Diabetes mellitus is a chronic metabolic disorder, which is based on a deficiency in the formation of its own insulin and an increase in blood glucose levels. It is manifested by a feeling of thirst, an increase in the amount of urine excreted, increased appetite, weakness, dizziness, slow healing of wounds, etc. The disease is chronic, often with a progressive course. There is a high risk of stroke, kidney failure, myocardial infarction, gangrene of the extremities, blindness. Sharp fluctuations in blood sugar cause life-threatening conditions: hypo- and hyperglycemic coma.
Meaning
Among the metabolic disorders that occur, diabetes mellitus ranks second after obesity. In the world, about 10% of the population suffers from diabetes, however, if we take into account the hidden forms of the disease, this figure may be 3-4 times more. Diabetes mellitus develops due to chronic insulin deficiency and is accompanied by disorders of carbohydrate, protein and fat metabolism. Insulin production occurs in the pancreas by the beta cells of the islets of Langerhans.
Participating in the metabolism of carbohydrates, insulin increases the intake of glucose into cells, promotes the synthesis and accumulation of glycogen in the liver, inhibits the breakdown of carbohydrate compounds. In the process of protein metabolism, insulin enhances the synthesis of nucleic acids, protein and suppresses its decay. The effect of insulin on fat metabolism is to activate the intake of glucose into fat cells, energy processes in cells, synthesis of fatty acids and slowing down the breakdown of fats. With the participation of insulin, the process of sodium entering the cell increases. Disorders of metabolic processes controlled by insulin can develop with insufficient synthesis (type I diabetes mellitus) or with tissue immunity to insulin (type II diabetes mellitus).
Causes
Type I diabetes mellitus is more often detected in young patients under 30 years of age. Violation of insulin synthesis develops as a result of autoimmune pancreatic damage and destruction of insulin-producing beta cells. In most patients, diabetes mellitus develops after a viral infection (mumps, rubella, viral hepatitis) or toxic effects (nitrosamines, pesticides, drugs, etc.), the immune response to which causes the death of pancreatic cells. Diabetes mellitus develops if more than 80% of insulin-producing cells are affected. Being an autoimmune disease, type I diabetes mellitus is often combined with other processes of autoimmune genesis: thyrotoxicosis, diffuse toxic goiter, etc.
In type II diabetes mellitus, insulin resistance of tissues develops, i.e. their insensitivity to insulin. At the same time, the insulin content in the blood may be normal or elevated, but the cells are immune to it. The majority (85%) of patients have type II diabetes mellitus. If the patient is obese, the susceptibility of tissues to insulin is blocked by adipose tissue. Type II diabetes mellitus is more susceptible to elderly patients who have a decrease in glucose tolerance with age.
The occurrence of type II diabetes mellitus may be accompanied by the following factors:
- genetic – the risk of developing the disease is 3-9% if relatives or parents have diabetes mellitus;
- obesity – with an excessive amount of adipose tissue (especially abdominal type of obesity), there is a noticeable decrease in tissue sensitivity to insulin, contributing to the development of diabetes mellitus;
- eating disorders – predominantly carbohydrate diet with a lack of fiber increases the risk of diabetes mellitus;
- cardiovascular diseases – atherosclerosis, arterial hypertension, coronary artery disease, reducing insulin resistance of tissues;
- chronic stressful situations – in a state of stress, the amount of catecholamines (norepinephrine, adrenaline), glucocorticoids that contribute to the development of diabetes increases in the body;
- diabetogenic effect of certain drugs – glucocorticoid synthetic hormones, diuretics, some antihypertensive drugs, cytostatics, etc.
- chronic insufficiency of the adrenal cortex.
In case of insufficiency or resistance to insulin, the intake of glucose into cells decreases and its content in the blood increases. The body activates alternative ways of processing and assimilation of glucose, which leads to the accumulation of glycosaminoglycans, sorbitol, glycylated hemoglobin in tissues. The accumulation of sorbitol leads to the development of cataracts, microangiopathies (disorders of capillaries and arterioles), neuropathy (disorders of the nervous system); glycosaminoglycans cause joint damage. In order for cells to receive the missing energy in the body, protein breakdown processes begin, causing muscle weakness and dystrophy of skeletal and cardiac muscles. The peroxidation of fats is activated, the accumulation of toxic metabolic products (ketone bodies) occurs.
