Reproducibility of gastric emptying in overweight and obese males.

BACKGROUND & AIM: To understand whether any change in gastric emptying (GE) is physiologically relevant, it is important to identify its variability. Information regarding the variability of GE in overweight and obese individuals is lacking. The aim of this study was to determine the reproducibility of GE in overweight and obese males. METHODS: Fifteen overweight and obese males [body mass index 30.3 (4.9) kg/m(2)] completed two identical GE tests 7 days apart. GE of a standard pancake breakfast was assessed by (13)C-octanoic acid breath test. Data are presented as mean (±SD). RESULTS: There were no significant differences in GE between test days (half time (t1/2): 179 (15) and 176 (19 min), p = 0.56; lag time (tlag): 108 (14) and 104 (8) min, p = 0.26). Mean intra-individual coefficient of variation for t1/2 was 7.9% and tlag 7.5%. Based on these findings, to detect a treatment effect in a paired design with a power of 80% and α = 0.05, minimum mean effect sizes for t1/2 would need to be ≥14.4 min and tlag ≥ 8.1 min. CONCLUSIONS: These data show that GE is reproducible in overweight and obese males and provide minimum mean effect sizes required to detect a hypothetical treatment effect in this population.