JAK3/STAT5b/PPARγ Pathway Mediates the Association between Di(2-ethylhexyl) Phthalate Exposure and Lipid Metabolic Disorder in Chinese Adolescent Students

Association of phthalate exposure with type 2 diabetes and the mediating effect of oxidative stress: A case-control and computational toxicology study

Phthalic acid esters (PAEs) are widely used as plasticizers and have been suggested to engender adverse effects on glucose metabolism. However, epidemiological data regarding the PAE mixture on type 2 diabetes (T2DM), as well as the mediating role of oxidative stress are scarce. This case-control study enrolled 206 T2DM cases and 206 matched controls in Guangdong Province, southern China. The concentrations of eleven phthalate metabolites (mPAEs) and the oxidative stress biomarker 8-hydroxy-2'-deoxyguanosine (8-OHdG) in urine were determined. Additionally, biomarkers of T2DM in paired serum were measured to assess glycemic status and levels of insulin resistance. Significantly positive associations were observed for mono-(2-ethylhexyl) phthalate (MEHP) and Mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) with T2DM (P < 0.001). Restricted cubic spline modeling revealed a non-linear dose-response relationship between MEHHP and T2DM (Pnon-linear = 0.001). The Bayesian kernel machine regression and quantile g-computation analyses demonstrated a significant positive joint effect of PAE exposure on T2DM risk, with MEHHP being the most significant contributor. The mediation analysis revealed marginal evidence that oxidative stress mediated the association between the mPAEs mixture and T2DM, while 8-OHdG respectively mediated 26.88 % and 12.24 % of MEHP and MEHHP on T2DM risk individually (Pmediation < 0.05). Di(2-ethylhexyl) phthalate (DEHP, the parent compound for MEHP and MEHHP) was used to further examine the potential molecular mechanisms by in silico analysis. Oxidative stress may be crucial in the link between DEHP and T2DM, particularly in the reactive oxygen species metabolic process and glucose import/metabolism. Molecular simulation docking experiments further demonstrated the core role of Peroxisome Proliferator Activated Receptor alpha (PPARα) among the DEHP-induced T2DM. These findings suggest that PAE exposure can alter oxidative stress via PPARα, thereby increasing T2DM risk.

Associations of urinary di(2-ethylhexyl) phthalate metabolites with lipid profiles among US general adult population

Background

Di(2-ethylhexyl) phthalate (DEHP) a parent compound that is metabolized into 4 phthalate metabolites, which correlate to adverse cardio-metabolic risk factors. This study aimed to explore the links between urinary DEHP metabolites and serum lipids in the U.S. general adult population.

Methods

In this cross-sectional study, data on 11 urinary phthalate metabolites from the 2005-2018 National Health and Nutrition Examination Surveys (NHANES) were analyzed. Multivariate linear regression and restricted cubic spline (RCS) were used to examine the relationship between phthalate metabolites [specific DEHPs: mono-(2-ethyl-5-carboxy-pentyl) phthalate (MECPP), mono-(2-ethyl-5-hydroxy-hexyl) phthalate (MEHHP), mono-(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-oxo-hexyl) phthalate (MEOHP)] and serum lipids (triglycerides [TG], total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], and high-density lipoprotein cholesterol [HDL-C]). To identify mixed exposure effects of phthalate metabolites, quantile g-computation (QG-C) and weighted quantile sum (WQS) regression were employed for the lipid profiles.

Results

A total of 9141 adults were included in the analysis. MECPP, MEHHP, MEHP, and MEOHP in the highest quartile had a negative relationship with HDL-C compared to the lowest quartile (All P for trend <0.05). TG showed a significant positive relation with MECPP, MEHHP, and MEOHP (All P for trend <0.05), but there was no notable association with MEHP. RCS demonstrated a linear relationship of DEHP metabolites with HDL-C, TC, TG, and LDL-C (all P for nonlinearity >0.05). The WQS index of DEHP metabolites showed independent correlations with HDL-C [β = -0.26, 95%CI (-0.43, -0.09), P = 0.002], TC [β = 0.55, 95%CI (0.13, 0.98), P = 0.011], and TG [β = 2.40, 95%CI (0.85, 3.96), P = 0.003].

Conclusion

Our study suggests that environmental DEHP exposure may affect serum HDL-C and TG levels in the general adult population. Further research is warranted to confirm these findings and illuminate the underlying mechanisms of DEHP exposure on lipids.