Human growth hormone: What is it?

Human growth hormone: What is it?Human growth hormone is a protein that is secreted by the anterior pituitary in short pulses, mostly during the first hours of sleep and in response to stress. It is released throughout a person's lifetime and controls the production of other hormones called growth factors, throughout the body.
It particularly stimulates body growth and development in children, as well as playing an important role in child and adult metabolism, regulating the amount of muscle and fat and has effect on blood sugar levels. It also has a role in immunity and healing. Growth hormone was first isolated in 1956 and its structure was identified in 1972.

Why is it used?

Human growth hormone (HGH) therapy has been used to help growth hormone deficient children in the UK to grow normally since 1959. All supplies of HGH are now manufactured using artificial techniques called recombinant technology, but before 1985 the only source of human growth hormone was from brain tissue of human cadavers. This held an infection risk of a prion (slow virus) disease called Creutzfeldt-Jakob disease (CJD). There are other causes of CJD however, and recombinant growth hormone therapy is now the only type of growth hormone used as it is safe and cannot cause CJD.
Between 1985 and 2003, 26 cases of CJD were identified in adults who had received cadaverous human growth hormone, as children, before 1977. CJD has an incubation period of up to 30 years so most cases following the use of cadaver HGH have now been identified, although it is possible that a few more will show up. In scientific circles, it was clear as early as 1977 that there was a risk of transmission. This date has now become the determining factor in who can claim for compensation.
In 1959, severely reduced height children were given HGH to help them grow. With HGH they could reach a height close to the normal of just over 180cm. It was hailed at the time as a great medical breakthrough but was in limited supply so could only be used in the most severe cases.
HGH has found a wide range of other uses now that it can be artificially synthesised in unlimited quantities in the laboratory.
In children, it is used, in a variety of conditions where growth is restricted, not just growth hormone deficiency. For example it may be used in small for gestational age babies, Turner syndrome, Prader-Willi syndrome, and chronic renal disease.
In adults it is also used in growth hormone deficiency, which may have started in childhood, or developed later in life, causing fatigue, sleep problems, psychological upset and muscle weakness.
There may be a role for HGH in treating HIV associated muscle wasting but its use is not fully established yet.
HGH has been used illegally by athletes to build muscle bulk but research has cast doubts as to whether there is any objective improvement in performance and there are possible risks such as the development of diabetes. HGH has also been promoted by some alternative therapists as an anti-ageing treatment but again there is no scientific evidence to support its use.

What are the risks?

Elevated levels of HGH due to benign tumours of the pituitary gland lead to swelling of the soft tissues in the body; abnormal growth of the hands, feet and face; high blood pressure and an increased tendency to sweat with excessive hair growth, a condition known as acromegaly. Injections of HGH without any underlying deficiency may cause diabetes.
READMORE:http://www.bbc.co.uk/health