Urinary Cotinine as a Biomarker of Cigarette Smoke Exposure: A Method to Differentiate Among Active, Second-Hand, and Non-Smoker Circumstances

Abstract

Objective: To review the literature on the use of urinary cotinine as a biological marker of cigarette smoke exposure. Methods: Narrative review of original and review articles on the topic of interest, published in Portuguese or English by June 2018, and selected in the following online databases: PubMed and Virtual Health Library (VHL). Results: Urinary cotinine is usually the recommended biomarker to estimate exposure to cigarette smoke, and can be used alone or, preferably, in association with questionnaires. Different analytical techniques can be used to quantify urinary cotinine and are differently performed because of urine sample interfering factors. Conclusion: The precise classification of smoking status is essential. It is advisable to use objective measurements regarding smoking habits since self-reported smoking may not always represent the true smoking status of the individual, particularly in groups that are more vulnerable to omitting the information of questionnaries, in addition, it has possible biases of memory. The accurate assessment of smoking is crucial to improve clinical management and counseling for different diseases as well as the establishment of preventive strategies. So, the use of urinary cotinine as a biomarker of cigarette smoke exposure seems to be a suitable assay to distinguish non-smokers from passive and active smokers.

High Urinary Cotinine Levels and Low Academic Performance of Elementary School Students in Families with Careless Smoking Habits

“…Urinary cotinine levels can be used to differentiate between smokers, passive smokers, and non-smokers. 18 However, due to differences in the technique for measuring urinary cotinine levels, to the best of the authors' knowledge, no fixed cut-off point is generally accepted to distinguish the three categories above. The consistent results showed that passive smokers (recipients of SHS and THS exposure from smokers) have significantly higher urinary cotinine levels than non-smokers.…”

Household smoking impact on the oral health of 5- to 7-years-old children

“…However, urine concentrations of cotinine possess four- to six folds the average concentration than that of saliva or blood. Accordingly, urine can be considered a noninvasive, highly sensitive matrix to detect even minimal concentrations caused by tobacco smoke exposure [ 31 ]. The number of cigarettes consumed by the smoker was found to have an association with the cotinine mean value in the urine of passive smokers [ 11 ].…”

“…The results of the present study revealed increased susceptibility to HSPM in children subjected to household smoking where limited impact of smoking form and pattern has been identified to affect the distribution of HSPM. Hypomineralization of the second primary molar (HSPM) describes a qualitative defect affecting tooth enamel that appears during development as well as demarcated opacity with possible enamel breakdown affecting one- to four-primary second molars [ 31 ]. The affected enamel was found to be porous and more liable to break down soon post-tooth eruption into the oral cavity.…”

Nutri-phenethyl Isothiocyanate Jelly Promotes Detoxification of a Tobacco-specific Oral Carcinogen in Male Active Cigarette Smokers

“…KA0930, Abnova, Taiwan), as described previously. 17 Ten microliters of each standard, control, or sample was pipetted into 96-well plates in duplicate by using a repeating pipette (Multipette, Eppendorf, Hamburg, Germany). Then, 100 µL of the enzyme conjugate was added to each well.…”