HEMOGLOBIN LEVEL IS LINKED TO GROWTH HORMONE-DEPENDENT PROTEINS IN SHORT CHILDREN

Erythropoiesis was investigated in 32 children with short stature and in eight children with skeletal dysplasia by studying blood hemoglobin in relation to growth and to serum concentrations of insulin-like gro wth factor I (IGF-I), IGF binding protein-3 (IGFBP-3), and erythropoie tin (EPO) before, during, and after 12 months of recombinant human gro wth hormone (GH) treatment. Blood hemoglobin concentration was positiv ely correlated with relative body height and with serum IGF-I and IGFB P-3 levels (P = .001 to .02), but not with the concentrations of EPO. The normal age-dependency of hemoglobin was lacking. Hemoglobin levels and their responses to GH treatment were similar in the patients with GH deficiency and those with normal GH secretion. Treatment with GH a ccelerated growth and elevated the concentrations of hemoglobin, IGF-I , and IGFBP-3. In the eight patients with skeletal dysplasia, body mas s increased similarly, but gain in height was less than in the other p atients, and the increase in hemoglobin was markedly pronounced. In th is group, the correlations between hemoglobin, IGF-I, and IGFBP-3 were extremely close (r = 0.80 to 0.85, P = .031 to .008). These findings are in accord with earlier observations from in vitro and animal studi es, and suggest that the GHIGF axis is involved in the physiologic ele vation of hemoglobin levels during childhood. (C) 1996 by The American Society of Hematology.