The measurement of exhaled carbon monoxide in healthy smokers and non-smokers

Echogenicity of the carotid arterial wall in active smokers

This pilot study evaluated associations between carotid wall echogenicity, cardiovascular disease (CVD) risk factors, and three markers of smoking heaviness in a cohort of active smokers. Common carotid artery (CCA) grayscale median (GSM) values were measured from sonographic images. Univariable correlations and exploratory multivariable models were used to determine associations between CCA GSM, CVD risk factors, and measures of smoking heaviness. CCA GSM was measured in 162 smokers and was correlated inversely with cigarettes smoked/day (r=-0.16, p=0.048), pack-years (r=-0.204, p=0.009), CVD risk factors such as age, male sex, waist circumference, and low-density lipoprotein cholesterol (all p≤0.03) and positively with high-density lipoprotein cholesterol (p<0.001). Associations between CCA GSM and smoking heaviness markers were not statistically significant after adjustment for traditional risk factors. The results from this pilot study demonstrate the feasibility of measuring the GSM value of the CCA far wall and its association with measures of smoking heaviness and traditional CVD risk factors among current smokers.

Electronic nicotine delivery system use behaviour and loss of autonomy among American Indians: results from an observational study

OBJECTIVE

American Indians (AI) have a high prevalence of electronic nicotine delivery system (ENDS) use. However, little information exists on (ENDS) use, either alone or in combination with cigarettes (dual use), among AI. The objective of this small-scaled study was to examine use behaviours and dependence among exclusive ENDS users and dual users of AI descent. Exclusive smokers were included for comparison purposes.

SETTING

Oklahoma, USA.

PARTICIPANTS

Adults of AI descent who reported being exclusive ENDS users (n=27), dual users (n=28) or exclusive cigarette smokers (n=27).

MEASURES

Participants completed a detailed questionnaire on use behaviours. The Hooked on Nicotine Checklist (HONC) was used to assess loss of autonomy over cigarettes and was reworded for ENDS. Dual users completed the HONC twice. Sum of endorsed items indicated severity of diminished autonomy. Comparisons were made with non-parametric methods and statistical significance was defined as P<0.05.

RESULTS

Median duration of ENDS use was 2 years among ENDS users and 1 year among dual users. Most ENDS and dual users reported <20 vape sessions per day (72.0% vs 72.0%) with ≤10 puffs per vape session (70.4% vs 69.2%). Severity of diminished autonomy over ENDS was similar among ENDS and dual users (medians: 4 vs 3; P=0.6865). Among dual users, severity of diminished autonomy was lower for ENDS than cigarettes (medians: 3 vs 9; P=<0.0001). Comparing ENDS users with smokers, ENDS users had a lower severity of diminished autonomy (4 vs 8; P=0.0077). Comparing dual users with smokers, median severity of diminished autonomy over cigarettes did not differ (P=0.6865).

CONCLUSIONS

Severity of diminished autonomy was lower for ENDS than cigarettes in this small sample of AI. Future, adequately powered studies should be conducted to fully understand ENDS use patterns and dependence levels in this population.

Levels of exhaled carbon monoxide measured during an intervention program predict 1-year smoking cessation: a retrospective observational cohort study

Life-long smoking cessation is a critical public health objective, but it is difficult for numerous people. This study aimed to identify the independent predictors of 1-year abstinence in smokers motivated to quit and participating in an intervention program. This 6-year retrospective observational cohort study was conducted in smokers who participated in an intervention program. The exhaled carbon monoxide (CO) was sequentially measured on day 1, 8, 15, and 22 of the intervention program. The primary outcome measure was smoking status at 1 year of follow-up. A total of 162 participants were enrolled and divided into a successful quit group (n = 52) and unsuccessful quit group (n = 110). Using a multivariate logistic regression analysis, we reported that the intention to quit (adjusted odds ratio [AOR] = 1.475, 95% confidence interval [CI] = 1.169-1.862, P-value = 0.001), varenicline use (AOR = 3.199, 95% CI = 1.290-7.934, P -value = 0.012) and the exhaled CO level on day 8 (AOR = 0.937, 95% CI = 0.885-0.992, P-value = 0.025) independently predicted 1-year smoking cessation. Moreover, the level of exhaled CO < 4.5 parts per million on day 8 significantly predict successful 1-year smoking cessation (area under curve 0.761, sensitivity 88.2%, and specificity 57.8%, P-value < 0.001). These independent predictors including intention to quit, varenicline use, and exhaled CO level on day 8, may help primary care physicians rearrange resources and refine the strategies for intervention programs to achieve a higher rate of long-term smoking cessation.

QUITTING SMOKING

IDENTIFYING PREDICTORS OF SUCCESS: Researchers in Korea identify key predictors that pinpoint people most likely to quit smoking successfully during intervention programs. Millions are spent each year supporting people to quit smoking. However, successful quitters remain in the minority, with only 9-35 per cent of those in intervention programs abstaining for at least a year. Hsin-Kuo Ko at Taipei Veterans General Hospital and co-workers identified key independent indicators of successful abstinence in 162 smokers attending an intervention program. Alongside having a high intention to quit and using varenicline medication, a potential predictor is having an exhaled carbon monoxide (CO) level of less than 4.5 parts-per-million by day 8 of the course. Exhaled CO is higher in smokers than in non-smokers. Measuring CO levels one week into courses may be a useful biomarker to identify those fully committed to quit.

Metabolomic Fingerprinting in Various Body Fluids of a Diet-Controlled Clinical Smoking Cessation Study Using a Validated GC-TOF-MS Metabolomics Platform

Untargeted GC-TOF-MS analysis proved to be a suitable analytical platform to determine alterations in the metabolic profile. Several metabolic pathways were found to be altered in a first clinical study comparing smokers against nonsmokers. Subsequently, we conducted a clinical diet-controlled study to investigate alterations in the metabolic profile during the course of 3 months of smoking cessation. Sixty male subjects were included in the study, and plasma, saliva, and urine samples were collected during four 24 h stationary visits: at baseline, while still smoking, after 1 week, after 1 month, and after 3 months of cessation. Additionally, subjects were monitored for their compliance by measurements of CO in exhaled breath and salivary cotinine throughout the study. GC-TOF-MS fingerprinting was applied to plasma, saliva, and urine samples derived from 39 compliant subjects. In total, 52 metabolites were found to be significantly altered including 26 in plasma, 20 in saliva, and 12 in urine, respectively. In agreement with a previous study comparing smokers and nonsmokers, the fatty acid and amino acid metabolism showed significant alterations upon 3 months of smoking cessation. Thus these results may indicate a partial recovery of metabolic pathway perturbations, even after a relatively short period of smoking cessation.

Cigarette smoking is associated with amplified age-related volume loss in subcortical brain regions

BACKGROUND

Magnetic resonance imaging studies of cigarette smoking-related effects on human brain structure have primarily employed voxel-based morphometry, and the most consistently reported finding was smaller volumes or lower density in anterior frontal regions and the insula. Much less is known about the effects of smoking on subcortical regions. We compared smokers and non-smokers on regional subcortical volumes, and predicted that smokers demonstrate greater age-related volume loss across subcortical regions than non-smokers.

METHODS

Non-smokers (n=43) and smokers (n=40), 22-70 years of age, completed a 4T MRI study. Bilateral total subcortical lobar white matter (WM) and subcortical nuclei volumes were quantitated via FreeSurfer. In smokers, associations between smoking severity measures and subcortical volumes were examined.

RESULTS

Smokers demonstrated greater age-related volume loss than non-smokers in the bilateral subcortical lobar WM, thalamus, and cerebellar cortex, as well as in the corpus callosum and subdivisions. In smokers, higher pack-years were associated with smaller volumes of the bilateral amygdala, nucleus accumbens, total corpus callosum and subcortical WM.

CONCLUSIONS

Results provide novel evidence that chronic smoking in adults is associated with accelerated age-related volume loss in subcortical WM and GM nuclei. Greater cigarette quantity/exposure was related to smaller volumes in regions that also showed greater age-related volume loss in smokers. Findings suggest smoking adversely affected the structural integrity of subcortical brain regions with increasing age and exposure. The greater age-related volume loss in smokers may have implications for cortical-subcortical structural and/or functional connectivity, and response to available smoking cessation interventions.

The Importance of Filter Collection for Accurate Measurement of Cigarette Smoking

OBJECTIVES

We examined the impact of cigarette filter collection on reports of cigarettes per day (CPD) versus self-reported CPD and to assess the utility of a pre-intervention baseline period in smoking studies.

METHODS

Using baseline data from 522 non-treatment seeking smokers, we assessed differences in self-reported CPD via phone screen (CPD PS) and during baseline (CPD BL). We analyzed self-reported cigarette measures to predict carbon monoxide (CO), a measure of smoke exposure.

