Influence of Full-body Water Immersion on Esophageal Motor Function and Intragastric Pressure

Aimi, Masahito; Furuta, Kenji; Saito, Tsukasa; Shimura, Shino; Fukazawa, Kousuke; Ohara, Shunji; Uno, Goichi; Tobita, Hiroshi; Adachi, Kyoichi; Kinoshita, Yoshikazu

Abstract

BACKGROUND/AIMS
In Japan, it is customary to take a daily bath during which the body is immersed in water to the neck. During full-body immersion, hydrostatic pressure is thought to compress the chest and abdomen, which might influence esophageal motor function and intra-gastric pressure. However, whether water immersion has a significant influence on esophageal motor function or intragastric pressure has not been shown. The aim of this study was to clarify the influence of full-body water immersion on esophageal motor function and intragastric pressure.
METHODS
Nine healthy male volunteers (mean age 40.1 +/- 2.8 years) were enrolled in this study. Esophageal motor function and intragastric pressure were investigated using a high-resolution 36-channel manometry device.
RESULTS
All subjects completed the study protocol. Intragastric pressure increased significantly from 4.2 +/- 1.1 to 20.6 +/- 1.4 mmHg with full-body water immersion, while the lower esophageal high pressure zone (LEHPZ) value also increased from 20.5 +/- 2.2 to 40.4 +/- 3.6 mmHg, with the latter being observed regardless of dietary condition. In addition, peak esophageal peristaltic pressure was higher when immersed as compared to standing out of water.
CONCLUSIONS
Esophageal motor function and intragastric pressure were altered by full-body water immersion. Furthermore, the pressure gradient between LEHPZ and intragastric pressures was maintained at a high level, and esophageal peristaltic pressure was elevated with immersion.