Gastroesophageal reflux patients' defective antioxidative capacity in the proximal esophageal mucosa before antireflux surgery and also after 4-year follow-up

BACKGROUND: Oxidative stress has a role in the pathogenesis of gastroesophageal reflux disease (GERD). AIM: To investigate the redox balance in proximal esophagus before and 6 and 48 months after antireflux surgery. METHODS: In 20 GERD patients and 9 controls oxidative stress by myeloperoxidase activity (MPO activity) and antioxidative capacity of esophageal mucosa by superoxide dismutase activity (SOD), and glutathione content (GSH) was measured from proximal esophageal samples. RESULTS: In proximal esophagus of GERD patients compared to controls', antioxidative capacity appearing as GSH level was significantly decreased (P < 0.001) at all time points and as SOD levels preoperatively (P < 0.001) and 4 years postoperatively (P = 0.01). MPO activity of patients was significantly lower than controls' preoperatively, and 6 months and 4 years postoperatively (P < 0.05). MPO activity remained lower than that of the distal esophagus at 6 months and 4 years (P < 0.01 for both). CONCLUSIONS: In GERD patients, proximal esophageal mucosal antioxidative defense is defective before and after antireflux surgery. Antireflux surgery seems not to change the level of oxidative stress in proximal esophagus, suggesting that defective mucosal antioxidative capacity plays a role in development of oxidative damage to the esophageal mucosa in GERD.