Effects of Postgastric 13C-Acetate Processing on 13CO2-Exhalation in Health–A Systematic Investigation

Aims: Uniform postgastric processing of the gastric emptying marker 13C-acetate (AC) is as yet an unverified assumption behind its use to measure gastric emptying. A systematic investigation of the effects of intraduodenally (i.d.) administered volume, caloric density, AC doses and administration rates on resulting 13CO2 exhalation was performed. Methods: 13CO2 recovery was assessed in 18 volunteers after i.d. administration of A (n=6): A1: randomized boluses of 50mg AC in 50, 100, 200ml water injected over 1 min every 1h; A2: randomized boluses of 12.5, 25, 50, 100mg AC in 50ml water injected over 1 min every 1…