Human growth hormone is an essential protein that facilitates normal physical development in humans as well as being responsible for the maturation and proper functioning of secondary sexual characteristics in males and females. Growth hormone deficiency in adults is a condition caused by issues that affect the pituitary gland in the brain that is responsible for the production of this hormone. In turn, a deficiency of this hormone in humans causes certain problems depending on the age of the affected individual. Growth hormone deficiency symptoms and signs may include the following:
- Micropenis in males.
- Jaundice (yellow discoloration of the skin and/or eyes) and/or hypoglycemia (low glucose levels) in the first few days of life.
- Short stature with poor growth velocity.
- Delayed bone maturation.
- Delayed onset of puberty.
- Slower muscular development.
- Delayed gross motor milestones such as jumping, walking and standing.
- The composition of fat, muscle, and bone may be disproportionate resulting in a mild to moderate chubby appearance.
- Prominent forehead.
- Sparse hair growth with the frontal recession.
Adult-onset growth hormone deficiency occurs in 1 in every 100,000 people and is caused by tumors of the pituitary gland. Signs and symptoms include:
- Baldness in men.
- Decreased muscle mass and strength.
- Reduced energy.
- Decreased bone mass resulting in osteoporosis.
- Increased body fat especially around the waistline.
- Increased LDL cholesterol levels.
- Cardiac dysfunction due to a thickened inner lining of the blood vessels.
- Memory loss and impaired concentration.
- Infertility due to absent or decreased production of sperm and ova in males and females, respectively.
Growth hormone deficiency treatment includes injecting synthetically produced growth hormone under the skin (subcutaneously) or into the muscle (intramuscularly).
The following points are made regarding treatment of childhood growth hormone deficiency:
- Administration of growth hormone in these patients is performed on a daily basis.
- Growth monitoring and dose adjustments are done every three to six months together with information gained from X-rays and blood tests.
- Treatment with the synthetic medication is provided as long as the child is growing and they may need to receive the hormone for the rest of their lives if the deficiency is severe.
- Injections sites include the stomach, biceps, buttocks, and thighs and the sites need to be rotated on a daily basis to avoid shrinking and hardening of these areas.
- Relatively pain-free devices are used to help with compliance.
Regarding the treatment of growth hormone deficiency in adults:
- A minimally invasive procedure known as transsphenoidal surgery is performed to remove the pituitary tumor. This involves removing the tumor through the sphenoid sinus, which is a hollow space in the skull behind the nasal passages and below the brain and is performed under general anesthesia. An image guiding system is placed on the head of the patient to help guide the surgeon. The overall success rate of the procedure when removing small tumors (microadenomas) is 90 percent and removing larger tumors (macroadenomas) is 60 percent.1
- The majority view amongst specialists is that most adults with growth hormone deficiency do not show an adequate response to the medication and therefore do not warrant treatment with the synthetic hormone.
- Treatment may be warranted in cases where there is a severe growth hormone deficiency, there’s major impairment of the patient’s quality of life, and if the affected individual is being treated for other pituitary hormone disorders.
- The duration of the treatment will depend on the indication for its use.