Association of urinary metal exposure with H. pylori seropositivity and mortality in the U.S. Population: NHANES 1999-2000 analysis.

Abstract

Background: The relationship between urinary heavy metal concentrations and overall mortality remains understudied, particularly among individuals with Helicobacter pylori (H. pylori) infection. This study aimed to explore the associations between urinary concentrations of specific metals and H. pylori seropositivity, as well as to evaluate their respective associations with all-cause mortality in both H. pylori-infected and non-infected subpopulations.

Methods: Data were derived from the 1999-2000 cycles of the National Health and Nutrition Examination Survey (NHANES), resulting a final analytical cohort of 1,086 participants. Multivariable logistic regression models were applied to identify predictors of H. pylori infection. Cox proportional hazards models and restricted cubic spline analyses were used to investigate associations between urinary metal concentrations and all-cause mortality, stratified by H. pylori status.

Results: Restricted cubic spline analyses revealed a significant association between urinary thallium levels and all-cause mortality in H. pylori-positive individuals (P for nonlinearity = 0.2731), with a nonlinear relationship observed in H. pylori-negative participants (P for nonlinearity = 0.0127). Elevated urinary tungsten concentrations were independently associated with H. pylori seropositivity (P overall = 0.0074). Notably, among H. pylori-negative participants, the highest tungsten quartile (Q4) showed a significant mortality risk increase (HR = 3.054, 95% CI: 1.083-8.608), while in H. pylori-positive individuals, tungsten was significantly associated with mortality only in continuous models (HR = 3.129, 95% CI: 1.031-9.493).

Conclusion: Elevated urinary tungsten levels were significantly linked to H. pylori infection, while the relationship between tungsten and mortality differed by infection status: a dose-response association was observed in H. pylori-negative individuals, while a nonlinear association emerged in H. pylori-positive participants.