Growth hormone (GH) is a protein hormone made by the pituitary, a gland located at the base of the skull. It was known for many years that growth hormone is needed for children to grow. The pituitary gland not only produces GH, but releases (secretes) GH into the bloodstream.
Growth hormone is secreted in pulses and most of the time the pituitary does not secrete growth hormone. GH goes to the liver to release a large protein called insulin-like growth factor, IGF-1.
This protein used to be called somatomedin C. IGF-1 goes to certain tissues, especially bones, and results in height increase in children. Damage to the pituitary gland in children results in low GH secretion in children, resulting in poor growth and resultant short stature. GH can be given to children to restore their normal growth and development.
Over the last 15 years, it has been discovered that adults need GH too. Like children, adults can be given this hormone if deficient. Sinceadultshave already achieved their genetically determined height, loss of GH does not impact height, but it does affect the body in many other ways. If adults have a deficiency of GH, major changes to the composition of the body results. These changes include loss of muscle, accumulation of fat, especially in the abdomen, and a decrease in the density (but not the length) of bones.
Because GH is also necessary for normal brain function, adults without this hormone have psychological changes in addition. Patients with
GH deficiency may have a lot of joint pain and many patients with fibromyalgia have been incorrectly diagnosed and are actually growth hormone deficient.
Patients with growth hormone deficiency often have trouble sleeping, which can lead to daytime fatigue. This article will focus on describing the GH deficiency syndrome as it applies to adults, and how it is currently
diagnosed and treated.
Description of the Adult GH deficiency syndrome
There are three main components to the adult GH deficiency syndrome. These are body composition changes, blood lipid (cholesterol and fat) changes, and psychological changes.