Serum and tissue zinc concentrations in patients with endoscopic esophagitis

Because zinc is an important metabolic requirement for growth and repair of squamous tissue, we questioned whether changes in serum and esophageal tissue zinc were present in patients with reflux esophagitis. To investigate this question, we prospectively studied 49 patients undergoing upper gastrointestinal endoscopy for symptoms of abdominal pain and discomfort; 19 patients were taking H2 antagonists at the time of the study. Blood was obtained to measure serum zinc concentrations prior to endoscopy and tissue zinc levels were obtained from esophageal biopsies from the distal, middle, and proximal esophagus in patients who were either endoscopically normal or who exhibited endoscopic esophagitis. Serum zinc concentrations were significantly lower in patients with endoscopic esophagitis compared to the endoscopically normal group (77±3.8 μg/dl vs 88±2.4 μg/dl,P<0.02). Distal esophageal tissue concentrations were significantly higher in patients with endoscopic esophagitis compared to the endoscopically normal group (200±30 μg/liter vs 135±15 μg/liter,P<0.05); whereas there were no differences between values obtained in the proximal or middle esophagus. Serum and tissue zinc concentrations in patients with esophagitis receiving H2 antagonists were more similar to values obtained in patients who were endoscopically normal than to patients with endoscopic esophagitis without treatment. This study suggests that in endoscopic esophagitis: (1) greater amounts of zinc are concentrated in the rapidly proliferating distal esophageal epithelium, (2) the serum zinc pool may serve as a major zinc source, and (3) decreasing esophageal mucosal inflammation with H2 antagonists may decrease zinc loss via the esophageal epithelium.