GROWTH HORMONE (GH) TREATMENT TO IDIOPATHIC SHORT STATURE (ISS) CHILDREN INCREASED PERIPHERAL THYROID HORMONE (TH) RECEPTOR EXPRESSION

SUSPERREGUY S,; MUÑOZ L; MONTESINOS M,; MASCANFRONI I, ; MASINI-REPISO A, ; PÁEZ A, ; TKALENKO N; MIRAS MB, ; PELLIZAS CG

Congreso; LWPES/ESPE 8TH” Joint Meeting Global Care in Pediatric Endocrinology.; 2009

Sociedad Europea de Endocrinología pediatrica (ESPE)

Introduction: ISS is defined as a condition in which the height of an individualis more than 2 SD score (SDS) below the mean height for a given age, sex,and population group without evidence of systemic, endocrine, nutritional,or chromosomal abnormalities. Several clinical trials demonstrated beneficialeffects of GH treatment (J Clin Endocrinol Metab 93:4210,2008). In turn, themajor systemic hormones that influence growth during childhood include notonly GH/ insulin-like growth factor I (IGF-I) but also thyroid hormones (TH).The impact of TH action at tissue level is determined by TH availability aswell as by TR expression at tissue level. We have reported (Clin Endocrinol67:629,2007) that GH treatment to Turner Syndrome patients impaired peripheralTH action. The aim of this study was to assess the effect of GH treatmenton peripheral TR expression in ISS patients.Patients & Methods: Twenty ISS patients (growth velocity <2 SD and normalGH secretion after pharmacological provocation tests), 10-14 y/o, wereanalyzed previous and after 6 and 12 months of GH therapy (50μg/kg/day).All patients were euthyroid. Peripheral blood mononuclear cells (PBMC) wereobtained (Fycoll-Hipaque), total RNA extracted (Trizol) and TR mRNA levelsdetermined by Real-time RT-PCR. In turn, thyroid function was tested by thyrotropin,total thyroxine, free thyroxine and total triiodothyronine serum levelsand the biochemical response to GH treatment by osteocalcin (OC), b-crosslaps(B-CL) and IGF-I serum levels (measured by electrochemiluminescence exceptfor IGF-I that was determined by a immunoradiometric assay).Results: As depicted in Table 1, results achieved showed a significant increasein TR mRNA expression in PBMC after both 6 and 12 months of GH treatment(ANOVA-Student-Neuman-Keuls, *p<0.05 vs pre GH treatment sample). Inturn, no changes in thyroid function tests and significant increases in IGF-I, OCand b-CL were registered.