Diabetes mellitus is a term that combines endocrine diseases, a characteristic feature of which is the lack of action of the hormone insulin. The main symptom of diabetes mellitus is the development of hyperglycemia – an increase in the concentration of glucose in the blood, which is persistent.
History of the discovery of diabetes mellitus
Diabetes mellitus has been known to people since ancient times. Even the ancient Greeks noticed its important signs – an increase in fluid secretion and increased thirst. It was believed that a diabetic patient was actively losing water and then must drink to replenish fluid reserves. Much later, scientists noticed that urine with diabetes has a sweet taste. Since then, the term “diabetes mellitus” has appeared. In ancient India, this disease was called “sweet urine disease” because the urine of diabetic patients attracted ants. Already in our time, people have been able to determine the concentration of glucose in the blood – it became clear that the level of glucose is increased not only in the urine, but also in the blood, and for a long time in diabetes mellitus only the level of blood glucose can be increased, and only then, with aggravation of diabetes, glucose appears in the urine. Today, high blood glucose (hyperglycemia) is considered the main symptom of diabetes mellitus, and it is on the detection of hyperglycemia that the diagnosis of diabetes is based.
As a result of experiments of the XIX-XX centuries, it was found that in some patients with diabetes mellitus, a lack of insulin in the blood is revealed. Insulin is a hormone produced in the pancreas by cells of the islets of Langerhans. Its main function is to stimulate the absorption of glucose by the cells of the human body. Without insulin, most human organs and tissues are unable to metabolize glucose. When the pancreas was removed, the clinical picture of diabetes mellitus developed in laboratory animals. The introduction of insulin eliminated the symptoms of the disease.
After establishing the important role of insulin in the development of diabetes mellitus, it became clear that this hormone can be used to treat the disease. Significant efforts have been made to organize the production of insulin, but it took a long time for the insulin preparations to reach the proper level of quality.
In the course of research, it was found that in a significant part of patients with diabetes mellitus, the level of insulin in the blood is not decreased, but increased. In such patients, the cause of the development of diabetes mellitus is a violation of the action of insulin on the cells of tissues and organs of the human body. Treatment of this type of diabetes (it was called type 2 diabetes mellitus) is based on the use of drugs that increase the sensitivity of cells to insulin, and insulin itself is used only in severe cases when other drugs are ineffective.
Types of diabetes
There are now two types of diabetes mellitus. In type 1 diabetes mellitus, the cells of the insulin-producing islets of the pancreas are destroyed. The result of this destruction is a decrease in the concentration of insulin in the blood and the appearance of symptoms of diabetes mellitus. Type 1 diabetes is treated by administering insulin to patients. Type 1 diabetes mellitus is more common in children and young patients.
Type 2 diabetes mellitus develops more often in the second half of life, mainly in patients with excess adipose tissue. The reason for the increase in blood sugar levels in type 2 diabetes is insulin resistance – a violation of the sensitivity of cells to insulin. In an attempt to “correct the situation”, the cells of the pancreas in type 2 diabetes mellitus produce excess amounts of insulin, proinsulin.
A common process for both types of diabetes mellitus is the impairment of glucose uptake by the cells of the human body. With a lack of insulin action, glucose stops moving from the blood into the cells, while unused glucose begins to accumulate in the blood. At the same time, a deficiency of glucose develops inside the cells, and the cells begin to experience an energy deficit, since glucose is the main supplier of energy.
Among the reasons for the development of diabetes mellitus, special attention is paid to heredity. It is well known that this disease is more common among blood relatives of a patient with diabetes mellitus than in the general population of people. If one of the parents was diagnosed with type 1 diabetes, then the probability of inheriting diabetes in children is approximately 10%. If one of the parents has type 2 diabetes, then the probability of its development in offspring can reach 80%.
Type 1 diabetes mellitus can occur after viral infections, removal of the pancreas during the development of tumors in it, destruction of pancreatic tissue by tumors, with traumatic damage to the pancreas, with the onset of pancreatitis (inflammation of the pancreas), with damage to the cells of the islets of Langerhans by the patient’s own immune system.
Among the causes of type 2 diabetes mellitus, in addition to the hereditary factor, obesity, smoking, excessive alcohol consumption, and a sedentary lifestyle should be named.
