Abstract
The aim of this study was to check on the reproducibility of two breath tests intended to test the pancreatic exocrine function accomplished with 13C-mixed triglyceride (13C-MTG) or cornflakes naturally enriched in 13C (13C-CF). The 13CO2 content within breath samples was determined with isotope-selective non-dispersive infrared spectrometry. A 72-h monitoring performed in healthy subjects revealed that a statistically significant rise in breath 13CO2 occurs between the 1st and the 9th hour and between the 1st and the 24th hour after intake of a test meal containing 300 mg 13C-MTG (n=10) or 100 g 13C-CF (n=12), respectively. In another two groups of 12 healthy volunteers each, short-term reproducibility of the two tests was assessed with paired examinations taken at a median interval of two days, whereas paired examinations separated by a median of 20 days served for the medium-term reproducibility assessment. In the case of either test, the medium-term reproducibility was not any worse than the short-term one. The reproducibility of the 13C-CF breath test tended to be slightly worse than that of the 13C-MTG breath test: a least detectable difference in 6-h cumulative 13C breath excretion (which is expressed as the percentage of the administered dose of the substrate) amounted to 2.7 and 4.4 % (short-term reproducibility) and to 3.5 and 4.4 % (medium-term reproducibility) in the case of the 13C-MTG breath test and the 13C-CF breath test, respectively. It is concluded that both tests offer a satisfactory reproducibility for use within a clinical setting. In case the lipolytic and the amylolytic activity would be required to be examined in the same patient, the 13C-CF breath test can be executed on the next day following the 13C-MTG breath test, whereas reciprocally, a 1-day break is recommended before accomplishment of a 13C-MTG breath test following a 13C-CF breath test.
Acknowledgements
A financial support of the project was provided by the Medical University of Silesia (contract KNW-1-047/P/1/0).