Association between cardiometabolic index and controlled attenuation parameter in U.S. adults with NAFLD: findings from NHANES (2017–2020)

Abstract Background Cardiometabolic index (CMI), a novel indicator that combines abdominal obesity and lipid levels, has been confirmed to correlate with non-alcoholic fatty liver disease (NAFLD). However, limited research has been conducted on the relationship between CMI and controlled attenuation parameter (CAP), a parameter measured by transient elastography and reflecting the extent of fat accumulation in the liver. The objective of our study was to investigate the relationship between the two variables. Methods This was a cross-sectional study with a sample size of 1,759 U.S. adults with NAFLD sourced from the NHANES 2017–2020. Participants with a median CAP ≥ 248 dB/m were considered to have hepatic steatosis. CMI was calculated as [waist circumference (cm)/height(cm)]×[TG (mmol/L)/HDL-C (mmol/L)]. Multivariate linear regression, generalized additive model and subgroup analysis were employed to examine the association of CMI and CAP. Results The average age of the 1,759 participants was 50.2 years, with males accounting for 50.76% and females 49.24%. The average BMI was 32.23 kg/m². The multivariate linear regression model indicated that with every 1-unit increase in CMI, there was an associated rise of 10.40 dB/m in CAP (95% CI, 7.14–13.67) after adjusting for covariates and a p for trend < 0.05 suggested the existence of a linear association between the two variables. Similarly, generalized additive model also found it a roughly linear relationship between the two. Subgroup analysis revealed a positive correlation in the majority of subgroups. Conclusions CMI was positively associated with CAP in U.S. adults with NAFLD. Our findings indicated that CMI may serve as an ideal indicator for monitoring the degree of hepatic steatosis among patients with NAFLD.