Hyperglycemia in the blood in diabetes mellitus causes increased urination to remove excess sugar from the body. Together with glucose, a significant amount of fluid is lost through the kidneys, leading to dehydration. Along with the loss of glucose, the energy reserves of the body decrease, therefore, weight loss is noted in patients with diabetes mellitus. Elevated sugar levels, dehydration and accumulation of ketone bodies due to the breakdown of fat cells causes a dangerous condition of diabetic ketoacidosis. Over time, due to high sugar levels, damage to nerves, small blood vessels of the kidneys, eyes, heart, brain develops.
Classification
By association with other diseases, endocrinology distinguishes symptomatic (secondary) and true diabetes mellitus.
Symptomatic diabetes mellitus accompanies diseases of the endocrine glands: pancreas, thyroid, adrenal glands, pituitary gland and serves as one of the manifestations of primary pathology.
True diabetes mellitus can be of two types:
- insulin-dependent type I, if your own insulin is not produced in the body or is produced in insufficient quantities;
- insulin-independent type II, if there is insensitivity of tissues to insulin with its abundance and excess in the blood.
Diabetes mellitus of pregnant women is singled out separately.
There are three degrees of severity of diabetes mellitus: mild (I), moderate (II) and severe (III) and three states of compensation for carbohydrate metabolism disorders: compensated, subcompensated and decompensated.
Symptoms
The development of type I diabetes occurs rapidly, type II – on the contrary, gradually. Often there is a latent, asymptomatic course of diabetes mellitus, and its detection occurs accidentally during fundus examination or laboratory determination of sugar in blood and urine. Clinically, type I and type II diabetes mellitus manifest themselves in different ways, but the following signs are common to them:
- thirst and dry mouth, accompanied by polydipsia (increased fluid intake) up to 8-10 liters per day;
- polyuria (copious and frequent urination);
- polyphagia (increased appetite);
- dryness of the skin and mucous membranes, accompanied by itching (including perineum), pustular infections of the skin;
- sleep disturbance, weakness, decreased performance;
- cramps in the calf muscles;
- visual impairment.
Manifestations of type I diabetes mellitus are characterized by intense thirst, frequent urination, nausea, weakness, vomiting, increased fatigue, constant hunger, weight loss (with normal or increased nutrition), irritability. A sign of diabetes in children is the appearance of nocturnal urinary incontinence, especially if the child has not previously urinated in bed. With type I diabetes, hyperglycemic (with critically high blood sugar) and hypoglycemic (with critically low blood sugar) conditions requiring emergency measures are more likely to develop.
In type II diabetes mellitus, itching, thirst, visual impairment, pronounced drowsiness and fatigue, skin infections, slow wound healing processes, paresthesia and numbness of the legs prevail. Patients with type II diabetes often have obesity.
The course of diabetes mellitus is often accompanied by hair loss on the lower extremities and an increase in their growth on the face, the appearance of xanthus (small yellowish growths on the body), balanoposthitis in men and vulvovaginitis in women. As diabetes progresses, the violation of all types of metabolism leads to a decrease in immunity and resistance to infections. Prolonged course of diabetes causes damage to the bone system, manifested by osteoporosis (thinning of bone tissue). There are pains in the lower back, bones, joints, dislocations and subluxations of vertebrae and joints, fractures and deformities of bones, leading to disability.
Complications
The course of diabetes mellitus can be complicated by the development of multiple organ disorders:
- diabetic angiopathy – increased vascular permeability, fragility, thrombosis, atherosclerosis, leading to the development of coronary heart disease, intermittent claudication, diabetic encephalopathy;
- diabetic polyneuropathy is a lesion of peripheral nerves in 75% of patients, as a result of which there is a violation of sensitivity, swelling and chilliness of the limbs, a burning sensation and “crawling” of goosebumps. Diabetic neuropathy develops years after the disease of diabetes mellitus, is more common in the insulin-independent type;
- diabetic retinopathy – destruction of the retina, arteries, veins and capillaries of the eye, decreased vision, fraught with retinal detachment and complete blindness. In type I diabetes mellitus, it manifests itself in 10-15 years, in type II – earlier, it is detected in 80-95% of patients;
- diabetic nephropathy is a lesion of the renal vessels with impaired renal function and the development of renal insufficiency. It is noted in 40-45% of patients with diabetes mellitus 15-20 years after the onset of the disease;
- diabetic foot – circulatory disorders of the lower extremities, pain in the calf muscles, trophic ulcers, destruction of bones and joints of the feet.
