Progression of structural lung disease on CT scans in children with cystic fibrosis related diabetes

Background: Diabetes has a deleterious effect on clinical status in children with Cystic Fibrosis (CF). We hypothesized that children with CF Related Diabetes (CFRD) or Impaired Glucose Tolerance (IGT) would have more rapidly progressive lung disease based on chest computed tomography (CT) than those with normal glucose tolerance (NGT).

Methods: In a retrospective study we compared lung structure changes over time, as assessed by CT, in 34 CF children with CFRD, IGT or NGT. We then compared CT findings with changes in lung function.

Results: Percentage forced expiratory volume in 1s (%FEV1) remained stable over time with a mean (±SD) yearly change of -0.5% (±3.9), -0.4% (±2.3) and -0.85% (±2.8) (p=0.92) for the CFRD, IGT and NGT groups respectively. However, there was a mean (95%CI) increase in % CT score of 3.86%/year (1.77-5.95%), 1.59%/year (0.6-2.58%) and 1.09%/year (0.07-2.11%) (p=0.023).

Conclusion: In patients with CFRD, there was a more rapid progression of structural lung disease, compared to those who had NGT that was not reflected by change in lung function.