Growth Hormone Therapy

Growth hormone (GH) is released by the anterior pituitary under hypothalamic control. It promotes protein synthesis and stimulates production of insulin-like growth factor 1 (IGF-1), largely through the liver and peripheral tissues. IGF-1 then drives much of linear bone growth in children and supports lean body mass, lipid metabolism, and glucose regulation throughout life. A child with GH deficiency (GHD) cannot sustain expected linear growth because the growth plates receive too little GH and IGF-1 signaling. In adults, whose epiphyses are closed, the same deficiency does not cause short stature; it more often contributes to increased fat mass, reduced lean mass, diminished exercise capacity, and poor quality of life. GHD may result from pituitary or hypothalamic disease, genetic defects, tumors, surgery, cranial irradiation, traumatic brain injury, or other acquired injury. The history matters because a person with pituitary damage may have deficiencies of several hormones, not GH alone.