The influence of age on esophageal acid defense mechanisms and spontaneous acid gastroesophageal reflux.

Association of age with gastroesophageal pH and motor parameters have been searched for previously, but most studies have been cross-sectional. The aim of the present investigation was to evaluate the influence of age on gastroesophageal sphincter pressure, acid clearing ability, and acid gastroesophageal reflux in the same group of normal subjects. Ten healthy subjects were investigated in the period May 4, 1977, to February 18, 1978, and reinvestigated in the period August 19, 1985, to January 29, 1986. The median interval between the two investigations was 8.0 yr, range 7.7-8.5 yr. There were eight men and two women, with a median age at the second investigation of 36 yr, range 30-53 yr. Measurement of gastroesophageal sphincter pressure (GESP) and an acid perfusion test were performed, and within the same week, an acid-clearing test and a prolonged monitoring of pH in the distal part of the esophagus were carried out (5 cm proximally to the GES). pH monitoring was initiated between 7 and 8 PM and terminated between 7 and 8 AM. There were no changes in GESP between the two investigations. All had a normal acid perfusion test in both investigations. No changes in acid-clearing ability could be demonstrated. Similarly, the number of reflux episodes, as well as the duration of acid reflux, were unchanged. Integration of the pH curve for pH values less than or equal to 4 gave similar results at both occasions. In addition, the relative time with pH values less than or equal to 4 was unchanged. The acidity of the potential reflux material did not change over time, as evaluated by intragastric pH before and after monitoring. In conclusion, this study did not demonstrate any influence of age on esophageal acid defense mechanisms or spontaneous gastroesophageal reflux.