13C labelled cholesteryl octanoate breath test forassessing pancreatic exocrine insufficiency

Background—A non-invasive test for assessment offat digestion has been developed based on the intraluminal hydrolysisof cholesteryl-[1-¹³C]octanoate by pancreatic esterase.
Aims—To determine the diagnostic performance ofthis breath test in the assessment of exocrine pancreatic function.
Methods—The test was performed in 20 healthycontrols, 22 patients with chronic pancreatic disease (CPD), four withbiliopancreatic diversion (BPD), and 32 with non-pancreaticdigestive diseases (NPD); results were compared with those of othertubeless tests (faecal chymotrypsin and fluorescein dilaurate test).
Results—Hourly recoveries of¹³CO₂ were significantly lower in CPD whencompared with healthy controls or NPD. In patients with CPD with mildto moderate insufficiency, the curve of ¹³CO₂recovery was similar to that of healthy controls, while in those withsevere insufficiency it was flat. In three patients with CPD withsevere steatorrhoea, a repeat test after pancreatic enzymesupplementation showed a significant rise in¹³CO₂ recovery. The four BPD patients had lowand delayed ¹³CO₂ recovery. Only eight of the32 patients with NPD had abnormal breath test results. There was asignificant correlation between the results of the breath test andthose of faecal chymotrypsin, the fluorescein dilaurate test, andfaecal fat measurements. For the diagnosis of pancreatic disease usingthe three hour cumulative ¹³CO₂ recovery test,the sensitivity was 68.2% and specificity 75.0%; values were similarto those of the other two tubeless pancreatic function tests. In sevenhealthy controls, nine patients with CPD, and nine with NPD a secondbreath test was performed using Na-[1-¹³C]octanoate and apancreatic function index was calculated as the ratio of¹³C recovery obtained in the two tests: at three hours thisindex was abnormal in eight patients with CPD and in three with NPD.
Conclusion—Thecholesteryl-[1-¹³C]octanoate breath test can beuseful for the diagnosis of fat malabsorption and exocrine pancreatic insufficiency.