Cystic Fibrosis Oral Glucose Tolerance Test (OGTT) Make an Appointment Patient Education Find a Doctor Download Patient Education The OGTT is a blood test that 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 cystic fibrosis (CF) may have trouble making insulin or using insulin their body makes. 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. It is important to know that there is nothing a person with CF has done to cause his/her diabetes, nor is there anything specific a person can do to prevent his/her diabetes. Rather, some people with CF will develop CFRD or IGT, while others may not Download PDF: Cystic Fibrosis Oral Glucose Tolerance Test (OGTT) Download PDF: Cystic Fibrosis Oral Glucose Tolerance Test (OGTT) View more information on Cystic Fibrosis National Jewish Health authors free downloadable patient education materials to provide you and your family the information and tools to help manage your disease. They include Understanding Booklets, Med Facts, Test Facts, Medication handouts and more. Search Free Education Materials