Pancreatic alpha and beta cell functions in cystic fibrosis.

Insulin and glucagon secretions were studied during oral glucose tolerance testing and 
arginine infusion in 13 patients with cystic fibrosis. Two groups of 
patients were identified; Group I (N=6) whose OGTT was entirely normal 
and Group II (N=7) who had some abnormality in glucose during 
OGTT. In each group basal glucagon concentrations were normal and supressed 
appropriately (p less than 0.05) after glucose; insulin responses were attenuated 
and the peak responses delayed. During arginine stimulation, insulin secretion was 
impaired in each group. However, glucagon secretion was diminished only in 
Group II. Thus, insulinopenia was found in both groups and hyperglucagonemia 
was not found as a contributory factor to the hyperglycemia in 
Group II. 