Determination of Glucose Concentration After 1 Hour

What is it? 

This is a blood test performed one hour after consuming a standard dose of glucose. It is most commonly used as part of the glucose tolerance test (GTT), which helps evaluate how the body manages sugar, i.e., how the pancreas releases insulin and how cells respond to glucose. 

How is the test performed? 

The patient needs to drink a certain amount of glucose solution (usually 50 or 75 g), and after one hour, a blood sample is taken to determine glucose concentration. This test is often performed during pregnancy as a preliminary test to diagnose gestational diabetes. 

When is it recommended? 

• For pregnant women – between the 24th and 28th week of pregnancy; 
• When fasting glucose is normal, but symptoms (fatigue, thirst, frequent urination) are present; 
• When suspecting prediabetes or metabolic syndrome. 

Benefits: 

The test allows for the detection of hidden carbohydrate metabolism disorders before the symptoms of diabetes become apparent. This is particularly important for pregnant women, as gestational diabetes can affect fetal development and the course of childbirth. 

What is important to know? 

Usually, no special preparation is needed before the test, but it is advised to avoid intense physical activity and stress on the day of the test. Sometimes this test is the first step – if the results are elevated, an extended GTT with measurements after 2–3 hours may be recommended.