RESULTS

On average, CPD PS was 2.8 CPD more than CPD BL, and reporting multiples of 10 were more often found in CPD PS compared with CPD BL (54.7% vs17.2%, respectively). CPD BL was more strongly associated with CO than self-report CPD. Number of cigarettes smoked today, time since last cigarette, and nicotine dependence were significantly associated with CO.

CONCLUSIONS

CPD BL using filter collection is a more accurate measure of cigarette consumption than self-report, which may have implications for assessment of nicotine dependence. When feasible, studies should include a pre-intervention baseline period for comparison data with study outcomes. In addition to CPD BL, studies should assess time since last cigarette and the number of cigarettes smoked today when using CO as a biological measure of smoke exposure.

Assessment of the validity of self-reported smoking status among schoolchildren in Sousse, Tunisia

INTRODUCTION

Tobacco use, which begins in adolescence and childhood and continues in later life, is the major avoidable risk for non-communicable diseases and death in the world. Self-reports have frequently been used to estimate smoking prevalence and health consequences. This study explores the validity of self-reports of smoking behavior among schoolchildren in Tunisia.

MATERIALS AND METHODS

This study was conducted in March 2014 among a sample of 147 schoolchildren randomly selected. Data concerning the smoking habit were collected by a questionnaire designed for the purposes of this work. Then, exhaled CO, a biochemical marker of smoke exposure, was measured using piCO+ Smokerlyzer® breath CO monitor among participants. Sensitivity and specificity of self-reports were calculated.

RESULTS

The prevalence of reported smoking was 9.5% with 16.7% and 1.7% respectively among boys and girls. Their mean age was 14.5±1.28 years old. When considering 4 ppm as the cut-off level of breath CO, sensitivity and specificity of self-reports were 100% and 93.7%, respectively. But at a breath CO cut-off of 3 ppm, self-reporting was 62.5% sensitive and 93.5% specific.

CONCLUSION

According to our findings, we suggest that self-reports can be considered as a good tool to be used with a reasonable confidence to assess the smoking status.

Measurement of cardiovascular and pulmonary function endpoints and other physiological effects following partial or complete substitution of cigarettes with electronic cigarettes in adult smokers

Acute changes in select physiological parameters associated with cardiovascular physiology (systolic and diastolic blood pressure (BP) and heart rate (HR)), pulmonary function (FVC, FEV1, and exhaled CO and NO) and adverse events were measured in 105 clinically confined subjects who were randomized into groups that either completely or partially switched from conventional cigarettes to e-cigarettes or completely discontinued using tobacco and nicotine products altogether. Use of the e-cigarettes for five days under the various study conditions did not lead to higher BP or HR values, negative respiratory health outcomes or serious adverse health events. Reductions in BP and HR vital signs were observed in most of the participants that either ceased tobacco and nicotine products use altogether or switched completely to using e-cigarettes. Pulmonary function tests showed small but non-statistically significant improvements in FVC and FEV1 measurements in most use groups. Statistically significant (p < 0.05) benefits associated with smoking reduction were also noted in exhaled CO and NO levels. All study products were well tolerated. The study findings suggest that there are potential cardiovascular and pulmonary function benefits when smokers switch to using e-cigarette products. This further reinforces the potential that e-cigarettes offer smokers seeking an alternative to conventional tobacco products.

Neural correlates of graphic cigarette warning labels predict smoking cessation relapse

Exposure to graphic warning labels (GWLs) on cigarette packaging has been found to produce heightened activity in brain regions central to emotional processing and higher-order cognitive processes. The current study extends this literature by using functional magnetic resonance imaging (fMRI) to investigate neural activation in response to GWLs and use it to predict relapse in an evidence-based smoking cessation treatment program. Participants were 48 treatment-seeking nicotine-dependent smokers who completed an fMRI paradigm in which they were exposed to GWLs, text-only warning labels (TOLs), and matched control stimuli. Subsequently, they enrolled in smoking cessation treatment and their smoking behavior was monitored. Activation in bilateral amygdala, right dorsolateral prefrontal cortex, right inferior frontal gyrus, left medial temporal gyrus, bilateral occipital lobe, and bilateral fusiform gyrus was greater during GWLs than TOLs. Neural response in the ventromedial prefrontal cortex (vmPFC) during exposure to GWLs (relative to a visual control image) predicted relapse during treatment beyond baseline demographic and dependence severity, but response in the amygdala to GWLs did not. These findings suggest that neurocognitive processes in the vmPFC may be critical to understanding how GWL's induce behavior change and may be useful as a predictor of smoking cessation treatment prognosis.

Measurement of exhaled breath carbon monoxide in clinical practice: A study of levels in Central Pennsylvania community members

BACKGROUND AND PURPOSE

Exhaled breath carbon monoxide (eBCO) reading is a useful tool for nurse practitioners to evaluate smoking status and other exposures to carbon monoxide (CO) to identify risk for cancer and chronic disease. This study aimed to measure one community's eBCO and identify potential environmental factors that may affect eBCO among nonsmokers.

METHODS

Data collected by convenience sampling at community health events included self-reported tobacco use and potential CO exposure. Means and frequency calculations describe the sample, two-sided t-tests determine differences in continuous variables, and chi-square tests determine differences in frequencies of CO levels between nontobacco users exposed to additional CO from their environment and nontobacco users who were not.

CONCLUSION

As expected, smokers have significantly higher mean eBCO than nonsmokers (20.1 ppm vs. 4.4 ppm, p < .001). The self-reported nonsmokers (16.2%) had an elevated eBCO (>6 ppm), although there were no environmental factors that explained a higher eBCO.

IMPLICATIONS FOR PRACTICE

Measuring eBCO provides an opportunity for the nurse practitioner to engage in a conversation about the impact of smoking and other environmental factors that contribute to eBCO and health. Keeping record of patients' smoking status and eBCO in their medical record is a valuable measure of the nurse practitioner's delivery of this care.

Clinical setting-based smoking cessation programme and the quality of life in people living with HIV in Austria and Germany

Purpose

To report on the global quality of life (QOL) in people living with HIV (PLWHIV) and how a smoking cessation intervention influences the changes in QOL.

Methods

Participants were asked to fill out a questionnaire during visits to their HIV outpatient clinic consisting of sociodemographic information, general health data and the WHOQOL HIV-Bref. Exhaled carbon monoxide measurements were used to confirm the smoking status, based on which participants classified as smokers received a short 5 min structured intervention and were offered participation in a full smoking cessation programme consisting of five sessions. Follow-up was done 8 months after the baseline.

Results

Overall 447 (mean age = 45.5) participants took part with 221 being classified as smokers. A total of 165 (74.6%) participants received a short intervention and 63 (29.4%) agreed to participate in the full program. At baseline, differences in QoL were observed, where smokers had lower QoL in domains of physical (M = 16.1 vs. 15.3, p = 0.009) and psychological (M = 15.3 vs. 14.6, p = 0.021) well-being, independency level (M = 16.1 vs. 15.2, p = 0.003) and environment (M = 16.5 vs. 16.0, p = 0.036). At study end, 27 (12.2%) participants quit smoking; 12 (19.0%) participants of the full programme and 15 (14.7%) that received the short intervention. There were no significant differences in QoL between those that continued to smoke and quitters at follow-up.

Conclusion

Quality of life results may be used to better understand the underlying motivation of PLWHIV who start cessation programs. In order to reduce the high prevalence and health burden that smoking causes in PLWHIV, it is necessary to introduce effective interventions that can be used in the clinical settings.

Exhaled carbon monoxide: a non-invasive biomarker of short-term exposure to outdoor air pollution

BACKGROUND

In urban settings of Africa with rapidly increasing population, traffic-related air pollution is a major contributor to outdoor air pollution (OAP). Although OAP has been identified as a leading cause of global morbidity and mortality, there is however, lack of a simple biomarker to assess levels of exposure to OAP in resource-poor settings. This study evaluated the role of exhaled carbon monoxide (exhCO) as a potential biomarker of exposure to ambient carbon monoxide (ambCO) from OAP.

METHODS

This was a descriptive study conducted among male commercial motorcycle riders in Cotonou - the economic capital of Benin. The participants' AmbCO was measured using a portable carbon monoxide (CO) data logger for 8 h during the period of their shift. ExhCO was measured just before and immediately after their shift (8-h) Participants were asked not to cook or to smoke during the day of the measurements. Linear regression analysis was used to assess the association between ambCO and exhCO for the last 2, 4 and 6 h of their shift.

