Co-exposure to polycyclic aromatic hydrocarbons and nicotine and their associations with cognitive impairment risk in older adults from southern China

Zhihui Guo; Qunlin Xiao; Tian Li; Yilan Deng; Peiyi Liu; Xiaohu Ren; Benhong Xu; Xiao Chen; Haiyan Huang; Weizhen Qin; Chengpeng Huang; Lan Luo; Jianjun Liu; Shaoyou Lu

doi:10.1016/j.fct.2025.115255

Co-exposure to polycyclic aromatic hydrocarbons and nicotine and their associations with cognitive impairment risk in older adults from southern China

Food Chem Toxicol. 2025 Jan 17:115255. doi: 10.1016/j.fct.2025.115255. Online ahead of print.

Authors

Zhihui Guo¹, Qunlin Xiao², Tian Li³, Yilan Deng⁴, Peiyi Liu⁵, Xiaohu Ren⁵, Benhong Xu⁵, Xiao Chen⁵, Haiyan Huang⁶, Weizhen Qin⁷, Chengpeng Huang⁷, Lan Luo⁷, Jianjun Liu⁵, Shaoyou Lu⁸

Affiliations

¹ School of Public Health (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518107, China.
² Department of Cardiology, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, China.
³ Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, China; Key Laboratory of Environment & Health (Huazhong University of Science and Technology), Ministry of Education, State Environmental Protection Key Laboratory of Environment and Health (Wuhan) and State Key Laboratory of Environment Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430074, China; Beijing Daxing District Center for Disease Control and Prevention, Beijng, 102699, China.
⁴ Zhuhai Maternity and Child Health Care Hospital, Zhuhai, 519001, China.
⁵ Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, China.
⁶ Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, China. Electronic address: [email protected].
⁷ Physical and Chemical Testing Department, Longhua District Center for Disease Control and Prevention, Shenzhen, 518109, China.
⁸ School of Public Health (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518107, China. Electronic address: [email protected].

PMID: 39828119
DOI: 10.1016/j.fct.2025.115255

Abstract

Exposure to polycyclic aromatic hydrocarbons (PAHs) and tobacco smoke is widespread and linked to various adverse health outcomes. Their potential to disturb the neurological system has raised much concern, particularly among older adults. Thus, we conducted a case-control study to assess the associations between co-exposure to PAHs and nicotine, and the risk of cognitive impairment and oxidative stress in older adults. A total of 384 adults aged 60 years and older were recruited from 2017-2018 in Shenzhen, China. Morning spot urine samples were collected for the analysis of 6 mono-hydroxylated PAHs, 8 nicotine metabolites, and a typical biomarker for oxidative stress, 8-hydroxy-2'-deoxyguanosine (8-OHdG). The Mini-Mental State Examination was used to assess the cognitive function of participants. Quantile-based g-computation (QGC), weighted quantile sum regression, and Bayesian kernel machine regression were used to analyze the associations between the exposure mixture and outcomes. QGC showed co-exposure to PAHs and nicotine were positively associated with cognitive impairment risk (OR: 1.66, 95% CI: 1.36-2.03, P<0.001) and 8-OHdG (β:11.19, 95% CI: 3.90-18.48, P<0.001). The primary contributors to cognitive impairment risk were (S)-nicotine-N-β-glucuronide (NicGluc), cotinine N-β-D-glucuronide (CotGluc) and (S)-cotinine N-oxide (CNO) and Cotinine (Cot), with no-linear dose-response relationships. However, 8-OHdG did not mediate the association between PAHs, nicotine and cognitive impairment risk.

Keywords: 8-hydroxy-2’-deoxyguanosine; cognitive impairment; mono-hydroxylated polycyclic aromatic hydrocarbons; nicotine metabolites; southern China.