Association between cardiometabolic index and liver function parameters: Analysis of NHANES 2007 to 2018

The cardiometabolic index (CMI) is widely used for risk prediction of metabolic diseases. This study examined the association between CMI levels and liver function parameters. This cross-sectional study analyzed data from the National Health and Nutrition Examination Survey from 2007 to 2018. The analysis encompassed 5 parameters of liver function: alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase, alkaline phosphatase, and ALT/AST ratio. Multivariate weighted linear regression models were used to examine the relationships between CMI values, CMI quartiles, and liver function parameters, respectively. Subgroup analyses and interaction tests were conducted to account for potential confounding factors. The final sample comprised 9960 participants. Multivariate linear regression modeling demonstrated a significant positive association between CMI levels and ALT (β = 0.30, 95% CI = 0.20-0.41), AST (β = 0.19, 95% CI = 0.06-0.32), alkaline phosphatase (β = 0.17, 95% CI = 0.05-0.29), gamma-glutamyltransferase (β = 0.84, 95% CI = 0.29-1.40), and ALT/AST ratio (β = 0.01, 95% CI = 0.00-0.01). Positive correlations were observed between CMI quartiles and ALT, as well as the ALT/AST ratio. Subgroup analyses further demonstrated that the correlation between CMI levels and ALT and AST remained consistent across age, gender, and body mass index subgroups. CMI is positively associated with markers of liver dysfunction in US adults. Liver function screening in populations with elevated CMI levels should be prioritized to facilitate early intervention for liver disease.