Associations between blood mercury levels and subclinical changes in liver enzymes among South Korean general adults: Analysis of 2008-2012 Korean national health and nutrition examination survey data

Abstract

Introduction: We herein used data from the Korean National Health and Nutritional Examination Survey (KNHANES) 2008-2012 to examine the associations between blood mercury levels and subclinical changes of liver function in a representative sample of the adult Korean population. Methods: This study was based on data obtained from KNHANES, in which a rolling sampling design was used to perform a complex, stratified, multistage probability cluster survey of a representative sample of the non-institutionalized civilian population in South Korea. The associations between subclinical hepatic changes and blood mercury levels were assessed after adjustment for various demographic and lifestyle factors. Results: Multivariate linear regression analyses revealed that each doubling of blood mercury increased serum aspartate transaminase (AST) by 0.676 U/L and serum alanine transaminase (ALT) by 1.067 U/L. The mean differences (95% CI) in serum AST and ALT between the lowest and highest quartiles were statistically significant at 1249 (0263-2235) U/L and 2.248 (0.648-3.848), respectively. Logistic regression analysis showed that the odd ratios for having serum AST and ALT levels above the median were statistically significant in both the models according to the increase of blood mercury. The risks of having serum AST and ALT levels higher than the median among subjects in 4th quartile of blood mercury were 1.524 and 1.947, respectively. Discussion: The present findings show that subclinical changes of liver function are associated with blood mercury levels. This is the first study to show an association between blood mercury levels and mild liver dysfunction, as a possible proxy measure of nonalcoholic fatty liver disease (NAFLD), in Asian population. (C) 2014 Elsevier Inc All rights reserved.