GROWTH-HORMONE SECRETION AND CIRCULATING INSULIN-LIKE GROWTH-FACTOR-I(IGF-I) AND IGF BINDING PROTEIN-3 CONCENTRATIONS IN CHILDREN WITH SICKLE-CELL DISEASE

Impaired growth involving both height and weight accompanying sickle c ell disease (SCD) poses diagnostic and therapeutic problems. We undert ook this study to test the hypothesis that this impaired growth is ass ociated with abnormalities of the growth hormone (GH)/insulin-like gro wth factor-I (IGF-I)/IGF binding protein-3 (IGFBP-3)axis in 21 childre n with SCD and that SCD is associated with GH resistance. Nine of 21 c hildren with SCT) had a defective GH response to both clonidine and gl ucagon provocation (peak, < 10 mu g/L); these children differed from t he 12 others in having slower linear growth velocity (GV and GVSDS), l ower circulating concentrations of IGF-I and IGFBP-3, and either parti al or complete empty sellae in computed tomographic scans of the hypot halamic-pituitary area. In this group of patients with SCD, it appears that defective GH secretion and consequent low IGF-I production are t he major etiological factors causing the slow growth. The two groups w ith SCD did not differ significantly in dietary intake, body mass inde x (BMI)), midarm circumference, skinfold thickness, serum albumin conc entration, or intestinal absorption of D-xylose. A single injection of GH produced a smaller increase in circulating IGF-I in children with SCD with or without defective GH secretion versus 10 age-matched child ren with idiopathic short stature (ISS) and 11 children with isolated GH deficiency(GHD), suggesting partial GH resistance in the SCD group. The presence of defective GH secretion, decreased IGF-I synthesis, an d partial resistance to GH in short children with SCD suggests that tr eatment with IGF-I may be superior to GH therapy for improving growth. Copyright (C) 1997 by W.B. Saunders Company.