Assessment of abdominal fat development in young adolescents using magnetic resonance imaging

OBJECTIVE: To determine the patterns of change and the best anthropometric indicators of intra-abdominal fat deposition in young adolescents from ages 11-13 y. SUBJECTS: Subjects were 25 boys (mean age 13.7 +/- 0.32 y) and 17 girls (me an age of 13.7 +/- 0.23 y) who had taken part in a similar study 2 y earlie r at ages 11.5 +/- 0.33 y and 11.5 +/- 0.27 y, respectively. METHODS: Intra-abdominal (IA) and subcutaneous adipose (SA) tissue areas an d IA/SA ratio were determined through four tranverse magnetic resonance ima ging scans on two occasions. Differences were investigated using t-tests an d ANOVA. Skinfolds, girths and circumferences, body mass index and hydrosta tic weighing were also recorded. Pearson correlation coefficients and regre ssion equations were calculated to determine the best anthropometric indica tors of intra-abdominal fat deposition. RESULTS: Intra-abdominal fat and subcutaneous fat areas had significantly i ncreased in boys and girls by the second measure. Boys had deposited greate r amounts of fat in intra-abdominal depots so that their intra-abdominal/su bcutaneous ratio had increased significantly from 0.31 to 0.39. This had re duced in girls from 0.39 to 0.35. However, patterns of change were variable within sexes. Truncal skinfold sites (r = 0.54-0.70) emerged as the best f ield indicators of intra-abdominal fat deposition. CONCLUSIONS: Patterns of intra-abdominal and subcutaneous fat distribution are identifiable in pubescent children using magnetic resonance imaging. An acceptable indication is provided by truncal skinfolds.