Recent Developments in the Determination of Biomarkers of Tobacco Smoke Exposure in Biological Specimens: A Review

Biomarkers of Waterpipe Tobacco Smoke Exposure: A Systematic Review and Meta-Analysis

INTRODUCTION

The prevalence of waterpipe tobacco smoking is increasing globally. Biomarkers of waterpipe tobacco smoke (WTS) exposure are less studied.

AIMS AND METHODS

To identify the types of biomarkers of WTS exposure and estimate changes in biomarker concentrations pre- to post-WTS exposure. PubMed, Embase, Web of Science, CINAHL Plus, PsycINFO, and Cochrane Library were searched for studies up to April 24, 2023. The types of biomarkers were identified. Random-effects models were used to estimate changes in biomarker concentrations pre- to post-WTS exposure.

RESULTS

Seventy-three studies involving 3755 participants exposed to WTS (49% male, mean age: 24.8 years) and 11 types of biomarkers of WTS exposure were identified. The biomarkers included tobacco alkaloids, expired carbon monoxide (eCO), carboxyhemoglobin (COHb), tobacco-specific nitrosamines, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, unmetabolized VOCs, unmetabolized PAHs, furan metabolites, and heterocyclic aromatic amines. Compared with pre-WTS exposure, eCO (breath; mean difference [MD] 27.00 ppm; 95% confidence interval [CI]: 20.91 to 33.08), COHb (blood; MD 4.30%; 95%CI: 2.57 to 6.03), COHb (breath; MD 7.14%; 95%CI: 4.96 to 9.31), nicotine (blood; MD 8.23 ng/mL; 95%CI: 6.27 to 10.19), and cotinine (urine; MD 110.40 ng/mL; 95%CI: 46.26 to 174.54) significantly increased post-WTS exposure.

CONCLUSIONS

Biomarkers of WTS exposure were systematically identified. The similarity between the biomarkers of WTS exposure and those of cigarette smoke and higher concentrations of some biomarkers post-WTS exposure underscore the need for further research on applying biomarkers in surveillance, interventions, and regulations to mitigate the harms of waterpipe tobacco smoking.

IMPLICATIONS

This study provides the first comprehensive overview of biomarkers investigated and available for assessing WTS exposure and their concentration changes in the human body. Researchers can use biomarkers such as eCO, COHb, nicotine, and cotinine to measure the health risks associated with WTS exposure and objectively evaluate the effectiveness of public health interventions aimed at reducing waterpipe tobacco smoking. Public health policymaking can also be informed through increased biomarker concentrations following WTS exposure, to implement regulations and public health education campaigns on limiting or preventing waterpipe tobacco smoking.

Occupational second-hand smoke exposure: a comparative shotgun proteomics study on nasal epithelia from healthy restaurant workers

Non-smokers exposed to second-hand smoke (SHS) present risk of developing tobacco smoke-associated pathologies. To investigate the airway molecular response to SHS exposure that could be used in health risk assessment, comparative shotgun proteomics was performed on nasal epithelium from a group of healthy restaurant workers, non-smokers (never and former) exposed and not exposed to SHS in the workplace. HIF1α-glycolytic targets (GAPDH, TPI) and proteins related to xenobiotic metabolism, cell proliferation and differentiation leading to cancer (ADH1C, TUBB4B, EEF2) showed significant modulation in non-smokers exposed. In never smokers exposed, enrichment of glutathione metabolism pathway and EEF2-regulating protein synthesis in genotoxic response were increased, while in former smokers exposed, proteins (LYZ, ATP1A1, SERPINB3) associated with tissue damage/regeneration, apoptosis inhibition and inflammation that may lead to asthma, COPD or cancer, were upregulated. The identified proteins are potential response and susceptibility/risk biomarkers for SHS exposure.

Association of environmental tobacco smoke exposure with chronic constipation: a nationwide survey (NHANES 2005-2010)

Environmental tobacco smoke (ETS) exposure has been proven to induce digestive diseases such as hepatic steatosis, cirrhosis, and gastrointestinal cancer, yet little is known about the link between ETS exposure and constipation. This study aimed to investigate the impact of ETS exposure on the risk of chronic constipation in adults aged 20 years or older. This is a cross-sectional study based on population. A total number of 7705 participants from the National Health and Nutrition Examination Survey (NHANES) 2005-2010 were included. Cotinine, an alkaloid found in tobacco, serves as a reliable and precise biomarker for measuring exposure to ETS. Hence, the categorization of exposure to ETS was conducted based on serum cotinine levels, resulting in four distinct categories. The association between ETS exposure and the risk of constipation was assessed using multivariable restricted cubic spline and logistic regression with odds ratio (OR) and 95% confidence interval (CI). The weighted prevalence of constipation in this study was estimated to be 7.51% based on stool consistency, or 3.11% based on stool frequency. The fully adjusted models indicated a positive correlation between exposure to ETS and constipation as measured by stool frequency, among adults with poor dietary quality (OR (95% CI): moderate exposure: 2.49 (1.05, 5.94); high exposure: 2.36(1.13, 4.95), P for trend = 0.03), while no significant difference was observed in the subgroup with a higher healthy eating index. Furthermore, the log10-transformed serum cotinine level exhibited a non-linear inverted U-shaped association with constipation in individuals with poor dietary quality (P overall = 0.0207, P non-linear = 0.0427). Conversely, a J-shaped non-linear relationship was observed in the subgroup with a higher healthy eating index (P overall = 0.0028, P non-linear = 0.0036). Our results show that ETS exposure appears to be positively associated with stool frequency-related chronic constipation in adults with poor dietary quality.

