[Performance of the "a body shape index" as a discriminator of obesity and sarcopenic obesity - ELSA-Brasil].

Abstract

The scope of this study was to determine the diagnostic performance of ABSI for obesity and sarcopenic obesity, compared to the results of bioimpedance analysis (BIA) and BMI, by sex and age group. It involved a cross-sectional study with 12,793 participants in the second round of ELSA-Brasil (Longitudinal Study of Adult Health in Brazil), which obtained measurements of body fat percentage using BIA and anthropometry, verifying the performance of the diagnostic tests in order to compare the indices. The results showed that for obesity in men in all three age groups, the sensitivity was below 49%. Specificity ranged from 73% to 93%, with a higher percentage in the 65 to 79 age group. The same pattern was found for women, with sensitivity lower than 42%, and specificity ranged from 85% to 92%, and was higher in older women. With respect to sarcopenic obesity, the sensitivity and specificity among men in the three age groups were 72% was 99%, respectively. Among women, sensitivity was around 95% and specificity around 70% in all age groups. ABSI, compared to BIA, showed a reduced ability to identify obesity. However, it proved to be a good marker of sarcopenic obesity.