Visceral fat in white and African American prepubertal children

The objectives of this study were 1) to examine interrelations among intraabdominal adipose tissue (IAAT) and other adiposity indexes, 2) to identify a visceral obesity index that is independent of total adiposity, and 3) to examine sex and ethnic (white compared with African American) differences in IAAT. We measured IAAT and subcutaneous abdominal adipose tissue (SAAT) using computed tomography, and total fat mass (FM) by dual-energy X-ray absorptiometry in a heterogenous sample of 101 children aged 7.7 +/- 1.6 y weighing 33.2 +/- 12.6 kg. IAAT was highly variable ((x) over bar +/- SE: 31 +/- 22 cm(2); range: 7-107 cm(2)) and related to SAAT (r = 0.87) and FM (r = 0.81). The regression slope between IAAT and SAAT was significantly lower in African Americans (0.17 +/- 0.02 cm(2) IATT/cm(2) SAAT) than in whites (0.23 +/- 0.02 cm(2) IAAT/cm(2) SAAT). Within each ethnic group there was no effect of sex on IAAT adjusted for SAAT ((x) over bar +/- SE: 40.2 +/- 3.1 and 43.2 +/- 2.7 cm(2) in white boys and girls, respectively; 26.4 +/- 1.9 and 25.1 +/- 1.6 cm(2) in African American boys and girls, respectively). We conclude that in children 1) there is wide variation in visceral fatness; 2) IAAT relative to SAAT is an index of visceral fat, independent of FM, allowing examination of the unique effects of IAAT; and 3) the relative distribution of adipose tissue in the intraabdominal compared with the subcutaneous abdominal region is significantly lower in African Americans than in whites.