Type 1 diabetes mellitus

Type 1 diabetes mellitusan endocrine disease characterized by insufficient insulin production and increased blood sugar levels. Due to prolonged hyperglycemia, patients suffer from thirst, lose weight and quickly tire. It is characterized by muscle and headache, cramps, skin itching, increased appetite, frequent urination, insomnia, and hot flashes. Diagnosis includes a clinical interview, blood and urine laboratory tests that reveal hyperglycemia, insulin deficiency, and metabolic disorders. Treatment is carried out with insulin therapy, diet and exercise are prescribed.

general information

The term "diabetes" comes from the Greek and means "flow, escape", so the name of the disease describes one of the most important symptoms - polyuria, the passing of large amounts of urine. Type 1 diabetes is also called autoimmune, insulin-dependent, and juvenile diabetes. The disease can manifest itself at any age, but it occurs more often in children and adolescents. Epidemiological indicators have increased in recent decades. The prevalence of all forms of diabetes mellitus is 1-9%, the insulin-dependent version of the pathology accounts for 5-10% of cases. The incidence depends on the ethnicity of the patients and is highest in Scandinavian peoples.

Causes of type 1 diabetes

Factors contributing to the development of the disease are still being investigated. It has now been established that type 1 diabetes mellitus is based on a combination of biological predisposition and external adverse effects. The most likely causes of pancreatic damage and reduced insulin production are:

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

Pathogenesis

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

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

Classification

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

1. Identifying the tendency.Preventive tests are carried out and genetic load is determined. Taking into account the average statistical indicators of the country, the risk of developing the disease in the future is calculated.
2. Initial starting moment.Autoimmune processes are activated and β-cells are damaged. Antibodies are already produced, but insulin production remains normal.
3. Active chronic autoimmune insulitis.The antibody titer increases and the number of insulin-producing cells decreases. They determine the high risk of developing diabetes in the next 5 years.
4. Hyperglycemia after carbohydrate loading.A significant part of the insulin-producing cells is destroyed. Hormone production decreases. Normal fasting glucose levels are maintained, but hyperglycemia can be seen within 2 hours after eating.
5. Clinical manifestation of the disease.Symptoms characteristic of diabetes mellitus appear. Hormone secretion decreases sharply, 80-90% of gland cells are subject to destruction.
6. Absolute insulin deficiency.All cells responsible for insulin synthesis die. The hormone enters the body only in the form of medicine.

Symptoms of type 1 diabetes

The main clinical symptoms of the disease are polyuria, polydipsia and weight loss. The urge to urinate becomes more frequent, the amount of urine per day reaches 3-4 liters, sometimes bedwetting also occurs. Patients feel thirsty, dry mouth and drink up to 8-10 liters of water per day. The appetite increases, but the body weight decreases by 5-12 kg in 2-3 months. You may also experience insomnia at night, sleepiness during the day, dizziness, irritability, and fatigue. Patients feel constant fatigue and find it difficult to perform their usual work.

Itching of the skin and mucous membranes, rashes and ulcers occur. The condition of hair and nails deteriorates, wounds and other skin changes do not heal for a long time. Impaired blood flow in capillaries and blood vessels is called diabetic angiopathy. Damage to the capillaries manifests itself in reduced vision (diabetic retinopathy), reduced kidney function with edema, arterial hypertension (diabetic nephropathy), uneven redness on the cheeks and chin. In the case of macroangiopathy, when veins and arteries are involved in the pathological process, atherosclerosis of the vessels of the heart and lower limbs progresses and gangrene develops.

Symptoms of diabetic neuropathy appear in half of the patients, which are the result of electrolyte imbalance, insufficient blood supply and swelling of nerve tissue. The conductivity of the nerve fibers deteriorates, convulsions occur. In the case of peripheral neuropathy, patients complain of a burning sensation 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 disturbances in the functioning of internal organs - symptoms of indigestion, bladder paralysis, urinary tract infections, erectile dysfunction. disturbances and angina occur. In case of focal neuropathy, pain of varying localization and intensity develops.

