Radiolabeled liquid and solid portions of standardized 300-g meals were administered on four different study days to eight healthy subjects in an attempt to define the range of inter- and intrasubject variability in gastric emptying. Meal half emptying times, analysis of variance, and intraclass correlations were computed and compared within and between subjects. The mean solid half emptying time was 58±17 min (range 29–92), while the mean liquid half emptying time was 24±8 min (range 12–37). A nested random effects analysis of variance showed moderate intrasubject variability for solid emptying and high intrasubject variability for liquid emptying. The variability of solid and liquid emptying was comparable and relatively large when compared with other reports in the literature. The isotopic method for measuring gastric emptying is a valuable tool for investigating problems in gastric pathophysiology, particularly when differences between groups of subjects are sought. However, meal emptying time is a variable phenomenon in healthy subjects with significant inter- and intraindividual day-to-day differences. These day-to-day variations in gastric emptying must be considered in interpreting individual study results.

To define the range of inter- and intra-subject variability on gastric emptying measurements, eight healthy male subjects (ages 19-40) received meals on four separate occasions. The meal consisted of 150 g of beef stew labeled with Tc-99m SC labeled liver (600 ..mu..Ci) and 150 g of orange juice containing In-111 DTPA (100 ..mu..Ci) as the solid- and liquid-phase markers respectively. Images of the solid and liquid phases were obtained at 20 min intervals immediately after meal ingestion. The stomach region was selected from digital images and data were corrected for radionuclide interference, radioactive decay and the geometric mean of anterior and posterior counts. More absolute variability was seen with the solid than the liquid marker emptying for the group. The mean solid half-emptying time was 58 +- 17 min (range 29-92) while the mean liquid half-emptying time was 24 +- 8 min (range 12-37). A nested random effects analysis of variance showed moderate intra-subject variability for solid half-emptying times (rho = 0.4594), and high intra-subject variability was implied by a low correlation (rho = 0.2084) for liquid half-emptying. The average inter-subject differences were 58.3% of the total variance for solids (rho = 0.0017). For liquids, the inter-subject variability was 69.1%more » of the total variance, but was only suggestive of statistical significance (rho = 0.0666). The normal half emptying time for gastric emptying of liquids and solids is a variable phenomenon in healthy subjects and has great inter- and intra-individual day-to-day differences.« less