Use of Continuous Glucose Monitoring in Diagnosis and Management of Cystic Fibrosis-related Diabetes in Children

Background: Cystic fibrosis related diabetes (CFRD) is the most common comorbidity in children with cystic fibrosis (CF). Routine screening for CFRD is the oral glucose tolerance test (OGTT) where blood glucose levels are measured at 0 and 120 min. Studies have found that patients with CFRD often have an initial postprandial raised blood glucose level at 60 min while still achieving a normal 120-min blood glucose level from an OGTT, resulting in delayed diagnosis and treatment of CFRD. The aim of this study was to assess whether the use of continuous glucose monitoring (CGM) could aid in early diagnosis and treatment in children with CFRD. Methods: We included five patients diagnosed with CFRD. All the patients had a raised 1-h OGTT blood glucose level (>11.0 mmol/L), and consented for CGM for two weeks. Treatment was commenced initially as bolus fast-acting insulin (Novorapid), which targeted the initial postprandial rise in blood glucose level. If the CGM showed continued overnight hyperglycemia, basal long-acting insulin (Lantus) was later added to the treatment regimen. Results: All the patients showed improvement in their forced expiratory volume at 1s and weights following insulin treatment. Conclusions: Abnormalities of glucose metabolism have an adverse impact on morbidity and mortality in patients with CF. Early detection of glucose abnormalities using CGM and early targeted intervention is an important factor to consider in improving lung function and nutritional status. Further studies are warranted on the use of CGM in the early detection and management of CFRD in children.