Short-term exposure evaluation of adult smokers switching from conventional to first-generation electrically heated cigarettes during controlled smoking

This randomized, controlled study in 110 male and female adult smokers evaluated biomarkers of tobacco smoke exposure (carbon monoxide [CO], carboxyhemoglobin [CO-Hb], nicotine, urine mutagenicity) under controlled smoking conditions when adult smokers of 1 conventional cigarette brand (CC1) were switched to an electrically heated cigarette smoking system (EHCSS) or a low-tar conventional cigarette (CC2). Baseline exposure was determined while all subjects smoked CC1. Subjects then were stratified for gender and cigarette consumption and randomized to 1 of 5 groups-EHCSS1, EHCSS2, CC1, CC2, or no smoking-and monitored for 8 days. Compared to baseline, biomarkers of exposure on day 8 decreased 53% to 93% (P < .0001) for EHCSS groups and 18% to 39% (P < .02) for CC2. Environmental tobacco smoke arising from the smoking activities of the different study groups was measured in the air of a separate smoking room over 1-hour periods. Concentrations of respirable suspended particulates in both EHCSS groups were about 90% lower than in the CC1 and CC2 groups, similar to the 95% reduction in the no-smoking group. CO was undetectable in the EHCSS and no-smoking groups. Results from this short-term clinical study indicate that switching from a conventional cigarette to a first-generation EHCSS reduces the generation of environmental tobacco smoke and can reduce the exposure to the measured, potentially harmful constituents in tobacco smoke if smokers do not compensate by numbers of cigarettes. The study design was found to be suitable for the evaluation of the exposure of adult smokers to the measured smoke constituents and to allow the differentiation of different cigarette designs.

Nicotine and cotinine in adults' urine: The German Environmental Survey 1998

In 1998, the German Environmental Survey (GerES III) recruited approximately 5000 adults between the ages of 18 and 69 years. The study population for these analyses consisted of 1580 smokers (34% of the total population) and 3126 nonsmokers. Nicotine and cotinine concentrations in urine were determined by HPLC methods with UV-detection and corrected for creatinine. Nicotine and cotinine concentrations differed between smokers and nonsmokers by factors of 10-100. The multiple linear regression models used for the analyses of nicotine detection in the urine of smokers explained 43.2% and 42.3% of the total volume-specific and creatinine-specific variances, respectively. Cigarette smoking was the major factor responsible for 41% of the total variance. The explained variances of the cotinine results were larger, 51.0% and 49.3% of the total variance were volume-specific and creatinine-specific, respectively. More than 20% of nonsmokers in GerES III were exposed to environmental tobacco smoke at home, at work or in other places. The logistic regression analysis approach used for the group of nonsmokers showed the greatest effects for those exposed to tobacco smoke at home (adjusted OR varied between 4 and 6). These results were seen for nicotine as well as for cotinine excretion. Exposure to tobacco smoke in the workplace doubled the risk for the detection of nicotine and cotinine in urine. When other risk factors such as age, sex, social status, community size, season of urine collection, and the consumption of food containing nicotine such as potatoes, cabbage, tea were included, the effect estimates for tobacco smoke exposure remained unchanged. A new federal bill to diminish environmental tobacco smoke (ETS) exposure in the workplace was recently passed in Germany, but protection of nonsmokers from smoking family members at home needs more attention.

Simultaneous and Sensitive Measurement of Anabasine, Nicotine, and Nicotine Metabolites in Human Urine by Liquid Chromatography–Tandem Mass Spectrometry

Background: Determination of nicotine metabolism/pharmacokinetics provides a useful tool for estimating uptake of nicotine and tobacco-related toxicants, for understanding the pharmacologic effects of nicotine and nicotine addiction, and for optimizing nicotine dependency treatment.

Methods: We developed a sensitive method for analysis of nicotine and five major nicotine metabolites, including cotinine, trans-3′-hydroxycotinine, nicotine-N′-oxide, cotinine-N-oxide, and nornicotine, in human urine by liquid chromatography coupled with a TSQ Quantum triple quadrupole tandem mass spectrometer (LC/MS/MS). Urine samples to which deuterium-labeled internal standards had been added were extracted with a simple solid-phase extraction procedure. Anabasine, a minor tobacco alkaloid, was also included.

