Effects of human growth hormone administration on serum somatomedins, somatomedin carrier proteins, and growth rates in children with growth hormone deficiency.

Abstract

We have determined the growth rates and serum somatomedin (Sm) and Sm carrier protein (CP) levels in 30 children with GH deficiency and short stature before and up to 3 yr of GH therapy. Initially, the mean (±SEM) bone age (BA) of this group (6.9 ± 0.5 yr) was significantly (P<0.001) less than the chronological age (CA; 10.4 ± 0.7 yr), and their growth rate (3.45 ± 0.33 cm/yr) was markedly less than those of normal control groups matched either for CA (5.45 ± 0.22 cm/yr) or BA (6.46 ± 0.33 cm/yr). Compared to serum levels in a group of 40 age-matched controls, we found diminished concentrations of total Sm insulin-like growth factor (IGF) activity (0.31 ± 0.03 vs. 1.61 ± 0.12 μg/ml), IGF-I (0.09 ± 0.02 vs. 0.44 ± 0.04/ig/ml), and CP (123 ± 18.8 vs. 366 ± 28.2 μg/ml). Both total IGF and IGF-I were inversely related to the degree of growth retardation, expressed as the ratio of BA to CA. Serum Sm increased in 19 of 21 subjects after short term (up to 18 h) GH administration (0.1 U/kg), but the magnitude of ...