Hormonal insufficiency
Somatotropic insufficiency( growth hormone insufficiency) occurs with a large number of diseases and syndromes. In most cases, this disease is manifested by the syndrome of nanism( from the Greek nanos - "dwarf").Nanizm is a state characterized by a sharp lag in the child's growth and physical development from his peers, which is due to the absolute or relative deficiency in the body of growth hormone. Since the growth hormone is produced by the endocrine gland of the brain, which is called the pituitary gland, then nanism is pituitary.
People with dwarf growth include men with growth below 130 cm and women below 120 cm. The smallest dwarf growth described in the literature was 38 cm. Pituitary nazism occurs with a frequency of 1 case per 5000 newborn children. Differences in the incidence of men and women are not observed. The most common form of growth hormone deficiency is idiopathic( 65-75%).It should be noted that with the introduction of MRI studies and the improvement of genetic methods of research, the proportion of patients with idiopathic growth hormone deficiency is gradually decreasing, since it is increasingly possible to identify specific causes of somatotropic insufficiency. In addition to disrupting the formation of growth hormone in the pituitary gland, some other causes may lead to pituitary nazism. These include: the formation of a hormone with an incorrect chemical structure and a congenital defect of receptors sensitive to this hormone, as a result of which they do not respond to the production of the somatotropin by the pituitary gland.
For the most part, somatotropic insufficiency is caused by a genetic defect. However, other causes of the development of this disease may be: hypoplasia, its wrong location in the brain, the formation of cysts, tumor compression, trauma of the central nervous system. In addition, infectious and toxic damage to the central nervous system in early childhood is of particular importance: intrauterine viral infections, tuberculosis, syphilis, malaria, toxoplasmosis, neonatal sepsis, inflammation of the brain and its membranes. Changes in internal organs during dwarfism consist in thinning of bones, delay in growth and ossification of the skeleton. Internal organs, muscles and subcutaneous fatty tissue are poorly developed.
For a long time, the deficit of growth hormone was regarded only as a problem of endocrinology of childhood. The main goal of treatment at the same time was the child's achievement of normal growth. Only recently it was found out that the presence of somatotropic insufficiency in adults causes a whole complex of serious metabolic disorders. This condition requires constant monitoring by specialists and the necessary medication. Deficiency of growth hormone, first appeared in adulthood, occurs with a frequency of 1 case per 10 000 population.
The main signs of nanism are the sharp lag in the growth and physical development of the child. Children with classical somatotropic insufficiency are born with normal weight and body length. They begin to lag behind in development from 2-4 years of age. This development of the disease is explained by the fact that the hormone prolactin, which enters the body of a child with mother's milk, in the early years in early childhood can give children a growth hormone-like effect. In the case of hereditary pathology of growth hormone in children with growth retardation and sexual development, in most cases it is possible to identify similar cases of short stature in the family of one parent during questioning. In adults, who did not receive the necessary treatment in childhood, children's proportions of the body are noted.
The features of the face are small( "doll face"), the bridge of the nose sinks. Skin pale with a yellowish hue, dry, sometimes there is a cyanotic color, marbling of the skin. In untreated patients, an old age appears early, the skin becomes thinner, becomes wrinkled. The distribution of subcutaneous fat varies from exhaustion to obesity, in which surpluses of adipose tissue are deposited mainly in the upper half of the trunk. Hair can be either normal, or dry, thin, brittle. Secondary hair, which should appear in the period of puberty, in most cases is absent. The muscular system is poorly developed. In boys, as a rule, the penis has an excessively small size, the sexual development is delayed. The majority of children with growth hormone deficiency have a concomitant deficiency of hormones that promote the development of genital organs( gonadotropins).
Laron's syndrome is an endocrine disease, which is based on the loss of sensitivity of the body cells to the growth hormone as a result of a genetic mutation. The manifestations of this deviation are approximately the same as in the case of pituitary nanism. Features in this case are: a high degree of growth retardation from birth, bone age lags behind the passport age, but outstrips the growth of the child, sexual development begins at a relatively normal time in 50% of children, there may be growth spikes. In addition, with Laron's syndrome there is a high risk of various congenital malformations, the most common of which are: shortening of the phalanges of the fingers, cataracts, involuntary movements of the eyeballs( nystagmus), narrowing of the aortic lumen, splitting of the upper lip, congenital dislocation of the hip joint,sclera.
The main methods by which it is possible to identify and confirm pituitary nanism are: anthropometry( measurement of growth) and comparison of its results with the proper values for the age of the child under study;dynamic observation of the growth of the child. In children with growth hormone deficiency, the growth rate does not exceed 4 cm per year. To exclude various congenital diseases of skeletal dysplasia, it is necessary to evaluate the proportions of the body. During the radiographic examination of the bones of the hands and wrist joints, the so-called bone( radiographic) age is determined. In the case of pituitary Nanism, a significant delay in ossification is revealed. Radiography of the skull reveals the size and shape of the Turkish saddle( bone container of the pituitary gland), characteristic for childhood. Regardless of the fact that all the above survey methods are highly informative, the most accurate method for the correct diagnosis of pituitary nanism is to determine the level of growth hormone in the blood serum. A single determination of the level of growth hormone in the blood for the diagnosis of somatotropic insufficiency does not matter because the hormone is secreted sporadically within 24 hours, which can lead to the determination of a low level even in healthy children.
Deficiency of growth hormone in adults is accompanied by a violation of all types of metabolism and very diverse manifestations. As a result of the violation of the metabolism of fats, obesity develops. Violation of protein synthesis leads to a decrease in the mass and strength of skeletal muscles, there is a depletion of the heart muscle. Quite often it can be noted the appearance of hypoglycemic conditions( arise with a deficiency of glucose in the blood), which are accompanied by excessive sweating during a night's sleep and the appearance of a headache in the morning.
In case of insufficiency of growth hormone, the most striking manifestation are changes on the part of the human psyche. There is a tendency to frequent depressions, anxious states, a person quickly becomes tired, suffers from general health, emotional reactions are violated. Over time, the tendency to social isolation of people suffering from this disease begins to be clearly traced.
Among people with growth hormone deficiency who receive treatment without growth hormone, there is a twofold increase in the death rate from cardiovascular diseases. The reason for this is a change in the composition of their blood, an increase in the amount of fat that begins to settle on the inner surface of the walls of the blood vessels, leading to the development of atherosclerosis.
When there is a lack of somatotropin, the bone mass decreases as a result of disturbance of all kinds of metabolism, including mineral metabolism. This increases the fragility of bones, which leads to an increase in the frequency of fractures.
Treatment. The basis of therapy for pituitary NAN is the replacement therapy with growth hormone preparations. The drug of choice in this case is human growth hormone, obtained by genetic engineering. Somatotropin in the treatment of the classic growth hormone deficiency is injected daily in the form of subcutaneous injections in the evening( 20.00-22.00).The use of growth hormone in Laron's syndrome does not have any effect.