A valid, accurate, office based non-radioactive test for gastric emptying of solids

BACKGROUND Current breath tests for measurement of gastric emptying of solids are expensive, possibly inaccurate, and require cumbersome calculations. AIMS We wished to validate a simplified solid gastric emptying test using a [13C]Spirulina platensisbreath test for accurate results relative to scintigraphy. SUBJECTS Thirty healthy volunteers. METHODS We measured gastric emptying of egg containing [13C]S platensis and99mTc sulphur colloid by breath13CO2 and scintigraphy over six hours. A generalised linear regression model was used to predict t1/2 and tLAG by scintigraphy from breath13CO2 data. The model was cross validated and normative data calculated for a prepacked [13C]meal. RESULTS Regression models using all breath data over six hours, for the first three hours, and for samples at 75, 90, and 180 minutes (“reduced model”) predicted t1/2 and tLAG values similar to scintigraphy (tLAG 43 (SD 12) min; t1/2 100 (20) min). Standard deviations of differences in t1/2 and tLAG between scintigraphy and the “reduced model” were both 10 minutes. Gastric t1/2 for the prepacked [13C]meal was 91 (15) min (10–90% range: 74–118). CONCLUSION The [13C]S platensis breath test and a simple formula using breath 13CO2 at baseline, 90, and 180 minutes measured gastric emptying t1/2 for solids with results that were comparable with scintigraphy.