MODY diabetes – group of clinically similar forms of diabetes with an autosomno-prepotent way of inheritance. The disease is shown in the childhood and youth. The main symptoms – frequent desires to an urination and increase in volume of urine, strengthening of thirst and appetite, loss of weight, reddening of integuments, temperature increase of a body. Diagnostics is difficult, includes clinical inspection, a complex of laboratory tests: glucose on an empty stomach and after food, hormonal and genetic blood test. The program of treatment assumes reception of hypoglycemic medicines, correction of food and systematic sports activities.
MODY diabetes is called diabetes of adult type at young people. For the first time this term was used in 1974-75. To them designated disease forms which are found in the childhood or in youth, but proceed rather easily, SD 2 types is similar, characteristic of people 45 years, and without decrease in sensitivity of cages to insulin influence are more senior. Indicators of prevalence of a disease are not defined, but at youth and patients of children's age it occurs among different types of SD in 2-5% of cases. The epidemiology and symptoms are most fully described for populations of Europe and North America, data on the countries of Asia remain very limited.
MODY diabetes reasons
This form of endocrine pathology is caused by mutational changes of genes which are responsible for activity of work of insular cells of the pancreas (P). The reasons of structural changes of sites of chromosomes remain obscure, but researches of epidemiology of a disease allow to reveal groups of the patients who are in a zone of the increased risk. Presumably development of MODY diabetes is connected with the following factors:
- Age. The vast majority of the diseased – children, teenagers and young people of 18-25 years. These age periods are considered the most dangerous concerning a disease demonstration.
- Gestational diabetes. About a half of cases of diabetes of MODY is diagnosed for pregnant girls. Pathology proceeds as gestational SD, but remains after the delivery.
- Glycemia at relatives. One of diagnostic criteria is presence of close relatives with the increased concentration of glucose in blood. At mother, the father, the grandfather or the grandmother diabetes, the postponed gestational SD was found, the hyperglycemia to and/or later after meal is defined two hours.
- Diseases at pregnancy. The genetic mutation at a fruit can be is provoked by diseases of mother during pregnancy. Carry bronchial asthma, heart ischemia, arterial hypertension to the most probable causes.
Pathology is formed on the basis of a mutation of the genes influencing functionality of cells of islets of Langerhans transmitted on autosomno-prepotent type that causes the inheritance which is not linked to a floor and identification of the close relatives suffering from this or that form of a hyperglycemia. MODY is the cornerstone a mutation only of one gene. Diabetes is shown by decrease of the activity of cages of PZh – a lack of production of insulin. As a result the glucose coming to blood from a stomach is not acquired by organism cages. The condition of a hyperglycemia develops. Excess sugar is removed by kidneys, the glucosuria (glucose in urine) and a polyuria (the increased urine volume) is formed. Because of the arising dehydration the feeling of thirst amplifies. Ketone bodies become a power source for fabrics instead of glucose. Their surplus in plasma provokes development of ketoacidosis – violation of metabolism with blood pH shift in the sour party.
MODY diabetes is presented by several forms having genetic, metabolic and clinical heterogeneity. Classification is based on distinction of types of a disease taking into account the site of the mutating gene. 13 genes which changes provoke diabetes are allocated:
- MODY-1. Damaged there is a factor participating in control of exchange and distribution of glucose. Pathology is peculiar to newborns, children of early age.
- MODY-2 Is defined a mutation of a gene of the glycolytic enzyme controlling the removal of insulin from ferruterous cages mediated by glucose. It is considered a favorable form, does not cause complications.
- MODY-3. Mutations of a gene are shown by progressive dysfunction of insulinproizvodyashchy cages, it provokes a disease demonstration at young age. The current is progressive, the condition of patients gradually worsens.
- MODY-4. The factor providing normal development of PZh, production of insulin changes. The mutation is capable to lead to resistant SD of newborns against the background of an underdevelopment of endocrine body or to dysfunction of beta cages.
- MODY-5. This factor influences an embryonal development and coding of genes of PZh and some other bodies. The progressing not diabetic nephropathy is characteristic.
- MODY-6. The differentiation insulin - the making cages, nervous cages of separate departments of a brain is broken. Mutations are shown by diabetes at children and adults, neonatal diabetes with neurologic pathology.
- MODY-7. The factor regulates formation and activity of PZh. The disease is characteristic of adults, but 3 cases from the beginning at early age are revealed.
- MODY-8. Mutations promote development of an atrophy, fibrosis and a lipomatoz of PZh. Hormonal insufficiency and diabetes is formed.
- MODY-9. The factor takes part in differentiation of the cages producing insulin. The course of disease with ketoacidosis is typical.
- MODY-10. Genetic changes of a factor become the frequent reason of neonatal diabetes. Production of pro-insulin is broken, the programmed death of cages of PZh is possible.
- MODY-11. The factor is responsible for stimulation of synthesis and secretion of hormone of insulin. Diabetes with obesity is characteristic. Extremely rare option of a disease.
- MODY-12. Change of sensitivity of receptors of sulphonylurea and the PZh potassium channels is the cornerstone. It is shown by neonatal, children's and adult diabetes.
- MODY-13. The receptor susceptibility of K+ channels decreases. The clinical picture is not investigated.
