Hormonal abnormalities of the pancreas and gut in cystic fibrosis.

We have investigated the effect of cystic fibrosis on alimentary hormones in 10 children by measuring the pancreatic and gut hormone rsponse to a milk drink. Plasma insulin and gastric inhibitory peptide were both significantly reduced (P < 0.05 and P < 0.005, respectively, at 15 min) in the patients with cystic fibrosis, compared with controls, even though the early glucose rise was greater in the former group (P < 0.05 at 15 min). Fasting levels of pancreatic polypeptide were significantly lower in the fibrocystic children (P < 0.01), and the normal response to milk was completely abolished in these patients (P < 0.001). Fasting plasma enteroglucagon concentrations were grossly abolished in the cystic fibrosis patients (P < 0.001) and these remained elevated throughout the test. No significant differences were seen in basal or postmilk responses of plasma glucagon, gastrin, secretin, vasoactive intestinal peptide, or motilin in cystic fibrosis. It would thus appear that the pancreatic polypeptide cell is more susceptible to the effects of the disease process than the beta or alpha cell in cystic fibrosis. Some aspects of the abnormalities in the gastrointestinal endocrine system were similar to those seen in celiac disease and tropical sprue and may, therefore, effect a similar hormonal response in these patients with cystic fibrosis to those with mucosal damage.