Results: The quantification limits of the method were 0.1–0.2 μg/L, except for nicotine (1 μg/L). Cotinine-N-oxide, trans-3′-hydroxycotinine, nicotine, and anabasine in urine were almost completely recovered by the solid-phase extraction, whereas the mean extraction recoveries of nicotine-N′-oxide, cotinine, and nornicotine were 51.4%, 78.6%, and 78.8%, respectively. This procedure provided a linearity of three to four orders of magnitude for the target analytes: 0.2–400 μg/L for nicotine-N′-oxide, cotinine-N-oxide, and anabasine; 0.2–4000 μg/L for cotinine, nornicotine, and trans-3′-hydroxycotinine; and 1.0–4000 μg/L for nicotine. The overall interday method imprecision and recovery were 2.5–18% and 92–109%, respectively.

Conclusions: This sensitive LC/MS/MS procedure can be used to determine nicotine metabolism profiles of smokers, people during nicotine replacement therapy, and passively exposed nonsmokers. This method avoids the need for a time-consuming and labor-intensive sample enrichment step and thus allows for high-throughput sample preparation and automation.

Measuring tobacco smoke exposure: quantifying nicotine/cotinine concentration in biological samples by colorimetry, chromatography and immunoassay methods

Procedures to assess tobacco smoke exposure are reviewed and biomarkers used for determining the smoking status of an individual are compared. Methods used to extract these biomarkers from saliva, urine, and blood and the advantages and disadvantages of the assays are discussed. Finally, the procedures used to measure the levels of cortisol, a stress hormone speculated to be linked to nicotine metabolism, are discussed.

A comparison of urinary biomarkers of tobacco and carcinogen exposure in smokers

Recently, several potential harm reduction strategies, such as reduction in the number of cigarettes smoked and the use of modified cigarette products, have been discussed as possible means by which to reduce tobacco-related disease. To assess any potential reduction in harm by either of these approaches requires an accurate assessment of tobacco toxin exposure. We have recently completed a cigarette reduction study in which smokers were required to reduce the number of cigarettes smoked by 75%. This reduction took place over a 6-week period. We report here the comparison of urinary concentrations of tobacco alkaloid and tobacco carcinogen biomarkers in a subset of these same smokers during a 7-week period prior to any reduction in cigarette consumption. Urine samples were collected at four time points and analyzed for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and its glucuronide, 1-hydroxypyrene, anatabine, free nicotine, total nicotine (free plus glucuronidated), free cotinine, total cotinine (free plus glucuronidated), and total trans-3'-hydroxycotinine (free plus glucuronidated). Anatabine is a minor alkaloid that may be useful in assessing tobacco exposure in individuals using nicotine replacement therapies. Urinary anatabine levels were well correlated (P < 0.0001) with both free and total nicotine (r = 0.753 and 0.773, respectively). Anatabine levels were also correlated with free cotinine (r = 0.465; P < 0.001), total cotinine (r = 0.514; P < 0.001), and total NNAL (r = 0.633; P < 0.001). These data support the role of anatabine as a biomarker of tobacco exposure. 1-Hydroxypyrene is a biomarker of polycyclic aromatic hydrocarbon exposure, but unlike NNAL it is not tobacco specific. Whereas urinary concentrations of 1-hydroxypyrene were consistent across the four visits, the levels were not correlated with NNAL, anatabine, nicotine, or any nicotine metabolites.

Smoking cigarettes of low nicotine yield does not reduce nicotine intake as expected: a study of nicotine dependency in Japanese males

BACKGROUND

Many Japanese believe that low-yield cigarettes are less hazardous than regular cigarettes, and many smokers consume low-yield cigarettes to reduce their risks from smoking. We evaluate the association between actual nicotine intake and brand nicotine yield, and the influence of nicotine dependence on this association.

