Objective: To examine the interaction between salt-intake and helicobacter pylori (H. pylori) infection in the development of stomach cancer in an ecological study of 67 Chinese rural counties.
Methods: Stomach cancer mortality data of 67 counties were derived from a national survey conducted in China between 1986 and 1988. Information regarding the prevalence of H. pylori infection and urinary sodium excretion were collected from the same individuals during a subsequent dietary survey in 1989.
Results: In these 67 counties, H. pylori prevalence and urinary sodium were correlated with stomach cancer mortality, with r=0.31 (p=0.01) and r=0.28 (p=0.03), respectively. After stratification, the significant correlation between H. pylori prevalence and stomach cancer mortality only existed in counties with high levels (> or =5.0 mg/mg creatinine/12-hour) of urinary sodium (r=0.5; p=0.002). Similarly, the significant correlation between urinary sodium and stomach cancer mortality was only presented in counties with high (> or =71.6%) H. pylori prevalence (r=0.4; p=0.017). Multivariate regression analysis showed results consistent with the correlation analysis.
Conclusion: These findings suggest that there may be an interaction between high salt consumption and H .pylori infection in the development of stomach cancer. Corroborating data from epidemiological, clinical, and experimental studies are needed.