Association of metabolites of benzene and toluene with lipid profiles in Korean adults: Korean National Environmental Health Survey (2015–2017)

Abstract

Background Environmental exposure to benzene and toluene is a suspected risk factor for metabolic disorders among the general adult population. However, the effects of benzene and toluene on blood lipid profiles remain unclear. In this study, we investigated the association between urinary blood lipid profiles and metabolites of benzene and toluene in Korean adults. Methods We analyzed the data of 3,423 adults from the Korean National Environmental Health Survey Cycle 3 (2015–2017). We used urinary trans,trans-muconic acid (ttMA) as a biomarker of benzene exposure, and urinary benzylmercapturic acid (BMA) as an indicator of toluene exposure. Multivariate logistic regression analyses were performed to explore the association between blood lipid profiles and urinary metabolites of benzene and toluene. Additionally, we examined the linear relationship and urinary metabolites of benzene and toluene between lipoprotein ratios using multivariate regression analyses. Results After adjusting for covariates, the fourth quartile (Q4) of ttMA [odds ratio (OR) (95% confidence interval, CI = 1.599 (1.231, 2.077)] and Q3 of BMA [OR (95% CI) = 1.579 (1.129, 2.208)] were associated with an increased risk of hypertriglyceridemia. However, the Q4 of urinary ttMA [OR (95% CI) = 0.654 (0.446, 0.961)] and Q3 of urinary BMA [OR (95% CI) = 0.619 (0.430, 0.889)] decreased the risk of a high level of low-density lipoprotein cholesterol (LDL-C). Higher urinary ttMA levels were positively associated with the ratio of triglycerides to high-density lipoproteins [Q4 compared to Q1: β = 0.11, 95% CI: (0.02, 0.20)]. Higher urinary metabolite levels were negatively associated with the ratio of low-density lipoprotein to high-density lipoprotein [Q4 of ttMA compared to reference: β = -0.06, 95% CI: (-0.11, -0.01); Q4 of BMA compared to reference: β = -0.13, 95% CI: (-0.19, -0.08)]. Conclusion Benzene and toluene metabolites were significantly and positively associated with hypertriglyceridemia. However, urinary ttMA and BMA levels were negatively associated with high LDL-C levels. These findings suggest that environmental exposure to benzene and toluene disrupts lipid metabolism in humans.

Microglial NF-κB Signaling Deficiency Protects Against Metabolic Disruptions Caused by Volatile Organic Compound via Modulating the Hypothalamic Transcriptome

“…The chosen studies encompassed a total of 26,313 subjects, spanning various demographics including pregnant women, children, young adults, adults and elderly individuals [6][7][8]10,[28][29][30][31] . As indicated in the forest plot (Figure 1), we found significant effects of environmental benzene exposure, at levels pertinent to highly polluted urban settings, on the risk of developing metabolic disease.…”

“…Our comprehensive meta-analysis, which covers a wide range of demographics such as the elderly, children, young adults, adults, and pregnant women [6][7][8]10,[28][29][30][31] , shows a strong positive relationship between levels of trans, trans-muconic acid (t,t-MA), benzene urinary metabolites, and indicators of insulin resistance and blood glucose levels. These data are in line with recent findings from a comprehensive cross-sectional study utilizing data from The National Health and Nutrition Examination Survey showed a strong correlation between VOCs exposure and development of insulin resistance within the broader population 56 .…”

Association of Urinary Benzene Metabolite and the Ratio of Triglycerides to High-Density Lipoprotein Cholesterol: A Cross-Sectional Study Using the Korean National Environmental Health Survey (2018–2020)

“…This study presents that environmental exposure to benzene is associated with an elevated TG/HDL-C ratio, a surrogate marker for cardiovascular disease in the general population. To our knowledge, only a few studies have assessed the association between environmental exposure to benzene and serum lipid profiles [ 32 ]. In this study, significant associations were found between urinary t,t-MA, a metabolite of benzene and elevated TG/HDL-C ratio, and these associations remained in both men and women, after stratification with sex.…”

“…Another cross-sectional study for children and adolescents also found a significant association between insulin resistance, fasting glucose, and fasting blood insulin with urinary t,t-MA [ 22 ]. A recent study of 3423 adults who participated in the Korean National Environmental Health Survey Cycle 3 (KoNEHS, 2015–2017) reported that the TG/HDL-C ratio was elevated as urinary t,t-MA was increased [ 32 ]. These results provided evidence that exposure to benzene can have negative health effects.…”

“…This oxidative stress has the potential to cause damage to DNA, proteins, and lipid peroxidation, which are potential pathophysiological factors contributing to various diseases such as diabetes, hypertension, and cardiovascular disease (CVD) [ 26 , 27 , 28 , 29 , 30 , 31 ]. However, there is limited epidemiologic evidence on the associations between exposure to benzene and toluene and blood lipid levels [ 32 ].…”