Optimal measurement of gastric emptying of solids in gastroparesis or functional dyspepsia: evidence to establish standard test

Objective Symptoms in gastroparesis (Gp) and functional dyspepsia (FD) overlap; using egg protein substitute to measure gastric emptying of solids (GES), ~40% of patients are reclassified from Gp to FD, and vice versa. Our aim was to assess inter-individual and intra-individual coefficients of variation (COV) in GES in symptomatic patients with Gp or FD with documented slow or normal GES, respectively. Design Scintigraphic GES (T_1/2 and GE% at 2 and 4 hours) using a 320 kcal real egg meal (30% fat) was tested in the following: single measurements in 20 patients with diabetes mellitus (10 each type 1 and type 2); repeat GES to estimate COV_intra measured: 3 days apart in 9 Gp, 4 weeks apart in 21 Gp and 18 with FD with normal GE assigned to placebo and in 70 patients at 94.3 weeks (median) apart. Results COV_inter for GE% at 4 hours and GE T_1/2 were respectively 14.2% and 23.5% in FD and 27.5% and 33% in Gp; COV_intra for GE% at 4 hours and GE T_1/2 up to 4 weeks apart were 23.4% and 37.9% in FD and 20.1% and 33% in Gp. GE% at 2 hours showed less consistent results. However, >85% retained original diagnosis as normal or delayed. From clinical GES to baseline researc for Gp group, repeat GES (after treatment) showed the COV_intra for GE% at 4 hours was 37.3% at median 94.3 weeks, with 26/70 changed diagnoses. Conclusion The 320 kcal (30% fat) GES scintigraphic test provides consistent diagnosis in >85% and should be the standard test for suspected gastric emptying disorders.