Comparison of total body and abdominal adiposity indexes to dual x-ray absorptiometry scan in obese adolescents.

Abstract

While indexes have been proposed to estimate total and abdominal adiposity in adults, the assessment of adiposity among obese adolescents remains difficult in clinical setting. The aim of this study was to evaluate the clinical applicability of total and visceral and fat mass indexes in obese adolescents. One hundred and thirty, 12-16 year old obese adolescents were enrolled in the study. Anthropometric characteristics [Height, weight, waist (WC), and hip (HC) circumferences] were measured and body composition assessed by Dual X-Ray absorptiometry (DXA) assessed. High Density Lipoprotein-Cholesterol (HDL-C) and Triglycerides (TG) plasma concentrations were assessed from fasting blood samples. Body Adiposity indexes (BAI) were calculated from formulas taking into account, height, weight, and WC, and for the Visceral Adiposity indexes, a formula including WC, HDL-C, and TG. Both the BAI and Pediatric Body Adiposity Index (BAIp) were significantly correlated to the percentage of total body fat assessed by DXA (DXA %FM; P < 0.001; r = 0.67 and r = 0.64, respectively). The best concordance with DXA %FM was found using BAI. The Visceral Adiposity Index was only weakly associated with abdominal fat mass assessed by DXA (r = 0.27, P < 0.01) and only significantly in boys (r = 0.41, P < 0.01) when the analysis was performed by gender. The BAI initially developed in adults presented a better but still weak association with DXA-%FM when compared with the BAIw and BAIp. The three indices thus do not provide better estimate of obese adolescents' adiposity than the widely used Body Mass Index.