Insulin | Laboratory research

Insulin Is a polypeptide Hormone, which is produced by the so-called pancreas. By β cells of the islets of Langerhans. The insulin molecule consists of 2 polypeptide chains: α chain - 21 amino acids and β chain - 30 amino acids, which are connected by two disulfide bridges. Insulin და C-peptide Produced by the pancreas Proinsulin As a result of proteolytic division.

Its main role is to regulate blood glucose levels. Although insulin is mainly related to blood sugar control, it is also involved in the metabolism of fats and proteins.

When you take carbohydrates in the form of food, your blood sugar level rises, the cells of the pancreas detect this change and release more insulin in response, the released insulin circulates in the blood and helps the cells absorb glucose. This process causes a gradual decrease in blood sugar.

Too high blood sugar levels can have toxic effects and even lead to death without treatment. Such high blood sugar levels can be found in people with diabetes. On the other hand, in some cases, excessive production of insulin can lead to low blood sugar.

When to take an insulin test?

• Assess the function of pancreatic insulin-secreting cells;
• Diagnosis of pancreatic tumor; (Insulin-secreting tumor)
• Diagnosing the causes of low blood glucose levels;
• Diagnosis of decreased cell sensitivity to insulin;
• In addition to tablets, decide to start treatment with injectable insulin in patients with type 2 diabetes.

Extended assessment of carbohydrate metabolism requires a serum insulin test in combination with a glucose tolerance test or a measurement of fasting blood glucose.

Serum insulin test should be performed if:

• You have low blood glucose levels that are accompanied by symptoms such as: sweating, palpitations (rapid heartbeat), dizziness, and loss of consciousness;
• You have diabetes and your doctor wants to test your ability to produce insulin by your pancreas;
• Your doctor suspects that you have diabetes (mainly type 2 diabetes, which is characterized by a decrease in the cells' sensitivity to insulin).

If you have diabetes, you may complain of one or more symptoms:

• Enhanced feeling of thirst, despite ingestion of large amounts of water;
• Weight loss or gain for no apparent reason;
• Easily tired;
• Impaired vision;
• Difficult wound healing;
• Burning, tingling or pain in the extremities.
• Changes in digestion, urination and sexual function.

How to prepare for the test?

The test should be performed at least 7 hours after the last meal.

Research material

Venous blood

Possible interpretation of the results

Insulin concentration increases: 

• Insulinoma;
• Type 2 diabetes (onset of the disease);
• Liver disease
• Acromegaly;
• Itzenko-Cushing syndrome;
• Muscle dystrophy;
• Fructose and galactose intolerance;
• Obesity;
• Pregnancy.

Insulin concentration decreases: 

• Type 1 diabetes;
• Type 2 diabetes;
• Hypopituitarism;
• Prolonged physical activity.

Against the background of prolonged starvation, when the patient's blood glucose (sugar) falls below 2.2 mmol / L, elevated insulin levels indicate a diagnostics of pancreatic tumor producing insulin.

Insulin levels are progressively reduced in patients with type 1 diabetes.

In the early stages of type 2 diabetes, insulin levels are normal or elevated, and in the late stages - decreased.

In the second and third trimesters of pregnancy, there is a decrease in the relative sensitivity of cells to insulin, an increase in insulin levels, and a progressive drop in blood glucose.

Fasting patients have higher insulin levels than normal weight patients.

Resources

https://spravochnik.synevo.ua/ru/carbohydratemetabolism/insulin.html  

https://www.synevo.bg/insulin/