Growth hormone is a protein hormone of about 190 amino acids that plays a major role in controlling several complex physiologic processes, including growth and metabolism. Growth hormone is also of considerable interest as a drug used in both humans and animals.
The primary role of growth hormone is to stimulate the liver and other tissues to secrete insulin-like growth factor-I (IGF-I), which in turn stimulates proliferation of chondrocytes (cartilage cells), resulting in bone growth. IGF-I also plays a major role in muscle growth.
Why should I be aware of this?
Recently growth hormone is produced using recombinant DNA technology for use in sever several applications to human and animal populations.
It is commonly used to treat children of pathologically short stature. There is apprehension that this may be extended to treat normal children under what is called "enhancement therapy" or growth hormone on demand. Growth hormones are already being used by athletes to enhance performance.
Although growth hormone therapy is generally safe, there can be unpredictable health risks. Research is under way to find the effectiveness of growth hormones in normal ageing. Information on risks and benefits are not clearly available.
Administration of growth hormones (bovine somatotropin) to lactating cows result in increased milk production in dairy cattle. This method of growth hormone administration has invited enough controversy, even among farmers.
Growth hormone deficiencies
There can be growth hormone deficiencies on account of gene mutations, congenial abnormalities involving the hypothalamus or the pituitary gland or injuries to either the hypothalamus or the pituitary gland as well.
In adults some of the growth hormone deficiencies manifest as:
- Reduced muscle mass and strength
- Reduction in bone mass and strength
- Lowering of physical, mental, and social energy
- Memory loss and impaired concentration and loss of memory
- Mild symptoms of depression
- Increase in body fat, specially in the abdomen.
Among children the symptoms include:
- Much lower height than their peers
- Almost negative growth rate
- Delayed onset of secondary sex characteristics
- Fatigue and lethargic feelings
Growth hormone and your health
With reduced production of human growth hormone with age, people tend to become overweight, flabby, frail, and lethargic. There is a 7 to 25 percent increase in body fat, while lean body mass decreases similarly. There is also considerable reduction in muscle strength and muscle mass.
Human growth hormone impairment also has negative effects on cholesterol. With decrease in bone density, risk of cardiovascular disease increases. These effects are accompanied by sleep disorder and impaired psychological well-being. Often signs of neuropsychiatric manifestations such as lack of concentration and memory impairment are seen. People who are deficient in human growth hormones tire easily, lose interest in sex, and in general, lose their zest for life.
What can I do about it?
Having growth disorder as a teen can affect a person's body image and self-esteem. Consult your doctor, take his advice and keep your body in top shape by eating a healthy diet, getting enough sleep, and exercising.
If a doctor finds that your growth hormone deficiency can be treated, he will arrange for replacement hormones which are given as a daily injection. Taking the hormone by mouth doesn't work because the hormone is destroyed by the stomach's digestive juices. Depending on when the diagnosis is made, treatment usually lasts for several years - until the growth areas of the bones close (after that, no more growth can occur).
During the first year children are known to grow two to five times faster than their ordinary growth. The growth rate usually slows down in the following years to about 3 to 4 inches (7.6 to 10.2 centimeters) per year.
Did you know?
- Most children with GHD grow less than two inches per year; other children usually grow at least two inches yearly. Often children with this condition grow normally until the age of two or three years, when their growth becomes noticeably slow.
- Your body can still produce growth hormone well into your 80's
- Vision problems can be a sighn of growth disease in adults