Advancing the use of molecularly imprinted polymers in bioanalysis: the selective extraction of cotinine in human urine

Aim: To characterize a molecularly imprinted polymer via precipitation polymerization for the extraction of cotinine in urine. Methods: The polymer was created via precipitation polymerization. Physical characteristics of the polymer were assessed via scanning electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. The polymer adsorption capacity was assessed and an solid-phase extraction method from urine by LC-MS/MS was developed. Results: The polymer had small, spherical morphology and little thermal decomposition. The extraction method yielded cotinine recoveries of 77-103% in urine. The molecularly imprinted polymer adsorption capacity for cotinine was 448.2 ± 2.1 μg/mg. Common interferants did not affect cotinine's extraction. Conclusion: The resulting polymer was determined to be specific for cotinine and can be used for the detection of cotinine in urine for clinical samples.

Biomarkers of Electronic Nicotine Delivery Systems (ENDS) Use

This perspective summarizes available evidence on biomarkers of exposure in electronic nicotine delivery system (ENDS) users to aid the overall assessment of the health consequences of using ENDS. Identification of novel biomarkers of exposure specific to ENDS use remains challenging because chemicals emitted from ENDS devices have many familiar sources. The biomarker levels of many tobacco-related toxicants measured in biological samples collected from ENDS users did not differ significantly from non-users, except for nicotine metabolites and a small number of biomarkers of exposure to volatile organic compounds and tobacco-specific tobacco nitrosamines. Several studies have shown that while exposed to nicotine, long-term exclusive ENDS users showed significantly lower levels of toxicant biomarkers than cigarette smokers. Studies have also shown that concurrent users of ENDS and combustible cigarettes ('dual users') are not reducing overall exposure to harmful toxicants compared to exclusive cigarette smokers. Because of an absence of validated ENDS-specific biomarkers, we recommend combining several biomarkers to differentiate tobacco product user groups in population-based studies and monitor ENDS compliance in randomized controlled trials. Using a panel of biomarkers would provide a better understanding of health effects related to ENDS use.

Does a human rights-based approach to harm reduction support commercialized harm reduction? Brief research

In recent years, the tobacco industry has been pushing a narrative that their newer lines of products-including electronic nicotine delivery devices-are offered in part to meet a social responsibility of providing potentially reduced-harm choices to their consumers. While some of the newer tobacco products might potentially be less harmful than combustible tobacco products, there is also significant deviation from the very concept of harm reduction when it is used for such a conspicuously commercialized purpose. The framing of commercialized tobacco harm reduction as a mere consumer preference by the industry is not clearly consistent with the core principles of harm reduction, let alone the human right to health and the highest attainable level of health. A human rights-based approach (HRBA) to harm reduction is a set of principles that frame an effort to respect and promote human rights, including the right to health. Whether the HRBA supports commercialized harm reduction requires study. We review industry materials from 2017 to 2022 to identify themes in the harm reduction narrative of the tobacco industry and analyse those themes using an HRBA to the tobacco harm reduction framework. Using this analysis, the industry's continued marketing of combustible products alongside their "potentially less harmful" products, and preference that their non-combustible products be regulated less strictly than cigarettes and cigars, adulterates the public health principles of harm reduction and undermines the right to health. We conclude that the tobacco industry's commercialized tobacco harm reduction is incompatible with a human rights-based approach to tobacco harm reduction.

Promotion of Smoking Cessation Using the Transtheoretical Model: Short-Term and Long-Term Effectiveness for Workers in Coastal Central Taiwan

Background

Smoking cessation reduces the risk of severe illnesses in the long run and contributes to improving health. This study evaluated the short-term and long-term effectiveness of workplace smoking cessation intervention implemented using the transtheoretical model.

Methods

Participants were assessed at baseline before the intervention and after 6 months and 4 years of follow-ups. Data on changes in participants' perception of smoking prohibition in the workplace, knowledge of the hazards of smoking, attitude towards quitting smoking, and behavior related to tobacco harm prevention were collected.

Results

Results showed the prevalence of smoking cessation was 31.5% (95% CI: 25.4-38.1%) after 6 months and 10.7% (95% CI: 6.9-15.6%) after 4 years. At the abovementioned time points, the prevalence of second-hand smoke exposure, and the proportion of people who demonstrated correct knowledge of smoke hazards initially decreased and then increased. The proportion of participants who had seen or received information about tobacco harm prevention provided in the workplace increased from 75.6% at baseline to 95.6% (increased by 20.0%) after 6 months and finally to 97.2% (increased by 21.6%) after 4 years (P < .001). However, the percentage of participants who hoped their workplace continued to provide smoking cessation services rose from 80.0% at baseline to 93.6% (increased by 13.6%) after 6 months and then fell to 78.0% (decreased by 2.0%) after 4 years (P < .001).

