Effect of intraduodenal fat on lower oesophageal sphincter function and gastro-oesophageal reflux

Abstract

Background and aims: Fatty foods are commonly reported to aggravate gastro-oesophageal reflux symptoms. In this study the hypothesis that fat provokes reflux by stimulating transient lower oesophageal sphincter relaxations via small intestinal receptors was investigated.

Methods: In 12 healthy volunteers and 11 patients with reflux oesophagitis, oesophageal motility and pH were measured over 30 minute periods during which saline or fat (10% Intralipid) were infused in random order into the duodenum. The infusion periods were separated by a 30 minute washout. The stomach was loaded with 200 ml 10% dextrose, maintained by an intragastric infusion.

Results: Fat decreased basal LOS pressure from 16.9 (SEM 2.1) to 12.4 (SEM 1.5) mm Hg in normal subjects but had no effect in patients with oesophagitis (18.8 (SEM 4.3) v 18.2 (SEM 3.0) mm Hg). During saline infusion, the rates of transient lower oesophageal sphincter relaxation and reflux episodes were greater in patients (4.5 (interquartile range 2-11)/30 min and 5 (2-14)/30 min respectively) than in controls (3 (2-4)/30 min and 3 (2-3.5)/30 min respectively). Fat increased the rate of reflux episodes in the reflux patients to 6.5 (3-25)/30 min. This effect was due to an increase in the incidence of reflux during transient LOS relaxations (65% v 91%), the rate of transient relaxations remaining unchanged.

Conclusions: Instillation of fat directly into the duodenum aggravates reflux in patients with reflux disease, by increasing the proportion of transient LOS relaxations accompanied by reflux.