Type 1 diabetes mellitus

Type 1 diabetes mellitusis an endocrine disease characterized by insufficient insulin production and elevated blood glucose levels. Due to prolonged hyperglycemia, patients suffer from thirst, lose weight and get tired quickly. It is characterized by muscle and headache, cramps, itchy skin, increased appetite, frequent urination, insomnia, hot flashes. Diagnosis includes a clinical interview, blood and urine laboratory tests that detect hyperglycemia, insulin deficiency, and metabolic disorders. Treatment is carried out using insulin therapy, diet and physical exercises are prescribed.

General information

The term "diabetes" comes from the Greek and means "flow, escape", so the name of the disease describes one of its main symptoms - polyuria, passing large amounts of urine. Type 1 diabetes is also called autoimmune, insulin-dependent, and juvenile diabetes. The disease can appear at any age, but more often it appears in children and adolescents. In recent decades, there has been an increase in epidemiological indicators. The prevalence of all forms of diabetes mellitus is 1-9%; the insulin-dependent variant of the pathology accounts for 5-10% of cases. The incidence depends on the ethnicity of the patients and is highest among the Scandinavian peoples.

Causes of type 1 diabetes

The factors that contribute to the development of the disease continue to be studied. It has now been proven that type 1 diabetes mellitus occurs based on a combination of biological predisposition and negative external influences. The most likely causes of damage to the pancreas and decreased insulin production include:

• Inheritance.The tendency to insulin-dependent diabetes is transmitted in a direct line - from parents to children. Several combinations of genes that predispose to the disease have been identified. They are more common among residents of Europe and North America. Having an affected parent increases the child's risk by 4-10% compared to the general population.
• Unknown external factors.There are several environmental influences that provoke type 1 diabetes. This fact is proven by the fact that identical twins, who have exactly the same set of genes, get sick together only in 30-50% of cases. It was also found that people who migrated from an area with a low incidence to an area with a higher epidemiology are more likely to develop diabetes than those who refused to migrate.
• Viral infection.An autoimmune response to pancreatic cells can be triggered by a viral infection. The most likely impact is Coxsackie virus and rubella.
• Chemicals, medicines.The beta cells of the insulin-producing gland can be damaged by certain chemicals. Examples of such compounds are rat poison and a drug for cancer patients.

Pathogenesis

The pathology is based on the insufficient production of the insulin hormone in the beta cells of the islets of Langerhans of the pancreas. Insulin-dependent tissues include liver, fat, and muscle. When the secretion of insulin decreases, they stop taking up glucose from the blood. A state of hyperglycemia appears - a main sign of diabetes mellitus. The blood thickens, the blood flow in the vessels is disrupted, which is manifested by deterioration of vision and trophic lesions of the extremities.

Lack of insulin stimulates the breakdown of fats and proteins. They enter the bloodstream and are then metabolized by the liver into ketones, which become energy sources for non-insulin-dependent tissues, including brain tissue. When the concentration of sugar in the blood exceeds 7-10 mmol/l, the alternative pathway for glucose secretion is activated - through the kidneys. Glucosuria and polyuria develop, resulting in an increased risk of body dehydration and electrolyte deficiency. To compensate for the loss of water, the feeling of thirst increases (polydipsia).

Distribution

According to the recommendations of the World Health Organization, type I diabetes mellitus is divided into autoimmune (provoked by the production of antibodies against gland cells) and idiopathic (there are no organic changes in the gland, the causes of the pathology remain unknown). The development of the disease occurs in several stages:

1. Identification of predisposition.Preventive examinations are carried out, the genetic load is determined. Taking into account the average statistical indicators for the country, the risk level of developing the disease in the future is calculated.
2. The initial starting moment.Autoimmune processes are activated and β cells are damaged. Antibodies are already produced, but insulin production remains normal.
3. Chronic active autoimmune insulitis.The antibody titer becomes high and the number of insulin-producing cells decreases. A high risk of developing diabetes in the next 5 years is determined.
4. Hyperglycemia after carbohydrate loading.A significant portion of the cells that produce insulin are destroyed. Hormone production decreases. Normal fasting glucose levels are maintained, but hyperglycemia is detected within 2 hours after eating.
5. Clinical manifestation of the disease.The characteristic symptoms of diabetes mellitus appear. Hormone secretion is significantly reduced, 80-90% of gland cells are subject to destruction.
6. Absolute lack of insulin.All cells responsible for insulin synthesis die. The hormone enters the body only in the form of a medicine.

Symptoms of type 1 diabetes

The main clinical signs of the disease are polyuria, polydipsia and weight loss. The urge to urinate becomes more frequent, the volume of daily urine reaches 3-4 liters, and sometimes even bedwetting occurs. Patients feel thirsty, dry mouth and drink up to 8-10 liters of water per day. Appetite increases, but body weight decreases by 5-12 kg in 2-3 months. In addition, you may experience insomnia at night and sleepiness during the day, dizziness, irritability and fatigue. Patients feel constant fatigue and have difficulty performing their usual work.

Itching of the skin and mucous membranes, rashes and ulcers appear. The condition of hair and nails worsens, wounds and other skin lesions do not heal for a long time. The disorder of blood circulation in the capillaries and vessels is called diabetic angiopathy. Capillary damage is manifested by decreased vision (diabetic retinopathy), decreased kidney function with edema, arterial hypertension (diabetic nephropathy), uneven redness on the cheeks and chin. With macroangiopathy, when veins and arteries are involved in the pathological process, atherosclerosis of the vessels of the heart and lower extremities begins to progress and gangrene develops.

