Association between exposure to volatile organic compounds and atherogenic index of plasma in NHANES 2011–2018

Volatile organic compounds (VOCs) are prevalent in daily life, yet the relationship between VOCs exposure and the atherogenic index of plasma (AIP) remains inadequately explored, especially in populations with high levels of exposure. This study aims to investigate the non-linear association between VOCs exposure and AIP in the U.S. adult population. Data from the National Health and Nutrition Examination Survey (NHANES) collected between 2011 and 2018 were analyzed. A range of statistical techniques, including Spearman's correlation analysis, weighted quantile sum (WQS), multivariate logistic regression, restricted cubic splines (RCS), stratified threshold models, and bayesian kernel machine regression (BKMR), were systematically employed to assess the relationship between high-dose VOCs exposure and AIP in U.S. adults. The study included 6,027 participants, with an average age of 37 (18-59), and 50.46% were male. Of these, 3,011 had elevated AIP levels. The Mann-Whitney U test compared VOCs exposure across quartiles (Q1-Q4). Spearman models revealed strong joint exposure effects between VOCs like IPMA3 and HMPMA (ρ = 0.97). WQS regression showed a positive association between VOCs and total cholesterol (TC) (β = 5.45, 95% CI = 5.42-5.58, P = 0.04) and high-density lipoprotein cholesterol (HDL-C) (β = 1.07, 95% CI = 1.03-1.10, P = 0.02). After adjusting for confounders, logistic regression revealed that VOCs such as 3-4MHA, 34DMA, AAMA, ATCA, CYMA, HEMA, and SBMA were linked to higher AIP. RCS analysis indicated a nonlinear association between VOCs and AIP. Stratified modeling found that ATCA was significantly and positively associated with AIP (OR = 1.60, 95% CI = 1.20-2.14, p < 0.01), and that when ATCA levels exceeded 128.60 ng/mL, there was a 60% increased risk of elevated AIP. Higher urinary VOCs levels, particularly ATCA, are significantly associated with increased AIP, offering new insights into the potential link between VOCs exposure and cardiovascular disease.