About this Study
The reason for diabetes development in CF is not entirely clear but may involve abnormalities in how the cells that make insulin
work. An early study suggests ivacaftor may improve blood sugar and insulin in CF. This study will examine whether ivacaftor improves
insulin secretion and glucose regulation in CF. Insulin secretion and glucose regulation will be studied prior to starting ivacaftor
and after approximately 4 months of ivacaftor therapy in individuals with CF who are starting ivacaftor as part of their clinical program
or as part of a separate clinical study.(Ivacaftor is not provided by this study).