Half of patients develop symptoms of diabetic neuropathy, which is the result of electrolyte imbalance, insufficient blood supply and swelling of nerve tissue. The conductivity of nerve fibers deteriorates, convulsions are provoked. With peripheral neuropathy, patients complain of burning and pain in the legs, especially at night, a feeling of "pins and needles", numbness and increased sensitivity to touch. Autonomic neuropathy is characterized by interruptions in the functions of internal organs - symptoms of digestive disorders, bladder paresis, genitourinary infections, erectile dysfunction and angina appear. With focal neuropathy, pain is formed with different localization and intensity.

Complications

Prolonged disruption of carbohydrate metabolism can lead to diabetic ketoacidosis, a condition characterized by the accumulation of ketones and glucose in the plasma and increased blood acidity. Occurs acutely: appetite disappears, nausea and vomiting appear, abdominal pain and the smell of acetone in exhaled air. In the absence of medical attention, confusion, coma and death occur. Patients with signs of ketoacidosis require urgent treatment. Other dangerous complications of diabetes include hyperosmolar coma, hypoglycemic coma (with improper use of insulin), "diabetic foot" with the risk of limb amputation, severe retinopathy with complete loss of vision.

Diagnosing

Patients are examined by an endocrinologist. Sufficient clinical criteria for the disease are polydipsia, polyuria, changes in weight and appetite - signs of hyperglycemia. During the survey, the doctor also explains the presence of hereditary burden. The suspected diagnosis is confirmed by the results of blood and urine laboratory tests. The detection of hyperglycemia makes it possible to distinguish diabetes mellitus from psychogenic polydipsia, hyperparathyroidism, chronic renal failure and diabetes insipidus. In the second stage of diagnosis, different forms of diabetes are differentiated. A comprehensive laboratory examination includes the following tests:

• Glucose (blood).Determination of sugar is performed three times: in the morning on an empty stomach, 2 hours after the carbohydrate load and before bedtime. Hyperglycemia is indicated by readings of 7 mmol/l on an empty stomach and 11. 1 mmol/l after eating carbohydrate foods.
• Glucose (urine).Glucosuria indicates persistent and severe hyperglycemia. Normal values for this test (in mmol/l) are up to 1. 7, borderline - 1. 8-2. 7, pathological - more than 2. 8.
• Glycated hemoglobin.Unlike free glucose that is not bound to proteins, the amount of glycosylated hemoglobin in the blood remains relatively constant throughout the day. The diagnosis of diabetes is confirmed at a rate of 6. 5% and above.
• Hormonal tests.Insulin and C-peptide tests are done. The normal concentration of immunoreactive insulin in fasting blood ranges from 6 to 12. 5 μU/ml. The C-peptide indicator allows you to evaluate the activity of beta cells and the volume of insulin production. The normal result is 0. 78-1. 89 μg/l; in diabetes mellitus, the concentration of the marker decreases.
• Protein metabolism.Creatinine and urea tests are done. The final data make it possible to clarify the functionality of the kidneys and the degree of change in protein metabolism. If the kidneys are damaged, the levels are higher than normal.
• Lipid metabolism.For the early detection of ketoacidosis, the content of ketone bodies in the blood and urine is examined. To assess the risk of atherosclerosis, the level of cholesterol in the blood (total cholesterol, LDL, HDL) is determined.

Treatment of type 1 diabetes

Doctors' efforts are aimed at eliminating the clinical manifestations of diabetes, as well as preventing complications, teaching patients to independently maintain normoglycemia. Patients are accompanied by a multi-professional team of specialists, which includes endocrinologists, nutritionists and exercise therapy instructors. Treatment includes consultations, the use of medications and educational sessions. The main methods include:

• Insulin therapy.The use of insulin preparations is necessary for the maximum possible compensation of metabolic disorders and prevention of hyperglycemia. Injections are vital. The administration regime is compiled individually.
• Diet.Patients are prescribed a low-carbohydrate diet, including a ketogenic one (ketones serve as an energy source instead of glucose). The basis of the diet is vegetables, meat, fish and dairy products. Sources of complex carbohydrates - whole grain bread, cereals - are allowed in moderation.
• Dosed individual physical activity.Physical activity is beneficial for most patients who do not have severe complications. Classes are individually selected by a physical therapy instructor and run systematically. The specialist determines the duration and intensity of exercise taking into account the patient's general health and the level of diabetes compensation. Regular walks, athletics and sports games are prescribed. Strength sports and marathon running are contraindicated.
• Self-control training.The success of maintenance treatment for diabetes largely depends on the level of motivation of the patients. During special classes, they are shown the mechanisms of the disease, possible ways of compensation, complications, and the importance of regular monitoring of the amount of sugar and the use of insulin is emphasized. Patients learn the ability to independently perform injections, choose food products and create menus.
• Prevention of complications.Medicines are used to improve the enzyme function of the gland cells. These include agents that promote tissue oxygenation and immunomodulatory drugs. Timely treatment of infections, hemodialysis and antidote therapy are carried out to remove compounds that accelerate the development of pathology (thiazides, corticosteroids).

Among the experimental methods of treatment, it is worth mentioning the development of special DNA vaccines for the treatment of diabetes mellitus at an early stage of development. In patients receiving intramuscular injections for 12 weeks, levels of C-peptide, a marker of pancreatic islet cell activity, increased. Another direction of research is the transformation of stem cells into cells of the insulin-producing glands. Experiments conducted on mice gave positive results, but to use the method in clinical practice, proof of the safety of the procedure is required.

Prognosis and prevention

The insulin-dependent form of diabetes mellitus is a chronic disease, but proper maintenance therapy allows patients to maintain a high quality of life. Preventive measures have not yet been developed, as the exact causes of the disease have not been clarified. Currently, all persons at risk are recommended to undergo annual examinations to detect the disease at an early stage and to start treatment immediately. This measure allows you to slow down the process of formation of persistent hyperglycemia and minimize the possibility of complications.