RESULTS

Of 170 participants who completed the study, their mean ± SD age was 42.2 ± 8.4 years, and their mean ± SD daily income was 7.3 ± 2.7$. Also, 95% of the participants' used solid fuels for cooking and only 2% had ever smoked. Average exhCO increased by 5.1 ppm at the end of the shift (p = 0.004). Post-shift exhCO was significantly associated to ambCO, this association was strongest for the last 2 h of OAP exposure before exhCO measurement (β = 0.34, p < 0.001).

CONCLUSION

ExhCO level was associated with recent exposure to ambCO from OAP with measurable increase after 8 h of exposure. These findings suggest that ExhCO may be a potential biomarker of short-term exposure to OAP.

Kinetics of Exhaled Carbon Monoxide After Water-pipe Smoking Indoors and Outdoors

BACKGROUND

Despite accumulating evidence about its adverse health effects, water-pipe tobacco smoking has become very popular among youth. The aim of this study was to compare smoke exposure and the kinetics of exhaled carbon monoxide (eCO) between water-pipe and cigarette smokers under different conditions.

METHODS

Using a cross-over study design, changes in eCO and urinary cotinine levels were measured in a cohort of 32 healthy university students after sessions of water-pipe smoking indoors and outdoors. An indoor cigarette smoking session with equal amounts of tobacco was conducted for reference purposes. Both active and passive smokers participated in all sessions.

RESULTS

In indoor sessions, we found that among active participants, eCO levels were approximately 7.5-fold higher in water-pipe users than cigarette smokers. eCO levels remained significantly elevated even 10 h after discontinuing water-pipe smoking. Notably, eCO levels in passive water-pipe smokers were in the same range as in active cigarette smokers. Compared with indoor sessions, eCO levels in active water-pipe users were reduced in outdoor environments. Nonetheless, levels were still higher in these subjects than those in active cigarette smokers measured in indoor sessions. Urinary cotinine levels were comparable in active water-pipe and cigarette smokers.

CONCLUSIONS

Our results suggest that water-pipe smoking is associated with significantly higher toxicant exposure than cigarette smoking even in outdoor environments. Furthermore, even passive, indoor water-pipe smoke exposure may have significant health hazards compared with those of active cigarette smoking.

Cardiorespiratory response to exercise of nonsmokers occupationally exposed to second hand smoke (SHS)

INTRODUCTION

Occupational exposure to Second Hand Smoke (SHS) continues to be an issue, even in countries with strong tobacco control legislation. The current study assessed the effect of chronic occupational exposure to SHS on cardiorespiratory exercise response among healthy adult non-smokers.

METHODS

60 healthy non-smokers; 38 men, 22 women, aged 18-58 years with body mass index (BMI)<30 were separated into exposed to occupational SHS (exposed, n=30) and those non-exposed (controls, n=30) to occupational SHS in the hospitality sector. All individuals underwent baseline spirometry and ergospirometry testing. Non-smoking status was confirmed with exhaled CO, SHS exposure with urine cotinine measurement and indoor environmental pollution with PM2.5 concentration. Statistical differences among groups were determined with an independent t-test and p-value set to <0.05.

RESULTS

The exposed group had an average range of 6.9% to 14% lower exercise performance against their % predicted compared to controls. Significant mean differences ±standard deviation found between groups for ergospirometry were: oxygen uptake (VO₂, mL/minute) 11.8 ±3.9 (p=0.004) and 11.7 ±4.8 (p=0.019); carbon dioxide output (VCO₂) 14.0 ±3.7 (p<0.001) and 13.4 ±5.0 (p=0.009); metabolic equivalents (METS) 11.9 ±3.9 (p=0.003) and 11.7 ±4.9 (p=0.018) and for oxygen pulse (VO₂/HR) 16.6 ±7.551 (p=0.032) and 11.9 ±4.554 (p=0.011) at points of maximum oxygen uptake (VO₂max) and recovery (RC) against % predicted values, respectively.

CONCLUSION

Chronic occupational SHS exposure among non-smokers deteriorates CR exercise performance. Its impact on chronic disease development should be further explored. These results add to the evidence of the importance of enforcing clean indoor air legislations..

Influence of air pollution on exhaled carbon monoxide levels in smokers and non-smokers. A prospective cross-sectional study

BACKGROUND

The poor air quality and cigarette smoking are the most important reasons for increased carbon monoxide (CO) level in exhaled air. However, the influence of high air pollution concentration in big cities on the exhaled CO level has not been well studied yet.

OBJECTIVES

To evaluate the impact of smoking habit and air pollution in the place of living on the level of CO in exhaled air.

METHODS

Citizens from two large cities and one small town in Poland were asked to complete a survey disclosing their place of residence, education level, work status and smoking habits. Subsequently, the CO level in their exhaled air was measured. Air quality data, obtained from the Regional Inspectorates of Environmental Protection, revealed the differences in atmospheric CO concentration between locations.

RESULTS

1226 subjects were divided into 4 groups based on their declared smoking status and place of living. The average CO level in exhaled air was significantly higher in smokers than in non-smokers (p<0.0001) as well as in non-smokers from big cities than non-smokers from small ones (p<0.0001). Created model showed that non-smokers from big cities have odds ratio of 125.3 for exceeding CO cutoff level of 4ppm compared to non-smokers from small towns.

CONCLUSIONS

The average CO level in exhaled air is significantly higher in smokers than non-smokers. Among non-smokers, the average exhaled CO level is significantly higher in big city than small town citizens. These results suggest that permanent exposure to an increased concentration of air pollution and cigarette smoking affect the level of exhaled CO.

Exhaled carbon monoxide is a marker of heavy nicotine dependence

BACKGROUND/AIM

Exhaled CO level provides an objective measure of a patient's smoking status. The relationship between CO levels and nicotine dependence is controversial. The aim of this study is to evaluate the relationship between exhaled CO levels and nicotine dependence as well as to demonstrate that exhaled CO levels may be used as a marker of nicotine dependence.

MATERIALS AND METHODS

Two hundred eighty-nine patients (132 females, 157 males) were included in the study. Smoking duration, the age of smoking initiation, exhaled CO levels, and Fagerström Test for Nicotine Dependence (FTND) scores were recorded. The relationship between FTND scores and exhaled CO levels was investigated.

RESULTS

There was a statistically significant correlation between FTND score and exhaled CO levels (P < 0.001). We found that a cut-off score of 7.5 ppm for exhaled CO may be useful as a marker for heavy smoking. The sensitivity and specificity of this cut-off score for exhaled CO was 69.3% and 49.3%, respectively (P < 0.001).

CONCLUSION

We found that exhaled CO levels significantly correlated with FTND scores. For patients who are unable to provide reliable answers to questions in the FTND, exhaled CO measurements may be used as an alternative test for estimating the status of heavy smoking.

Cigarette smoke and related risk factors in neurological disorders: An update

Cigarette smoking is known to be harmful to health, and is considered the main cause of death worldwide, especially in India. Among the well-distinguished diseases related to smoking are, chronic obstructive pulmonary disease, oral and peripheral cancers, and cardiovascular complications. However, the impact of cigarette smoking on neurocognitive and neuropathological effects, including anxiety, Alzheimer's disease, Parkinson's disease, ischemic stroke, and blood-brain barrier dysfunction, still remains unclear. Cigarette smoke consists of more than 4500 toxic chemicals that combine to form free radicals, which lead to oxidative stress-associated neurological disorders. Herein, we discuss the role of antioxidant agents in delaying or attenuating disease complications. In addition, in this review, we discuss the neuropathological effect of cigarette smoke and its interference in neurodegeneration.

The temporal window of valuation is constricted among adolescent smokers

Healthy decisions are associated with valuation of the future whereas unhealthy decisions are associated with devaluation of the future. Comparisons of future discounting of delayed rewards in adolescent smokers and non-smokers have been equivocal and past discounting of monetary gains has not been reported in adolescents. Here, adolescents completed future and past delay discounting tasks. A mixed-model analysis of covariance using a model with the lowest Bayesian Information Criterion revealed that adolescents discount the past more than the future and smokers discount more than non-smokers. These results suggest that adolescent smokers have a constricted temporal window, which may lead to disadvantageous decisions.

Representativeness of the participants in the smoking Cessation in Pregnancy Incentives Trial (CPIT): a cross-sectional study

Background

The limited representativeness of trial samples may restrict external validity. The aim of this study was to ascertain the representativeness of the population enrolled in the Cessation in Pregnancy Incentives Trial (CPIT), a therapeutic exploratory study to examine the effectiveness of financial incentives for smoking cessation during pregnancy.

