OBJECTIVE: The U.S. standard C-13-urea breath test (C-13-UBT) has proven to
be extremely reliable but entails several complicated performance requirem
ents and a test period of approximately 1 h. The aim of this study was to c
ompare the standard C-13-UBT with a simplified version embodying modificati
ons of test meal, duration of fasting, amount of C-13-urea, method of breat
h collection, and duration of test.
METHODS: This was a randomized, three-way, crossover study of the standard
U.S. C-13-UBT, which contains 125 mg of C-13-urea and a pudding test meal.
The final breath sample is taken 30 min after urea ingestion. This test was
compared with a formulation containing 75 mg of C-13-urea, a 2.5-g citric
acid test meal (UBT-Lite), and a final breath sample taken by direct exhala
tion into tubes 15 min after urea ingestion. We also compared the effect of
prior meals versus fasting on the test outcome with the UBT-Lite.
RESULTS: A total of 259 subjects were enrolled in the trial, and 249 comple
ted all three urea breath tests. There was excellent agreement between the
three versions of the UBT with > 98% of subjects having concordant results.
Using predetermined criteria, there was substantial equivalence between th
e tests. Neither solid and/or liquid food up to 1 h before performing the U
BT-Lite affected outcome.
CONCLUSION: The UBT-Lite formulation of the C-13-UBT proved to be an improv
ed Version of the U.S. standard C-13-UBT offering less expensive ingredient
s, shorter test duration, and a simplified breath test collection method, w
ithout sacrificing accuracy. (C) 2001 by Am. Coil. of Gastroenterology.