Growth hormone treatment in children with idiopathic short stature: correlation of growth response with peripheral thyroid hormone action

SEBASTIÁN SUSPERREGUY; LILIANA MUÑOZ; NATALIA KTALENKO; IVAN MASCANFRONI; ALAMINO VANINA ALEJANDRA; MONTESINOS MARÍA DEL MAR; ANA MASINI-REPISO; MIRTA MIRAS; CLAUDIA GABRIELA PELLIZAS

CLINICAL ENDOCRINOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2011 vol. 74 p. 346 - 353

0300-0664

Objective Idiopathic short stature (ISS) describes short childrenwith normal GH secretion. Although GH treatment increases theirheights, growth response to the therapy differs among patients.Thyroid hormones (TH) are essential for longitudinal growth acting mainly through TH receptors (TR) a and b. We have previouslyreported that GH treatment reduced peripheral TH action inTurner Syndrome by TR down-regulation. The aims of the studywere to assess the effect of GH treatment to ISS on peripheral THaction and the correlation between thyroid status and growthresponse to the therapy.Subjects, design and measurements Eighteen normal (control) and twenty-five ISS children were enrolled and evaluatedbefore and after 12 months of life time (control) or 12 months ofGH therapy (ISS). Fasting blood was used for serum biochemicalevaluations, peripheral blood mononuclear cells for TR mRNAdetermination by QRT-PCR and growth parameters by standardmethods.Results GH treatment modified neither TR mRNA levels norserum markers of TH action in ISS evaluated as a whole group.However, the individual change in TRb mRNA levels correlated tothe change in sex hormone?binding globulin (SHBG) levels afterGH therapy. The growth response to GH correlated positively withthe change in TRa mRNA level and negatively with that in TRbmRNA, TSH and SHBG levels. The change in each TR mRNA isoform after GH treatment correlated negatively with its own basallevel.Conclusions GH therapy induced individual changes in TRexpression in ISS that correlated with their growth response. Thebasal TR mRNA level could predetermine the change in TR expression and therefore the sensitivity to GH treatment