Abstract
It is essential to establish whether and how environmental factors affect the reliability of [13C]methacetin breath test (13C-MBT). In 12 healthy volunteers (smokers), a standard 13C-MBT with 75 mg [13C]methacetin was performed twice in random order: on a control day without smoking and on another day with smoking two cigarettes antecedently. A considerable flattening of the curve of the momentary 13C recovery within the expiratory air was observed when the 13C-MBT was performed after smoking. The maximum of the momentary 13C recovery, D max, decreased from 37.20±2.58 to 25.39±2.29% dose/h (p=0.00052). Moreover, the time to reach D max was prolonged after cigarette smoking (26.5±3.1 vs. 16.5±1.9 min, p=0.0199). The curve of the cumulative 13C recovery on the cigarette smoking day appeared to be shifted downwards, and statistically significant differences relative to the control situation were found between the 24th and 75th minute following [13C]methacetin administration. Smoking cigarettes immediately prior to the 13C-MBT diminishes the ability of the liver to handle methacetin, and hence a possibility of such an interaction should be excluded in order to interpret the results of the test correctly.
Acknowledgements
A financial support of the project was provided by the Medical University of Silesia (contract nos KNW-1-043/08 and KNW-1-154/09).