Association between C-reactive protein-triglyceride glucose index and NAFLD in US adults: A nationally cross-sectional study using NHANES 2017-2020 data

The C-reactive protein-triglyceride glucose index (CTI) is a novel biomarker for assessing insulin resistance and the severity of inflammation. However, its association with nonalcoholic fatty liver disease in United States adults has not been well established. Using data from the 2017 to 2020 National Health and Nutrition Examination Survey, this cross-sectional study applied multivariate linear regression models to investigate the linear relationship between CTI and controlled attenuation parameters (CAP). In addition, we performed stratified and interaction analyses to evaluate the stability of the relationships within different subgroups. The study enrolled 3248 participants, comprising 1474 males (45.4%) and 1774 females (54.6%) with a median age of 49 years. All 3 models demonstrated a positive association between CTI and CAP: Model 1 (beta [β] = 33.79; 95% confidence interval [CI]: 31.8-35.78), Model 2 (β = 31.80; 95% CI: 29.75-33.86), and Model 3, a fully adjusted model, (β = 13.85; 95% CI: 11.51-16.2). The CTI was stratified into quartiles, and a trend test indicated a linear relationship between the CTI and CAP across all 3 models (P for trend < .05). Similarly, smooth curve analysis indicated a linear relationship (P for nonlinearity = .178). The subgroup analyses also demonstrated a positive association in each subgroup. The CTI is positively associated with CAP in adults in the United States, suggesting its potential as a reliable indicator for nonalcoholic fatty liver disease monitoring.