ORIGINAL RESEARCH |
https://doi.org/10.5005/jp-journals-10015-2415 |
Comparison of Carbon Monoxide Breath Levels in Smokers and Nonsmokers: A Cross-sectional Study
1–7Department of Oral Medicine and Radiology, Sibar Institute of Dental Sciences (SIDS), Guntur, Andhra Pradesh, India
Corresponding Author: Sethu M Saranu, Department of Oral Medicine and Radiology, Sibar Institute of Dental Sciences (SIDS), Guntur, Andhra Pradesh, India, Phone: +91 9963428526, e-mail: drsethuphanindra@gmail.com
Received: 03 March 2024; Accepted: 05 April 2024; Published on: 17 May 2024
ABSTRACT
Aim: To assess and compare the carbon monoxide (CO) levels in smokers and nonsmokers.
Materials and methods: The CO levels of 200 participants (150 smokers and 50 nonsmokers) who visited the tobacco cessation center (TCC) at the Sibar Institute of Dental Sciences (SIDS), Guntur, Andhra Pradesh, India, were analyzed.
Results: The exhaled CO levels of smokers and nonsmokers were 7.40 ± 5.90 and 1.06 ± 0.71, respectively. A cutoff of 2.5 ppm or above was given with 81% sensitivity and 72% specificity to distinguish smokers from nonsmokers. There was also a significant positive correlation between CO levels and daily cigarette consumption and CO levels and duration of smoking, with r = 0.63, p = 0.0001 and r = 0.272, p = 0.001, respectively.
Conclusion: The purpose of the current study is to educate people regarding the ill effects caused by smoking and emphasize the role of using a breath analyzer to determine one’s smoking status by providing visual proof of CO exposure and the necessity of quitting.
Clinical significance: To educate and create awareness among smokers through behavior counseling and CO breath analyzers as well as to enhance the lifestyle by preventing the ill effects of CO on the respiratory system and the environment.
How to cite this article: Peetha K, Saranu SM, Yalamanchali S, et al. Comparison of Carbon Monoxide Breath Levels in Smokers and Nonsmokers: A Cross-sectional Study. World J Dent 2024;15(4):316–319.
Source of support: Nil
Conflict of interest: None
Keywords: Carbon monoxide, Cross-sectional study, Passive smoking, Smokers, Tobacco
INTRODUCTION
Tobacco is one of the most abused drug substances in the world. Over the last decade, there has been a steady increase in the rate of tobacco consumption and the number of smokers worldwide, and it is the leading cause of premature death in developing countries. According to the Global Adult Tobacco Survey conducted in 2016–2017, the overall prevalence of smoking tobacco use is 10.38%. According to World Health Organization statistics, over 8 million people die every year due to cigarette smoke, where 1.2 million of those deaths are the consequence of exposure to secondhand smoke.1,2
Smoked tobacco products include cigarettes, chutta, beedi, water pipes, electronic cigarettes, and many others. Smokeless tobacco products are khaini, ghutkha, pan masala, and others. Smoking form of tobacco releases various chemicals that are biologically detrimental, and it is abundantly obvious from the findings of numerous research that over 7,000 compounds have been established to be present in tobacco smoke, which include carbon monoxide (CO), benzene, formaldehyde, polycyclic aromatic hydrocarbons (PAHs), hydrogen cyanide, nitrosamines, and many others.1,2 These components are responsible for several health effects, especially on the lungs. In smokers, CO plays a major role in affecting the respiratory system.
Carbon monoxide is an odorless, tasteless, colorless, and poisonous gas produced from the incomplete combustion of organic compounds.3,4 It is also formed in the burnt cigarette by oxidation of nonvolatile carbonaceous matter, by reduction of CO2, and by pyrolysis of nonvolatile organic matter, primarily cellulose and cellulose-like materials.5,6 It behaves similarly to oxygen in the body but has around 200–260 times higher affinity to hemoglobin (Hb) and forms as carboxy Hb (COHb) in the blood. In acute conditions, high levels of CO can cause hypoxia and symptoms like headaches, nausea, exhaustion, respiratory problems, tissue damage, and even death.5,7-10 In chronic conditions, accumulation of CO in the body causes serious effects involving respiratory, cardiovascular, and renal systems.11-14
In view of the fact that the rise in tobacco-related morbidity and mortality, it is crucial to counsel the patients regarding the ill effects of smoking tobacco. Oral physicians are the first to diagnose any changes in the oral mucosa and have a major role in the cessation of this deleterious habit. Behavior counseling is frequently used as the first step in tobacco cessation centers (TCCs), and the disadvantage is that there has been no progress in the effectiveness of behavioral treatments for many years, and one of the primary reasons is a lack of a shared language for expressing the content. It would be more effective when we use additional devices/tools, such as a CO breath analyzer, which gives personalized feedback.15,16
Since cigarette smoking is strongly correlated with the amounts of CO in the body, measuring CO levels can be a significant aid in patient education. There are both invasive and noninvasive ways to do this. The invasive method includes measuring CO levels in blood or urine.17 As these tests are invasive, time-consuming, and nonimmediate methods to determine CO levels, measuring exhaled CO levels would provide a noninvasive, immediate, and quick way of determining one’s smoking status.