Conclusion

The short-term effectiveness of the transtheoretical model in promoting workplace smoking cessation is substantial, but in the long-term, effectiveness weakens.

Characterization of molecularly imprinted polymers for the extraction of tobacco alkaloids and their metabolites in human urine

Molecularly imprinted polymers (MIPs) are synthetic polymers designed to selectively extract target analytes from complex matrices (including biological matrices). The literature shows that MIPs have a degree of cross-selectivity from analytes within the same class of compounds. A commercially available MIP for tobacco-specific nitrosamines (TSNAs) is designed to be class selective for four TSNA compounds. This study sought to characterize the extent of cross-selectivity of the TSNA MIPs with other tobacco alkaloids. Cross-selectivity and recovery of the SupelMIP™ TSNA SPE cartridges was assessed with N-nitrosonornicotine (NNN), nicotine, cotinine and morphine. Their recoveries were compared with the recoveries of a nonimprinted polymer SPE cartridge, and two traditional SPE cartridges: a Waters mixed-mode cation exchange cartridge and a Waters hydrophilic-lipophilic balance cartridge. NNN and cotinine had the highest recoveries with the MIP cartridge, over 80%, and cotinine samples in urine had >80% recoveries. Nicotine had highly variable recoveries, possibly owing to differing chemical properties from the TSNAs. All three analytes had significantly different recoveries with the MIP cartridges compared with the traditional SPE cartridges. Morphine displayed nonspecific interactions with the MIP cartridges. Utilization of the TSNAs' cross-selectivity allows for simultaneous extraction and identification of multiple tobacco biomarkers using one extraction technique.

Optimization and validation of a procedure using the dried saliva spots approach for the determination of tobacco markers in oral fluid

Exposure to tobacco smoke is one of the most common causes of premature death worldwide and is the cause of 8 million deaths annually. We have developed, optimized, and validated a procedure for the detection of nicotine, cotinine and trans-3-hydroxycotinine (biomarkers of tobacco exposure) in oral fluid using the dried saliva spots sampling approach and gas chromatography coupled to tandem mass spectrometry, thus allowing the distinction between active and passive smokers. For optimization, four parameters were evaluated, namely extraction solvent, extraction solvent volume, extraction time and spots drying time. During method validation, the parameters selectivity, linearity, precision and accuracy, recovery, stability, and dilution factor were assessed. Linearity was obtained for all target analytes in the concentration range of 10-200 ng/mL allowing the quantification of compounds up to 1000 ng/mL considering the dilution factor. The method recoveries ranged from 29.2% to 43.30% for nicotine, 66.60-89.10% for cotinine and 80.30-92.80% for trans-3-hydroxycotinine, while achieving intra-day, inter-day and intermediate precision and accuracy values never higher than 10.37% and ±6.62% respectively for all compounds. The herein described analytical method is the first to allow the determination of tobacco biomarkers in oral fluid using dried saliva spots, which is considered a sensitive, simple and low-cost alternative to conventional methods.

Automated Solid Phase Extraction and Polarity-Switching Tandem Mass Spectrometry Technique for High Throughput Analysis of Urine Biomarkers for 14 Tobacco-related Compounds

Tobacco use is the leading preventable cause of premature disease and death in the United States. Approximately, 34 million U.S. adults currently smoke cigarettes. We developed a method for automated sample preparation and liquid chromatography-tandem mass spectrometry quantitation of 14 tobacco-related analytes: nicotine (NICF), cotinine (COTF), trans-3'-hydroxycotinine (HCTF), menthol glucuronide (MEG), anabasine (ANBF), anatabine (ANTF), isonicoteine (ISNT), myosmine (MYOS), beta-nicotyrine (BNTR), bupropion (BUPR), cytisine (CYTI), varenicline (VARE), arecaidine (ARD), and arecoline (ARL). The method includes automated solid-phase extraction using customized positive-pressure functions. The preparation scheme has the capacity to process a batch of 96 samples within 4 h with greater than 88% recovery for all analytes. The 14 analytes, separated within 4.15 min using reversed-phase liquid chromatography, were determined using a triple-quadrupole mass spectrometer with atmospheric-pressure chemical ionization and multiple reaction monitoring in negative and positive ionization modes. Wide quantitation ranges, within 1.2-72,000 ng/mL, were established especially for COTF, HCTF, MEG, and NICF to quantify the broad range of biomarker concentrations found in the U.S. population. The method accuracy is above 90% while the overall imprecision is below 7%. Finally, we tested urine samples from 90 smokers and observed detection rates of over 98% for six analytes with urinary HCTF and MEG concentrations ranging from 200-14,100 and 60-57,100 ng/mL, respectively. This high throughput analytical process can prepare and analyze a sample in 9 min and along with the 14-compound analyte panel can be useful for tobacco-exposure studies, in smoking-cessation programs, and for detecting changes in exposure related to tobacco products and their use.