Continuous glucose monitoring guided insulin therapy is associated with improved clinical outcomes in cystic fibrosis-related diabetes.

Introduction: Continuous glucose monitoring (CGM) allows assessment of day to day glycaemic excursions and detects early glucose handling abnormalities that may not be apparent on oral glucose tolerance testing (OGTT). However, there is little published evidence as to whether these early dysglycaemic changes are amenable to treatment. We present outcomes following CGM guided insulin initiation at our centre.

Methods: Adults without a prior diagnosis of cystic fibrosis related diabetes (CFRD) whom underwent >72 h CGM at our adult CF centre were included in the study. Clinical outcomes including weight and pulmonary function changes over the next 12 months were compared between groups based on CGM results and subsequent management.

Results: CGM profiles for 59 patients were analysed. Insulin was commenced in 37 patients who had evidence of hyperglycaemia on CGM. Significant improvements in mean [95% confidence intervals] forced expiratory volume in 1 s (FEV) (+4.3% predicted [1.06-7.48], p = 0.01) and weight (+1.2 kg [0.32-2.15], p = 0.01) were observed at 3 months in the insulin group. Annual rate of pulmonary function decline was also improved following insulin initiation.

Conclusion: Insulin treatment targeted towards glycaemic excursions seen on CGM is associated with improvements in lung function and weight with subsequent reduced pulmonary function decline.