Normal Progression of Testicular Size in Boys with Idiopathic Short Stature and Isolated Growth Hormone Deficiency Treated with Growth Hormone: Experience from the KIGS

The aim of this retrospective analysis was to evaluate the effects of growth hormone (GH) treatment on testicular development in boys with idiopathic short stature (ISS) and isolated GH deficiency (IGHD) followed in the KIGS (Pharmacia International Growth Database).For inclusion in the study, the patients had to have received more than 1 year of prepubertal GH treatment, at least 4 consecutive years of GH treatment in total, and to have attained their final height, defined as a height velocity of less than 2 cm/year. Data on 107 boys in the KIGS database have been analyzed.No significant differences in duration of GH treatment and testicular volume at the start of treatment or at final height were found between the boys with ISS and those with IGHD. The progression of testicular volume in boys with ISS or IGHD during GH treatment did not differ from the reference population.This analysis shows that GH treatment does not alter testicular growth in boys with ISS or IGHD. However, prospective controlled studies are needed to rule out moderate attenuating or stimulating effects.