The association of the advanced lung cancer inflammation index with the risk of Helicobacter pylori infection and mortality: a study of populations from two countries.

BACKGROUND: Helicobacter pylori (H. pylori) infection is strongly linked to multiple diseases. Inflammation and nutritional status are intricately intertwined with H. pylori infection; however, most prior studies failed to integrate these two dimensions in a unified assessment. METHODS: This study enrolled 3,718 eligible participants from the 1999-2000 National Health and Nutrition Examination Survey (NHANES). Multivariate logistic regression was utilized to examine the association between the ALI and H. pylori infection. Cox proportional hazards regression was employed to evaluate the association between ALI and all-cause mortality in H. pylori-infected patients. Restricted cubic splines (RCS) were implemented to characterize potential nonlinear relationships. Subgroup analysis explores the consistency of the associations among different populations. An independent duplicate cohort from the Second Affiliated Hospital of Nanchang University was additionally incorporated. RESULTS: Elevated ALI emerged as a relevant factor for H. pylori infection. Higher ALI levels were associated with improved survival prognosis. Beyond an inflection point (log2ALI=5.44) this negative association gradually diminished. Subgroup analyses revealed that the interaction test showed that no significant interaction was found for all stratification factors. The association between ALI and H. pylori infection was consistent among the above subgroups. Independent duplicate cohort corroborated that as the level of log2ALI increases, the likelihood of H. pylori infection showed a monotonous increasing trend. CONCLUSION: Higher ALI levels were positively associated with an increased risk of H. pylori infection, and this association was consistent in an independent duplicate cohort. Among H. pylori-infected individuals, higher ALI was related to reduced all-cause mortality, with the association most prominent at lower ALI ranges.