Performance characteristics of scintigraphic measurement of gastric emptying of solids in healthy participants

Background Gastric emptying (GE) is measured in pharmacodynamic and diagnostic studies. Our aim was to assess inter- and intra-subject coefficients of variation (COV) of scintigraphic GE measurements in healthy subjects, and associations of GE with gender and body mass index (BMI). Methods Data from participants with scintigraphic measurements of gastric emptying of solids were analyzed. Primary endpoints were gastric emptying T_1/2 (GE T_1/2) and GE at 1, 2, 3, and 4h. Key Results The patient cohort consisted of 105 males and 214 females; at least two studies were performed in 47 subjects [16 males (M), 32 females (F)]. Inter-subject COV (COV_inter) for GE T_1/2 were similar in M and F: overall 24.5% (M 26.0%, F 22.5%); COV are predictably lowest for GE at 4h (COV_inter 9.6%). COV_intra for T_1/2 and GE at 4h were overall 23.8% and 12.6%, and were similar to COV_inter values. Gender (but not age or BMI) was significantly associated with GE T1/2 [P<0.001, F 127.6±28.7 (SD) min; M 109.9±28.6min] and with GE at 1h and 2h. Repeat GE T_1/2 values in 47 participants were significantly correlated (r=0.459, P<0.001) with median difference of -6min (mean -1.6, range -56 to 72min). Bland-Altman plots showed Δ GE T_1/2 similarly distributed across mean GE T_1/2 100-155min, and across studies conducted 90-600days apart. Conclusions & Inferences Inter-subject variations in scintigraphic GE results are only slightly higher than the intra-subject measurements, which are also reproducible over time in healthy volunteers. Gender, but not BMI, is significantly associated with GE results.