Efeito do tratamento com hormônio de crescimento na baixa estatura idiopática com deficiência moderada do GH ou insensibilidade parcial ao GH

Abstract

Idiopathic Short Stature is a heterogeneous set of conditions without obvious hormonal changes or defined etiologies. It may include the partial insensitivity to GH (PGHI) and the moderate GH deficiency (MGHD), both of them with low concentrations of growth factor like insulin type I (IGF-I) and hyper or sub-answer of GH on tests of stimulation, respectively. The objective of this study is to assess the response to treatment with GH in PGHI and MGHD, comparing them twith the results obtained in a group with severe GH deficiency (SGHD). It was studied in PGHI (GH peak ≥18 ng/ml) 20 individuals (14 boys), 12.07 (2.57-year-old); in MGHD (GH peak between 5 and 10 ng/ml) 12 (7 boys), 10.73 (1.79-year-old); and in SGHD (GH peak lower than 5 ng/ml) 19 (10 boys), 10.90-(3.51) yearold, treated with GH for one to ten years. The initial and present GH doses were, respectively, 43.33(10.00) and 49.61 (12.90) μg/kg/day in SGHD, 50.27 (11.76) and 57.27 (15.83) μg/kg/day in MGHD; and50.18 (6.99) and 55.66 (9.61) μg/kg/day in PGHI. The standard deviation score (SDS) of initial height of the SGHD group was lower than MGHD group (p< 0.01) and PGHI group (p <0.001).The SDS of initial IGF-I of SGHD was similar to MGHD and lower than PGHI group (p<0.0001).The initial bone age (BA) in SGHD group was similar to MGHD and lower than PGHI group GH (p < 0.01). GH treatment has brought about a lower increase in the height SSD and in the IGF-I SSD (both, p < 0.05) and in the bone age (p< 0.01) in the PGHI group than in the SGHD group, probably due to the more accentuated height deficit in the SGHD group and lower IGF-I increase in the PGHI group. Treatment response was similar in MGHD and SGHD groups. The lowest height gain in the PGHI suggests that the partial GH insensitivity needs higher GH doses to be effective.