Oral Glucose Tolerance Test (OGTT)

Beginning at age 10 years, your child will have an oral glucose tolerance test (OGTT) during your annual visit. Your CF care team will be testing every year for diabetes. The OGTT may be done sooner than 10 years of age if a person is having any symptoms of diabetes. 

How it is performed:  
An OGTT is done after a person has had nothing to eat or drink for 8 to 12 hours. Blood samples are taken before and up to 2 hours after drinking a set amount of glucose. 

How does it work:
The OGTT measures how your body removes glucose (a kind of sugar) from the blood. Insulin is made in the pancreas and it helps change glucose into energy for your body. 

People with CF may have trouble making insulin because the pancreas may not work correctly. This could lead to CF-related diabetes (CFRD) or impaired glucose tolerance (IGT). CFRD and IGT are not caused by eating too much sugar or carbohydrates. An OGTT can diagnose CFRD or IGT.