Association between cardiometabolic index and high-sensitivity C-reactive protein: A cross-sectional study from National Health and Nutrition Examination Survey 2015 to 2018

Objective High-sensitivity C-reactive protein, a key inflammatory biomarker, can indicate the risk of cardiovascular diseases. The cardiometabolic index has been associated with metabolic and cardiovascular outcomes; however, its direct relationship with high-sensitivity C-reactive protein remains unclear. This study aimed to explore this association and identify influencing factors in adult population. Methods This retrospective cross-sectional study used data from the 2015–2018 National Health and Nutrition Examination Survey. A multivariate logistic regression model was applied to assess the association between cardiometabolic index and high-sensitivity C-reactive protein levels (>3.0 mg/L) in 3970 adults, with adjustment for demographic characteristics, comorbidities, and lifestyle factors. Results Cardiometabolic index was independently associated with high-risk high-sensitivity C-reactive protein (adjusted odds ratio = 1.11, 95% confidence interval: 1.03–1.19, p = 0.007). Subgroup analyses indicated that the association was more pronounced in females and non-Hispanic Black participants (p values for interaction were <0.001 and 0.004, respectively). Restricted cubic spline curves confirmed a nonlinear relationship between cardiometabolic index and high-risk high-sensitivity C-reactive protein (nonlinearity p < 0.001). Conclusion Cardiometabolic index demonstrated a significant positive association with high-risk high-sensitivity C-reactive protein in US adults, serving as a marker linking cardiometabolic status to chronic inflammation. Further studies are needed to validate causality and explore cardiometabolic index–guided prevention.