HUMAN GROWTH HORMONE AND HYPOPITUITARY GROWTH RETARDATION

Human growth hormone (HGH) has somatotropic, luteotropic and adipotropic/diabetogenic activities. It is a potent antigen, and serum concentrations can be determined immunologically. However, we do not know whether the somatotropic core or another part of the molecule is active antigenically. The secretion of HGH is influenced by humoral agents as well as by psychical and physical stress. HGH stimulation tests are negative in several states beside hypopituitarism. The diagnosis of hypopituitary nanism can be difficult, especially in isolated growth hormone deficiency, which is not uncommon. Clinical and laboratory characteristics in the diagnosis of pituitary nanism are discussed. It is emphasized that growth retardation usually starts in infancy, and that hereditary types are rather frequent. The most important criteria in the diagnosis are: negative HGH stimulation tests, increased nitrogen retention and urinary hydroxyproline excretion during a metabolic study with HGH, and the catch-up growth at a therapeutical trial with HGH. Experiences in HGH-treatment of 20 children with idiopathic hypopituitary nanism are given. They all responded well, and the mean growth velocity increased from 2.8 cm yearly before to 9.7 cm the first year on treatment. Two patients with organic hypopituitarism did not respond to HGH treatment. The principles for hormonal replacement therapy in pituitary nanism are discussed.