Type 1 diabetes

Type 1 diabetesis an endocrine disease characterized by insufficient insulin production and elevated blood glucose levels. Due to prolonged hyperglycemia, patients suffer from thirst, lose weight and tire quickly. It is characterized by muscle and headaches, cramps, itchy skin, increased appetite, frequent urination, insomnia, hot flashes. Diagnosis involves a clinical interview, blood and urine laboratory tests that reveal hyperglycemia, insulin deficiency, and metabolic disorders. Treatment consists of insulin therapy, prescribed diet and physical exercise.

General information

The term "diabetes" comes from the Greek and means "flowing, escaping", so the name of the disease describes one of its main symptoms - polyuria, the passing of large amounts of urine. Type 1 diabetes is also called autoimmune, insulin-dependent and juvenile diabetes. The disease can occur at any age, but is more common in children and adolescents. In recent decades, an increase in epidemiological indicators has been observed. 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 nationality of the patients and is higher among Scandinavian peoples.

Causes of type 1 diabetes

The factors that contribute to the development of the disease continue to be studied. It is now established that type 1 diabetes occurs based on a combination of biological predisposition and external adverse influences. The most likely causes of damage to the pancreas and reduced insulin production include:

• Heredity.The tendency to insulin-dependent diabetes is transmitted in a direct line - from parents to children. Several gene combinations 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 certain environmental influences that cause type 1 diabetes. This fact is confirmed by the fact that identical twins, who have exactly the same set of genes, get sick together only 30-50% of the time. It was also found that people who migrated from an area with a low incidence to an area with a higher incidence 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 influence is the Coxsackie and rubella viruses.
• Chemicals, drugs.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 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 receiving glucose from the blood. A state of hyperglycemia occurs - a key sign of diabetes mellitus. The blood thickens, the blood flow in the vessels is disturbed, which is manifested by deterioration of vision and trophic lesions of the extremities.

Insulin deficiency 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 blood sugar concentration exceeds 7-10 mmol/l, the alternative pathway for glucose excretion is activated - through the kidneys. Glycosuria and polyuria develop, resulting in an increased risk of body dehydration and electrolyte deficiency. To compensate for water loss, the feeling of thirst increases (polydipsia).

Classification

According to the recommendations of the World Health Organization, type I diabetes mellitus is divided into autoimmune (caused by the production of antibodies in the cells of the gland) 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. Determination of predisposition.Preventive tests are carried out, the genetic burden is determined. Taking into account the average statistical indicators for the country, the level of risk of occurrence of the disease in the future is calculated.
2. Initial start time.Autoimmune processes are activated and β-cells are destroyed. Antibodies are already produced, but insulin production remains normal.
3. Active chronic 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 defined.
4. Hyperglycemia after carbohydrate loading.A significant part of the cells that produce insulin is 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.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 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 enuresis 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 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 worsens, wounds and other skin lesions do not heal for a long time. Impaired blood flow in the capillaries and vessels is called diabetic vasculopathy. Damage to the capillaries is manifested by reduced vision (diabetic retinopathy), reduced 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 experience symptoms of diabetic neuropathy, which is a result of electrolyte imbalance, poor blood supply and swelling of nerve tissue. The conductivity of nerve fibers deteriorates, convulsions are caused. With peripheral neuropathy, patients complain of burning and pain in the legs, especially at night, "pins and needles", numbness and increased sensitivity to touch. Autonomic neuropathy is characterized by disturbances in the functions of internal organs - symptoms of digestive disorders, bladder paresis, infections of the genitourinary system, erectile dysfunction and angina pectoris appear. With focal neuropathy, pain of varying location and intensity is formed.

Complications

Prolonged disruption of carbohydrate metabolism can lead to diabetic ketoacidosis, a condition characterized by accumulation of ketones and glucose in the plasma and increased acidity of the blood. 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 hyperosmotic coma, hypoglycemic coma (with inappropriate use of insulin), "diabetic foot" with the risk of limb amputation, severe retinopathy with complete loss of vision.

Diagnostics

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 examination, the doctor also clarifies the existence of a hereditary burden. The suspected diagnosis is confirmed by the results of laboratory tests of blood and urine. 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, differentiation of various forms of diabetes is carried out. A comprehensive laboratory examination includes the following tests:

• Glucose (blood).Determination of sugar is carried out 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 consumption of carbohydrate foods.
• Glucose (urine).Glycosuria 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 protein, the amount of glycated hemoglobin in the blood remains relatively constant throughout the day. The diagnosis of diabetes is confirmed in rates of 6. 5% and above.
• Hormonal tests.Insulin and C-peptide tests are performed. The normal concentration of immunoreactive insulin in fasting blood ranges from 6 to 12. 5 μU/ml. The C-peptide index allows you to assess 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 indicator decreases.
• Protein metabolism.Creatinine and urea tests are performed. 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 bloodstream 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

The efforts of doctors are aimed at eliminating the clinical manifestations of diabetes, as well as at preventing complications, teaching patients to independently maintain normoglycemia. Patients are accompanied by a multi-professional team of specialists, which includes endocrinologists, nutritionists and exercise instructors. Treatment includes counseling, medication, 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 the prevention of hyperglycemia. Injections are vital. The administration scheme is drawn up 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 - wholemeal bread, cereals - are allowed in moderation.
• Dosed individual physical activity.Physical activity is beneficial for most patients who do not have serious complications. Lessons are individually selected by a physical therapy instructor and conducted systematically. The specialist determines the duration and intensity of training taking into account the general health of the patient and the level of diabetes compensation. Regular walking, athletics and sports games are prescribed. Strength sports and marathon running are contraindicated.
• Self-control training.The success of maintenance therapy for diabetes is highly dependent on the motivation level of the patients. During the special courses, they are informed about the mechanisms of the disease, the possible compensation methods, the 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 give injections, choose food products and create menus.
• Prevention of complications.Medicines are used to improve the enzyme function of the glandular cells. These include agents that promote tissue oxygenation and immunomodulatory drugs. Timely treatment of infections, dialysis 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 noting the development of specific DNA vaccines for the treatment of diabetes mellitus at an early stage of development. In patients who received 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 glandular cells that produce insulin. The experiments carried out on rats gave positive results, but in order to use the method in clinical practice, evidence of the safety of the procedure is required.

Prognosis and prevention

The insulin-dependent form of diabetes mellitus is a chronic disease, but appropriate 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, it is recommended that all people at risk undergo annual examinations to detect the disease at an early stage and start treatment in time. This measure allows you to slow down the process of formation of persistent hyperglycemia and minimizes the possibility of complications.