METHODS

The study subjects included 458 Japanese male smokers, aged 51.2 +/- 9.9 years, who participated in health check-ups in a hospital in 1998 and 2000. Each subject filled out a self-administered smoking questionnaire and the score of each on the Fagerström Test for Nicotine Dependence was calculated. Urinary cotinine concentration was measured at the time of participation.

RESULTS

The geometric mean of urinary cotinine concentration was 535 ng/mgCr for those who smoked brands with the lowest nicotine (0.1 mg on the package), compared with 1010 ng/mgCr for those who smoked brands with the highest (0.9-2.4 mg, weighted mean of 1.1 mg). Thus, despite the 11-fold ratio of nicotine yield on the packages, the ratio of urinary cotinine level was less than twofold. Both nicotine yield on the package and nicotine dependence significantly increased urinary cotinine concentration, and the negative interaction between them almost attained statistical significance. Cotinine concentration in heavily dependent smokers was consistently high regardless of the nicotine yield of brands.

CONCLUSIONS

The nicotine yield of cigarettes measured by machine-smoking does not reliably predict the exposure of smokers. Smokers consuming low-yield nicotine cigarettes did not reduce actual intake of nicotine to the level that might be expected, especially for those heavily dependent on nicotine. Current labeling practices are misleading for the two-third of smokers who are moderately or highly dependent on nicotine.

Feedback from a point-of-care test for nicotine intake to reduce smoking during pregnancy

BACKGROUND

Smoking is the most important modifiable risk factor for adverse pregnancy outcome in the UK. New tools are needed to improve smoking cessation advice. The aim was to investigate a point-of-care urine test for smoking, to provide feedback to women, to improve awareness about the effects of smoking during pregnancy and to relate the test results to pregnancy outcome.

METHODS

A cross-sectional randomized controlled trial involving 856 pregnant women. All intervention patients were interviewed at their initial visit and tested for smoking. The test provided visual and numerical feedback. Smokers were followed up and retested at subsequent visits. The control group received anti-smoking counselling as part of routine care, but their smoking was monitored using the test. Both groups were interviewed and retested at 36 weeks' gestation.

RESULTS

Self-reported cigarette consumption fell significantly (P < 0.001) in the intervention group, with 16.2% giving up and 33.3% significantly reducing their cigarette consumption. There was a significant fall in test results from 'booking' to 36 weeks' gestation (P < 0.0001). In the control group, only 8% reported stopping and 23% reducing their cigarette consumption. Combined smoking test results at 36 weeks correlated significantly with birth weight (P = 0.006) and body length (P = 0.011).

CONCLUSIONS

Point-of-care testing and feedback coupled with counselling can significantly reduce smoking during pregnancy and increase birthweight.

Assessment of smoking status among workers using an improved colorimetric method

To monitor smoking status among workers, we improved the colorimetric method to detect cotinine and other nicotine metabolites in urine. In adding ethanol in the reaction mixture, the quantitative measurable time defined as the duration with more than 95% of the peak absorbance, extended to 80 min in contrast to 16 min in the original method. As the analytical condition, a aliquot of urine sample (0.5 ml) was mixed with 0.5 ml of ethanol, with 0.2 ml of 4 M acetate buffer (pH: 4.7), with 0.1 ml of 150 mM KCN, with 0.1 ml of 0.44 M chloramin and then with 0.5 ml of 78 mM barbituric acid. A linear relationship was observed between cotinine concentration up to 80 microM and absorbance at 508 nm (r=0.998, p<0.01). Mean levels of nicotine metabolites among non smokers and smokers were 4.9 and 47.4 microM cotinine equivalent, respectively. Sensitivity and specificity were 96.1% and 96.7%, respectively for nicotine metabolites concentration among workers (n=385) when adopting 6.9 microM cotinine equivalent as a cut off value and the area under the ROC curve was 0.982. This method can be applicable to quantitative detection of smoking status.

