A Modified 13C-Mixed Triglyceride Breath Test Detects Moderate Pancreatic Exocrine Insufficiency

Objectives: The noninvasive C-13-mixed triglyceride breath test (C13--MTG-T) has been shown to diagnose severe pancreatic exocrine insufficiency reliably. We hypothesized that sensitivity of the test could be increased by strict limitation of physical activity, correction for gastric emptying velocity, and/or increased lipid dose. Methods: In 10 healthy volunteers and 9 patients with suspected pancreatic disease, a secretin test, a modified C-13-MTG-T (250 mg C-13-MTG, 26 g fat, breath samples over 8 hours), and a C-13-octanoic acid gastric emptying test were performed. Subjects remained strictly seated during breath testing. Results: Intravenously administered secretin 1 U/kg.h stimulated outputs of all enzymes significantly. Mean basal and stimulated enzyme outputs were similar in patients and healthy controls; however, compared with normal values, 5 patients and 1 control had moderately decreased lipase output. Cumulative 4-, 6-, and 8-hour C-13 exhalation was significantly lower in patients than in controls. Sensitivity of C-13-MTG-T (6-h cumulative C-13 exhalation <27% of dose) for detection of decreased lipase output was 100%; specificity was 92%. Gastric emptying parameters were similar in patients and controls, and correction for these did not improve accuracy of C-13-MTG-T. Conclusions: The modified C-13-MTG-T detects moderate pancreatic exocrine insufficiency.