The glucose tolerance test (GTT), also known as the oral glucose tolerance test (OGTT), is a laboratory study used to assess how the body processes glucose. It is applied for the diagnosis of diabetes mellitus, prediabetes, and gestational diabetes in pregnant women.
When is a glucose tolerance test required?
In cases of elevated blood glucose detected during routine testing. When symptoms of hyperglycemia are present, such as excessive thirst, fatigue, and frequent urination. In individuals with overweight, insulin resistance, or metabolic syndrome. For the diagnosis of gestational diabetes during pregnancy.
How is the test performed?
The test is conducted in the morning on an empty stomach. The first blood sample is taken to determine fasting glucose levels. The patient then drinks a glucose solution (75 g of glucose dissolved in 250 ml of water). Subsequent blood samples are collected 1 hour and 2 hours after glucose intake. During the test, it is important to remain at rest, avoid eating, and refrain from physical activity.
Interpretation of results
Normal values: fasting glucose up to 5.6 mmol/L, and less than 7.8 mmol/L after 2 hours. Prediabetes: 7.8–11.0 mmol/L after 2 hours. Diabetes mellitus: more than 11.1 mmol/L after 2 hours.
Main advantages of the glucose tolerance test in Belarus
The test allows early detection of diabetes and prediabetes. It evaluates the body’s ability to metabolize glucose and helps initiate timely preventive measures and treatment.
The examination is performed in modern laboratories with high analytical accuracy. Experienced endocrinologists interpret the results and provide recommendations on nutrition and further management.
