Intraduodenal lipase activity in celiac disease assessed by means of 13C mixed-triglyceride breath test

Background: In patients with celiac disease, the occurrence of exocrine pancreatic insufficiency has been related to an impairment of the gut-mediated stimulatory effect of the meal on the pancreas. The purpose of this study was to assess the intraduodenal lipase activity in patients with celiac disease by means of the 13 C mixed-triglyceride breath test and to monitor pancreatic function after the institution of a gluten-free diet. Methods: Seventeen untreated patients with celiac disease (mean age, 17.4 ± 10.5 years) were studied. After an overnight fast, patients were given a standard test meal consisting of 100 g of white bread and 0.25 g of butter per kilogram of body weight, to which 16 mg di-stearyl- 13 C-octanoyl-glyceride (mixed triglyceride) had been added. Breath samples were taken twice at baseline and at 30-minute intervals for 6 hours after the meal. 13 C enrichment in breath was determined by means of Isotope Ratio Mass Spectrometer (IRMS) (ANCA-NT; Europa Scientific, Crewe, UK). Results were expressed as the maximum percentage of 13 C recovery per hour at any time, the time to reach peak excretion of 13 C, and the percentage of 13 C cumulative dose over 6 hours. Results: Mixed-triglyceride breath test results were pathologic in three patients and at the lower limit of the normal range in another patient. In the remaining 13 patients, the results were within normal values. At the 6- and 12-month follow-ups, all patients showed normal intraduodenal lipase activity. Conclusions: In approximately 24% of patients with celiac disease, the intraduodenal pancreatic lipolytic activity is impaired. The mixed-triglyceride breath test could be used to assess fat maldigestion and to monitor the need for enzyme replacement therapy in such patients.