Nicotine and cotinine levels in blood and urine from forensic autopsy cases

We measured nicotine and cotinine levels in blood and urine from 31 forensic autopsy cases. Initially, we developed a sensitive and reproducible gas chromatographic method with a minimum limit of detection of 2.1 ng/ml for both nicotine and cotinine. Calibration curves for nicotine and cotinine were linear in the ranges of 2.1-1030 ng/ml (r2=0.994-0.999) and 2.1-1380 ng/ml (r2=0.998-0.999) respectively. Our population included 13 smokers and eight of these smokers committed suicide. They showed high levels of nicotine and cotinine at 65.1-205 ng/ml (mean: 115 ng/ml) and 31.3-938 ng/ml (mean: 405 ng/ml) in blood, respectively, and 234-7290 ng/ml (mean: 1940 ng/ml) and 143-4620 ng/ml (mean: 1170 ng/ml) in urine, respectively. None of these individuals consumed nicotine preparations or tobacco leaves. In five smokers who did not commit suicide, nicotine and cotinine levels were 4.4-62.1 ng/ml (mean: 33.2 ng/ml) and 49.9-217 ng/ml (mean: 140 ng/ml) in blood, respectively, and 158-314 ng/ml (mean: 246 ng/ml) and 68.9-300 ng/ml (mean: 179 ng/ml) in urine, respectively. Our results suggest that there may be a marked increase in consumption of cigarettes in smokers with suicidal thoughts.

Determination of nicotine and cotinine in tobacco harvesters’ urine by solid-phase extraction and liquid chromatography

A solid-phase extraction method using Drug Test-1 column containing chemically modified silica as a solid support for sample clean up and reversed phase ion-paired high-pressure liquid chromatography method have been developed for the simultaneous determination of nicotine and its metabolite cotinine from the urine samples. Mobile phase was consisted of acetate buffer (containing 0.03 M sodium acetate and 0.1 M acetic acid) pH 3.1 and acetonitrile (78:22% (v/v)) containing 0.02 M sodium octanosulfonate as an ion pair agent. pH of the mobile phase was adjusted to 3.6 with triethylamine for better resolution and to prevent peak tailing. The linearity was obtained in the range of 0.5-10 microg/ml concentrations of nicotine and cotinine standards. The correlation coefficients were 0.998 for cotinine and 0.999 for nicotine. The recoveries were obtained in the range of 79-97% with average value of 85% for nicotine and in the range of 82-98% with average value of 88% for cotinine. The limit of detection was 2 ng/ml for cotinine and 5 ng/ml for nicotine with 2 ml urine for extraction, calculated by taking signal to noise ratio 10:3. The intra-day co-efficient of variation (CV) were <4 and 7% and inter-day CV were <9 and 7% for nicotine and cotinine, respectively. The method was applied to the urine samples of tobacco harvesters, who suffer from green tobacco sickness (GTS) to check the absorption of nicotine through dermal route during the various processes of tobacco cultivation due to its good reproducibility and sensitivity.

Comparison between self-report and a dipstick method (NicCheck 1) to assess nicotine intake

The purpose of this study was to investigate the agreement between self-reported tobacco consumption and NicCheck 1 (Dynagen Inc. Cambridge, Mass., USA) regarding smoking status and nicotine intake in a population of smokers (20.8%) and non-smokers. NicCheck 1 is a dipstick that changes colour in the presence of urinary nicotine metabolites. Smoking was assessed by self-report and NicCheck 1 in 169 males and 191 females (mean age 36.0 SD 0.7). Self-report and NicCheck 1 agreed highly on smoking status, especially in moderate to heavy smokers. With regard to nicotine intake, there was a large overlap in self-reported tobacco consumption between NicCheck 1 levels, despite a relatively high correlation coefficient between self-report and NicCheck 1 in smokers (i.e. 0.74). No effect modification by gender or BMI was found. When both methods were validated against two blood lipid parameters, self-report seemed to do equally well as NicCheck 1 in assessing nicotine intake.

