Contributions of gastric volumes and gastric emptying to meal size and postmeal symptoms in functional dyspepsia

Background & Aims: The aim was to assess relative contributions of gastric volumes (GV) and gastric emptying (GE) to meal size and postprandial symptoms in patients with functional dyspepsia. Methods: Patients with chronic upper gastrointestinal symptoms were prospectively evaluated. GV during fasting and after 300 mL Ensure was measured with Tc-99m-single-photon emission computed tomography imaging and solid GE (Tc-99m-egg) by scintigraphy. Maximum tolerated volume (MTV) and symptoms were measured after Ensure challenge. Results: Of 57 adult patients evaluated, 39 (23 women, 16 men) met Rome II criteria for functional dyspepsia and had no other diagnosis to account for dyspepsia. The most frequent symptoms were abdominal pain (90%), pain predominantly after meals (76%), nausea (85%), and early fullness after meals (79%). Relative to established laboratory normal values, MTV was abnormal in 82%, aggregate symptom score > 209 in 72%, GE (at 1 hour) accelerated in 41%, GE (at 4 hours) delayed in 41%, and postmeal GV reduced in 52%. Lower body mass was associated with lower MTV and higher postchallenge symptoms. Lower fasting (not postprandial) GV and faster GE were independent predictors of lower MTV, explaining 18% of the variance after adjusting for body weight (32% of variance). GE was an independent predictor of postchallenge symptoms (10% of variance) after adjusting for volume ingested (10%), age (20%), and weight (10%). Conclusions: In adults with functional dyspepsia seen in a tertiary referral practice, decreased meal size and postmeal symptoms are associated with low fasting GV and faster GE. These data provide physiologic targets for ameliorating symptoms of functional dyspepsia.