MATERIALS AND METHODS
A total of 200 subjects who visited the Department of Oral Medicine and Radiology at Sibar Institute of Dental Sciences (SIDS), Guntur, Andhra Pradesh, India, were randomly selected. It is a cross-sectional study, and the duration is of 3 months. Out of 200 subjects, 150 were smokers and categorized as group I, while the remaining 50 were nonsmokers, categorized as group II based on convenience. The study was reviewed and approved by the Ethical Committee of Sibar Institute of Dental Sciences (Pr.174/IEC/SIBAR/2022), Guntur, Andhra Pradesh, India. It is a cross-sectional study, and the duration of the study was 3 months. A detailed case history including age, gender, the status of health, especially respiratory disorders, and smoking habit (frequency and duration) was taken and did not include the time of the last puff of smoke and the time of assessment of exhaled CO levels done was not uniform, a form of tobacco (cigarette, chutta, and beedi) and any smoke exposure near workplace/home was taken, and informed consent was taken from all the subjects prior to the procedure. A cigarette smoker was defined as someone who smoked at least one cigarette each day.11 Subjects with the habit of smoking were taken as smokers and without smoking habit as nonsmokers.11 Among the nonsmokers taken, few were identified as passive smokers who were in close vicinity to smoke exposure.
Breath CO levels were assessed using a Bedfont PICO smoke analyzer. Bedfont smoke analyzer is reported to correlate closely with blood COHb concentration in smokers and nonsmokers.14 The procedure was done at the TCC in the Department of Oral Medicine and Radiology, Sibar Institute of Dental Sciences (SIDS), Guntur, Andhra Pradesh, India. All the subjects were given instructions regarding the procedure and to standardize the breath being analyzed by the smoke analyzer; every subject was asked to exhale completely, inhale fully and asked to hold the breath for 15–20 seconds and exhale slowly into a disposable sterile breath mouthpiece attached to the smoke analyzer device and the CO levels were displayed on the device.18 Obtained data was recorded and entered into an Excel spreadsheet. Data was statistically analyzed and depicted in the form of graphs and bar diagrams (Fig. 1). All statistical analyses were done using Statistical Package for the Social Sciences v10.0 software. Results were expressed as mean ± standard deviation (SD).
Fig. 1: Study flowchart
RESULTS
Breath CO levels were assessed in a total of 200 subjects; 150 of them were smokers (150 men; 0 women; mean age 44.28 ± 15.16), and 50 of them were nonsmokers (35 men, 15 women; mean age 31.6 ± 8.84). As shown in Figure 2, the mean exhaled CO level was 7.40 ± 5.90 ppm for smokers and 1.06 ± 0.71 ppm for nonsmokers. Hence, the mean exhaled CO levels were significantly higher in smokers compared to nonsmokers.
Fig. 2: The CO concentrations of exhaled air in smokers (n = 150), nonsmokers (n = 50)
The mean daily cigarette consumption (frequency) for smokers was 9.41 ± 10.92 per day. Results showed that there was a strong correlation between the breath CO levels and frequency of smoking (r = 0.635; p = 0:0001) and breath CO levels and duration of smoking (r = 0:272; p = 0:001) (Figs 3 and 4).
Fig. 3: Exhaled CO levels and the number of cigarettes smoked in a day (frequency)
Fig. 4: Exhaled CO levels and duration of smoking
Results showed that the cutoff point between smokers and nonsmokers was 2.5 ppm of CO levels with a sensitivity of 81% and specificity of 72%. Our study showed that smokers had higher exhaled CO levels than nonsmokers. Using a smoke analyzer for monitoring breath CO levels was an immediate, effective, and self-motivating tool for a person to quit smoking than tobacco cessation counseling alone.
