The laboratory method that evaluates the level of glucose in the blood on an empty stomach and 2 hours after a "sugar load", which makes it possible to detect a violation of carbohydrate metabolism, diagnose diabetes and prediabetes, as well as monitor the condition of patients with these diseases and monitor the effectiveness of treatment.

To make the results of the glucose tolerance test more informative, the insulin level is sometimes determined along with the blood sugar level. Insulin is a hormone that is produced by the pancreas and helps lower blood sugar levels. By measuring insulin before and after taking a glucose solution, the doctor can understand how well the pancreas reacts to the sugar load. If the sugar and insulin levels deviate from the norm, it is easier for the doctor to identify metabolic disorders and make a diagnosis at an early stage.

Who is shown the analysis?

· Patients with questionable glycemic parameters to clarify the diagnosis

· Patients who have been diagnosed with diseases of the cardiovascular system, disorders of the pancreas or adrenal glands

· To detect gestational diabetes mellitus (with a glucose level of no more than 5.1 mmol/l)

· Patients with risk factors for diabetes mellitus (family history, obesity, metabolic syndrome, impaired fat metabolism)

· The appointment of a glucose tolerance test to determine the level of insulin, as well as the interpretation of the results obtained, is carried out exclusively by the attending physician

How is the glucose tolerance test performed?

- The first test is performed in the morning on an empty stomach

- After taking blood on an empty stomach, the patient should drink 75 g of anhydrous glucose or 82.5 g of glucose monohydrate dissolved in 250-300 ml of water in 5 minutes, For pregnant women — the same 75 g as standard (unless otherwise specified by the doctor)

-After 2 hours, repeated blood sampling is performed

- Attention! The laboratory does NOT dispense glucose, the patient must have it with him.

Preparation for the study:

· Preparation for the glucose tolerance test includes following a regular diet with sufficient carbohydrates for three days prior to the study. During this time, alcohol consumption should be eliminated, intense physical exertion and stressful situations should be avoided.

· The study is conducted strictly on an empty stomach, therefore, 8-14 hours before the test, it is necessary to completely abandon food intake; only non-carbonated water is allowed.

· On the day of the study, you should not smoke, drink tea, coffee, or other beverages other than water.

· Taking medications that may affect blood glucose levels must be coordinated with your doctor in advance and stopped 3 days before blood donation.

· Smoking is prohibited during blood donation and physical activity is excluded (you can sit, read or watch a movie). The patient must be under the supervision of medical staff for the entire period until the next blood collection.

When can I not take the test?

· on the background of acute illness , exacerbation of chronic diseases

· while taking medications that increase blood sugar levels (glucocorticoids, thyroid hormones, thiazides, beta-blockers, etc.)

· when diagnosed with diabetes mellitus

· if the glucose level exceeds 7 mmol/l  

Interpretation of results:

No more than 7.8 mmol/l - the norm

is 7.8 - 11.0 mmol/l – impaired glucose tolerance (manifestation of prediabetes, diabetes mellitus)

More than 11.1 mmol/l – diabetes mellitus

Insulin: 1.9 0– 23.00 Ui/ml

A marker of insulin resistance and a harbinger of the development of type 2 diabetes: the level of insulin after exercise increased more than three times compared with the "lean" value; the glucose level may be equal to the "lean" value or lower

Important note: The result of laboratory tests is not the only parameter for making a diagnosis. For interpretation of the results, it is necessary to consult your doctor. The results of the analysis should be analyzed taking into account the clinical symptoms, duration of the disease and concomitant pathology.