Methods

CPIT participants (n = 492) were compared with all self-reported smokers at maternity booking who did not participate in the trial (n = 1982). Both groups were drawn from the National Health Service (NHS) Greater Glasgow and Clyde area over a 1-year trial enrolment period. Variables used for comparison were age, area-based deprivation index, body mass index, gestation, and carbon monoxide (CO) breath test level. Chi-square and Mann-Whitney U tests were used to compare groups.

Results

From January to December 2012, 2474/13,945 (17.7 %) women, who booked for maternity care, self-reported as current smokers (at least one cigarette in the last week). Seven hundred and fifty-two were ineligible for trial participation because of a CO breath test level of less than 7 parts per million (ppm) used as a biochemical cut-off to corroborate self-report of current smoking. At telephone consent 301 could not be contacted, 11 had miscarried, 16 did not give consent and 3 opted out after randomisation, leaving 492 participants for analysis. There were no differences in demographic or clinical characteristics between trial participants, and self-reported smokers not enrolled in the trial in terms of CO breath test (as a measure of smoking level for those with a CO level of 7 ppm or higher), material deprivation (using an area-based measure), maternal age and maternal body mass index. Gestation at booking was statistically significantly lower for participants.

Conclusions

To ensure that all trial participants were smokers, biochemical validation excluded self-reported smokers with a CO level of less than 7 ppm from taking part in the trial, which excluded 30 % of self-reported smokers who were ‘lighter’ smokers. The efficacy of financial incentives would not have been likely to decrease if ‘lighter’ smokers had been included in the trial population. Trial participants were slightly earlier in their pregnancy at maternity booking, but this difference would not clinically affect the provision of financial incentives if provided routinely. Overall, the trial population was representative of all self-reported smokers with regard to available routinely collected data. Appropriate comparison of trial and target populations, with detailed reporting of exclusion criteria would contribute to the understanding of the wider applicability of trial results.

Trial registration

Current Controlled Trials ISRCTN87508788. Registered/Assigned on 1 September 2011.

Neural response to pictorial health warning labels can predict smoking behavioral change

In order to improve our understanding of how pictorial health warning labels (HWLs) influence smoking behavior, we examined whether brain activity helps to explain smoking behavior above and beyond self-reported effectiveness of HWLs. We measured the neural response in the ventromedial prefrontal cortex (vmPFC) and the amygdala while adult smokers viewed HWLs. Two weeks later, participants’ self-reported smoking behavior and biomarkers of smoking behavior were reassessed. We compared multiple models predicting change in self-reported smoking behavior (cigarettes per day [CPD]) and change in a biomarkers of smoke exposure (expired carbon monoxide [CO]). Brain activity in the vmPFC and amygdala not only predicted changes in CO, but also accounted for outcome variance above and beyond self-report data. Neural data were most useful in predicting behavioral change as quantified by the objective biomarker (CO). This pattern of activity was significantly modulated by individuals’ intention to quit. The finding that both cognitive (vmPFC) and affective (amygdala) brain areas contributed to these models supports the idea that smokers respond to HWLs in a cognitive-affective manner. Based on our findings, researchers may wish to consider using neural data from both cognitive and affective networks when attempting to predict behavioral change in certain populations (e.g. cigarette smokers).

Reductions in biomarkers of exposure, impacts on smoking urge and assessment of product use and tolerability in adult smokers following partial or complete substitution of cigarettes with electronic cigarettes

Background

Electronic cigarettes (e-cigarettes) are popular alternatives to conventional cigarettes among adult smokers wishing to reduce their exposure to harmful smoke constituents. However, little information exists on the relative internal exposures resulting from the exclusive or dual use of e-cigarettes.

Methods

Measurements of product use; adverse events; changes in smoking urge; and blood, urine and exhaled breath biomarkers of exposure (BoE) representing toxicants believed to contribute to smoking related diseases were made at baseline and after five days of product use in 105 clinically-confined smokers randomized into groups that partially or completely substituted their usual brand combustible cigarette with commercial e-cigarettes, or discontinued all nicotine and tobacco products.

Results

Subjects switching to e-cigarettes had significantly lower levels (29 %–95 %) of urinary BoEs after 5 days. Nicotine equivalents declined by 25 %–40 %. Dual users who substituted half of their self-reported daily cigarette consumption with e-cigarettes experienced 7 %–38 % reductions, but had increases (1 %–20 %) in nicotine equivalents. Blood nicotine biomarker levels were lower in the cessation (75 %–96 %) and e-cigarette use groups (11 %–83 %); dual users had no significant reductions. All groups experienced significant decreases in exhaled CO (27 %–89 %). Exhaled NO increases (46 %–63 %) were observed in the cessation and e-cigarette use groups; dual users had minimal changes. By Day 5, all groups had greater reductions in smoking urge compared to cessation. However, reductions were larger in the dual use group. No serious adverse events were observed.

Conclusions

Exposures to harmful smoke toxicants were observed to be lower in smokers who completely or partially replaced their cigarettes with e-cigarettes over five days.

Reductions in biomarkers of exposure (BoE) to harmful or potentially harmful constituents (HPHCs) following partial or complete substitution of cigarettes with electronic cigarettes in adult smokers

Changes in fifteen urine, blood and exhaled breath BoEs of HPHCs representing classes of compounds reported by FDA to be significant contributors to smoking-associated disease risks were measured in 105 clinical-confined subjects following randomization and a five-day forced-switch from usual brand conventional combustible cigarettes to: (i) exclusive commercial e-cigarette use; (ii) dual-use of commercial e-cigarettes and the subject's usual cigarette brand; or (iii) discontinued use of all tobacco or nicotine products. Levels of urinary biomarkers in subjects that completely substituted their usual cigarette with e-cigarettes were significantly lower (29-95%) after 5 days. Percent reductions in eight of nine urinary BoEs were indistinguishable to smokers who had quit smoking, except for nicotine equivalents, which declined by 25-40%. Dual users who halved self-reported daily cigarette consumption with e-cigarettes exhibited reductions (7-38%) in eight of nine urinary biomarkers, but had increase (1-20%) in nicotine equivalents. Reductions were broadly proportional to the reduced numbers of cigarettes smoked. Dual user urinary nicotine equivalents were slightly higher, but not statistically significant. After 5 days, blood nicotine biomarker levels were lower in the cessation (75-96%) and exclusive use groups (11-83%); with dual users experiencing no significant reductions. All subjects experienced significant decreases in exhaled CO. Decreases in the cessation and exclusive groups ranged from 88-89% and 27-32% in dual users. Exhaled NO increased in the cessation and exclusive groups (46-63% respectively), whereas the dual users experienced minimal changes. Overall, smokers who completely or partially substituted conventional cigarettes with e-cigarettes over five days, experienced reductions in HPHCs.

Electronic Noses for Well-Being: Breath Analysis and Energy Expenditure

The wealth of information concealed in a single human breath has been of interest for many years, promising not only disease detection, but also the monitoring of our general well-being. Recent developments in the fields of nano-sensor arrays and MEMS have enabled once bulky artificial olfactory sensor systems, or so-called "electronic noses", to become smaller, lower power and portable devices. At the same time, wearable health monitoring devices are now available, although reliable breath sensing equipment is somewhat missing from the market of physical, rather than chemical sensor gadgets. In this article, we report on the unprecedented rise in healthcare problems caused by an increasingly overweight population. We first review recently-developed electronic noses for the detection of diseases by the analysis of basic volatile organic compounds (VOCs). Then, we discuss the primary cause of obesity from over eating and the high calorific content of food. We present the need to measure our individual energy expenditure from our exhaled breath. Finally, we consider the future for handheld or wearable devices to measure energy expenditure; and the potential of these devices to revolutionize healthcare, both at home and in hospitals.

Mapping Smoking Addiction Using Effective Connectivity Analysis

Prefrontal and parietal cortex, including the default mode network (DMN; medial prefrontal cortex (mPFC), and posterior cingulate cortex, PCC), have been implicated in addiction. Nonetheless, it remains unclear which brain regions play a crucial role in smoking addiction and the relationship among these regions. Since functional connectivity only measures correlations, addiction-related changes in effective connectivity (directed information flow) among these distributed brain regions remain largely unknown. Here we applied spectral dynamic causal modeling (spDCM) to resting state fMRI to characterize changes in effective connectivity among core regions in smoking addiction. Compared to nonsmokers, smokers had reduced effective connectivity from PCC to mPFC and from RIPL to mPFC, a higher self-inhibition within PCC and a reduction in the amplitude of endogenous neuronal fluctuations driving the mPFC. These results indicate that spDCM can differentiate the functional architectures between the two groups, and may provide insight into the brain mechanisms underlying smoking addiction. Our results also suggest that future brain-based prevention and intervention in addiction should consider the amelioration of mPFC-PCC-IPL circuits.

