Effect of obesity on esophageal transit.

Esophageal transit time as measured by radionuclide scintigraphy using a swallowed technetium sulfur colloid bolus was measured in obese patients with gastroesophageal reflux, lean patients with reflux, and lean volunteers without reflux. The esophageal transit time was significantly prolonged in the obese group compared with both lean groups (p less than 0.001). Esophageal manometric measurement also confirmed that obese patients have an elevated gastroesophageal pressure gradient, presumably caused by increased intraabdominal pressure resulting from the mechanical burden of excess fat. The esophageal transit time is significantly related to the gastroesophageal pressure gradient. This finding, coupled with those in previous manometric investigations showing that esophageal muscle has a decreased maximum velocity with increasing afterload, explains in part why obese patients have delayed esophageal transit time. Therapy for reflux in obese patients should be aimed at improving esophageal transit.