Transient Elastography-Assessed Hepatic Steatosis and Fibrosis Are Associated With Body Composition in the United States

Background & Aims: We examined transient elastography assessed hepatic steatosis and fibrosis distributions and relationships with body composition in a representative United States population sample.

Methods: Liver stiffness and controlled attenuation parameter (CAP) were assessed on 4870 non-Hispanic White, non-Hispanic Black, non-Hispanic Asian, and Hispanic men and women aged 20 years and over in the National Health and Nutrition Examination Survey (NHANES) 2017-2018. Participants underwent anthropometry and dual-energy x-ray absorptiometry (DXA).

Results: Compared to women, men had higher mean CAP (274.2 dB/m vs 254.4 dB/m) and liver stiffness (6.4 kPa vs 5.5 kPa). CAP and liver stiffness increased through middle age and markedly with BMI. In multivariate-adjusted analysis, CAP in the upper quartile was associated with increased age, BMI, waist-to-hip ratio, diabetes, hypertension, alanine aminotransferase (ALT) and C-reactive protein and decreased HDL cholesterol. After adjustment, non-Hispanic Blacks had lower CAP and non-Hispanic Asians had higher CAP. In multivariate-adjusted analysis, liver stiffness in the upper quartile was associated with male sex, increased age, BMI, diabetes, hepatitis C virus positivity, ALT and CAP. Lower stiffness among Non-Hispanic Asians was not significant after adjustment for BMI. DXA trunk and extremity fat mass were positively related to both CAP and liver stiffness with multivariate adjustment (P < .001 for each). Results were similar with CAP and liver stiffness as continuous characteristics.

Conclusions: In the United States population, increased anthropometric and DXA body composition measures were associated with higher CAP and liver stiffness. Racial-ethnic differences observed merit further research to elucidate the burden of obesity and liver health disparities.