Objectives: White wine has been demonstrated to induce gastroesophageal reflux (GER) in healthy people and GER patients. This GER is characterized by reflux episodes of prolonged duration. Our aim was to explore the pathogenesis of the prolonged reflux duration.
Methods: Twelve healthy volunteers received in a randomized order 300 ml of white wine and tap water together with a standardized meal. Esophageal pH and motility were continuously monitored by a glass pH electrode and a strain gauge manometry probe (four measuring points in the esophagus and one in the pharynx to register swallowing) for 90 min after ingestion. Blinded to the ingested beverage, we calculated the fraction of time esophageal pH was <4, the number of reflux episodes and their duration, the swallowing and contraction rate, the contraction amplitude, and the distribution of primary, secondary, simultaneous, and nonpropagated contractions. The motility analysis was separately performed for periods with and without GER. During GER, the time until occurrence of the first contraction, its type, the type of the contraction that raises pH to >4, and the number of peristaltic contractions necessary to raise pH to >4 were also determined. The percentage of GER episodes with simultaneous contractions and failed peristalsis (nontransmitted swallows and nonpropagated contractions) as calculated. The percentage of GER episodes with signs of "rereflux" (further pH drop, common cavity phenomenon in the motility trace) into the acidic esophagus was also determined. The mean reflux duration and the number of peristaltic contractions needed to raise pH to >4 were recalculated by taking the rereflux events into account.
Results: White wine significantly increased the fraction of time esophageal pH was <4, reflux frequency, and reflux duration compared to water. During periods without GER, no differences in the motility data were observed between wine and water. During GER, the contraction rate after white wine was significantly lower because of an increase in nontransmitted swallows. The time until occurrence of the first contraction after GER was significantly prolonged after white wine. Primary peristalsis was the main first and clearance contraction type. The percentage of GER episodes with simultaneous contractions and with failed peristalsis was significantly increased with wine. Similarly, the percentage of GER episodes with rereflux was significantly increased. The "corrected" mean reflux duration was still prolonged relative to water, but the difference was no longer significant. The numbers of peristaltic contractions necessary to raise pH to >4, which significantly differed for conventionally defined GER episodes between wine and water, were similar when counted only from onset of the latest rereflux event until pH rose to >4.
Conclusions: The pathogenesis of white wine-induced GER episodes of long duration is 2-fold. First, white wine provokes a disturbed esophageal clearance due to an increase in simultaneous contractions and in failed peristalsis. The second mechanism is the occurrence of repeated reflux events into the esophagus when pH is still acidic from a previous reflux episode.