Cystic fibrosis–related diabetes (CFRD) is the most common comorbidity in subjects with cystic fibrosis (CF). A consensus conference on CFRD was cosponsored by the Cystic Fibrosis Foundation (CFF), the American Diabetes Association (ADA), and the Pediatric Endocrine Society (PES) in September 2009. The committee’s evidencebased recommendations for clinical management of CFRD are published in this issue of Diabetes Care. This review article describes the epidemiology, pathogenesis, and prognostic implications of CFRD.

Epidemiology CFRD is part of a continuum of glucose tolerance abnormalities, ranging from normal glucose tolerance (NGT), to impaired glucose tolerance (IGT), to CFRD without fasting hyperglycemia (CFRD FH), to CFRD with fasting hyperglycemia (CFRD FH)(Fig. 1). Unlike patients with type 1 diabetes, those with CFRD do not develop complete absence of insulin secretion. At the other end of the spectrum, few CF patients have truly normal glucose metabolism. Approximately 20% of children who are categorized as having NGT based on their fasting and 2-h oral glucose tolerance test