ABSTRACT
Growth hormone plays a key role in reproduction, interacting with the pituitary-gonadal axis at different levels, via direct action or by stimulation of insulin-like growth factor-1 (IGF-1) at systemic and local levels. The classical view of the “somatomedin” mechanism is under question since more important seems to be the IGF-1 production at peripheral tissues. All components of the axis are represented in the testis, which can be defined as “minihypophysis.” Growth hormone (GH) actions are important in the development and maturation of the male reproductive system, as demonstrated by in vitro and in vivo models. Despite clear physiological involvement, no clear evidence correlates the somatotropic axis with male infertility; similarly, studies on GH administration in male infertile patients are inconclusive. However, a proper assessment of the GH dynamics in selected populations can be fundamental for a personalized treatment. GH deficiency can be a cause of unexplained infertility in a subgroup of infertile patients.