Determination of nicotine and its metabolites in urine by solid-phase extraction and sample stacking capillary electrophoresis-mass spectrometry

The combination of capillary electrophoresis (CE) and mass spectrometry (MS) with solid-phase extraction (SPE) has been used for the identification of nicotine and eight of its metabolites in urine. The recovery of cotinine from cotinine-spiked urine, by C18 SPE, was found to be 98%. Smokers urine (200 ml) was preconcentrated 200-fold via SPE prior to analysis. The sample stacking mode of CE, when compared to capillary zone electrophoresis, was shown to improve peak efficiency by 132-fold. The combination of hydrodynamic and electrokinetic injection was studied with sample stacking/CE/MS. The on-column limits of detection (LOD) of nicotine and cotinine, by this technique, were found to be 0.11 and 2.25 microg/ml, respectively. Hence, LODs of nicotine and cotinine in urine after 200-fold preconcentration were 0.55 and 11.25 ng/ml, respectively.

Urinary levels of nicotine & cotinine in tobacco users

BACKGROUND & OBJECTIVES

Of the various biochemical markers used to validate the smoking status of a person, nicotine and continine are considered as good markers for both active and passive smoking. In the present study an attempt was made to estimate urinary levels of nicotine and cotinine in healthy individuals from north India using different types of tobacco to identify and validate the smoking status.

METHODS

Twenty four hour urine sample of 130 healthy volunteers (smokers=70, passive smokers=20, tobacco chewers=20, non smokers=20) were analyzed by high-pressure liquid chromatography (HPLC) assay. Smokers were divided into different groups, viz., cigarette, bidi and hooka smokers.

RESULTS

The mean values of nicotine (ng/ml) and cotinine (ng/ml) in urine were highest in cigarette smokers (nicotine=703.50+/-304.34; cotinine=2736.20+/-983.29), followed by hooka smokers (nicotine 548.0+/-103.47 and cotinine 2379.0+/-424.25), and bidi smokers (nicotine=268.53+/-97.62, cotinine=562.60+/-249.38). There was no correlation of nicotine or cotinine values with smoking index. In passive smokers (nicotine=109.75+/-22.33, cotinine=280.75+/-86.30) and in nonsmokers, the values were much lower (nicotine=55.00+/-13.71, cotinine=7.30+/-2.47) compared to smokers. In tobacco chewers, the values for nicotine and cotinine were 447.75+/-145.09 and 2178.30+/-334.29 respectively.

INTERPRETATION & CONCLUSION

All forms of tobacco users had significantly higher values compared to passive smokers and nonusers. Thus, cotinine and nicotine levels in urine may be considered as good indicators to assess the exposure to tobacco in our population.

The influence of pH and nicotine concentration in oral moist snuff on mucosal changes and salivary pH in Swedish snuff users

The use of Swedish oral moist snuff is a widespread habit in Sweden. In 1999, 25% of the adult male population and 3.1% of the female population were users of snuff. The aim of the present study was to evaluate how variations in pH and nicotine concentrations of snuff affect the oral mucosa, clinically and histologically, salivary pH and daily nicotine intake in 20 habitual users of loose snuff. The subjects were studied during use of their usual brand, after 12 weeks use of a snuff with lower pH and after another 12 weeks use of a snuff with both lower pH and lower nicotine concentration. Consumption data, oral soft tissue changes, salivary pH and nicotine intake were measured. Further, biopsies were taken from the central part of the clinically observed lesions and histological changes were analysed. The subjects maintained their snuff consumption during the observation periods. The average salivary pH was higher during snuff use than in the morning. Further, it was higher shortly after the snuff was removed than during snuff use. After having switched to the snuff with both lower pH and lower nicotine concentrations, they showed a significant reduction in daily nicotine intake and developed significantly less pronounced clinical and histological changes. These results indicate that nicotine is one of the substances in snuff that has a biological effect on the oral mucosa. However, there also seems to be a synergistic effect between the pH and nicotine concentration in the snuff.

