The [ 13C]acetate breath test accurately reflects gastric emptying of liquids in both liquid and semisolid test meals

Abstract

Background/Aims: The current standard for gastric emptying studies are radioactive isotope methods. [ 13C]breath tests have been developed as a nonradioactive alternative. The aim of this study was to validate a [ 13C]acetate breath test as a measure of gastric emptying of the liquid phase both in liquid and semisolid test meals by simultaneous radioscintigraphy. Methods: Thirty-five patients with dyspeptic symptoms and 20 healthy volunteers were tested using a semisolid oatmeal or a liquid test meal. Both test meals were labeled by 150 mg sodium [ 13C]acetate and (in patients) by 45 MBq 99mTc-albumin colloid. Half-time of gastric emptying was calculated after curve fitting of the 13C exhalation to a modified power exponential function. 99mTc-albumin emptying was measured by conventional radioscintigraphy. Results: The half-emptying times for the [ 13C]acetate breath test closely correlated to those measured by radioscintigraphy both for semisolids ( r = 0.87) and liquids ( r = 0.95). The time of maximum 13CO 2 exhalation was itself a reliable parameter compared with the half-emptying times obtained by scintigraphy ( r = 0.85 for semisolids; r = 0.94 for liquids). Conclusions: The [ 13C]acetate breath test is a reliable and noninvasive tool for the analysis of gastric emptying rates of liquid phases without radiation exposure.