Description and mechanism of development of diabetes
Diabetes mellitus is a pathology of carbohydrate metabolism, which has a chronic course and is characterized by the development of hyperglycemia. The pathogenesis of diabetes is associated with one of two mechanisms: decreased secretion or impaired insulin action. Decreased secretion occurs due to damage to the pancreas – the organ in which insulin is produced. This is manifested due to autoimmune damage, pancreatitis, tumor damage to the pancreas.
A decrease in insulin concentration can also occur in cases where counterinsular hormones are prescribed uncontrollably , most often glucocorticoids as anti-inflammatory therapy.
The second mechanism is associated with a violation of tissue susceptibility to the action of the hormone. The specific reasons for this condition have not been established, but it is believed that the main factor is associated with a hereditary predisposition. Thus, there are 2 main types of the disease:
- Type 1 diabetes mellitus – in which there is a destruction of beta cells and insulin deficiency;
- Type 2 diabetes – manifested by a decrease in the sensitivity of all cells to insulin.
In diabetes, disorders of carbohydrate, protein, fat and water metabolism occur. At the same time, prolonged hyperglycemia affects the state of blood vessels and peripheral nerves.
The role of insulin in the treatment of disease
By its nature, insulin is a biologically active substance (hormone) that is synthesized by the endocrine pancreas. Its activity is associated with increased utilization of glucose in adipose tissue. The effects of the hormone:
- Activates the transfer of glucose into tissues,
- Stimulates the conversion of glucose to glycogen,
- Stimulates the synthesis of proteins and fats.
Physiological insulin secretion is subject to fluctuations. Nutritional fluctuations occur in response to surges in blood glucose levels. Daily fluctuations are based on the fact that a strong jump in blood glucose occurs in the morning.
When insulin is prescribed, its dosage and type should correspond to physiological fluctuations.
In diabetes, there is a deficiency of insulin (or a violation of its action), in this regard, a pathology of carbohydrate metabolism occurs. A hormone deficiency leads to the fact that glucose is not broken down and its level in the blood remains the same. At the same time, an increase in its level is observed – there is a lot of glucose, but it is not absorbed. Glucose is the main nutrient for body tissues. Despite its excessive amount, insulin deficiency leads to the fact that glucose does not enter the tissues. Accordingly, the body experiences a lack of nutrients. Prolonged hyperglycemia is accompanied by damage to the heart and blood vessels, brain, peripheral nervous system, kidneys and eyes. Therefore, it is so important to compensate for the condition and strive to normalize the glucose concentration.
When is insulin therapy indicated?
Insulin therapy is an important treatment for diabetes. The disease is characterized by a decrease in insulin secretion, therefore, replacement therapy is often used for treatment.
The need for insulin medications depends on various conditions. For example, the type of diabetes, the level of glycemia, the presence of complications and comorbid pathology.
The main indication for insulin therapy is a condition that is accompanied by an insulin deficiency .
For type 1 diabetes
Type 1 (autoimmune) diabetes is characterized by an absolute lack of insulin. In this regard, diabetes therapy cannot be carried out without insulin therapy. In diabetes, insulin is used as replacement therapy. The therapy aims at replicating the natural production of the hormone as much as possible. The schemes of insulin therapy are used, which take into account food and daily fluctuations in physiological secretion. Basal secretion is provided by the administration of prolonged-release insulin. If drugs are administered, the effect of which lasts for 24 hours, an injection once a day is sufficient. Schemes with the introduction of insulin 2 times are more often used – in the morning and in the evening. Food secretion is provided by the administration of fast-acting insulin. The dosage is calculated individually and depends on 2 main factors:
- the amount of carbohydrates per serving,
- the existing level of glycemia.
In type 1 diabetes, insulin is prescribed anyway. The initial level of glycemia does not affect the appointment of insulin either. Therapy is aimed at correcting hyperglycemia, avoiding complications and maintaining intact areas of the pancreas.
Diabetes manifests itself when more than 80–90% of the cells that are capable of producing insulin are destroyed. Substitution therapy aims to keep the remaining 10-20%.
For type 2 diabetes
In this form of diabetes, tissue resistance to insulin develops. In most cases, the pancreas is not affected and there is no insulin deficiency. Despite the normal level of insulin secretion, tissues are insensitive to it, which is why diabetes occurs. Thus, insulin therapy for type 2 diabetes is rarely used. In most cases, it is enough to follow a diet in combination with an active motor regimen and take oral antihyperglycemic drugs. But sometimes insulin therapy is indicated even for type 2 diabetes. Cases when the drug is prescribed:
- In the presence of obvious symptoms of insulin deficiency: weight loss, ketosis ;
- If the fasting glucose level exceeds 13-15 mmol / L;
- With an acute infectious disease;
- With the development of acute vascular complications;
- Before undergoing surgery;
- With acute somatic diseases;
- With severe manifestations of late complications (retinopathy, nephropathy, diabetic foot syndrome).
In addition, insulin is prescribed in cases where it is not possible to achieve compensation through diet and maximum dosages of oral medications.
With acute decompensation
A dangerous and rapidly developing complication of diabetes is the development of coma. Early complications of the disease include:
- diabetic ketoacidosis ,
- hyperosmolar coma,
- hyperlactacilemic (lactic acid) coma.
The presence of any of these conditions is an indication for the use of insulin therapy. The mode of “small doses” is used – fast-acting insulin preparations are introduced. First, intravenous insulin is administered. The dose is selected based on the blood sugar level. In the first hour, about 20 units are administered, then the dosage is reduced – by 6–10 units. When insulin is prescribed, you need to be careful: a sharp decrease in glucose concentration can lead to cerebral edema.
For diabetic coma, in addition to insulin, infusion therapy (saline solutions) is also used .
Possible complications from treatment
Complications of insulin therapy are infrequent and are usually associated with a violation of insulin administration or an incorrect dosage. The most common complication is lipodystrophy . This is a lesion of subcutaneous fat, which is characterized by its atrophy or hypertrophy. Those parts of the fatty tissue where insulin is injected are affected. Lipodystrophy is manifested by atrophy of cellulose, less often – by its growth, the formation of lipomas. Outwardly, it looks like a small depression at the injection site. In severe cases, large areas of fiber are affected. To prevent the development of lipodystrophy, you must follow the rules for administering insulin. First of all, change the injection site. Another common complication is a sharp drop in blood sugar (hypoglycemia). Hypoglycemia is a pathological condition characterized by a decrease in the level of glycemia. The use of high doses of insulin increases the risk of hypoglycemia. In addition, there are other factors:
- Significant physical activity,
- Reduced portion of food, fasting,
- Drinking alcohol,
- Violation of the technique of insulin administration (parenteral administration instead of subcutaneous administration).
Mild hypoglycemia in diabetes occurs frequently and is easily corrected by the use of sweet juice and sweets. Symptoms of hypoglycemia include: weakness, muscle tremors, hunger and nausea, dizziness, and increased heart rate. In severe cases, hypoglycemic coma develops – a decrease in glycemia below 2 mmol / l, which is accompanied by loss of consciousness. A rare complication of insulin therapy is cerebral edema. This condition can develop with a rapid decrease in glucose concentration. For example, in the treatment of ketoacidotic or hyperglycemic coma.
To avoid cerebral edema, it is necessary to reduce the level of glycemia by no more than 5 mmol per hour.
If the wrong dose of insulin is selected, the Samoji phenomenon can develop . The condition is characterized by the occurrence of hypoglycemia at night and compensatory hyperglycemia in the morning. Samoji syndrome develops with an excessive evening dose of insulin.