Increased respiratory symptoms following surgery in children exposed to environmental tobacco smoke

OBJECTIVE

The aim of this study was to determine if children exposed to environmental tobacco smoke (ETS) via parental smoking (ETS+) developed more respiratory symptoms resulting in longer recovery times following surgical outpatient procedures compared with children of nonsmoking parents (ETS-).

METHODS

One hundred and forty six children (4.9 +/- 3 years) undergoing inguinal hernia repair were prospectively studied. Parental smoking behaviour was determined by survey and urine analysis. Seven respiratory symptoms were evaluated during induction and emergence from anaesthesia and during the recovery room (RR) stay.

RESULTS

Fifty-seven (39%) families admitted a smoking history while 89 (61%) denied it. This strongly correlated with the cotinine/creatinine ratio (Pearson correlation coefficient = 0.76; P = 0.01). ETS exposure was associated with an increased frequency of RR symptoms (ETS+: 56%; ETS-: 31%; P = 0.007).

CONCLUSIONS

In children undergoing general anaesthesia for inguinal hernia repair, ETS exposure was associated with an increased frequency of respiratory symptoms during emergence from anaesthesia and during postoperative recovery.

Occupational exposure of non-smoking restaurant personnel to environmental tobacco smoke in Finland

BACKGROUND

Environmental tobacco smoke (ETS) exposure levels in different restaurant types in Finland were assessed before the National Tobacco Act restricting smoking in restaurants was activated.

METHODS

Exposure to ETS was determined by measuring nicotine in the breathing zone of non-smoking restaurant workers and by quantification of the nicotine metabolites cotinine and 3-hydroxycotinine in the urine of these workers during one whole work week. Altogether 23 workers from 15 restaurants were included in the study.

RESULTS

The geometric mean (GM) breathing-zone nicotine level was 3.9 microg/m(3) (3.7 microg/m(3) in pubs, 1.4 microg/m(3) in dining restaurants, and 10.2 microg/m(3) in nightclubs). The GM cotinine and trans-3'-hydroxycotinine level in urine were 3.3 ng/mg((creatinine)) and 15.3 ng/mg((creatinine)), respectively. The exposure to ETS of restaurant workers in dining restaurants was clearly lower than that of workers in pubs and nightclubs as indicated by all ETS-markers used in the present study. During the work week, the cotinine and 3'-hydroxycotinine levels in urine of the study subjects increased. The correlation between breathing zone nicotine and urine cotinine and hydroxycotinine was 0.66 for both compounds. Post-shift cotinine and hydroxycotinine levels were not significantly higher than the pre-shift levels.

CONCLUSIONS

If 9 ng cotinine/mg((creatinine)) is considered as the level above which heavy exposure has occurred, then this level was exceeded by 14 (approximately 60%) subjects at least once during the work week. Nicotine metabolite concentrations in the urine increased during the work week in 80% of the subjects, and the increase was especially noticeable for subjects working in both pubs and nightclubs. The study indicates that measures to restrict ETS exposure in restaurants are needed.

Exposure to environmental tobacco smoke in restaurants without separate ventilation systems for smoking and nonsmoking dining areas

In this study, the author examined (a) levels of airborne pollutants from environmental tobacco smoke in 8 restaurants, and (b) changes in urinary cotinine and nicotine levels among 97 nonsmoking subjects (i.e., 40 restaurant employees, 37 patrons, and 20 referents). Airborne pollutant levels were significantly lower in the control environments than in the nonsmoking dining rooms in which smoking was not permitted, and the levels were significantly lower in the dining rooms in which smoking was not permitted than in the dining rooms in which smoking was permitted. Levels of urinary cotinine and nicotine increased among subjects in the dining rooms in which smoking was permitted, and the increase was significantly greater in employees than patrons. There was a significant positive correlation between levels of urinary nicotine increase and the levels of airborne nicotine and solanesol. The results of this study support the restriction of smoking to designated areas that have separate ventilation systems, or the prohibition of smoking in restaurants.

