Endocrine and exocrine pancreatic function and the delta F508 mutation in cystic fibrosis

The relationship between the cystic fibrosis (CF) genotype and endocrine and exocrine pancreatic function was studied in 215 CF patients. In the 211 patients with the delta F508 mutation, endocrine pancreatic function (oral glucose tolerance; WHO criteria) was normal in 72.5%, impaired in 12.3%, and diabetic in 15.2% of the patients, with no difference between CF patients homozygous (N = 163, median age 15 years, range 2-40) or heterozygous (N = 48, 18 years, 3-40; age difference not significant) for the delta F508 mutation. Exocrine pancreatic sufficiency (no need for pancreatic enzyme substitution) was found in 0.6% of the patients homozygous for the delta F508 mutation and in 10.4% of the heterozygotes (p less than 0.01). Homozygous patients with pancreatic insufficiency took more pancreatic enzyme capsules (median 42 per day, range 0-192) than the heterozygotes (29 per day, 0-300; p less than 0.001). The four patients (1.9%) without the delta F508 mutation had normal glucose tolerance but exocrine pancreatic insufficiency. In conclusion, the major mutation genotype in CF (delta F508) affects the severity of the exocrine pancreatic insufficiency, whereas endocrine pancreatic function is unrelated to this genotype.