IGF1 and pulmonary arterial hypertension: BMI – body mass index; FT4 – free thyroxine; GH – growth hormone; GV – growth velocity; IGF-1 – insulin-like growth factor-1; LT4 – levothyroxine; PAH – predicted adult height; SDS – standard deviation scores; TSH – thyroid-stimulating hormone; rhGH – recombinant human growth hormone.