Relationship between the level and time of exposure to tobacco smoke and urine nicotine and cotinine concentration

The study attempts to evaluate whether it is possible to determine time and level of exposure of rats to tobacco smoke based on nicotine and cotinine content in urine. The animals were exposed to tobacco smoke by inhalation in a specially designed experimental chambers. The exposure to three different tobacco smoke levels (500, 1000 and 1500 mg CO/m3 of air) lasted 6 h per day, for one, three and five days. Nicotine and cotinine concentrations were measured in daily urine using high performance liquid chromatography procedure developed by the authors. It has been shown that cotinine but not nicotine can be used as a biomarker of time and extent of exposure to tobacco smoke.

Anabasine and anatabine as biomarkers for tobacco use during nicotine replacement therapy

In this study we determined urine concentration of the tobacco alkaloids anabasine and anatabine, nicotine and its metabolites cotinine, and nornicotine in 99 cigarette smokers and 205 smokeless tobacco users. We also investigated the possibility that anabasine and anatabine can be used as biomarkers for tobacco use during nicotine replacement therapy. Urine samples and data on self-reported tobacco use were obtained from subjects enrolled in tobacco cessation programs. Urine concentrations of tobacco alkaloids and metabolites were measured and correlated with self-reported tobacco use. Concentrations of anabasine and anatabine were used to validate abstinence in smokeless tobacco users who used nicotine gum as part of the therapy. Correlations of alkaloid concentration with self-reported tobacco use before treatment ranged from fair to poor. In subjects abstaining from smokeless tobacco but using nicotine gum, anabasine and anatabine levels were below the cut-point of 2 ng/ml despite high concentrations of nicotine and cotinine resulting from nicotine gum use. Anabasine and anatabine concentrations in urine can be used to validate abstinence or measure the extent of tobacco use in persons undergoing nicotine replacement therapy.

[The exposure to tobacco smoking]

The exposition to tobacco smoke is overall: in home, work and public places. For the examination of the presence and concentration of environmental tobacco smoke (ETS) in indoor environments the nicotine and respirable suspended particulates (RSP) are determined. A variety of biomarkers (nicotine, cotinine, thiocyanate, carboxyhemoglobin, protein and DNA adducts) are propose for measurement of exposure to tobacco smoke. The most popular is measurement of cotinine concentration in body fluids (blood, urine, saliva). Plasma cotinine concentration correlated to numbers of cigarettes smoked and to various biological effects of cigarette smoking and exposure to ETS. Other biomarkers as carboxyhemoglobin, thiocyanate, and amines and polycyclic aromatic hydrocarbons adduct can be also use.

Tobacco-smoke exposure indicators and urinary mutagenicity

In this study, the correlation of indicators of external (i.e. mean daily intake of condensate, nicotine, tobacco and tobacco proteins, and daily number of cigarettes smoked) and of internal tobacco-smoke exposure (i.e. urinary 1-pyrenol, nicotine and its metabolites and trans,trans-muconic acid) with urinary mutagenicity, detected on YG1024 Salmonella typhimurium strain with S9, were examined in 118 smokers. An increase in urinary mutagenicity was clearly significantly correlated with each external and internal indicators of exposure to tobacco smoke (correlation coefficient (r) ranging between 0.22 and 0.54, P<0.01), with a greater extent in the case of indicators of internal dose. In multiple regression analysis, among the indicators of external exposure, daily tobacco intake was the only variable significantly associated with urinary mutagenicity (t=2.47, P=0.015, with partial contribution to r(2)=5.15%). Instead, when all indicators of exposure (external and internal) were considered in the analysis, the influence of urinary 1-pyrenol on urinary mutagenicity was predominant, followed by those of urinary trans,trans-muconic acid and nicotine plus metabolites (t=4.63, 2.73 and 2.08, P<0.001, P=0.002 and 0.04, with partial contribution to r(2)=17.0, 6.66 and 3.96%, respectively), with no influence at all of external tobacco-smoke exposure indicators. In conclusion, our results show that indicators of internal dose are better correlated with formation of mutagens in urine of smokers. Among these, the best indicator was urinary 1-pyrenol and this result designates the combustion processes of tobacco as the determining step for the formation of urinary mutagens. However, as these biomarkers cannot be analysed the amount of daily tobacco intake represent the best valuable index of external (presumptive) exposure to tobacco-smoke genotoxins.

