Body fat distribution in pubertal girls quantified by magnetic resonance imaging.

We examined body fat distribution in relation to anthropometrically derived variables in 24 girls in early and late stages of puberty. The amounts of subcutaneous and intra-abdominal body fat were derived from transverse slices at the levels of the waist, hip and trochanter using magnetic resonance imaging (MRI), and were compared to the related circumferences, the circumference ratios and the trunk-to-extremity skinfold ratios. Waist, hip and trochanter circumferences were highly correlated to the respective related MRI total fat surface area both in early and late pubertal girls (r = 0.79-0.97), while waist circumference, and waist-hip, waist-thigh or skinfold ratios were not significantly correlated to intra-abdominal fat areas. Late pubertal girls (n = 11) were significantly taller, heavier and fatter compared to early pubertal girls (n = 13), yet their anthropometric waist-to-hip or waist-to-trochanter circumference ratios were significantly lower. The intra-abdominal fat area measured in a transverse MRI section at the level of the waist was 24.1 +/- 4.1 cm2 in early pubertal girls and 25.7 +/- 4.1 cm2 in late pubertal girls (mean +/- s.e.m.). As compared to early pubertal girls, the MRI derived amount of subcutaneous fat in late pubertal girls was significantly higher at the trochanter level (142.1 +/- 12.7 vs. 201.3 +/- 26.3 cm2; P less than 0.05). We conclude that circumferences at the trunk are good measures for the related amounts of fat in pubertal girls. In contrast conventional anthropometric measurements, such as trunk-to-extremity skinfold ratio or waist-to-hip circumference ratio, cannot be used to predict the amount of intra-abdominal fat in pubertal girls.(ABSTRACT TRUNCATED AT 250 WORDS)