Effects of duodenal lipids on gastric sensitivity and relaxation in patients with ulcer-like and dysmotility-like dyspepsia

Background/Aims: Functional dyspepsia (FD) according to Rome II is divided into ulcer-like dyspepsia (ULD) and dysmotility-like dyspepsia (DLD). The rationale behind this is the assumption that the underlying pathophysiology is different, but this is largely unexplored. Our aim was to elucidate the differences in gastric sensorimotor function in these subgroups of FD. 13 healthy controls (HC) and 20 patients with FD, 10 ULD and 10 DLD, were included. Methods: A feeding tube was placed fluoroscopically in the proximal duodenum and a barostat balloon was placed in the proximal stomach. Sensory thresholds to gastric distention for first sensation, bloating and discomfort were assessed before and after duodenal lipid infusion (2 kcal/min, 60 min). Results: Volume changes in the balloon were recorded as a measure of gastric tone. In FD patients, sensory thresholds in the fasting state were significantly lower than in HC, mostly due to gastric hypersensitivity in ULD. After lipid infusion, 95% of FD patients fell outside the normal range of HC for first sensation, bloating and/or discomfort, compared with 65% in the fasting state. Patients with ULD but not DLD had impaired fundic relaxation after duodenal lipids compared with HC. Conclusions: Investigating gastric sensorimotor function after duodenal lipid infusion, FD patients can accurately be differentiated from HC. Impaired fundic relaxation seems to be more common in patients with ULD.