Lack of recruitment

The purpose of this study is to determine whether the dipeptidyl peptidase IV (DPPIV) inhibitor sitagliptin is effective in the treatment of cystic fibrosis-related diabetes (CFRD). We hypothesize that sitagliptin will improve meal-stimulated insulin secretion.

To date, no clinical trials have been conducted using the DPPIV inhibitor sitagliptin in cystic fibrosis-related diabetes. Cystic fibrosis-related diabetes is characterized initially by post-prandial hyperglycemia, with normal fasting sugars. As the disease progresses, fasting hyperglycemia develops. As sitagliptin augments post-prandial insulin release, while avoiding fasting hypoglycemia, it may be an alternative therapy for cystic fibrosis-related diabetes in individuals who do not yet require basal insulin therapy.

Inclusion Criteria:

• 19 years of age or older
• Cystic fibrosis-related diabetes with or without fasting hyperglycemia either untreated or using only pre-prandial repaglinide or pre-prandial bolus insulin therapy

Exclusion Criteria:

• Age under 19 years
• Use of basal insulin therapy
• Creatinine Clearance < 50 mL/min
• Active cystic fibrosis exacerbation
• Pregnancy
• Women of child-bearing age not using effective contraception
• Current or prior use of DPPIV inhibitor