Head circumference in untreated and IGF-I treated patients with Laron syndrome Comparison with untreated and hGH-treated children with isolated growth hormone deficiency

Background: Head circumference (HC) is a simple and practical measure of brain size, development and longitudinal measurements of the HC in childhood are an index of brain growth. Objective: To determine the effects of long IGF-I deficiency and treatment on HC in patients with Laron syndrome (LS). Patients: 20 untreated adult LS patients, aged 48.4 +/- 11.2 years and 13 LS patients treated between ages of 5.6 +/- 4 to 11.3 +/- 3 years were studied. 15 patients with congenital IGHD treated between age 6.1 +/- 4 and 13 +/- 4 by hGH served as controls. Methods: HC was expressed as standard deviation (SD) and Ht as SDS. HC was measured and plotted on Nellhaus charts. Linear height (Ht) was measured by a Harpenden Stadiometer. Results: The mean HC deficit of the adult untreated LS males was -2.9 +/- 0.6 SD compared to a Ht deficit of -7.0 +/- 1.7 SDS. The HC of the LS adult females was -3.6 +/- 1 SD compared to a Ht SDS of -6.9 +/- 1.5 (p<0.001). IGF-I treatment (150-200 mu g/kg once daily) increased the HC from -3.3 +/- 0.9 (m +/- SD) to normal values (0.87 +/- 1.8 SD) (p<0.001) in 11/13 children. The Ht SDS deficit decreased only by 1.5 SDS. hGH treatment of cIGHD children increased the HC from -2.0 +/- 1.8 to 0.3 +/- 1.2 SD and the Ht SDS from -4.8 +/- 1.6 to 1.6 +/- 1.0. Conclusions: a) Untreated children and adults with LS and cIGHD have a reduced HC (i.e. brain size). IGF-I treatment of LS children and hGH treatment of IGHD children induced a fast catch-up growth denoting the role of IGF-I on brain growth. b) Comparison between IGF-I and hGH on linear growth stimulation revealed a greater potency of hGH. (C) 2012 Elsevier Ltd. All rights reserved.