Increased plasma levels of peptide YY in coeliac disease.

Peptide YY (PYY) is exclusively localized in endocrine cells in the gut, and these cells are most numerous in the distal small intestine, colon, and rectum. We have earlier shown that PYY coexists with enteroglucagon in the gut endocrine cells. High basal and postprandial plasma enteroglucagon concentrations have earlier been found in patients with untreated coeliac disease. PYY circulates in human plasma and is detectable in most healthy adults. We have therefore studied the basal PYY levels in patients with coeliac disease. Marked elevated basal plasma PYY levels were found in patients with coeliac disease compared with an age- and sex-matched control group. The PYY levels were inversely correlated to the concentration of folate acid in serum. The PYY levels were studied in four patients with newly diagnosed disease and had normalized within 8 months on a gluten-free diet.