Gastric juice ascorbic acid is related to Helicobacter pylori infection but not ethnicity

Background: Maori and Pacific Island ethnic groups in New Zealand have a hi gh risk for gastric cancer. Low levels of gastric juice ascorbic acid (vita min C) have been suggested to be a risk factor for gastric cancer. Previous studies have shown that gastric juice ascorbic acid may be independently a ssociated with both ethnicity and Helicobacter pylori infection. This study aimed to examine the interrelationship between H. pylori and ethnicity in New Zealand. Methods: Gastric juice was collected into 70% perchloric acid preservative and stored at -80 degrees C. Ascorbic acid was analysed by high-performance liquid chromatography using ion-pair chromatography and electrochemical de tection. Inflammation and atrophy was graded from biopsies from multiple si tes in the antrum and body. Gastric juice was collected from 89 patients du ring routine endoscopy. Results: There was a wide range of measured gastric juice ascorbic acid fro m 0.001 to 410 mu g/mL. The median concentration of ascorbic acid for H. py lori-negative patients was 1.78 mu g/mL (n=57) and 0.12 mu g/mL (n=32) for H. pylori-positive patients (P=0.001). Gastric juice ascorbic acid concentr ation was not associated with age, endoscopic diagnosis or intestinal metap lasia, but was significantly associated with the degree of acute inflammati on (P=0.01) and the presence of atrophy (P=0.04). The median ascorbic acid concentration for European patients was 0.92 mu g/mL (n=44) and 0.09 mu g/m L (n=38) for Maori and Pacific Island ethnic groups combined (P=0.1). Multi ple step-wise regression analysis showed that only H. pylori infection was a significant factor for predicting ascorbic acid concentrations (r(2)=0.12 ). Conclusions: This study has confirmed that gastric juice ascorbic acid conc entration is lower in the presence of H. pylori infection. (C) 1999 Blackwe ll Science Asia Pty Ltd.