrs), from which, BMI (kg/m 2 ) and A Body Shape Index (ABSI) were calculated. VAT, SAT, and TAT volumes (cm 3 ) were concurrently measured by computed tomography (n=3,155). Linear regression was used to assess the amount of variation in VAT, SAT and TAT explained by BMI, WC and ABSI composition measure accounting for age, sex, race, and study center Results: Height, weight, BMI, WC and ABSI were all univariately associated with VAT, SAT and TAT with significant interactions by race and sex. Across all race/sex groups, BMI, WC and weight explained greater variance in VAT, SAT and TAT compared to ABSI (Table 1). WC generally explained the most variance in abdominal adiposity measures (R 2 =0.56-0.74). BMI explained the largest amount of variance in SAT (R 2 = 0.74-0.78). ABSI and height explained the least variance in abdominal adiposity (range R 2 < 0.29). Conclusions: Although ABSI may provide additional information related to mortality that is not explained by more simple anthropometric measurements, the associations reported may not be strongly mediated through abdominal adiposity. BMI and WC remain simple clinical measures that strongly account for variations in abdominal adiposity.