Non-linear association between cardiometabolic index and helicobacter pylori infection: a cross-sectional study

BACKGROUND: Helicobacter pylori (H. pylori) infection poses a significant global public health challenge. While prior studies have examined metabolic abnormalities in relation to H. pylori infection, the association between the cardiometabolic index (CMI) and H. pylori infection remains understudied. METHODS: The present cross-sectional study utilized information from the National Health and Nutrition Examination Survey (NHANES) 1999-2000, encompassing 3357 participants with complete H. pylori serology, CMI, and relevant covariate data. Multivariable regression models, smoothing curve fitting, and threshold effect analysis were implemented to examine the link between CMI and H. pylori infection, alongside subgroup analyses to confirm consistency across various populations. RESULTS: Increased CMI levels were associated with a higher likelihood of H. pylori infection. Each standard deviation increase in CMI was associated with a 21% higher odds of H. pylori infection (OR = 1.21, 95% CI 1.06-1.39, P = 0.005). A significant non-linear relationship was identified, with an inflection point at a CMI of approximately 2.8. Below this threshold, elevations in CMI were associated with a significant increase in infection risk (OR = 1.41, 95% CI 1.18-1.69, P = 0.0002). In contrast, increases beyond this point showed no statistically significant relationship (OR = 0.74, 95% CI 0.49-1.12, P = 0.1604). Tests for interaction indicated no significant differences across subgroups (P-interaction > 0.05). CONCLUSION: This cross-sectional study demonstrates a substantial non-linear association between the CMI and the risk of H. pylori infection. Future research should seek to confirm this association in contemporary, longitudinal cohorts to further validate these findings.