Critical, acute conditions in diabetes mellitus are diabetic (hyperglycemic) and hypoglycemic comas.
Hyperglycemic condition and coma develop as a result of a sharp and significant increase in blood glucose levels. The precursors of hyperglycemia are increasing general malaise, weakness, headache, depression, loss of appetite. Then there are abdominal pains, Kussmaul’s noisy breathing, vomiting with the smell of acetone from the mouth, progressive apathy and drowsiness, a decrease in blood pressure. This condition is caused by ketoacidosis (accumulation of ketone bodies) in the blood and can lead to loss of consciousness – diabetic coma and death of the patient.
The opposite critical condition in diabetes mellitus – hypoglycemic coma develops with a sharp drop in blood glucose levels, more often due to an overdose of insulin. The increase in hypoglycemia is sudden, rapid. There is a sharp feeling of hunger, weakness, trembling in the limbs, shallow breathing, hypertension, the patient’s skin is cold, moist, sometimes convulsions develop.
Prevention of complications in diabetes mellitus is possible with constant treatment and careful monitoring of blood glucose levels.
Diagnostics
The presence of diabetes mellitus is indicated by the glucose content in the capillary blood on an empty stomach, exceeding 6.5 mmol / l. Normally, there is no glucose in the urine, because it is delayed in the body by a renal filter. With an increase in blood glucose of more than 8.8-9.9 mmol / l (160-180 mg%), the renal barrier fails and passes glucose into the urine. The presence of sugar in the urine is determined by special test strips. The minimum blood glucose level at which it begins to be determined in the urine is called the “renal threshold”.
Examination for suspected diabetes mellitus includes determining the level of:
- fasting glucose in capillary blood (from the finger);
- glucose and ketone bodies in the urine – their presence indicates diabetes mellitus;
- glycosylated hemoglobin – significantly increased in diabetes mellitus;
- с-peptide and insulin in the blood – in type I diabetes mellitus, both indicators are significantly reduced, in type II – practically unchanged;
- carrying out a stress test (glucose tolerance test): determination of glucose on an empty stomach and 1 and 2 hours after taking 75 g of sugar dissolved in 1.5 cups of boiled water. Negative (not confirming diabetes mellitus) the test result is calculated for samples: on an empty stomach < 6.5 mmol / l, after 2 hours – < 7.7mmol / l. The presence of diabetes mellitus is confirmed by indicators > 6.6mmol/l at the first measurement and >11.1 mmol/l 2 hours after glucose loading.
To diagnose complications of diabetes mellitus, additional examinations are carried out: ultrasound of the kidneys, rheovasography of the lower extremities, rheoencephalography, EEG of the brain.
Treatment
The implementation of the recommendations of a diabetologist, self-monitoring and treatment for diabetes mellitus are carried out for life and can significantly slow down or avoid complicated variants of the course of the disease. Treatment of any form of diabetes mellitus is aimed at lowering blood glucose levels, normalizing milestones in the types of metabolism and preventing complications.
The basis for the treatment of all forms of diabetes is diet therapy, taking into account the gender, age, body weight, physical activity of the patient. Training is conducted on the principles of calculating the caloric content of the diet, taking into account the content of carbohydrates, fats, proteins, vitamins and trace elements. In case of insulin-dependent diabetes mellitus, it is recommended to consume carbohydrates at the same hours to facilitate the control and correction of glucose levels with insulin. With type I ISSD, the intake of fatty foods that contribute to ketoacidosis is limited. With insulin-independent diabetes mellitus, all types of sugars are excluded and the total caloric content of food is reduced.
