Glucose Tolerance Test After 1 Hour in Plasma

What is it? 

This is a blood test conducted one hour after consuming a standard dose of Glucose. It is most commonly used as part of the glucose tolerance test (GTT), which helps assess how the body handles sugar – i.e., how the pancreas secretes insulin and how cells respond to glucose. 

How is the test conducted? 

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 conducted during pregnancy as a primary test to diagnose gestational diabetes. 

When is it recommended? 

• For pregnant women – during the 24–28 week of pregnancy; 
• When fasting glucose is normal, but there are symptoms (fatigue, thirst, frequent urination); 
• 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 especially important for pregnant women, as gestational diabetes can affect fetal development and the course of childbirth. 

What is important to know? 

Usually, there is no special preparation required 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.