Prevalence and Correlates of Smoking and Readiness to Quit Smoking in People Living with HIV in Austria and Germany

We aimed to investigate the prevalence and correlates of smoking in people living with HIV (PLWHIV) in Germany and Austria and their readiness to quit. A total of 447 consecutive patients with confirmed positive HIV status who were treated in different outpatient HIV centres in Austria and Germany were included. Nicotine dependence and stages of change were assessed by standardized questionnaires, and this was confirmed by measuring exhaled carbon monoxide. Prevalence of smoking was 49.4%. According to a multivariate logistic regression analysis, higher age (for each year of life OR = 0.96; 95% CI 0.92–1.00) and tertiary education level (OR = 0.43; 95% CI 0.15–0.79) were associated with a lower chance, and occasional (OR = 3.75; 95% CI 1.74–8.07) and daily smoking of the partner (OR 8.78; 95% CI 4.49–17.17) were significantly associated with a higher chance of smoking. Moderate (OR = 3.41; 95% CI = 1.30–9.05) and higher nicotine dependency level (OR = 3.40; 95% CI 1.46–7.94), were significantly associated with higher chance, and older age (for each year of life OR = 0.95; 95% CI = 0.91–0.99), with lower chance for readiness to quit smoking. Those results may be used to address preventive measures to quit smoking aimed at PLWHIV and the importance of addressing smoking habits.

The Collection and Analysis of Carbon Monoxide Levels as an Indirect Measure of Smoke Exposure in Pregnant Adolescents at a Multidisciplinary Teen Obstetrics Clinic

STUDY OBJECTIVE

In this study we aimed to collect and analyze CO levels as an indirect measure of smoke exposure in pregnant adolescents.

DESIGN, SETTING, AND PARTICIPANTS

Participants included pregnant adolescents who received antenatal care over 18 months (2012-2013) at the Multidisciplinary Teen Obstetrics Clinic at a tertiary-care hospital in Southeastern Ontario.

INTERVENTIONS

The CO breath test is a noninvasive method that is used to assess smoke exposure, in which nonsmokers have levels of 0-6 ppm, and levels of 7-10, 11-20 and more than 20 ppm are consistent with light, typical, and heavy smokers, respectively. Expired CO, smoking status, cigarette number, and home secondhand smoke exposure were documented at 3 clinic visits.

MAIN OUTCOME MEASURES

To determine mean CO levels as a measure of smoke exposure and prevalence of secondhand smoke exposure.

RESULTS

The mean age of participants was 17.6 years. CO means (ppm) across 3 visits were 6.0, 5.9, and 4.8. Sixty-two percent of patients were self-reported nonsmokers, 38% were self-reported smokers (n = 93). CO means (standard error of the mean) were consistently different for nonsmokers vs smokers at visits 1 to 3, respectively: 2.9 (0.79) vs 9.7 (1.8); 3.0 (0.71) vs 12.9 (2.2), and 2.4 (0.71) vs 8.8 (1.5; P < .01, t test; n = 91). Of patient's highest CO (COmax), 62%, 9%, 15%, and 12% had levels of 6 or less, 7-10, 11-20, and greater than 20, respectively. Eighty-four percent of pregnant adolescents had home secondhand smoke exposure, which included 40% of nonsmokers and 100% of smokers (n = 57). Although most nonsmokers had a COmax of 6 or fewer ppm, 56% of smokers had COmax greater than 10 ppm (P < .05, χ(2)).

CONCLUSION

Emphasis on smoking cessation is imperative in pregnant adolescents and should particularly target partners and families, because secondhand smoke exposure was very prevalent.

Atypical valuation of monetary and cigarette rewards in substance dependent smokers

OBJECTIVE

Substance dependent (SD) relative to non-dependent (ND) individuals exhibit an attenuated reward positivity, an electrophysiological signal believed to index sensitivity of anterior cingulate cortex (ACC) to rewards. Here we asked whether this altered neural response reflects a specific devaluation of monetary rewards relative to drug-related rewards by ACC.

METHODS

We recorded the reward positivity from SD and ND individuals who currently smoke, following an overnight period of abstinence, while they engaged in two feedback tasks. In a money condition the feedback indicated either a monetary reward or no reward, and in a cigarette condition the feedback indicated either a drug-related reward or no reward.

RESULTS

Overall, cigarette relative to monetary rewards elicited a larger reward positivity. Further, for the subjects who engaged in the money condition first, the reward positivity was smaller for the SD compared to the ND participants, but for the subjects who engaged in the cigarette condition first, the reward positivity was larger for the SD compared to the ND participants.

CONCLUSIONS

Our results suggest that the initial category of feedback "primed" the response of the ACC to the alternative feedback type on subsequent trials, and that SD and ND individuals responded differently to this priming effect.

SIGNIFICANCE

We propose that for people who misuse addictive substances, the prospect of obtaining drug-related rewards engages the ACC to exert control over extended behaviors.

Anxiety Sensitivity and Smoking Behavior Among Trauma-Exposed Daily Smokers: The Explanatory Role of Smoking-Related Avoidance and Inflexibility

Anxiety sensitivity (AS), defined as the extent to which individuals believe that anxiety-related sensations have harmful consequences, is associated with smoking processes and poorer clinical outcomes among trauma-exposed smokers. Yet the specific mechanisms underlying this association are unclear. Smoking-specific avoidance and inflexibility is a construct implicated in multiple manifestations of mood regulation that may underlie smoking behavior. The current study examined the explanatory role of smoking-specific avoidance and inflexibility in terms of the relation between AS and indices of smoking behavior among trauma-exposed smokers. The sample consisted of 217 treatment-seeking adult smokers (44% female; M age = 37.8; SD = 13.2; age range: 18-65 years), who were exposed to at least one lifetime Criterion A trauma event (Diagnostic and Statistical Manual of Mental Disorders [4th ed., text rev.; DSM-IV-TR] Criterion A for trauma exposure). Bootstrap analysis (5,000 re-samples) revealed that AS was indirectly related to the (a) number of cigarettes smoked per day, (b) number of years being a daily smoker, (c) number of failed quit attempts, and (d) heaviness of smoking index among trauma-exposed smokers through its relation with smoking-specific avoidance and inflexibility. These findings provide initial evidence suggesting that smoking-specific avoidance and inflexibility may be an important construct in better understanding AS-smoking relations among trauma-exposed smokers. Future work is needed to explore the extent to which smoking-specific avoidance and inflexibility account for relations between AS and other smoking processes (e.g., withdrawal, cessation outcome) in the context of trauma and smoking comorbidity.

Environmental Tobacco Smoke Exposure in Pregnancy is Associated With Earlier Delivery and Reduced Birth Weight

The association between maternal smoking and preterm birth (PTB) has been known for more than 50 years but the effect of passive smoking is controversial. This retrospective cohort study in Bristol, United Kingdom, examines the effect of environmental tobacco smoke exposure (ETSE) on gestational age at delivery, birth weight, PTB, and being small-for-gestational age (SGA). Environmental tobacco smoke exposure was defined by either self-report or exhaled carbon monoxide (eCO) levels, and exposed women were compared with unexposed controls. Two models were used: The first included all women with adjustment for maternal smoking, and the second considered nonsmokers alone. Both models were further adjusted for maternal age, body mass index, parity, ethnicity, employment status, socioeconomic position, asthma, preeclampsia, and offspring sex. Logistic regression and likelihood ratio tests were used to test for any association between exposure and the binary outcomes (PTB and SGA), while linear regression and F tests were used to test for associations between exposure and the continuous outcomes. There were 13 359 deliveries in 2012 to 2014, with complete data for 5066 and 4793 women in the self-reported and eCO-measured exposure groups, respectively. Self-reported exposure was associated with earlier delivery (-0.19 weeks; 95% confidence interval [CI]: -0.32 to -0.05) and reduced birth weight (-56 g, 95% CI: -97 to -16 g) but no increase in the risk of PTB or SGA. There was no evidence for an association between eCO-measured exposure and any of the outcome measures. This information is important when advising women and their families and adds further support to continued public health efforts to reduce exposure to tobacco smoke.

Comparison between objective measures of smoking and self-reported smoking status in patients with asthma or COPD: are our patients telling us the truth?

OBJECTIVE:

Smoking prevalence is frequently estimated on the basis of self-reported smoking status. That can lead to an underestimation of smoking rates. The aim of this study was to evaluate the difference between self-reported smoking status and that determined through the use of objective measures of smoking at a pulmonary outpatient clinic.

METHODS:

This was a cross-sectional study involving 144 individuals: 51 asthma patients, 53 COPD patients, 20 current smokers, and 20 never-smokers. Smoking status was determined on the basis of self-reports obtained in interviews, as well as through tests of exhaled carbon monoxide (eCO) and urinary cotinine.

