Human growth hormone is basically a protein containing a sequence of 91 amino acids. It is secreted by anterior part of pituitary gland. Hypothalamus (a small gland situated in brain) controls the secretion of this hormone, by pituitary gland, with the help of GHRH (growth hormone releasing hormone).
It is basically related to the normal physiologic growth of our body. It has following effects:
- Increases the size and number of cells in a tissue
- Differentiation and development of particular type of cells, for e.g. bone and muscle cells.
Growth hormone is secreted in high quantities in our body at the time of birth, and the secretions decrease to 25% at the time of adolescence.
There are many factors which can affect the secretion of growth hormone:
Factors increasing secretions are Starvation, Hypoglycemia, Exercise, Trauma, Excitement, Stress, GHRH, and Deep sleep
Factors decreasing secretions are Lack of sleep, High blood sugar, Obesity, High levels of free fatty acids in blood, and Aging
Causes of deficiency:
Causes can be classified into three types:
- Congenital: The low levels of hormone, in this case, are present since birth. These include Prader-willi syndrome, Turner syndrome, and Malformation of pituitary gland
- Acquired: In this case the, low levels of human growth hormone are due to some acquired causes such as Infections, Brain tumors, Injury, Surgery, Radiation to the head, and Autoimmune diseases
- Idiopathic: In this case, the cause of deficiency of growth hormone is unknown.
Symptoms of human growth hormone deficiency:
- In children it manifests as Delayed development of tooth, Delayed puberty onset, Child looks younger then children of same age group, increased fat in belly, and Low growth rate
- In adults it manifests as Dry and thin skin, Low quality of hair, Deposition of fat around waist, Decrease in strength, Unable to perform exercise, Anxiety, Depression, Change in behavior, and Decrease in muscle mass
Short stature of a child can severely affect the self esteem of that child, as he/she may be teased by friends, teachers, family and other people. Hence, mental support is necessary. In medical treatment, injections of human growth hormone should be prescribed, based on the level of deficiency in blood. The child can gain up to 4 inches in first year of treatment, 3 inches in next two years. Then the rate of growth decreases in subsequent years.
There may be serious side effects of this therapy:
- Fluid retention
- Muscle and joint pain
Complications of growth hormone deficiency:
If deficiency of growth hormone is left untreated, it can cause deficiency of other hormones also in our body, which includes following:
- Adrenocorticotrophic hormone
Human growth hormone is essential for our body for normal growth and development. Any factor causing its deficiency should be treated first, and then further treatment should be planned.