Growth Hormone Deficiency – Basics
Growth hormone is also called as somatotropin. GHD or growth hormone deficiency is a condition caused by the problems arising within the pituitary gland due to which the levels of the growth hormone are insufficient. The anatomical location of the pituitary gland is within the base of the skull. The gland is as small as a pea and it secretes eight different hormones each having its unique action on different parts of the body. The main function of growth hormone is to stimulate cell reproduction and growth. As age advances, the amount of growth hormone secretion decreases and there is a change in the pattern of its secretion also.
The incidence of GHD is roughly one in 7000 births. The condition affects both adults and children alike. In children the commonest manifestation of growth hormone deficiency is short height. In adults the hormone is responsible mainly for maintenance of the body structure and regulating the metabolism. So the manifestations of somatotropin deficiency are rare in adults.
Causes of Growth Hormone Deficiency
- Growth hormone deficiency is caused by the deficiency or complete absence of the growth hormone secretion from the pituitary gland. The condition can be congenital or acquired. Congenital deficiency of the growth hormone is due to abnormalities within the pituitary gland itself or as a part of other syndromes.
- Acquired growth hormone deficiency or AGHD can occur as a result of infections, serious head injuries, radiation treatments etc.
- Children who are born with anomalies like cleft lip and cleft palate also are more likely to have GHD as their pituitary glands are poorly developed.
- If GHD is not present since birth, then it can be because of tumours in the brain that are located near the base of the brain or the hypothalamus.
Symptoms of Growth Hormone Deficiency
- Children who have growth hormone deficiency will be shorter than their peers and have more rounded faces with normal body proportions. Hormones in children need to be present in the correct proportions to ensure adequate growth. They may also have baby fat deposits around the abdomen. The intelligence levels are normal in these children.
- If the deficiency of growth hormone occurs later in life as a result of a brain tumour or head injury, then the most important symptom will be delayed sexual development and due to this the onset of puberty and the physical changes associated with it are also delayed.
- In the growing years, growth hormone deficiency can lead to abnormalities like poor breast development in young girls and absence of voice change in young boys along with a short stature and stunted growth.
- Low amounts of growth hormone can lead to weakness and lack of stamina. There is increased sensitivity to hot and cold in such children.
- In acquired growth hormone deficiency, the bones are weak and so there is a risk of repeated fractures. In older individuals, this is seen more prominently along with easy tiredness and poor stamina.
- Adults who have AGHD (adult ghd), are more prone to getting diabetes and cardiac diseases. They also have high levels of cholesterol which is not due to a faulty diet but more because of the disturbance in the metabolism of the body as a result of growth hormone deficiency.
- Psychological symptoms like these may also be seen in some adults:
- Lack of concentration
- Poor memory
- Emotional disturbances
- Mood swings
Diagnosis of Growth Hormone Deficiency
The physical attributes like the height and weight of the child will raise the suspicion of a probable growth hormone deficiency diagnosis. The growth will be stunted and the puberty will be delayed with undeveloped secondary sexual characters like development of breast in girls and hair growth on the face in young boys. The next step is to confirm the diagnosis by means of different tests. These tests can determine whether the anomaly is present since birth or acquired in the later stages of life.
- Blood test for growth hormone deficiency are the most useful tests to detect the levels of growth hormone. The hormone shows a diurnal variation but the levels of GH if found lower than normal indicate that there is a growth problem.
- X-rays of long bones can be used to detect the extent of fusion at the ends of long bones and also the presence of growth plates. These X-rays give a clear picture whether the bone growth is normal or not.
- Kidney and thyroid function tests are used to assess the normal functioning of the body and production of hormones.
- MRI of the brain is mainly used in cases of GHD in adults which occurs secondary to a pituitary tumor or a head injury. They give a detailed picture of the brain and the structures inside it.
Treatment of Growth Hormone Deficiency
In the early days, gh treatment was carried out by giving the patient natural growth hormone derived from cadavers (gh therapy). Currently the most popular mode of treatment is use of synthetic hormones that are prepared by recombinant DNA technique. It is also referred to as recombinant growth hormone. The main aim of the treatment is to stimulate the pituitary gland which will help to increase energy and restore the normal functions. The synthetic hormone is injected into the fatty tissues of the body like the arms, hips and buttocks. The side effects of hormone therapy are rare and they include redness of injection site, pain in the hips, curving of the spine and headaches. Long continued treatment can lead to diabetes in some patients especially those with a positive family history. The side effects of growth hormone therapy are:
In children, if the growth is deficient but the hormone levels are found to be normal, no treatment is required but if the levels are low then life time growth hormone replacement or replacement therapy has to be done. These growth shots have to be given under strict medical guidance at regular intervals.
In adults, the treatment has multiple benefits including an enhanced energy and strength, increase in muscle mass and higher bone density.
For tumors of the brain and pititutary gland, radiation therapy may be required especially if the complete tumour is not removed by surgical means.