RESULTS:

All of the asthma patients and COPD patients declared they were not current smokers. In the COPD and asthma patients, the median urinary cotinine concentration was 167 ng/mL (range, 2-5,348 ng/mL) and 47 ng/mL (range, 5-2,735 ng/mL), respectively (p < 0.0001), whereas the median eCO level was 8 ppm (range, 0-31 ppm) and 5 ppm (range, 2-45 ppm), respectively (p < 0.05). In 40 (38%) of the patients with asthma or COPD (n = 104), there was disagreement between the self-reported smoking status and that determined on the basis of the urinary cotinine concentration, a concentration > 200 ng/mL being considered indicative of current smoking. In 48 (46%) of those 104 patients, the self-reported non-smoking status was refuted by an eCO level > 6 ppm, which is also considered indicative of current smoking. In 30 (29%) of the patients with asthma or COPD, the urinary cotinine concentration and the eCO level both belied the patient claims of not being current smokers.

CONCLUSIONS:

Our findings suggest that high proportions of smoking pulmonary patients with lung disease falsely declare themselves to be nonsmokers. The accurate classification of smoking status is pivotal to the treatment of lung diseases. Objective measures of smoking could be helpful in improving clinical management and counseling.

Transcranial Magnetic Stimulation Combined With Nicotine Replacement Therapy for Smoking Cessation: A Randomized Controlled Trial

BACKGROUND

Further evidence suggests that repetitive Transcranial Magnetic Stimulation (rTMS) is an effective method to reduce tobacco craving among smokers.

HYPOTHESIS

As relapse is common within a few days after smoking cessation, we hypothesized that combining the anti-craving effects of rTMS with Nicotine replacement therapy (NRT) to attenuate withdrawal symptoms could increase abstinence rates in smokers with severe nicotine dependence who quit smoking.

METHODS

Thirty-seven smokers who failed to quit with the usual treatments were randomly assigned to two treatment groups to receive either active (n = 18) or sham (n = 19) 1-Hz rTMS of the right dorsolateral prefrontal cortex. The day after quitting smoking, each patient combined NRT (21-mg patch) with active or sham rTMS (10 sessions) for 2 weeks. Cessation support was then continued with NRT alone using lower-dose patches. Abstinence rates and self-report craving scales were used to assess the therapeutic results during the combined treatment and for up to 12 weeks after quitting.

RESULTS

At the end of the combined treatment, there were significantly more abstinent participants in the active rTMS group (n = 16) than in the sham rTMS group (n = 9) (P = 0.027). The craving scales analysis revealed that active rTMS (P = 0.011) but not sham rTMS (P = 0.116) led to a significant decrease in the compulsive factor. However, no lasting rTMS effect was found.

CONCLUSIONS

1-Hz rTMS combined with NRT improved the success rate of abstinence in smokers during tobacco cessation. The stimulation-induced reduction in compulsivity may explain this result.

The possible role of maternal bonding style and CHRNB2 gene polymorphisms in nicotine dependence and related depressive phenotype

OBJECTIVES

Neuronal nicotinic acetylcholinergic receptors (nAChR) and especially α4β2 nAChRs are the major targets for cessation medications and also for some promising antidepressant agents. Furthermore, depressive symptoms pose multifacet difficulties during cessation therapy. However, gene encoding for the β2 subunit of nAChRs has been poorly investigated in association with depression. Since both nicotine dependence (ND) and depressive phenotype are complex disorders, we investigated the effects of a significant early life experience, maternal bonding style (MB) and CHRNB2 gene SNPs on smoking-related depression.

METHODS

We recruited two hundred and thirty-two treatment-seeking smokers in our study. Phenotypic variants were evaluated using the Fagerstrom Test for Nicotine Dependence (FTND), the Zung Self-Rating Depression Scale (ZSDS) and the Parental Bonding Instrument (PBI). Besides the total score (TS) of ZSDS, impulsivity (ZSDS-I) and suicidal ideation (ZSDS-S) were distinguished as phenotypic variable. DNAs were extracted from buccal mucosa samples and one SNP in promoter and two SNPs in 3' UTR of CHRNB2 gene were genotyped. GLM and ANOVA tests were performed for genotype associations and interaction analyses.

RESULTS

Maternal bonding had a significant impact on depressive phenotypes. Low care, high protection and affectionless control (ALC) were associated with ZSDS-TS and all subphenotypes of ZSDS. One SNP, the rs2072660 in 3' UTR, had a significant effect on the FTND score (p=0.010). Direct association of CHRNB2 variants and depressive phenotypes were not significant. However, in interaction with ALC, rs2072660 was significantly associated with ZSDS-S (p=0.005). MB had no significant effect on smoking-related phenotype.

CONCLUSIONS

Our results highlight the important role of 3' UTR in the CHRNB2 gene in the shared molecular background of ND and depressive phenotype. Parental bonding style can be suggested as a significant environmental factor in further GxE studies of depression. The presented significant GxE interaction on smoking-related suicidal subphenotype may help establish further investigations on development of more effective and safer smoking cessation and antidepressant agents.

Real-world comparative study of behavioral group therapy program vs education program implemented for smoking cessation in community-dwelling elderly smokers

BACKGROUND

Tobacco smoking is known to be an important contributor to a wide variety of chronic diseases, especially in older adults. Information on health policy and practice, as well as evaluation of smoking cessation programs targeting older people, is almost nonexistent.

PURPOSE

To compare the real-world implementation of behavioral group therapy in relation to education alone for elderly smokers.

MATERIALS AND METHODS

Elderly smokers ready to quit smoking were identified from a cohort who completed a questionnaire at a smoking exhibition. They were allocated into two groups, behavioral therapy (3 days 9 hours) and education (2 hours), depending on their preferences. Demographic data, the Fagerstrom test for nicotine dependence (FTND) score, and exhaled carbon monoxide level were recorded at baseline. Smoking status of all subjects was followed at months 3, 6, and 12. Statistical differences in continuous abstinence rate (CAR) between the two groups were analyzed using chi-square tests.

RESULTS

Two hundred and twenty-four out of 372 smoking exhibition attendants met the enrollment criteria; 120 and 104 elected to be in behavioral group therapy and education-alone therapy, respectively. Demographic characteristics and smoking history were similar between both groups, including age, age of onset of smoking, years of smoking, smoking pack-years, education level, and nicotine dependence as measured by the FTND scale. The CAR of the behavioral therapy group at the end of the study (month 12) was significantly higher than the education group (40.1% vs 33.3%, P=0.034). Similar results were also found throughout all follow-up visits at month 3 (57.3% vs 27.0%, P<0.001) and month 6 (51.7% vs 25%, P<0.001).

CONCLUSION

Behavioral group therapy targeting elderly smokers could achieve higher short-and long-term CARs than education alone in real-world practice.

Exposure to household air pollution from wood combustion and association with respiratory symptoms and lung function in nonsmoking women: results from the RESPIRE trial, Guatemala

BACKGROUND

With 40% of the world's population relying on solid fuel, household air pollution (HAP) represents a major preventable risk factor for COPD (chronic obstructive pulmonary disease). Meta-analyses have confirmed this relationship; however, constituent studies are observational, with virtually none measuring exposure directly.

OBJECTIVES

We estimated associations between HAP exposure and respiratory symptoms and lung function in young, nonsmoking women in rural Guatemala, using measured carbon monoxide (CO) concentrations in exhaled breath and personal air to assess exposure.

METHODS

The Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) Guatemala study was a trial comparing respiratory outcomes among 504 women using improved chimney stoves versus traditional cookstoves. The present analysis included 456 women with data from postintervention surveys including interviews at 6, 12, and 18 months (respiratory symptoms) and spirometry and CO (ppm) in exhaled breath measurements. Personal CO was measured using passive diffusion tubes at variable times during the study. Associations between CO concentrations and respiratory health were estimated using random intercept regression models.

RESULTS

Respiratory symptoms (cough, phlegm, wheeze, or chest tightness) during the previous 6 months were positively associated with breath CO measured at the same time of symptom reporting and with average personal CO concentrations during the follow-up period. CO in exhaled breath at the same time as spirometry was associated with lower lung function [average reduction in FEV1 (forced expiratory volume in 1 sec) for a 10% increase in CO was 3.33 mL (95% CI: -0.86, -5.81)]. Lung function measures were not significantly associated with average postintervention personal CO concentrations.

CONCLUSIONS

Our results provide further support for the effects of HAP exposures on airway inflammation. Further longitudinal research modeling continuous exposure to particulate matter against lung function will help us understand more fully the impact of HAP on COPD.

