A modified ¹³C-mixed triglyceride breath test detects moderate pancreatic exocrine insufficiency

The noninvasive ¹³C-mixed triglyceride breath test (¹³C-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.

In 10 healthy volunteers and 9 patients with suspected pancreatic disease, a secretin test, a modified ¹³C-MTG-T (250 mg ¹³C-MTG, 26 g fat, breath samples over 8 hours), and a ¹³C-octanoic acid gastric emptying test were performed. Subjects remained strictly seated during breath testing.

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 ¹³C exhalation was significantly lower in patients than in controls. Sensitivity of ¹³C-MTG-T (6-h cumulative ¹³C 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 ¹³C-MTG-T.

The modified ¹³C-MTG-T detects moderate pancreatic exocrine insufficiency.