Growth Hormone Use in Children with Idiopathic Short Stature

Growth failure is among the most common reasons forpresentation of a child to a pediatric endocrinologist. There are several known causes of growth failure includ-ing Turner syndrome, growth hormone deficiency (GHD), Prader–Willi syndrome, chronic renal insufficiency, and children born small for gestational age (SGA). GHD is the only true state of deficiency.1 One of the most devastating diagnoses for growth fail-ure has been that of idiopathic short stature (ISS). ISS is essentially failure to grow for unknown reasons and is mainly a diagnosis of exclusion, as there are no specific criteria defining this disorder.1-5 It is generally agreed that, for a final diagnosis of ISS, a child must have been born normal size (height and weight), be proportional in stature, have a stimulated growth hormone response>10 µg/L, and be –2 or less standard deviations below the average height for age (≤3rd percentile for growth according to age).2-4,6-8 This definition has also served as the main inclusion crite-ria for most studies of growth hormone in ISS for the past 2 decades. It is estimated that there are>1 million children with ISS in the US who are potential candidates for treatment with growth hormone.7,8 However, until recently, ISS was not an approved indication for treatment with human growth hormone. Yearly expenditures for a typical course of treatment with recombinant human growth hormone (rhGH) range from $14 000 to $20 000, and the impact to an individual patient or the healthcare system may be sig-nificant. It has been estimated that cost per 2.54 cm gained from treatment averages above $35 000.8 Thus, proper pa-tient selection for treatment and maximizing treatment out-comes are critical