Association of polycyclic aromatic hydrocarbons with systemic inflammation and metabolic syndrome and its components

Abstract Objective This study aimed to evaluate the relationship of polycyclic aromatic hydrocarbon (PAH) exposure with metabolic syndrome (MetS) and its components and to explore the potential mechanism. Methods Participants from the National Health and Nutrition Examination Survey (NHANES 2001–2016) were included. Results A total of 6532 adults and 1237 adolescents were included in the present analysis. For adults, the odds ratios (ORs) and 95% CIs for each one‐unit increase in the log‐transformed level of 1‐hydroxynaphthalene (1‐OHNa), 2‐hydroxynaphthalene (2‐OHNa), 3‐hydroxyfluorene (3‐OHFlu), 2‐hydroxyfluorene (2‐OHFlu), 1‐hydroxyphenanthrene (1‐OHPh), 1‐hydroxypyrene (1‐OHP), 2‐ and 3‐hydroxyphenanthrene (2&3‐OHPh), and total urinary PAH metabolites (∑OH‐PAHs) with MetS were 1.11 (1.03–1.20), 1.18 (1.07–1.29), 1.10 (1.01–1.12), 1.18 (1.07–1.30), 1.17 (1.03–1.33), 1.09 (1.01–1.22), 1.24 (1.09–1.40), and 1.17 (1.06–1.29), respectively. They were 1.61 (1.21–2.14) for 2‐OHNa, 1.27 (1.01–1.60) for 2‐OHFlu, 1.53 (1.15–2.03) for 1‐OHPh, and 1.61 (1.20–2.15) for ∑OH‐PAHs among adolescents. C‐reactive protein was not only positively associated with urinary PAH metabolites, but also positively related to MetS, and it mediated 10.23% to 20.21% for urinary PAH metabolites and MetS among adults. Conclusions PAH exposure is associated with a higher prevalence of MetS or MetS components among adults and adolescents. Systemic inflammation partly mediated the association among adults.