Reproducibility and reliability of the 13C-acetate breath test to measure gastric emptying of liquid meal in infants

Objective This study assessed the noninvasive 13C-acetate breath test (13C-ABT) as a reliable and reproducible method to evaluate gastric emptying in infants Methods Gastric emptying was measured simultaneously by scintigraphy and 13C-ABT in 11 infants with clinical symptoms of gastroesophageal reflux to validate the method compared with the gold standard. Gastric emptying was also measured with 13C-ABT in a separate group of 14 healthy infants on 2 consecutive days to evaluate reproducibility of the method. Half-emptying times obtained with scintigraphy and 13C-ABT were correlated with Pearson’s analysis. The variability of the half-emptying times obtained on 2 consecutive days was analyzed with paired t test and by the coefficient of variation as proposed by Bland and Altman. Results The mean emptying times obtained with scintigraphy and 13C-ABT were not different (89 ± 27 min and 70 ± 39 min, respectively, P = 0.22). Both methods correlated significantly (r = 0.75, P < 0.05). Half-emptying times measured on 2 consecutive days with 13C-ABT were 69 ± 31 min and 68 ± 30 min, respectively (mean difference = 1.4 ± 12.4 min, P = 0.67). Intraindividual coefficient of variation was 6.3%. Conclusions This study supports the 13C-ABT method as a useful tool to evaluate gastric emptying of liquids in healthy infants and in infants with gastroesophageal reflux in the field of research and in clinical evaluations.