Tobacco smoking as an endocrine disrupting chemical: An assessment through biological monitoring.

Introduction: Tobacco smoke is a mixture of endocrine disrupting chemicals (EDCs), which may accelerate biological ageing.

Methods: Within this cross-sectional study we recruited adult and adolescent subjects (2013-2014) and performed biological monitoring to clarify health end points of tobacco smoking between adolescents and adults (n=620) with exposure biomarkers, i.e. CO, urinary cotinine, t,t-muconic acid (TTMA), malondialdehyde (MDA), and obtained information of behavioral factors and tobacco addiction status in South Korea. We also analyzed the 96 SNPs for metabolism, addiction, and expression differences and compared mtDNA abnormalities in buccal and blood cells.

Results: There was an association between tobacco smoking and oxidative stress with urinary cotinine and MDA levels. Youth smokers showed lower frequency in some of mtDNA alteration, SNPs for consistent bases between buccal and blood cells, than youth non-smokers or adult smokers. Among the SNPs, the polymorphisms on SULT1A1, DRD2, and ADH1B were related to multiple of the above exposure biomarkers. Interestingly, urinary MDA or TTMA in youth were similar to those in adults (MDA, 2.7 ± 1.5 vs 2.4 ± 1.3 μM; TTMA, 74.1 ± 129.9 vs 98.8 ± 126.1 μg/L), although urinary cotinine levels were approximately four-fold lower in youth than adults (0.1 ± 0.4 vs 0.6 ± 0.9 mg/L; p<0.0001). Urinary MDA, an oxidative stress biomarker, were negatively associated with the growth rate among the adolescents.

Conclusions: The present biological monitoring study assessed the impact of combustible cigarette smoking with various exposure, susceptibility and response biomarkers to clarify how tobacco smoking differently affects adolescents and adults in South Korea.