Simultaneous determination of nicotine and eight nicotine metabolites in urine of smokers using liquid chromatography-tandem mass spectrometry

A method based on liquid chromatography tandem mass spectrometry (LC-MSMS) applying atmospheric pressure chemical ionisation (APCI) in the positive ion mode was developed for the direct determination of nicotine, cotinine, trans-3'-hydroxycotinine, their corresponding glucuronide conjugates as well as cotinine-N-oxide, norcotinine, and nicotine-N'-oxide in the urine of smokers. The assay involves filtration of crude urine, fast liquid chromatography on a reversed-phase column and mass-specific detection using MSMS transitions. Deuterium-labeled nicotine, cotinine, and trans-3'-hydroxycotinine were used as internal standards. Glucuronides used as reference material were either chemically (cotinine-N-glucuronide) or enzymatically synthesized (nicotine-N-glucuronide and trans-3'-hydroxycotinine-O-glucuronide). Precision for the major nicotine analytes at levels observable in urine of smokers was better than 10%. Accuracy expressed in recovery rates in urine matrix for nicotine, cotinine, trans-3'-hydroxycotinine, and cotinine-N-glucuronide ranged from 87 to 113%. Quantitative results for the three glucuronides in urine samples of 15 smokers were compared to an indirect method in which the aglycons were determined with gas chromatography and nitrogen-selective detection (GC-NPD) before and after enzymatic splitting of the conjugates. Good agreement was found for cotinine-N-glucuronide (coefficient of variation, CV: 9%) and trans-3'-hydroxycotinine-O-glucuronide (CV: 20%), whereas the accordance between both methods was moderate for nicotine-N-glucuronide (CV: 33%). The described LC-MSMS method allows the simultaneous determination of nicotine and eight of its major metabolites in urine of smokers with good precision and accuracy. Since the method requires a minimum of sample clean-up and a very short time for chromatography (3 min), it is suitable for determining the nicotine dose in large-scale human biomonitoring studies.

Simultaneous analysis of nicotine, nicotine metabolites, and tobacco alkaloids in serum or urine by tandem mass spectrometry, with clinically relevant metabolic profiles

BACKGROUND

Assessment of nicotine metabolism and disposition has become an integral part of nicotine dependency treatment programs. Serum nicotine concentrations or urine cotinine concentrations can be used to guide nicotine patch dose to achieve biological concentrations adequate to provide the patient with immediate relief from nicotine withdrawal symptoms, an important factor in nicotine withdrawal success. Absence of nicotine metabolites and anabasine can be used to document abstinence from tobacco products, an indicator of treatment success.

METHODS

The procedure was designed to quantify nicotine, cotinine, trans-3'-hydroxycotinine, anabasine, and nornicotine in human serum or urine. The technique required simple extraction of the sample with quantification by HPLC-tandem mass spectrometry.

RESULTS

The procedure for simultaneous analysis of nicotine, its metabolites, and tobacco alkaloids simultaneously quantified five different analytes. Test limit of quantification, linearity, imprecision, and accuracy were adequate for clinical evaluation of patients undergoing treatment for tobacco dependency. The test readily distinguished individuals who had no exposure to tobacco products from individuals who were either passively exposed or were abstinent past-tobacco users from those who were actively using a tobacco or nicotine product.

CONCLUSIONS

Nicotine, cotinine, trans-3'-hydroxycotinine, nornicotine, and anabasine can be simultaneously and accurately quantified in either serum or urine by HPLC-tandem mass spectrometry with imprecision <10% at physiologic concentrations and limits of quantification ranging from 0.5 to 5 micro g/L. Knowledge of serum or urine concentrations of these analytes can be used to guide nicotine replacement therapy or to assess tobacco abstinence in nicotine dependency treatment. These measurements are now an integral part of the clinical treatment and management of patients who wish to overcome tobacco dependence.