Among the nonsmokers in our study, subjects who were in the vicinity of smokers were classified as passive smokers. For passive smokers (n = 12), the mean exhaled CO level was 1.53 ± 0.51 ppm, and for nonsmokers (n = 38), it was 0.84 ± 0.73 ppm. Hence, passive smokers had higher mean CO levels than nonsmokers.
Among the smokers, the mean exhaled CO levels in different types of products like cigarette (n = 136), chutta (n = 4), and beedi (n = 10) were 7.88 ± 5.97, 2.5 ± 1.73, and 2.9 ± 2.93, respectively (Fig. 5). As a result, participants who smoked cigarettes most frequently (90.6%) considerably had higher mean exhaled CO levels followed by beedi (6.8%) and chutta (2.6%).
Fig. 5: Exhaled CO levels in cigarettes (n = 135), chutta (n = 4), and beedi (n = 10)
DISCUSSION
Tobacco users are on the rise all over the world, but most people are unaware of the harmful consequences brought on by the chemicals or gases generated by cigarette smoke. According to the National Center for Health Statistics, a smoker is an adult who has smoked 100 cigarettes in his or her lifetime and who currently smokes cigarettes. As a part of raising awareness among them, behavior counseling for quitting smoking at TCCs may have a significant influence on a few smokers. However, along with the counseling, utilizing noninvasive smoke analyzer monitors to visually demonstrate the dangerous habit they are engaged in could have a psychological influence, which might lead to an effective method of helping people break their habit and lead a healthy life. This research demonstrates the noninvasive method of CO analysis by using a CO breath monitor.
Deveci reported that the mean exhaled CO level was 17.13 ± 8.50 ppm for healthy smokers and 3.61 ± 2.15 ppm for healthy nonsmokers.11 Similarly, in this study, exhaled CO level with the PICO smoker analyzer was significantly higher in smokers compared to the nonsmokers, with mean values of 7.40 ± 5.90 ppm and 1.06 ± 0.71 ppm for smokers and nonsmokers, respectively.
Cunnington et al. demonstrated that the average breath CO levels increased in direct proportion to the frequency of cigarettes smoked.19 Our results also showed that there was a significantly positive correlation between daily consumption of cigarettes, duration of smoking and CO levels in smokers.
In our study, the cutoff was 2.5 ppm to separate smokers from nonsmokers, giving 81% sensitivity and 72% specificity. Deveci et al. reported that the optimal cutoff was 6.5 ppm, giving 90% sensitivity and 83% specificity.11 Similarly, Middleton and Morice reported that the optimal cutoff was 6 ppm with selectivity of 96% and sensitivity of 94%.16 Crowley et al. also reported that a breath CO level with a cutoff of 48 ppm was strongly associated with current smoking status. To differentiate smokers from nonsmokers, the cutoff was about 7 ppm with sensitivity 93% and specificity 95%.20
In the present study, the mean exhaled CO levels were 1.53 ± 0.51 ppm in passive smokers. Deveci et al. reported that exhaled CO levels were 5.20 ppm in passive smokers,11 and studies reported that the exhaled breath CO levels were higher in passive smokers compared to nonsmokers.21-26
The present study demonstrated the exhaled CO levels in three types of tobacco products and showed significantly higher CO levels in cigarettes, followed by beedi and chutta, with mean values of 7.88, 2.9, and 2.5 ppm, respectively.
Smoke analyzers, or breath analyzer monitors, may be used in regular dental practice or in hospitals for smokers to raise awareness and lower the prevalence of premature deaths globally. The limitations of this study include a small sample size and not including other forms of smoked tobacco. This study did not include the time of the last puff of smoke and did not record the time of breath analysis. Taking a large sample size will help in quitting and creating awareness among a large number of smokers and also passive smokers.
CONCLUSION
The present study concluded that the exhaled CO levels were higher in smokers than nonsmokers. Among the nonsmokers, few passive smokers were identified, and their exhaled CO levels were higher than those of nonsmokers. This study also demonstrated that smokers had higher levels of exhaled CO than chutta and beedi users, respectively.
Clinical Significance
The clinical significance of the present study was to educate and create awareness among smokers through behavior counseling and CO breath analyzers, as well as to enhance lifestyle by preventing the ill effects of CO on the respiratory system and the environment.
ORCID
Samata Yalamanchali https://orcid.org/0000-0003-1603-2253
Shruthi Pingili https://orcid.org/0000-0003-4321-1839
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