What happens when growth hormone is discontinued at completion of growth? Metabolic aspects.

Continuing growth hormone (GH) replacement therapy in patients with childhood-onset GH deficiency (GHD) that persists into adulthood is an emerging issue. The prospective, long-term metabolic consequences of discontinuing GH therapy in adolescent patients with childhood-onset GHD and short stature have only recently been reported. These studies demonstrate that serum concentrations of total cholesterol, low-density lipoprotein-cholesterol and apolipoprotein B are higher in adolescents in whom severe GHD continues into adulthood. Upon discontinuation of GH therapy, serum concentrations of high-density lipoprotein-cholesterol have been found to decrease in patients with severe GHD and increase in patients regarded as GH sufficient when retested for GHD. Furthermore, total body fat and truncal fat mass increase after discontinuation of GH in both these patient groups, but more markedly in the patients with severe GHD. In adolescents with severe GHD persisting into adulthood, the discontinuation of GH therapy produces, over a period of 2 years, the accumulation of important cardiovascular risk factors that are associated with GHD in adults. Continuing replacement therapy into adulthood should therefore be considered.