Altered human brain anatomy in chronic smokers: a review of magnetic resonance imaging studies

Cigarette smoking is becoming more prevalent in developing countries, such as China, and is the largest single cause of preventable death worldwide. New emerging reports are highlighting how chronic cigarette smoking plays a role in neural dysfunctions, such as cognitive decline. Basic animal experimental studies have shown that rats undergo persistent pathological brain changes after being given chronic levels of nicotine. What is perhaps less appreciated is the fact that chronic cigarette smoking induces subtle anatomical changes in the human brain. Consequently, this chapter aims to summarize and integrate the existing magnetic resonance imaging studies on both gray- and white-matter marcostructural and microstructural changes. The reviewed studies demonstrate that chronic cigarette smoking results in discrete and localized alterations in brain region tissue (both the gray and white matter of different brain regions), which may, in part, be responsible for different neural dysfunctions. In addition, we further discuss the possible pathological and neurobiological mechanisms of these nicotinic effects on the brain tissue. We will also address the limitations of the current studies on this issue and identify opportunities for future research.

Smoking and Preterm Birth

Premature birth is a significant global problem and the leading cause of newborn deaths. Tobacco smoking has been associated with premature birth for over 50 years. The mechanisms through which smoking exerts its effects on pregnancy outcomes remain unclear. In this review, we discuss rates of prematurity and smoking in pregnancy, the evidence of a causal relationship between tobacco and preterm birth, and proposed biochemical pathways through which the interaction is mediated. The suggested mechanisms include nicotine-induced vasoconstriction, carbon monoxide-induced fetal hypoxia, cadmium disruption of calcium signaling, altered steroid hormone production, disruption of prostaglandin synthesis, and changed responses to oxytocin. The relative importance of each of these pathways is yet to be ascertained. Further research is necessary to explore the mechanisms through which smoking exerts its effect on gestational length and the process of parturition. Moreover, the risks of nicotine replacement in pregnancy should be investigated further.

Acute effect of Snus on physical performance and perceived cognitive load on amateur footballers

Smokeless tobacco (Snus) is a substance that contains nicotine, which has been placed on World Anti-Doping Agency's 2014 Monitoring Program. A proliferation of nicotine use in sport has been observed in recent years, but little is known regarding its effects, especially on football players' performance. Therefore, the aim of this study was to assess the effect of Snus on physical performance, heart rate variability, subjective activation, mental fatigue, and perceived readiness before a physical test in non-smoker, non-Snus user, amateur football players. Participants were administered either Snus or placebo 40 min prior to a fitness test battery (handgrip test, countermovement jump, agility test, and Yo-Yo intermittent recovery test). Results showed that Snus intake (compared with placebo) increased perceived mental fatigue level and mental load, and reduced perceived readiness level and heart rate variability. No significant differences between the two experimental conditions were found in either performance in the physical tests or perceived physical fatigue levels. In light of these results, Snus could not be considered an ergogenic substance. On the contrary, based on the extant evidence linking mental load and fatigue with physical performance, we argue that the observed negative effects on mental fatigue, perceived readiness, and heart rate variability should be considered.

A randomized study of contingency management and spirometric lung age for motivating smoking cessation among injection drug users

Background

Even after quitting illicit drugs, tobacco abuse remains a major cause of morbidity and mortality in former injection drug users. An important unmet need in this population is to have effective interventions that can be used in the context of community based care. Contingency management, where a patient receives a monetary incentive for healthy behavior choices, and incorporation of individual counseling regarding spirometric “lung age” (the age of an average healthy individual with similar spirometry) have been shown to improve cessation rates in some populations. The efficacy of these interventions on improving smoking cessation rates has not been studied among current and former injection drug users.

Methods

In a randomized, factorial design study, we recruited 100 active smokers from an ongoing cohort study of current and former injection drug users to assess the impact of contingency management and spirometric lung age on smoking cessation. The primary outcome was 6-month biologically-confirmed smoking cessation comparing contingency management, spirometric lung age or both to usual care. Secondary outcomes included differences in self-reported and biologically-confirmed cessation at interim visits, number of visits attended and quit attempts, smoking rates at interim visits, and changes in Fagerstrom score and self-efficacy.

Results

Six-month biologically-confirmed smoking cessations rates were 4% usual care, 0% lung age, 14% contingency management and 0% for combined lung age and contingency management (p = 0.13). There were no differences in secondary endpoints comparing the four interventions or when pooling the lung age groups. Comparing contingency management to non-contingency management, 6-month cessation rates were not different (7% vs. 2%; p = 0.36), but total number of visits with exhaled carbon monoxide-confirmed abstinence were higher for contingency management than non-contingency management participants (0.38 vs. 0.06; p = 0.03), and more contingency management participants showed reduction in their Fagerstrom score from baseline to follow-up (39% vs. 18%; p = 0.03).

Conclusions

While lung age appeared ineffective, contingency management was associated with more short-term abstinence and lowered nicotine addiction. Contingency management may be a useful tool in development of effective tobacco cessation strategies among current and former injection drug users.

Trial registration

Clinicaltrials.gov NCT01334736 (April 12, 2011).

Comparison of end tidal carbon monoxide (eCO) levels in shisha (water pipe) and cigarette smokers

Background

Measuring eCo is rapid, non-invasive and inexpensive tool and correlate correctly with carboxyhemoglobin levels in blood. The aim of this study was to evaluate and compare the increase in end tidal carbon monoxide (eCO) levels in exhaled breath of passive smokers and healthy smokers after cigarette and shisha smoking.

Findings

In a cross sectional study eCO levels were measured in 70 subjects (24 cigarette smokers, 20 shisha smoker, 26 passive smokers) by use of portable device. Smokers were asked to smoke shisha for 30 mins in shisha cafe or to smoke 5 cigarettes in 30 mins in a restaurant. eCo levels were measured at baseline (30 mins), 35 mins, 60 mins and 90 mins in all groups after entry to the venue. The baseline mean eCO level among cigarette smokers was 3.5 +/- 0.6 ppm (part per million), passive cigarette smokers 3.7+/-1.0 ppm, shisha smokers 27.7+/-4.9 ppm and passive shisha smokers 18.3+/-8.4 ppm .The mean increase in eCO after 90 min among smokers was 9.4+/-4.6 (p < 0.005), passive cigarette smokers 3.5+/-2.5 (p < 0.05), shisha smokers 57.9+/-27.4 (p <0.005) and passive shisha smokers 13.3+/-4.6 (p = 0.03).

Conclusion

Exposure to shisha smoke is a cause of elevated eCO in smokers and passive smokers and due to in-door pollution, sitting in shisha bar causes significant increase in eCO levels.

A mobile-phone-based breath carbon monoxide meter to detect cigarette smoking

INTRODUCTION

Mobile phones hold considerable promise for delivering evidence-based smoking cessation interventions that require frequent and objective assessment of smoking status via breath carbon monoxide (Breath CO) measurement. However, there are currently no commercially available mobile-phone-based Breath CO meters. We developed a mobile-phone-based Breath CO meter prototype that attaches to and communicates with a smartphone through an audio port. We then evaluated the reliability and the validity of Breath CO measures collected with the mobile meter prototype and assessed the usability and acceptability of the meter.

METHODS

Participants included 20 regular smokers (≥10 cigarettes/day), 20 light smokers (<10 cigarettes/day), and 20 nonsmokers. Expired air samples were collected 4 times from each participant: twice with the mobile meter and twice with a commercially available Breath CO meter.

RESULTS

Measures calculated by the mobile meter correlated strongly with measures calculated by the commercial meter (r = .96, p < .001). Additionally, the mobile meter accurately distinguished between smokers and nonsmokers. The area under the receiver-operating characteristic curve for the mobile meter was 94.7%, and the meter had a combined sensitivity and specificity of 1.86 at an abstinence threshold of ≤6 ppm. Responses on an acceptability survey indicated that smokers liked the meter and would be interested in using it during a quit attempt.

CONCLUSIONS

The results of our study suggest that a mobile-phone-based Breath CO meter is a reliable, valid, and acceptable device for distinguishing between smokers and nonsmokers.

Smoking and increased Alzheimer's disease risk: a review of potential mechanisms

BACKGROUND

Cigarette smoking has been linked with both increased and decreased risk for Alzheimer's disease (AD). This is relevant for the US military because the prevalence of smoking in the military is approximately 11% higher than in civilians.

METHODS

A systematic review of published studies on the association between smoking and increased risk for AD and preclinical and human literature on the relationships between smoking, nicotine exposure, and AD-related neuropathology was conducted. Original data from comparisons of smoking and never-smoking cognitively normal elders on in vivo amyloid imaging are also presented.

