Management of cystic fibrosis-related diabetes in children and adolescents.

• Cystic fibrosis-related diabetes (CFRD) is the most common co-morbidity associated with cystic fibrosis (CF). • The pathophysiology of CFRD is complex and includes the loss of pancreatic islet cells leading to both insulin and glucagon deficiency, fluctuating insulin resistance, the requirement for high caloric intake, gut abnormalities including delayed gastric emptying, altered intestinal motility, and liver disease. • CFRD can occur at any age, including infancy, and its prevalence increases as patients get older. • Few individuals with CF have normal glucose tolerance and even when the fasting and 2-h oral glucose tolerance test (OGTT) glucose levels are normal, variable, intermittent post-prandial hyperglycemia can often be detected by continuous glucose monitoring (CGM). • CF is associated with a progressive deterioration in glucose tolerance as individuals grow older, including indeterminate glycemia followed by impaired glucose tolerance (IGT) and finally diabetes. • Early CFRD is characterized by normal fasting glucose levels, but over time fasting hyperglycemia develops. At any particular time blood glucose levels can vary, dependent upon acute changes in pulmonary and infectious status. • The majority of patients have no obvious symptoms at diagnosis, although symptoms may develop insidiously. Presentation with CFRD is more likely during times when insulin resistance is increased (e.g. pulmonary infection, use of glucocorticoid agents). • Presentation with Diabetic ketoacidosis (DKA) is rare. • The onset of CFRD is defined as the date a person with CF first meets diabetes diagnostic criteria, even if hyperglycemia subsequently abates. [E, Consensus] • During a period of stable baseline health the diagnosis of CFRD can be made in CF patients according to standard American Diabetes Association (ADA) criteria. [E, Consensus] • The diagnosis of CFRD can be made in CF patients with acute illness when fasting plasma glucose (FPG) levels ≥126 mg/dL (7.0 mmol/L) or 2-h post-prandial