Fig. 5

Results of the weighted quantile sum regression analyses. Notes: The ln-transformed urinary concentrations of the LASSO-selected mVOCs corrected with creatinine were introduced into weighted quantile sum regression models with all covariates adjusted, including gender, age, race or ethnicity, education level, marriage status, poverty-income ratio, smoking status, alcohol drinking, daily total energy intake, physical activity, and history of cancer. The weighted quantile sum regression models were constructed in both the positive direction (A) and negative direction (B). The estimate weights of each selected mVOCs in the positive association (C) and negative (D) association between mVOC mixtures and MetS were demonstrated as bar plots. Abbreviations: mVOCs, metabolites of volatile organic compounds; MetS, metabolic syndrome; TG, triglyceride; HDL, high-density lipoprotein; BP, blood pressure; FBG, fasting blood glucose; OR, odd ratio; 95% CI, 95% confident interval; HMPMA, N-Acetyl-S-(3-hydroxypropyl-1-methyl)-L-cysteine; CEMA, N-Acetyl-S-(2-carboxyethyl)-L-cysteine; AAMA, N-Acetyl-S-(2-carbamoylethyl)-L-cysteine; 2HPMA, N-Acetyl-S-(2-hydroxypropyl)-L-cysteine; PGA, Phenylglyoxylic acid; SBMA, N-Acetyl-S-(benzyl)-L-cysteine; CYMA, N-Acetyl-S-(2-cyanoethyl)-L-cysteine; 2MHA, 2-Methylhippuric acid