Growth Hormone Deficiency
A condition where the pituitary gland produces insufficient growth hormone, causing growth failure in children and metabolic effects in adults. Somatropin (recombinant GH), somapacitan, and somatrogon are approved for GH replacement therapy in deficient patients.
Technical Context
Paediatric GHD: diagnosed by failure to achieve expected growth velocity + low IGF-1 + failure of GH to rise above defined threshold (typically 7-10 μg/L depending on assay) during two stimulation tests (insulin tolerance test, glucagon stimulation, GHRH-arginine, or clomiphene). Treatment: daily SC somatropin injection titrated to IGF-1 levels and growth response; next-generation weekly options include somapacitan (Sogroya — albumin-binding long-acting GH) and somatrogon (Ngenla — CTP-fused long-acting GH), improving convenience from daily to weekly injection. Adult GHD: diagnosed by ITT (gold standard, GH peak <3-5 μg/L) or GHRH-arginine test; symptoms include: increased visceral fat, decreased lean mass, reduced bone density, fatigue, impaired quality of life. Adult treatment: lower somatropin doses than paediatric, titrated to mid-normal IGF-1 range. Transition period (adolescent→adult) requires re-testing to confirm persistent GHD.