What is Cystic Fibrosis Related Diabetes (CFRD)?
Diabetes is very common in CF. As patients get older, scarring occurs in the pancreas. This scarring prevents insulin from getting into the bloodstream where it is needed to maintain a normal blood sugar. Up to 75% of adults with CF have some form of glucose intolerance.
Diabetes results in weight loss, inability to gain weight and lack of energy. Food is normally broken down into sugar, fat and protein. As sugar enters your bloodstream and blood sugar levels rise, this signals the pancreas to secrete insulin. Insulin then works to help protein, fat and sugar leave the blood and enter cells where they are used for energy. People with diabetes do not efficiently convert food into energy, therefore, have difficulty gaining weight.
Cystic fibrosis-related diabetes (CFRD) is different than the diabetes that occurs in people without CF, therefore, the diagnosis and management of the disease is different. CFRD can occur some of the time, or can occur at all times. With glucose intolerance that occurs only when you are sick, you may only need to take insulin during those times of infection/illness. With CFRD, you will likely require insulin treatment at all times.
The current CF foundation guidelines regarding screening for CFRD is that any patient with a random (meaning not taken when you are fasting) blood sugar of more than 126 have further testing. Our center's recommendation is that all CF patients 8 years of age and older have an annual Oral Glucose Screening Test. This requires coming in without eating or drinking anything for 6 hours, and drinking a special sugary drink called "Glucola". Your blood will be drawn before you drink and 2 hours after. Your blood will be tested for glucose as well as insulin levels since insulin resistance is a big factor in CFRD. If any of your results are positive (fasting > 126 or 2hour > 200 or Hemoglobin A1C ≥ 6.0) you will be referred to see an endocrinologist to help manage your disease. Your CF Team follows these values very closely and will notify you when further testing is needed.
This information was borrowed from the CF Foundation article, Managing Cystic Fibrosis-Related Diabetes—An Instruction Guide for Patients and Families. To view the full report and the most up to date published guidelines, go to the CF Foundation website.