Lipodystrophy is a hypoplasia of the subcutaneous fat layer in the projection of the upper half of the trunk with simultaneous excessive accumulation of adipose tissue in the projection of the lower extremities, the lower half of the abdomen and buttocks, caused by severe metabolic disturbances.
Lipodystrophy can have both limited and diffuse spread, and depending on etiopathogenetic mechanisms of development, the following forms of this disease are distinguished: hypermuscular, congenital diffuse lipodystrophy, segmental progressive, post-injection and painful lipomatosis.
A prolonged course of lipodystrophy causes the development of severe metabolic disturbances in the form of development of insulin-resistant diabetes mellitus , hypertriglyceridemia and liver steatosis.
Causes of lipodystrophy
Despite the rapid development of diagnostic technologies in medicine, in most cases it is not possible to establish an etiopathogenetic factor in the development of lipodystrophy. As the provoking risk factors for the emergence of one form or another of dystrophy, generalized infectious infection of the body, the use of operational aids, as well as a severe craniocerebral injury should be considered.
Congenital and acquired types of lipodystrophy are equally important, mainly in women, and the debut of the disease usually occurs at the age of 40 years.
In the course of conducting numerous randomized studies, several etiopathogenetic theories of lipodystrophy emerged, each of which has the right to exist.
According to the first theory in the body of each patient there is an abnormal protein substance, which is pituitary in nature and has pronounced fat-mobilizing properties. It is certainly impossible to establish a clear relationship between the amount of this abnormal peptide and the development of lipodystrophy, since there are no laboratory methods for its quantitative determination. However, an increase in the lipolytic properties of the plasma of a patient suffering from generalized lipodystrophy is indicative of the presence in the patient's body of a substance with a pronounced heat-mobilizing effect.
The carried out researches in the field of endocrinology have contributed to the theory of lipodystrophy development, which is based on a clear dependence of the development of subcutaneous adipose tissue development disorders with increased secretion of growth hormone. According to this theory, in the structure of growth hormone in patients with lipodystrophy there is a fragment of the molecule, which is characterized by an increase in the heat-mobilizing activity.
The development of signs of lipodystrophy in patients with HIV infection with increasing phenomena of hyperinsulinism is due to the prolonged intake of drugs from the group of protease inhibitors.
The most widespread theory was the occurrence of lipodystrophy, due to the presence of an enzymatic defect, namely the congenital absence of triglyceride receptors on the surface of adipocytes.
The main pathogenetic mechanisms of lipodystrophy are based on the loss of the body's ability to accumulate neutral fats in physiological fat stores, followed by the development of generalized lipoatrophy and severe hyperlipidemia . With this pathology, lipid elimination is possible only in the liver and gastrointestinal tract, as a result of which fatty degeneration of the liver develops. In the initial stage of the disease compensatory secondary hyperinsulinemia develops.
Manifestations of lipodystrophy
The totality of certain clinical manifestations predetermines the development of a total or partial form of lipodystrophy. The total form of lipodystrophy is accompanied by a significant decrease in the subcutaneous fat layer in all parts of the trunk, in contrast to the partial one, in which there are no changes in subcutaneous tissue in the face area. The debut of the disease is equivalent for any age period from childhood to the elderly.
In view of the development of chronic endogenous hyperinsulinemia, dysmetabolic disorders occur in the patient's body, predetermining the appearance of typical clinical symptoms. Phenotypic manifestations of lipodystrophy are the development of true hypertrophy of skeletal muscles and moderately pronounced prognathism, enlargement of the bones of the distal limbs and regional hypertrichosis .
During the onset of a typical attack of hyperinsulinemia, the patient is disturbed by a sudden onset of unmotivated weakness, a marked feeling of hunger, excessive sweating, and a feeling of inner trembling.
Lipodystrophy, accompanied by endogenous hyperinsulinemia, becomes the cause of increased sclerosis of the parenchyma of internal organs of various localization. Thus, lipodystrophy of the pancreas is not accompanied by a marked clinical symptomatology, however, when radiotherapy is performed, a focal lesion of the organ structure is detected.
The generalized lipodystrophy of congenital genesis is a rare pathology and is more pronounced in girls in the period of 6-7 years. This disease is characterized by a slow flow with minimal changes in the patient's health (some decrease in working capacity, anorexia and insomnia), so patients in this category do not need specific therapy.
Lipodystrophy of the hypermuscular type is characterized by a sharp restriction of the development of adipose tissue with simultaneous hypertrophy of skeletal musculature. In addition to changes in the muscular system, patients have severe headaches, a tendency to hypertension, increased hairiness, and women have dysmenorrhea. This type of lipodystrophy belongs to the category of favorable and well treatable with the use of symptomatic groups of drugs.
