Effect of growth hormone (GH) treatment to idiopathic short stature (ISS) patients on peripheral thyroid hormone (TH) mechanism of action

PELLIZAS CG; SUSPERREGUY S; MONTESINOS MM; MASCANFRONI ID; MASINI-REPISO AM; MUÑOZ L; PAEZ A; AYAN D; TKALENKO N; MIRAS MB

Lima, Perú

Congreso; XX Congress of the Latin American Pediatric Endocrinology Society; 2008

Latin American Pediatric Society

Introduction: In previous studies we demonstrated that GH administration to experimental animals and to Turner Syndrome Patients reduced TH mechanism of action evaluated through the expression of its nuclear receptors (TRa and b) and serum markers of TH action (SHBG and TSH). The aim of this work is to study the response to TH in ISS patients under GH therapy. In ISS the height of the individual is more than 2.5 SD below the mean height for a given age, sex and population with no identifiable disorder. Several clinical trials demonstrated beneficial effects of GH treatment. Patients & Métodos: Five ISS patients that exhibited a growth velocity (GV)<2.5 SD and positive GH generation tests were evaluated and analyzed previous (pre) and after (post) 12 months of GH therapy (1UI/kg/week). Peripheral blood mononuclear cells were obtained and total RNA extraction for the expression of TRb and a (real-time RT-PCR) performed. In turn, SHBG and TSH were measured in serum (electrochemiluminescence) Results: The results achieved in post samples (vs. pre samples designed as 1.00) were: TRb: 0.44±0.19; TRa: 3.12±1.60; SHBG: 0.73±0.06; TSH: 1.87±0.50 (test t, p<0.05) Conclusions: These results indicate that GH treatment to ISS patients reduced the expression of TRb and enhanced that of TRa. In agreement, a reduction of SHBG and an increase of TSH serum levels were recorded. These preliminary results are being analyzed in a larger number of patients. Since the bone is a target tissue for TH action, these findings may have repercussions in the growth response to GH therapy.