Management of Recombinant Human Growth Hormone Therapy at Puberty

Abstract

Treatment modalities for growth hormone (GH) substitution in GH-deficient children at puberty is still a matter of debate. Although circulating GH levels increase during puberty, it has not been proven that the increase of exogenous GH is necessary for a normal pubertal growth spurt. Increasing GH levels may thus well be the consequence and not the cause of the pubertal growth spurt. A permissive role of GH for pubertal growth has been hypothesized. Some effects of exogenous GH may even be detrimental to pubertal growth; specifically, puberty seems to be shortened by GH administration. Further aspects of the physiology of GH secretion and the poor imitation by current replacement schemes are discussed. Only randomized, prospective studies will allow to define the optimal dose of GH at puberty. As long as these studies are missing, a pragmatic approach is an individualized, minimalistic GH substitution scheme under close surveillance. GH dose at puberty should be kept at prepubertal levels, but must be increased once height velocity drops below the 50th percentile. This widely used approach ensures unnecessary, costly and potentially harmful overdosages of GH.