Correlation between biomarkers of exposure, effect and potential harm in the urine of electronic cigarette users. Issue 1 (19th February 2020)

• Record Type: Journal Article
• Authors: Sakamaki-Ching, Shane; Williams, Monique; Hua, My; Li, Jun; Bates, Steve M; Robinson, Andrew N; Lyons, Timothy W; Goniewicz, Maciej Lukasz; Talbot, Prue
• Is Part Of: BMJ open respiratory research. Volume 7:Issue 1(2020)
• Publication Date: 2020-02-19
• Subjects: electronic cigarettes -- cigarettes -- non-smokers -- metals -- biomarkers; Respiratory organs -- Diseases -- Periodicals; Respiratory organs -- Diseases -- Treatment -- Periodicals; Respiratory therapy -- Periodicals; 616.2005
• DOI: 10.1136/bmjresp-2019-000452
• Languages: English
• ISSNs: 2052-4439

Abstract

Abstract : Objectives: To determine if urinary biomarkers of effect and potential harm are elevated in electronic cigarette users compared with non-smokers and if elevation correlates with increased concentrations of metals in urine. Study design and setting: This was a cross-sectional study of biomarkers of exposure, effect and potential harm in urine from non-smokers (n=20), electronic cigarette users (n=20) and cigarette smokers (n=13). Participant's screening and urine collection were performed at the Roswell Park Comprehensive Cancer Center, and biomarker analysis and metal analysis were performed at the University of California, Riverside. Results: Metallothionein was significantly elevated in the electronic cigarette group (3761±3932 pg/mg) compared with the non-smokers (1129±1294 pg/mg, p=0.05). 8-OHdG (8-hydroxy-2′-deoxyguanosine) was significantly elevated in electronic cigarette users (442.8±300.7 ng/mg) versus non-smokers (221.6±157.8 ng/mg, p=0.01). 8-Isoprostane showed a significant increase in electronic cigarette users (750.8±433 pg/mg) versus non-smokers (411.2±287.4 pg/mg, p=0.03). Linear regression analysis in the electronic cigarette group showed a significant correlation between cotinine and total metal concentration; total metal concentration and metallothionein; cotinine and oxidative DNA damage; and total metal concentration and oxidative DNA damage. Zinc was significantly elevated in the electronic cigarette users (584.5±826.6 µg/g) compared with non-smokers (413.6±233.7 µg/g, p=0.03). Linear regression analysis showed a significant correlation between urinary zinc concentration and 8-OHdG in the electronic cigarette users. Conclusions: This study is the first to investigate biomarkers of potential harm and effect in electronic cigarette users and to show a linkage to metal exposure. The biomarker levels in electronic cigarette users were similar to (and not lower than) cigarette smokers. In electronic cigarette users, there was a link to elevated total metal exposure and oxidative DNA damage. Specifically, our results demonstrate that zinc concentration was correlated to oxidative DNA damage.