Rarely and at the same time, a serious form of lipodystrophy for the patient is progressive segmental. A characteristic feature of this disease is a sharp restriction to the complete absence of subcutaneous fat in any part of the body in the absence of changes in the remaining parts of the body. As a rule, in order to establish the correct diagnosis, it is sufficient to conduct a visual examination of the patient. In some cases, segmental lesions of subcutaneous fat can be combined with violations of bone structures in this region in the form of cysts. With prolonged course of the disease, women begin to show symptoms characterizing hormonal disorders ( hypothyroidism , dysmenorrhea). Among the treatment activities, special attention should be given to physiotherapeutic methods of therapy.
Lipodystrophy among patients with injecting drug addiction is a frequent occurrence, and the localization of its manifestations has a clear dependence on the place of injection, especially with repeated episodes. In connection with the constant irritation of the receptors, trophic changes develop not only in the skin but also in the subcutaneous adipose tissue. A feature of this form that distinguishes it from all the previous ones is that at the injection site, both lipoatrophy and the opposite phenomenon can develop-hypertrophy. In addition to the complete absence of the fatty layer in the lesion region, a complete absence of all kinds of sensitivity is observed.
Lipodystrophy in diabetes mellitus, which also belongs to the postinjection category, needs treatment with highly purified insulin in combination with 0.5% Novocaine solution.
This form of the disease refers rather to a cosmetic defect and has a second formulation of "cellulite". The gynoid type of lipodystrophy is more typical for female patients and the depth of violations of the subcutaneous fat layer is usually small. According to statistics, at least 90% of women suffer from gynoid lipodystrophy of varying degrees of intensity, with the debut of the disease occurring during the period with the maximum hormonal activity (pubertal period, pregnancy and prolonged intake of hormonal contraceptives).
In the development of the gynoid type of lipodystrophy, several stages are gradually distinguished, gradually replacing each other. In the initial stage of the disease, dense collagen fibers form with the formation of septum, which complicate lympho- and blood circulation at the microcirculatory level. Prolonged disturbance of circulation of lymphatic tissue and blood is accompanied by pronounced edema of soft tissues. In this stage of lipodystrophy, there is no defect in adipose tissue and collagen synthesis is more affected.
Expressed clinical manifestations of gynoid lipodystrophy are observed only in the third stage, when there is excessive proliferation of adipose tissue in combination with the rapid development of collagen septal septa. Gynoid lipodystrophy of the mammary glands in the third stage of the disease is also a frequent pathology and is characterized by bilateral lesion.
In the terminal stage of lipodystrophy, not only external manifestations in the form of a violation of the relief of the skin in various regions with the presence of large nodes of increased density and regional changes in the color of the skin are observed, but also marked pain during palpation. This pathology needs an individual approach to the treatment of the patient with the involvement of specialists of a narrow profile (cosmetologist, plastic surgeon, physiotherapist, nutritionist, endocrinologist).
The gynoid type of lipodystrophy is dangerous by the occurrence of infectious and inflammatory complications of the skin with a tendency to necrotic tissue.
Treatment of lipodystrophy
Despite the fact that lipodystrophy has long been identified as a separate nosological form, a single pathogenetically substantiated method for treating this pathology has not yet been revealed, since etiopathogenesis has not been fully understood.
This pathology belongs to the category of general societal problems, therefore, an increasing number of scientific studies are aimed at developing new methods of therapy for lipodystrophy. Currently, the symptomatic type of treatment of lipodystrophy is applied depending on the clinical manifestations of the patient.
Due to the fact that lipodystrophy of different localization most often acts as a complication in patients suffering from HIV infection, a large-scale randomized study was conducted and it was concluded that the provocateur of violations of fat metabolism in this category of patients is a prolonged intake of "Retrovir" and "Zerit". In this regard, the appearance of the first signs of lipodystrophy is the rationale for replacing drugs with their analogs.
Plastic maxillofacial surgery offers a wide range of surgical manuals for the treatment of lipodystrophy of any location. In a situation where there are violations of subcutaneous fat in the limbs or buttocks area, the technique of implant implantation is applied. To eliminate soft tissue defects of the face, injectable fillers are used, however, it should be borne in mind that this manipulation has a short-term positive effect and needs periodic correction.
As a medicamentous conservative treatment of lipodystrophy in diabetes mellitus, the drugs of the thiazolidinedione group are used, which contribute to the restoration of the function of adipocytes. In view of the fact that these drugs have a limited scope and do not have an evidentiary basis for effectiveness, therapy with their use is extremely rare.