MODY diabetes symptoms
Among all kinds of diabet of MODI of 50-70% of clinical cases it is the share of MODI 3. On the second place on prevalence – MODI 2, on the third – MODI 1 (1%). Other options of a disease meet less often, are insufficiently studied, do not represent the clinical importance. The second type of a disease often demonstrates at children's age. Proceeds asymptomatically or with ill-defined manifestations, extremely seldom is followed by complications therefore it is diagnosed at screening inspections and during pregnancy when the gestational form of diabetes develops.
The third type has a progressive current, at most of patients begins aged from 20 up to 40 years. Manifestations are similar to symptoms of classical diabetes of 1 type: the amount of urine increases, thirst amplifies, appetite increases, body weight is lost, sleeplessness, spasms, in the afternoon – heat inflows, excitement, increase in blood pressure and temperature is possible at night. Without treatment symptoms progressively accrue, the high risk of micro and macrovascular complications remains. Long "honeymoon" – and more is characteristic 3 years. This phrase designate the period after the beginning of insulin therapy when the doses of medicine which are initially picked up by the doctor lower the blood sugar level stronger expected, and correction of treatment up to full cancellation of insulin is required. The first type of diabetes of MODI is similar in a clinical picture with the third, but demonstrates more often at newborns and children of younger age. The macrosomia and neonatal hypoglycemia of a fruit is defined.
At MODY diabetes of the third type gradual progressive increase of symptoms is observed. Therapy by insulin and hypoglycemic medicines yields good result, but at patients the risk of development of an angiopatiya remains. Defeat of capillary networks in a retina of an eye leads to a diabetic retinopathy (decrease in sight), in kidney balls – to a nephropathy (violation of a filtration of urine). Atherosclerosis of large vessels is shown by neyropatiya – a sleep, pain, a pricking in legs, violation of food of the lower extremities ("diabetic foot"), failures in work of internals. At future mothers the disease of the second and first type is capable to provoke a fruit macrosomia.
Because of similarity of symptoms of various forms of diabetes and a rarity of MODY diagnostics is rather difficult, volume and long. From the moment of the first address of the patient before confirmation of the diagnosis there passes not less than a month. The doctor-endocrinologist directs inspection, consultations of the geneticist, the ophthalmologist, the neurologist are in addition appointed. The main stages – identification of a hyperglycemia, differentiation of MODY diabetes with usual diabetes of 1 and 2 types. The complex of diagnostic procedures includes the following methods:
- Clinical poll, survey. The early beginning, absence of obesity is characteristic of MODI. From diabetes of the I type it is distinguished by the high hereditary nature of transfer (about 100%) – the patient has at least one close relative with any form of diabetes, prediabety, an easy hyperglycemia on an empty stomach. Other differential sign – lack of symptoms of ketoacidosis (vomiting, belly-aches, an acetone smell from a mouth). Long remissions are peculiar.
- Standard laboratory analyses. Level of glucose, insulin, S-peptide, antibodies is defined (blood), the glyukozotolerantny test is carried out. At MODI 2 the long, but easy or moderate hyperglycemia on an empty stomach is found (on average 5,5-8,5 mmol/l). For type 3 and 1 the sugar indicator on an empty stomach normal, but after carbohydrate loading remains raised more than 2 hours (from 11,1 mmol/l). Antibodies to insulin and cells of a pancreas are absent, there is no correlation with HLA system. C-peptide level rather normal.
- Genetic tests. Authentically it is possible to diagnose disease type by means of the molecular and genetic research revealing mutations in genes. The procedure is long, all sites of the allocated chromosome, but first of all those are in detail studied, changes in which are associated with development of 1, 2, 3 MODI.
Treatment of MODY diabetes
The principles of therapy at MODI diabetes same, as at treatment of widespread options of a disease. They are directed to elimination of a hyperglycemia, normalization of metabolic processes in an organism. Methods depend on type of a disease and from pregnancy existence – at incubation of the child the hyperglycemia can influence negatively on only the woman, but also on a fruit therefore insulin therapy is applied. The general scheme of therapeutic influence includes:
- Medicamentous correction. These types of diabet are sensitive to the hypoglycemic tableted medicines. Antihyperglycemic means are appointed to most of patients, at a disease of the second type there is enough change of food. To pregnant women, teenagers at puberty, and also to patients with it is long the current third type of a disease for prevention of complications use of insulin can be required.
- Observance of a diet. Food with the lowered content of carbohydrates is shown – the products containing the refined sugar in moderate quantities are excluded sources of complex carbohydrates are admissible (grain, grain). The basis of a diet is made by vegetables, dairy and meat products, fish, eggs. Fractional meal allows to avoid the expressed fluctuations of level of glucose.
- Regular physical activities. The majority of cases proceeds softly, patients can independently organize sports activities. Aerobic loadings – sports walking, jogging, team games, gymnastics are recommended. It is undesirable to carry out heavy athletics exercises.
Forecast and prevention
The course of MODY diabetes is considered more favorable, than other kinds of diabetes – the symptomatology which was less expressed, the disease well gives in to correction by means of a diet, physical exercises and reception of hypoglycemic drugs. At strict observance of appointments and recommendations of the doctor the forecast positive. As decrease in production of insulin is caused by genetic factors, prevention is ineffective. Patients from risk groups should make periodically blood tests for early identification of a hyperglycemia and the prevention of complications.