Thyroid hormone levels in children with Prader–Willi syndrome: a randomized controlled growth hormone trial and 10-year growth hormone study

Our findings suggest that GH treatment decreases FT4 levels, due to increased peripheral conversion of FT4 to T3 in the first months of treatment, but thereafter, FT4 and T3 normalize and remain stable during long-term GH treatment in almost all children and adolescents with PWS.