Body Composition, IGF-I and IGFBP-3 Concentrations as Outcome Measures in Severely GH-Deficient (GHD) Patients after Childhood GH Treatment: A Comparison with Adult Onset GHD Patients

Abstract

If GH therapy of children with GH deficiency (GHD) has been adequate, body composition should be comparable to that of patients who have undergone normal childhood development and become hypopituitary thereafter. To assess this, body composition was determined in 92 patients with childhood onset (CO) GHD, aged 18–30 yr, who had been treated to final height with GH for 8.98 ± 4.30 yr and had stopped treatment 1.57 ± 1.20 yr previously, but who remained GHD (assessed by a GH stimulation test and IGF-I values). These were compared with 35 age-matched GH-naïve hypopituitary patients with adult onset (AO) GHD. Lean body mass, fat mass, and total bone mineral content were assessed by dual energy x-ray absorptiometry and corrected for actual height. CO patients were shorter (CO height, −1.18 ± 1.16 sd score; AO height, −0.38 ± 1.12 sd score; P < 0.001) and had lower body mass index (CO, 23.19 ± 5.76 kg/m2; AO, 28.9 ± 6.27 kg/m2; P < 0.001) than the AO group. Although there were gender differences, within genders CO patients had lower lean body mass, fat mass, and bone mineral content (P < 0.001 in all cases) compared with AO patients. Standard deviation scores for IGF-I (CO female, −9.2 ± 3.1; AO female, −5.2 ± 2.6; CO male, −6.4 ± 2.7; AO male, −3.5 ± 2.3; P < 0.001 within each gender) and IGFBP-3 (CO female, −3.5 ± 2.5; AO female, −1.7 ± 1.5; CO male, −2.8 ± 2.0; AO male, −1.1 ± 1.6; P < 0.001 within each gender) were significantly lower in the CO group. These results suggest that patients with CO GHD who were treated to final height suffer a significant maturational deficit despite GH replacement during childhood.