Blood lead level is associated with advanced liver fibrosis in patients with non-alcoholic fatty liver disease: A nationwide survey (NHANES 2011-2016)

Abstract

Introduction and objectives: Non-Alcoholic Fatty Liver Disease (NAFLD) is linked to obesity and metabolic syndrome, but increasing evidence also implicates environmental toxins. In this study, we aim to show that in elevated blood Lead levels in NAFLD patients result in worsening liver fibrosis.

Materials and methods: 30,172 patients from NHANES 2011-2016 met inclusion criteria. 2499 patients ages 20-74 were identified with NAFLD as determined by the Fatty Liver Index score, and 425 with advanced liver fibrosis were identified using the NAFLD Fibrosis Score. Simple linear regression, Student's T-test, and Rao-Scott Chi-Square test was used for continuous and categorical variables. Multivariate regression analysis was used to adjust for confounders to determine odds of Advanced Fibrosis.

Results: Increased serum Lead level was independently associated with increased risk of Advanced Fibrosis (OR 5.93, 95% CI 2.88-12.24) in the highest Lead quartile (Q4). In subgroup analysis stratified by BMI, a significant association between advanced liver fibrosis and blood Lead levels was consistently present, Q4 (OR 5.78, 95% CI 0.97-33.63) and Q4 (OR 6.04, 95% CI 2.92-12.48) in BMI <30 and >30, respectively. Increased Lead exposure was also evident in patients who were older, less educated, male, and drank alcohol and smoked tobacco.

Conclusions: Our findings show that advanced liver fibrosis is up to six times more likely in NAFLD patients with increased Lead exposure.

Keywords: Fibrosis; Lead; Nonalcoholic fatty liver disease.