Short- and medium-term reproducibility of gastric emptying of a solid meal determined by a low dose of 13C-octanoic acid and nondispersive isotope-selective infrared spectrometry

Figure 1 Repeatability of the measurement of 13CO2 enrichment (d) in expiratory air after intake of a solid meal labeled with 75 mL (68 mg) 13C-octanoic acid. Ninety-six pairs of d measurements taken from three randomly selected examinations were considered.

Figure 2 Individual curves reflecting the increment in 13CO2 enrichment in exhaled air after intake of a 378 kcal solid meal containing 75 mL (68 mg) 13C-octanoic acid (the 36 curves were obtained in 12 healthy subjects at three separate days).

Figure 3 Momentary (empty squares) and cumulative (filled squares) 13C recovery in exhaled air after ingestion of a 378 kcal solid meal containing 75 mL (68 mg) 13C-octanoic acid. The data are grand means with standard errors (bars) calculated on average values obtained in 12 healthy volunteers during three examinations carried out on separate days.

Figure 4 Bland and Altman statistics (plot of differences between pairs vs their names) of the short-(open symbols) and medium-term( filled symbols) reproducibility of the measurement of the lag phase (T-Lag, panel A), the gastric half emptying time (T½ , panel B), and the gastric emptying coefficient (GEC, panel C) of the solid phase gastric emptying with a breath test using 75 mL (68 mg) 13C-octanoic acid and the isotope-selective nondispersive infrared spectrometry. On each panel the respective borders of the 95% confidence intervals are plotted - cf. the legend of the GEC graph, panel C.