Mediating role of chronic inflammatory airway diseases in the association between volatile organic compounds exposure and depression

Depression is a prevalent mental disorder that imposes a substantial global burden, and environmental exposure has been increasingly implicated in its etiology. However, the specific mechanisms linking urinary exposure to volatile organic compounds (VOCs) with depression remain poorly understood. A potential association of VOCs with depression prevalence was explored in this study, which also assessed the mediating effect of chronic inflammatory airway diseases (CIAD). This study analyzed data from the National Health and Nutrition Examination Survey from 2011 to 2020, involving 1696 participants. An ultra-high-performance liquid chromatography-tandem mass spectrometry assay was employed to quantify the levels of 16 VOCs in urine samples. We employed weighted multivariable logistic regression models, coupled with mediation analysis, to assess the potential association between urinary concentrations of VOCs and the risk of depression, while also investigating the intermediary pathway involving CIAD. The diagnostic potential of urinary VOCs as biomarkers for depression was further assessed through receiver operating characteristic curve analysis. Screening of the 1696 study subjects indicated a depression prevalence of 11.4%. Notably, 4 urinary VOC metabolites demonstrated a statistically significant positive association with the disorder (odds ratio > 1, P < .05). The dose-response relationship between them was also statistically significant. Mediation analysis indicated that CIAD mediated 7.3% of the total effect of VOC exposure on depression (P < .05). Contact with certain VOCs has been linked to an elevated incidence of depression disorder. CIAD plays a mediating role in the correlation between urinary VOCs and depression.