Association between Liver Function, Hepatic Fibrosis Index and Urinary Thiodiglycolic Acid in School-Aged Children Living near a Petrochemical Complex

Abstract

Background/AimWhether children are susceptible to hepatotoxicity when exposed to vinyl chloride monomer (VCM) is unknown. Epidemiological studies revealed high prevalence of liver fibrosis and abnormal liver function in high VCM/PVC exposed workers, and previous study indicated that using urinary thiodiglycolic acid (TDGA) as a biomarker of VCM metabolites is reliable in children living near VCM/PVC factories. We aim to assess the association among urinary TDGA levels, liver function, and hepatic fibrosis in school-aged children.Methods 303 school-aged children (aged ≥6-<13 years) were recruited in central Taiwan. First morning urine and blood samples were collected in each participants, and urinary TDGA levels were analyzed by LC/MS-MS. Liver function was determined by subclinical abnormal serum aspirate aminotransferase (AST) and alanine aminotransferase (ALT). Hepatic fibrosis was assessed by AST to platelet ratio index (APRI), and fibrosis-4 score (FIB-4).Results Median levels of all subjects urinary TDGA (range), AST/ALT (range; subclinically abnormal rate) were 95.2 μg/g-creatinine, 26.0 IU/L (17.0-99.0; 26%)/15.0 IU/L (7.0-211.0; 6%), respectively. Third quartile of urinary TDGA levels in children (Q3: ≥ 95.2 - <160.0 μg/g-creatinine) and highest quartile (Q4: ≥ 160.0 μg/g-creatinine) had significantly increased the odds ratio (OR) (Q3: OR= 3.54, 95% confidence interval (CI): 1.35-9.30; Q4: OR= 5.26, 95% CI: 1.93-14.31) of subclinically abnormal AST compared with those in the lowest quartile after adjustment for elementary schools, age, sex, BMI, annual family income, physical activity, and passive smoking. A trend for a dose-response (p for trend= 0.001) was also observed.ConclusionsOur findings supported the hypothesis that urinary TDGA levels in children living near VCM/PVC industries are associated with susceptibility to hepatotoxicity.