Background
To investigate if age affects the results of the 13C-mixed triglyceride (13C-MTG) breath test.
Material and Method
Two groups of 12 healthy subjects (group Y, 25.0+/-0.7 years; group MA, 48.8+/-2.4 years), each comprising 6 men and 6 women, were examined. The fasted volunteers had a 349-kcal test breakfast of 50 g of white bread with 30 g of butter to which 300 mg of 13C-MTG was added. Then a series of samples of exhaled air for the measurement of 13CO2 concentration was collected over a period of 9 hours.
Results
A maximum momentary 13CO2 breath excretion of 9.6+/-0.5%dose/h at 295+/-19 min in the young subjects and of 9.4+/-0.4%dose/h at 270+/-15 min in the middle-aged volunteers was observed. The group curves of cumulative 13C recovery in breath air exhibited a virtually overlapping time course. The 6-h cumulative 13C recovery amounted to 32.01+/-1.78%dose and 31.84+/-1.73%dose in the Y and MA groups, respectively. Extension of the collection of breath air samples from the standard six to nine hours resulted in an increase in the cumulative 13C recovery by 51.5+/-3.2%. Accordingly, the 9-h cumulative 13C recovery was 47.59+/-2.26%dose and 48.28+/-2.36%dose in the Y and MA groups, respectively.
Conclusions
An age difference of over two decades does not compromise intrajejunal lipolytic activity taken as a measure of pancreatic exocrine function. Therefore reference values for the 13C-MTG breath test can be obtained from a population of healthy subjects of a relatively wide age range.

Keywords: Carbon Isotopes - analysis, Carbon Dioxide - analysis, Breath Tests, Triglycerides - analysis