Beyond the stomach: a cross-sectional analysis of H. pylori infection and the TyG index in a high-risk population from Southwest China

Abstract Background and aims Helicobacter pylori infection has been suggested to influence systemic metabolism through low-grade inflammation. The triglyceride-glucose (TyG) index, a validated surrogate marker of insulin resistance, may help clarify this relationship. This cross-sectional study aimed to investigate the association between H. pylori infection and the TyG index in a high-risk population from Southwest China, with particular attention to the role of potential confounders. Methods This cross-sectional study included 6,998 adults from a health-screening cohort in Wenshan, Southwest China (2020–2024). H. pylori infection was diagnosed using the ¹⁴C-urea breath test (cut-off > 50 DPM). The TyG index was calculated as ln[fasting triglycerides (mg/dL) × fasting glucose (mg/dL) / 2]. Multivariable logistic regression with stepwise adjustment, restricted cubic splines, and stratified analyses were applied. Results Of the 6,998 participants, 2,736 (39.1%) were H. pylori-positive. The TyG index was slightly higher in the positive group (8.83 ± 0.73 vs. 8.76 ± 0.70, p < 0.001). In univariate analysis, a higher TyG index showed a modest association with H. pylori infection (OR = 1.14, 95% CI 1.06–1.21, p < 0.001). However, after adjustment for age and sex (Model 1), this association was no longer significant (OR = 1.022, 95% CI 0.950–1.100, p = 0.553). Further adjustment for TBIL, ALP, GGT, and LDL-C did not materially change the null estimate. Independent correlates in Model 3 were age, male sex, and TBIL. This attenuation after adjustment for age and sex indicates that the crude association was largely driven by demographic differences rather than lipid-related confounders. Conclusion In this high-risk population, the univariate association between an elevated TyG index and H. pylori infection did not persist in any multivariable model. The TyG index should not be considered an independent marker or a screening tool for H. pylori infection. Our findings serve as a methodological caution: rigorous adjustment for demographic confounders—particularly age and sex—is essential in future studies, as unadjusted estimates may yield misleading positive signals. Prospective studies employing direct measures of insulin resistance are needed to further explore the metabolic implications of H. pylori infection.