Factors influencing gastroduodenal mucosal prostaglandin concentrations: Roles of smoking and aging

Objective: To evaluate behavioral, demographic, clinical, and histologic variables that independently influence gastroduodenal mucosal prostaglandin concentrations. Design: Prospective study. Setting: A clinical research laboratory located in a Department of Veterans Affairs hospital. Patients: Fifty-two healthy adults who had no history of peptic ulcer disease and who were not receiving nonsteroidal anti-inflammatory drugs. Measurements: Mucosal biopsy specimens were obtained endoscopically from the stomach (body and antrum) and the duodenum (bulb and postbulbar area). Mucosal extracts from each of these four regions were assessed by radioimmunoassay to determine prostaglandin E₂ and prostaglandin F(2α) concentrations. Specimens were also examined histologically for inflammation and the presence of Helicobacter pylori. A multivariate linear regression model was used to determine which behavioral, demographic, and histologic variables significantly and independently influenced gastroduodenal mucosal prostaglandin concentrations. Results: Smoking and older age were independently associated with lower prostaglandin concentrations in all four mucosal regions (P = 0.0001 to P = 0.05). Compared with results in young nonsmokers, mucosal prostaglandin concentrations were reduced by 70% to 80% in older smokers. Gender, alcohol use, endoscopic appearance, dyspeptic symptoms, mucosal inflammation, and the presence of H. pylori had no consistent effect on prostaglandin content. Conclusion: Smoking and older age are associated with significantly reduced gastric and duodenal prostaglandin concentrations. These observations may help explain the predisposition to ulcer disease in smokers and older persons.