Complications

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

Diagnostics

Patients are examined by an endocrinologist. The corresponding clinical criteria of the disease are polydipsia, polyuria, changes in body weight and appetite - signs of hyperglycemia. During the assessment, the doctor also clarifies the presence of a hereditary burden. The presumed diagnosis is confirmed by the results of blood and urine laboratory tests. 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 distinguished. The comprehensive laboratory examination includes the following tests:

• Glucose (blood).Sugar determination is performed three times: in the morning on an empty stomach, 2 hours after the carbohydrate load and before going to bed. Hyperglycemia is indicated by a value of 7 mmol/l on an empty stomach and 11. 1 mmol/l after eating carbohydrate-containing foods.
• Glucose (urine).Glucosuria indicates persistent and severe hyperglycemia. Normal values of 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, which is not bound to protein, 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 performed. The normal fasting blood concentration of immunoreactive insulin is between 6 and 12. 5 µU/ml. The C-peptide indicator makes it possible to evaluate the activity of beta cells and the amount 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 performed. The final data make it possible to clarify the functionality of the kidneys and the extent of changes in protein metabolism. If the kidneys are damaged, the levels are higher than normal.
• Lipid metabolism.In order to detect ketoacidosis early, the content of ketone bodies in the bloodstream and urine is examined. To assess the risk of atherosclerosis, the blood cholesterol level (total cholesterol, LDL, HDL) is determined.

Treatment of type 1 diabetes

The efforts of doctors are aimed at eliminating the clinical manifestations of diabetes, as well as at preventing complications, and they teach patients to independently maintain normoglycemia. Patients are accompanied by a multi-professional team of specialists, whose members are endocrinologists, nutritionists and exercise therapy instructors. Treatment includes consultations, medication and educational sessions. The main methods are:

• Insulin therapy.The use of insulin preparations is necessary for the maximum possible compensation of metabolic disturbances and the prevention of hyperglycemia. Injections are vital. The dosage regimen is compiled individually.
• Diet.Patients are prescribed a low-carbohydrate diet, including a ketogenic diet (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 without serious complications. The lessons are selected individually by the physical therapy instructor and conducted systematically. The duration and intensity of the training is determined by the specialist, taking into account the patient's general state of health and the level of diabetes compensation. Regular walking, athletics and sports games are required. Strength sports and marathon running are contraindicated.
• Self-control training.The success of the maintenance treatment of diabetes depends to a large extent on the motivation level of the patients. In the special classes, the mechanisms of the disease, the possible compensation methods and complications are explained, and the importance of regular control of the amount of sugar and the use of insulin is emphasized. Patients learn to self-administer injections, select foods, and prepare menus.
• Prevention of complications.Medicines are used to improve the enzyme function of glandular cells. These include agents that promote tissue oxygenation and immunomodulatory drugs. Timely treatment of infections, hemodialysis and antidote therapy are performed to remove compounds that accelerate the development of pathology (thiazides, corticosteroids).

Among the experimental treatment methods, it is worth mentioning the development of special DNA vaccines for the treatment of diabetes mellitus in the early stages of development. In patients who received intramuscular injections for 12 weeks, levels of C-peptide, a marker of pancreatic islet cell activity, increased. The other research direction is the transformation of stem cells into insulin-producing gland cells. Experiments on rats gave positive results, but to use the method in clinical practice, evidence of the safety of the procedure is needed.

Prognosis and prevention

The insulin-dependent form of diabetes mellitus is a chronic disease, but adequate 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 are unclear. Currently, all people at risk are recommended to undergo an annual examination in order to recognize the disease at an early stage and start treatment immediately. This measure allows you to slow down the process of developing persistent hyperglycemia and minimize the likelihood of complications.