Urinary C-peptide excretion in obese and anorectic children.

To assess the total insulin secretion in children in different nutritional states we have analysed the 24 h urinary C-peptide excretion in 32 obese children (16 boys and 16 girls) 8-15 years of age as well as in 7 girls with anorexia nervosa 11-16 years of age. Obese children had a median urinary C-peptide excretion rate of 0.27 nmol/kg/24 h, which was not different from that of a group of normal-weight children. In the group of anorectic girls, on the other hand, the median value 0.47 nmol/kg/24 h was significantly (p less than 0.05) higher than for normal-weight girls of the same age (median = 0.26 nmol/kg/24 h). These results indicate that in obese children insulin secretion, measured as the 24 h urinary C-peptide excretion per kg body weight, is the same as in normal-weight children. Total insulin secretion is consequently increased. In anorexia nervosa, on the other hand, the higher C-peptide excretion per kg body weight compared with normal-weight children, indicates that insulin secretion is increased in relation to body weight.