Measurement of Beta Cell Death in Individuals With Cystic Fibrosis

Cystic fibrosis related diabetes (CFRD) causes increased morbidity and mortality in people with cystic fibrosis (CF). The prevalence of CFRD increases with age. While CFRD is diagnosed in only 2 percent of children under 10 year sof age, it is present in 19 percent of adolescents and up to 50 percent of adults with CF. Although CFRD is uncommon in children, recent animal and human studies have shown that milder glycemic abnormalities are common in infants and young children with CF. One of the proposed mechanisms for early glucose dysregulation in CF is related to ongoing beta cell death that may start at a very early age. The assay to be used in this study measures differentially methylated insulin DNA, released exclusively by beta cells, to determine levels of beta cell death. This assay has been shown to detect beta cell death in individuals at risk of developing type 1 diabetes. If this assay successfully detects beta cell death in individuals with CF, the investigators can identify critical time points of beta cell loss in people with CF. Understanding how and when glycemic dysregulation occurs in CF will lead to better treatment of CFRD in the future.