Association of triglyceride-glucose index with helicobacter pylori infection and mortality among the US population

Limited research has explored the potential association between the Triglyceride-Glucose (TyG) and mortality, especially in individuals with Helicobacter pylori (H. pylori) infection. This study seeks to investigate the correlation between the TyG index and H. pylori infection and investigate whether the associations between the TyG index exposure and all-cause mortality are mediated by H. pylori infection. The study utilized data from the National Health and Nutrition Examination Survey (NHANES) 1999–2018, incorporating a final sample size of 2,187 participants. Both univariable and multivariable-adjusted logistic regression analyses were employed to examine the relationship between H. pylori infection and relevant covariates. To assess the association between TyG index, and all-cause mortality in individuals with or without H. pylori infection, Cox regression analysis, and restricted regression cubic spline analysis were implemented. A significant positive correlation was observed between the TyG index and an elevated risk of H. pylori infection [OR 1.157, 95% CI (1.383 ~ 1.664)]. This correlation persisted even after adjusting for confounding factors [OR 1.189, 95% CI (1.003, 1.411), P < 0.05]. Furthermore, in patients with positive H. pylori infection, a noteworthy nonlinear correlation between the TyG index and all-cause mortality was identified (P = 0.0361). With an increase in the TyG index, all-cause mortality exhibited a corresponding rise, particularly following adjustment for all potential confounding factors. Conversely, in patients with negative H. pylori infection, no significant association was observed between the TyG index and all-cause mortality after adjusting for potential confounding factors. A higher TyG index was linked to increased H. pylori infection risks. Participants in the higher quantile group of the TyG index are positively associated with higher all-cause mortality compared to the higher quantile group of the TyG index in H. pylori-positive participants instead of H. pylori-negative participants.