Researchers from the University Medical Centers Amsterdam, The Netherlands conducted a study to evaluate sleep positions and acid reflux occurring at night time in 57 patients with symptoms of acid reflux. A sleep position measurement device assessed the left, right, supine and prone sleep positions and gastroesophageal acid reflux was measured via ambulatory pH-impedance reflux monitoring. The most common sleeping position was the left lateral position (median 30.6%) followed by the right lateral decubitus position (median 27.3%) and the supine position (median 26.0%). Though the number of reflux episodes were comparable between the sleep positions assessed, esophageal exposure time to gastric acid was shortest in the left lateral sleeping position (median 0.0%) compared to the right lateral (median 1.2%) and the supine (median 0.6%) sleeping positions. The median esophageal acid clearance time for every episode of reflux ranged from 16-115 seconds (median 35 second) in the left lateral position, 22-257 seconds (median 76 seconds) in the supine position and 26-250 seconds (median 90 seconds) in the right lateral position. 

This study has demonstrated the effect of sleep position on acid reflux and exposure of esophagus to the acid. The left lateral position was the most favorable sleeping position not only because the night time esophageal acid exposure time was shorter, the esophageal acid clearance was shorter too. Hence, patients with nocturnal acid reflux should be advised to sleep in the left lateral position to reduce the reflux symptoms and esophageal acid exposure leading to less damage to the esophageal mucosa.

Schuitenmaker JM, et al. Am J Gastroenterol. 2021 Dec 20. Doi: 10.14309/ajg.0000000000001588.