ESPE Abstracts

Background: Cystic fibrosis (CF) is the most common genetic sever disease in Caucasian populations. It is crucial to identify patients with CF who are at increased risk of acquiring CF-related diabetes (CFRD).

Objective: To identify potential demographic, clinical, and laboratory predictors of CFRD in patients with CF.

Method: The study group included patients more than 10 years of age with CF and pancreatic insufficiency who attended the CF clinic in 1999-2013. The following data were collected: demographics, anthropometric and laboratory data including annual oral glucose tolerance test (OGTT) values. Findings were compared between patients with CFRD and those with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT).

Results: Forty-four patients met the study criteria. The patients with CFRD (N=16) had significantly higher glucose levels at 60 and 90 minutes after OGTT, area under the curve (AUC) of glucose, and HbA₁c concentrations one and two years before CFRD was diagnosed than the patients in whom CFRD did not develop (n=28). On multiple regression analysis, the best predictor of CFRD was the AUC of glucose. Analysis of HOMA-IR at diagnosis in patients without CFRD as compared to those in whom CFRD developed, yielded a significant between-group difference (0.95 and 1.78, respectively, P=0.02). No significant differences were found in levels of insulin, C-peptide, and C-reactive peptide. The rate of liver disease was higher in the patients who acquired CFRD (62.5%) than in the patients with NGT or IGT (28.6%; P=0.028). There were no differences between the two groups in BMI SDS, FEV₁, or history of diabetes in the family.

Conclusion: Glucose levels at 60 and 90 minutes after OGTT AUC, and HbA₁c values may predict an increased risk of CFRD. Insulin resistance appears to be the major cause of CRFD. CFRD is apparently not preceded by a significant decrease in insulin secretion.