RESULTS

Overall, literature indicates that former/active smoking is related to a significantly increased risk for AD. Cigarette smoke/smoking is associated with AD neuropathology in preclinical models and humans. Smoking-related cerebral oxidative stress is a potential mechanism promoting AD pathology and increased risk for AD.

CONCLUSIONS

A reduction in the incidence of smoking will likely reduce the future prevalence of AD.

Differences between 1-month quitters and relapsers in biospsychosocial characteristics among male smokers in Korea

PURPOSE

The purpose of this study was to compare and contrast biopsychosocial characteristics and processes of change (POC) between 1-month quitters and relapsers among male smokers in Korea.

METHODS

This study employed a prospective study design. Forty-one male smokers were recruited on one university campus. The instruments used in this study included blood pressure (BP), body mass index, salivary cortisol, perceived stress, self-efficacy, and POC. After collection of baseline data, participants were encouraged to adopt smoking cessation, either by obtaining smoking cessation counseling or self-abstinence. Baseline data and data collected after 1 month from smoking cessation were compared.

RESULTS

The mean age of the participants was 24.9 years (SD = 1.90 years), and 51.2% were overweight or obese. According to results of the study, SBP, DBP, and perceived stress were significantly lower, whereas self-efficacy was significantly higher among quitters, compared with relapsers, after 1 month (p < .05). Results of within-group comparison indicated that, among POC, self-liberation, helping relationship, and reinforcement management showed a significant decrease among 1-month relapsers (p < .05), whereas, counter conditioning showed a significant increase among 1-month quitters (p < .05).

CONCLUSIONS

According to the results of this study, BP and perceived stress showed a significant decrease among 1-month quitters, whereas those less likely to utilize behavioral processes were more likely to have relapsed after 1 month.

An asthma sports camp series to identify children with possible asthma and cardiovascular risk factors

BACKGROUND

The prevalence of asthma and obesity in children has increased over the past several years, with obesity being associated with higher rates of asthma. In response to known disparities in asthma prevalence and morbidity, along with barriers to diagnosis, assessment and education, a comprehensive asthma sports camp series was developed and implemented.

OBJECTIVE

The primary objective was to evaluate the effectiveness of utilizing a sports camp model to identify children with undiagnosed and uncontrolled asthma, and to provide recommendations for follow-up care. The secondary objectives were to identify the presence of and associations between related co-morbidities and risk factors for asthma morbidity such as obesity, hypertension and exposure to tobacco smoke; and to assess asthma medication use.

METHODS

Six daylong camps at an inner-city university were offered to children 5-17 years of age over a period of two years. Asthma, body mass index, blood pressure (BP) and carbon monoxide screenings were conducted at each camp.

RESULTS

In this sample, 43.7% of children had previously diagnosed asthma, and 12.6% were classified as having potential, undiagnosed asthma. Of the children with previously diagnosed asthma, 76% were considered uncontrolled. Thirty-eight percent were determined to be overweight or obese and 17% had elevated BP.

CONCLUSIONS

An interdisciplinary sports camp model can be used to identify children with undiagnosed and uncontrolled asthma and cardiovascular risk factors; and to provide recommendations for follow-up care.

The effectiveness of breath carbon monoxide analyzer in screening for environmental tobacco smoke exposure in Saudi pregnant women

BACKGROUND:

Exposure to environmental tobacco smoke (ETS) has harmful effects on the pregnancy outcomes similar to those observed in actively smoking pregnant women. The aim of this study was to estimate the sensitivity and specificity of the breath carbon monoxide (BCO) analysis in the assessment of smoking status among Saudi pregnant women, including ETS exposure compared to self-reported tobacco smoke exposure.

METHODS:

A cross-sectional design was used during January 2012, 560 pregnant women, irrespective of their gestational age, agreed to undergo BCO testing and completed the data collection sheet for the study. Sensitivity, specificity, positive and negative predictive values were calculated to compare the BCO test with self-reported exposure to ETS.

RESULTS:

Of the study population 151 (27%) women self-reported ETS exposure during the index pregnancy, 409 (73%) self-reported non-exposure. Sensitivity of the test was 32.5% (95% CI; 25.2-40.3%), the Specificity was much higher at 69.2% (95% CI; 64.4-73.5%), the positive predictive value was 28% (95% CI, 21.9-35.1%), and the negative predictive value was 73.5% (95% CI; 68.9-77.7%).

CONCLUSION:

The BCO test is an ineffective tool to detect the level of ETS exposure among Saudi pregnant women.

Alcohol, nicotine, and iatrogenic withdrawals in the ICU

OBJECTIVES

The neurophysiology, risk factors, and screening tools associated with alcohol withdrawal syndrome in the ICU are reviewed. Alcohol withdrawal syndrome assessment and its treatment options are discussed. Description of nicotine withdrawal and related publications specific to the critically ill are also reviewed. A brief comment as to sedative and opiate withdrawal follows.

DATA AND SUMMARY

The role of currently published alcohol withdrawal syndrome pharmacologic strategies (benzodiazepines, ethanol, clomethiazole, antipsychotics, barbiturates, propofol, and dexmedetomidine) is detailed. Studies on nicotine withdrawal management in the ICU focus mainly on the safety (mortality) of nicotine replacement therapy. Study characteristics and methodological limitations are presented.

CONCLUSION

We recommend a pharmacologic regimen titrated to withdrawal symptoms in ICU patients with alcohol withdrawal syndrome. Benzodiazepines are a reasonable option; phenobarbital appears to confer some advantages in combination with benzodiazepines. Propofol and dexmedetomidine have not been rigorously tested in comparative studies of drug withdrawal treatment; their use as additional or alternative strategies for managing withdrawal syndromes in ICU patients should therefore be individualized to each patient. Insufficient data preclude recommendations as to nicotine replacement therapy and management of iatrogenic drug withdrawal in ICU patients.

The effect of reducing the threshold for carbon monoxide validation of smoking abstinence--evidence from the English Stop Smoking Services

INTRODUCTION

The most commonly used threshold of expired-air carbon monoxide (CO) concentration to validate self-reported smoking abstinence is <10 parts per million (ppm). It has been proposed to reduce this threshold. This study examined what effect a reduction would have on short-term success rates in clinical practice.

METHODS

A total of 315,718 quit attempts supported by English NHS Stop Smoking Services were included in the analysis. The proportion of 4-week quits as determined by the Russell standard (<10ppm) that also met lower thresholds was calculated for each unit change from <9ppm to <2ppm. Additionally, associations of established predictors with outcome were assessed in logistic regressions for selected thresholds.

RESULTS

At <10ppm, 35% of quit attempts were regarded as successful. Differences for a single unit reduction increased with each reduction; small reductions had very little impact (e.g. <8ppm: 34.7% success), but at <3ppm, only 26.3% would still be regarded as successful. With the threshold reduced to <3ppm established predictors of cessation showed a weaker association with outcome than with the threshold at <10ppm suggesting an increase in error of outcome measurement.

CONCLUSIONS

Reducing the threshold for expired-air CO concentration to validate abstinence would have a minimal effect on success rates unless the threshold were reduced substantially which would likely increase error of measurement.

Exhaled carbon monoxide and its associations with smoking, indoor household air pollution and chronic respiratory diseases among 512,000 Chinese adults

BACKGROUND

Exhaled carbon monoxide (COex) level is positively associated with tobacco smoking and exposure to smoke from biomass/coal burning. Relatively little is known about its determinants in China despite the population having a high prevalence of smoking and use of biomass/coal.

METHODS

The China Kadoorie Biobank includes 512,000 participants aged 30-79 years recruited from 10 diverse regions. We used linear regression and logistic regression methods to assess the associations of COex level with smoking, exposures to indoor household air pollution and prevalent chronic respiratory conditions among never smokers, both overall and by seasons, regions and smoking status.

RESULTS

The overall COex level (ppm) was much higher in current smokers than in never smokers (men: 11.5 vs 3.7; women: 9.3 vs 3.2). Among current smokers, it was higher among those who smoked more and inhaled more deeply. Among never smokers, mean COex was positively associated with levels of exposures to passive smoking and to biomass/coal burning, especially in rural areas and during winter. The odds ratios (OR) and 95% confidence interval (CI) of air flow obstruction (FEV1/FVC ratio<0.7) for never smokers with COex at 7-14 and ≥14 ppm, compared with those having COex<7, were 1.38 (1.31-1.45) and 1.65 (1.52-1.80), respectively (Ptrend<0.001). Prevalence of other self-reported chronic respiratory conditions was also higher among people with elevated COex (P<0.05).

CONCLUSION

In adult Chinese, COex can be used as a biomarker for assessing current smoking and overall exposure to indoor household air pollution in combination with questionnaires.