Cystic fibrosis related diabetes (CFRD) is a common co-morbidity in patients with CF. The underlying pathophysiology of cystic fibrosis related diabetes (CFRD) is still a matter of investigation. In addition to localized tissue damage developing similar to that of the exocrine pancreas, other mechanisms may be involved. We have shown that a potential contributing factor to the patho-physiology of CFRD may be an abnormal gut derived hormonal profile, specifically of lower incretin hormone responses, prior to development of CFRD.