Nutrition should be fractional (at least 4-5 times a day), with an even distribution of carbohydrates, contributing to a stable glucose level and maintaining the basic metabolism. Special diabetic products based on sweeteners (aspartame, saccharin, xylitol, sorbitol, fructose, etc.) are recommended. Correction of diabetic disorders with only one diet is applied to a mild degree of the disease.
The choice of drug treatment for diabetes mellitus is determined by the type of disease. Patients with type I diabetes mellitus are shown insulin therapy, with type II – diet and hypoglycemic agents (insulin is prescribed when taking tablet forms is ineffective, ketoazidosis and precomatous state develop, tuberculosis, chronic pyelonephritis, liver and kidney failure).
The administration of insulin is carried out under systematic control of glucose levels in the blood and urine. According to the mechanism and duration of action, there are three main types of insulins: prolonged (prolonged), intermediate and short-acting. Insulin of a prolonged nature is administered 1 time a day, regardless of food intake. More often, injections of prolonged insulin are prescribed together with intermediate and short-acting drugs, allowing for compensation of diabetes mellitus.
The use of insulin is dangerous by overdose, leading to a sharp decrease in sugar, the development of hypoglycemia and coma. The selection of drugs and the dose of insulin is carried out taking into account changes in the patient’s physical activity during the day, the stability of blood sugar levels, calorie intake, fractional nutrition, insulin tolerance, etc. With insulin therapy, local (pain, redness, swelling at the injection site) and general (up to anaphylaxis) allergic reactions may develop. Also, insulin therapy can be complicated by lipodystrophy – “dips” in adipose tissue at the site of insulin injection.
Sugar-lowering tablet drugs are prescribed for insulin-independent diabetes mellitus in addition to diet. According to the mechanism of reducing blood sugar , the following groups of hypoglycemic agents are distinguished:
- sulfonylureas (gliquidone, glibenclamide, chlorpropamide, carbutamide) – stimulate the production of insulin by beta cells of the pancreas and promote the penetration of glucose into tissues. The optimally selected dosage of drugs in this group maintains a glucose level of not > 8 mmol /l. In case of overdose, hypoglycemia and coma may develop.
- biguanides (metformin, buformin, etc.) – reduce the absorption of glucose in the intestine and contribute to the saturation of peripheral tissues with it. Biguanides can increase the level of uric acid in the blood and cause the development of a severe condition – lactic acidosis in patients over 60 years of age, as well as people suffering from liver and kidney failure, chronic infections. Biguanides are more often prescribed for insulin-independent diabetes mellitus in young obese patients.
- meglitinides (nateglinide, repaglinide) – cause a decrease in sugar levels, stimulating the pancreas to secrete insulin. The effect of these drugs depends on the sugar content in the blood and does not cause hypoglycemia.
- alpha-glucosidase inhibitors (miglitol, acarbose) – slow down the increase in blood sugar by blocking enzymes involved in the absorption of starch. Side effect – flatulence and diarrhea.
- thiazolidinediones – reduce the amount of sugar released from the liver, increase the susceptibility of fat cells to insulin. Contraindicated in heart failure.
In diabetes mellitus, it is important to train the patient and his family members in the skills of monitoring the well-being and condition of the patient, first aid measures for the development of precomatous and comatose states. A beneficial therapeutic effect in diabetes mellitus has a reduction in excess weight and individual moderate physical activity. Due to muscular efforts, glucose oxidation increases and its content in the blood decreases. However, physical exercises should not be started when the glucose level is > 15 mmol / l, first you need to wait for its decrease under the influence of drugs. In diabetes mellitus, physical activity should be evenly distributed to all muscle groups.
Prognosis and prevention
Patients with detected diabetes mellitus are registered with an endocrinologist. With the organization of a proper lifestyle, nutrition, treatment, the patient can feel satisfactory for many years. Aggravate the prognosis of diabetes mellitus and shorten the life expectancy of patients with acute and chronically developing complications.
Prevention of type I diabetes mellitus is reduced to increasing the body’s resistance to infections and eliminating the toxic effects of various agents on the pancreas. Preventive measures of type II diabetes mellitus provide for the prevention of the development of obesity, nutrition correction, especially in people with a burdened hereditary history. Prevention of decompensation and complicated course of diabetes mellitus consists in its proper, systematic treatment.
