Objective: To evaluate the pituitary hormone axes in adolescents with constitutional tall stature (CTS).
Materials and methods: About 120 patients (54 males and 66 females) with CTS aged 9.616.5 years (13.6±2.7 years, mean±S.D.) were enrolled in this study. Sixty-eight normal subjects (24 males and 44 females) aged 9.816.2 years (13.1±2.1 years), who were comparable in socioeconomic and nutritional terms, served as controls. Growth hormone, insulin-like growth factor-I (IGF-I), IGF-binding protein-3 (IGFBP-3), luteinizing hormone, follicle-stimulating hormone and prolactin levels were measured.
Results: In comparison with controls, CTS children showed a slightly lower concentration of IGFBP-3 and a higher concentration of IGF-I but these differences were not significant. In contrast the IGFBP-3/IGF-I molar ratio was significantly lower (0.7±0.1 vs 1.1±0.2; P<0.001) in CTS children than in controls. The concentrations of other pituitary hormone in CTS-affected subjects were not significant different from those determined in controls.
Conclusions: This study has demonstrated that in CTS the most components of pituitary hormone axes are normal, but the IGFBP-3/IGF-I molar ratio is increased, and, therefore, a greater availability of free IGF-I for target tissues may be responsible for overgrowth in CTS.
03 - 07 May 2008
European Society of Endocrinology