THYROID FUNCTION IN NON-GH-DEFICIENT SHORT CHILDREN DURING A PLACEBO-CONTROLLED DOUBLE-BLIND TRIAL OF GH THERAPY

Abstract

Growth hormone (GH) therapy has been reported to cause changes in thyroid function in GH deficiency including decreases in T4 and TSH and an increase in T3. We sought to determine if GH therapy alters thyroid function in non-GH-deficient short children. Twenty-two children (19 boys) were followed for 12 months while receiving either GH (Humatrope, Eli Lilly) 0.074mg/kg t.i.w. s.c. (n=10) or placebo (n=12). Total T4, free T4, T3 and TSH were measured every 3 months and in 13 children also at 1 and 2 months. A TRH test and nocturnal TSH surge were performed at baseline and 6 months in 19. There were no significant clinical differences at baseline between the placebo and GH groups. The results below are mean (SD). There were no significant differences between the two groups in any of the above measurements or in TSH response to TRH or in nocturnal TSH surge. We conclude that GH therapy over 12 months does not alter thyroid function significantly in non-GH-deficient children.