Signs of diabetes
Among the main symptoms of diabetes mellitus, the most important are:
- increased excretion of urine, manifested by increased frequency of urination and an increase in urine volume;
- thirst, which arises from the excretion of water in the urine;
- hunger, which occurs due to the development of energy “starvation” of the cells of the patient’s body, despite the significant content of glucose in the blood;
- weight loss, which develops mainly in type 1 diabetes mellitus due to the “burning” of proteins and fats for energy in conditions where it is impossible for cells to obtain energy from glucose.
Many patients develop other symptoms of diabetes mellitus: itchy skin, vaginal itching in women, dry mouth, weakness, headaches, purulent skin lesions, decreased visual acuity, decreased sensitivity of the legs.
Diagnosis of diabetes mellitus
Diagnosis of diabetes mellitus is based mainly on determining the concentration of glucose in the blood. The diagnosis of diabetes mellitus is established for a patient if the fasting capillary blood glucose (taken from a finger) exceeds 6.1 mmol / L, or the fasting venous blood glucose exceeds 7.1 mmol / L. Additional signs of diabetes are the appearance of sugar in the urine, or the appearance of acetone in the urine.
When describing diabetes mellitus, in addition to its type, the course of the disease and its phase must be indicated. Diabetes can be mild, moderate, or severe.
With a mild course of diabetes mellitus, the fasting blood glucose level does not exceed 8 mmol / l, and a very low glucose content is noted in the urine (up to 20 g / l). Such a course of diabetes is possible only with type 2 diabetes mellitus. In the treatment of mild diabetes, diet, antihyperglycemic drugs, and regulation of the level of physical activity are used.
Diabetes mellitus of moderate severity, the level of blood glucose in the morning can reach 14 mmol / l, more glucose appears in the urine – up to 40 g / l, ketosis can develop. Patients develop complications of diabetes. For treatment, in addition to diet, drugs are necessarily used – from hypoglycemic drugs to insulin.
In severe diabetes mellitus, the blood glucose level exceeds 14 mmol / L, the level of glucose in the urine exceeds 40 g / L. Treatment consists of the use of insulin.
With diabetes mellitus of any severity, it is necessary to prevent the development of complications of the disease.
When treating diabetes, it is also necessary to take into account the degree of compensation for the disease. With compensated diabetes, treatment leads to a complete normalization of blood sugar levels. In the urine, glucose is not detected. Subcompensated diabetes is manifested by an increased blood glucose level, but its level does not exceed 13.9 mmol / L. In the urine with subcompensation of diabetes, glucose is detected – its excretion per day does not exceed 50 g. In the decompensated form of diabetes, the glucose level exceeds 13.9 mmol / l, in the urine, in addition to glucose, acetone appears. Decompensation of diabetes is fraught with the development of formidable complications, up to coma.
Complications of diabetes mellitus
Among the complications of diabetes mellitus, acute complications (occurring within a matter of hours or days) and late ones, developing very slowly, are distinguished. Acute complications can lead to rapid death of the patient, and late complications can significantly shorten the patient’s life and worsen its quality.
Among the acute complications of diabetes mellitus, one should mention diabetic ketoacidosis (accumulation of fat breakdown products in the blood – ketone bodies), hypoglycemia (a decrease in blood glucose levels due to an overdose of insulin, hypoglycemic drugs, excessive physical activity, alcohol intake), hyperosmolar coma (occurs due to dehydration of the body from – due to increased urine excretion and the disappearance of thirst), lactacidotic coma (due to the accumulation of lactic acid in the blood).
Among the late complications of diabetes mellitus, diabetic retinopathy (damage to the retina of the eye with the development of vasodilation, hemorrhage, edema), micro- and macroangiopathy (damage to large and small vessels with the appearance of a tendency to thrombosis, fragility of blood vessels, accelerated development of atherosclerosis), polyneuropathy ( violation of sensitivity – pain and temperature due to malnutrition of peripheral nerve cells, subsequently paresthesias appear – feelings of burning and pain, often intensifying at night), nephropathy (kidney damage with increased protein excretion, up to the appearance of renal failure), arthropathy (the appearance of pain in the joints, decreased joint mobility), encephalopathy (mental disorder of the patient, the appearance of emotional instability, depressive conditions), diabetic foot syndrome (purulent lesion of the feet up to gangrene of the limb).