Background: Cystic fibrosis-related diabetes (CFRD) and glucose abnormalities have a negative impact on pulmonary function and survival in cystic fibrosis (CF) patients. Oral glucose tolerance test (OGGT) is the screening test of choice for CFRD, although undetected high glucose levels can be missed with this test. The use of a continuous intersticial fluid glucose monitoring system (CGM) can be useful in these patients.
Objective and hypotheses: To determine the role of CGM in the early detection of glucose abnormalities in CF.
Method: All CF children aged 1017 years without known diabetes and followed by our hospital CF team were included. Those with infections or under a corticosteroid treatment course in the last 6 weeks were excluded. OGGT in the last year was reviewed with special attention in intermediate values over 200 mg/dl. CGM system was placed during 5 days.
Results: Among 13 children, six girls, we found: High glucose levels in OGGT in three patients, none CFRD. Two of them had intermediate values over 200 mg/dl; glucose excursions above 200 mg/dl in CGM in six patients, four with normal OGGT. The patient with impaired glucose tolerance in OGGT showed in CGM a glucose mean of 136±28 mg/dl and 10% of time above 190 mg/dl with excursions above 200 mg/dl. Mean level of 24 h blood glucose values for all patients was 109±14 mg/dl. The patients with normal CGM had lower mean levels than those with impaired CGM (99.8±9.3 mg/dl vs 119.6±10.6 mg/dl, P=0.005).
Conclusion: CGM could be a useful tool to detect glucose excursions in CF children with normal OGGT. The CGM systems are a comfortable way to detect hyperglucemia in a real situation. It is still unknown how the development of CFRD in these patients with impaired glucose can be delayed.