Dr. Juan Manuel Sánchez is coauthor of the paper entitled 2,5-Dimethylfuran as a Validated Biomarker of Smoking Status, together with Dr. Mar Castellanos (Department of Neurology of the Complejo Hospitalario Universitario de A Coruña and Instituto de Investigación Biomédica de A Coruña, Spain), Dr. Rosa Suñer (Department of Nursing, University of Girona) and Dr. José M. Fernández-Real (Department of Diabetes, Endocrinology and Nutrition, Dr. Josep Trueta University Hospital, Spain). The paper has been published in the Nicotine & Tobacco Research journal.

The authors explain that exposure biomarkers are required in tobacco use studies to accurately assess smoking status since self-reporting usually results in misclassification estimates. This study uses breath analysis and assesses some volatile organic compounds (VOCs) as potential biomarkers of tobacco smoke exposure.

Regarding the methodology, forced-expiratory breath samples were obtained from 377 volunteers (174 smokers and 203 nonsmokers). Exhaled breath levels of different VOCs previously related to tobacco smoke were evaluated. The toluene-to-benzene ratio was evaluated as this ratio has been found to be different in atmospheric samples and tobacco smoke emissions. Finally, breath analyses from 64 patients attending a clinical practice were evaluated and the results were compared to their self-reporting status.

Univariate analysis shows that all compounds evaluated gave significant differences (p < .001). Receiver operating characteristic (ROC) curves suggest that xylenes and toluene are not able to accurately determine smoking status, and benzene and the T/B ratio present potential utility in certain conditions. The highest discriminant capacity was obtained for 2,5-dimethylfuran (AUC = 0.982, 95% confidence interval : 0.969–0.995), with a cut-off value of 0.016 ppbv (sensibility = 0.965, specificity = 0.896). Drinking coffee was the only confounding parameter that can give low breath levels for this compound. The evaluation of the results obtained from the patients attending a clinical practice showed that 8% of people who claim to be nonsmokers hid their real smoking status.

The authors point out the implications of this study. Analysis of 2,5-dimethylfuran in breath samples results in a simple and fast method for the determination of the smoking status of a person. This methodology presents multiple advantages as it is neither invasive nor embarrassing for patients attending clinical practices. Moreover, analysis of biomarkers in breath samples is simpler and faster than using conventional methods based on urine or blood analysis.

The study concludes that the determination of 2,5-dimethylfuran in breath samples is a good and simpler alternative to conventional blood or urine tests for assessing smoking status.

This study was conducted within the “biomedicine” research line of the Analytical and Environmental Chemistry research group and was supported by the University of Girona (MPCUdG2016/100).