Estimation of urinary cotinine cut-off points distinguishing non-smokers, passive and active smokers

An objective assessment of exposure to tobacco smoke may be accomplished by means of examining particular biomarkers in body fluids. The most common biomarker of tobacco smoke exposure is urinary, or serum, cotinine. In order to distinguish non-smokers from passive smokers and passive smokers from active smokers, it is necessary to estimate cotinine cut-off points. The objective of this article was to apply statistical distribution of urinary cotinine concentration to estimate cut-off points distinguishing the three above-mentioned groups. The examined group consisted of 327 volunteers (187 women and 140 men) who were ethnically homogenous inhabitants of the same urban agglomeration (Sosnowiec, Poland). The values which enabled differentiation of the examined population into groups and subgroups were as follows: 50 µg l^-1 (differentiation of non-smokers from passive smokers), 170 µg l^-1 (to divide the group of passive smokers into two subgroups: minimally and highly exposed to environmental tobacco smoke), 550 µg l^-1 (differentiation of passive smokers from active smokers), and 2100 µg l^-1 (to divide group of active smokers into two subgroups: minimally and highly exposed to tobacco smoke). The results suggest that statistical distribution of urinary cotinine concentration is useful for estimating urinary cotinine cut-off points and for assessing the smoking status of persons exposed to tobacco smoke.     

Estimation of urinary cotinine cut-off points distinguishing non-smokers,passive and active smokers

Abstract

An objective assessment of exposure to tobacco smoke may be accomplished by means of examining particular biomarkers in body fluids. The most common biomarker of tobacco smoke exposure is urinary, or serum, cotinine. In order to distinguish non-smokers from passive smokers and passive smokers from active smokers, it is necessary to estimate cotinine cut-off points. The objective of this article was to apply statistical distribution of urinary cotinine concentration to estimate cut-off points distinguishing the three above-mentioned groups. The examined group consisted of 327 volunteers (187 women and 140 men) who were ethnically homogenous inhabitants of the same urban agglomeration (Sosnowiec, Poland). The values which enabled differentiation of the examined population into groups and subgroups were as follows: 50 µg l^?1 (differentiation of non-smokers from passive smokers), 170 µg l^?1 (to divide the group of passive smokers into two subgroups: minimally and highly exposed to environmental tobacco smoke), 550 µg l^?1 (differentiation of passive smokers from active smokers), and 2100 µg l^?1 (to divide group of active smokers into two subgroups: minimally and highly exposed to tobacco smoke). The results suggest that statistical distribution of urinary cotinine concentration is useful for estimating urinary cotinine cut-off points and for assessing the smoking status of persons exposed to tobacco smoke.     

Passive exposure to tobacco smoke in children aged 5-7 years: individual,family, and community factors.

OBJECTIVE--To examine the importance of parental smoking on passive exposure to tobacco smoke in children and the social and geographical patterns of exposure. DESIGN--Cross sectional study. SETTING--Schools in 10 towns in England and Wales; five towns with high adult cardiovascular mortality and five with low rates. SUBJECTS--4043 children aged 5-7 years of European origin. MAIN OUTCOME MEASURES--Salivary cotinine concentration and parents self reported smoking habits. RESULTS--1061 (53.0%) children were exposed to cigarette smoke at home or by an outside carer. Geometric mean cotinine rose from 0.29 (95% confidence interval 0.28 to 0.31) ng/ml in children with no identified exposure to 4.05 (3.71 to 4.42) ng/ml in households where both parents smoked and 9.03 (6.73 to 12.10) ng/ml if both parents smoked more than 20 cigarettes a day. The effect of mothers'' smoking was greater than that of fathers'', especially at high levels of consumption. After adjustment for known exposures geometric mean cotinine concentrations rose from 0.52 ng/ml in social class I to 1.36 ng/ml in social class V (P < 0.0001); and were doubled in high mortality towns compared with the low mortality towns (P = 0.002). In children with no identified exposure similar trends by social class and town were observed and the cotinine concentrations correlated with the prevalence of parental smoking, both between towns (r = 0.69, P = 0.02) and between schools within towns (r = 0.50, P < 0.001). CONCLUSIONS--Mothers'' smoking is more important that fathers'' despite the lower levels of smoking by mothers. Children not exposed at home had low cotinine concentration, the level depending on the prevalence of smoking in the community.     

Increases in tobacco exposure biomarkers measured in non-smokers exposed to sidestream cigarette smoke under controlled conditions

National surveys of the exposure of non-smokers to secondhand smoke based on serum cotinine analyses have consistently identified certain groups within the population including children, males and non-Hispanic Blacks as having relatively greater exposure. Although these differences in mean serum cotinine concentrations probably represent differences in exposure of individuals in their daily lives, it is also possible that metabolic or other differences in response might influence the results. To better define the nature of those findings, we have examined the response of 40 non-smokers including both men and women and African-Americans and whites to sidestream (SS) cigarette smoke generated by a smoking machine under controlled conditions. In this study, participants were exposed to aged, diluted SS smoke (ADSS) generated in an environmental chamber with a mean air nicotine concentration of 140 μg m^?3 and 8.6?ppm CO for 4?h. Salivary cotinine was measured every 30?min, and serum cotinine samples were taken prior to, and 2?h after exposure. Urinary nicotine metabolites and NNAL, a tobacco-specific nitrosamine, and 4-aminobiphenyl (4-AB) haemoglobin adducts were also measured prior to and 2?h following the exposure. Under these uniform, controlled conditions, we found a similar response to ADSS smoke exposure among all the participants. In all cases a significant increase in biomarker concentration was noted following exposure, and the short-term increases in salivary cotinine concentration were quite similar at approximately 12?pg ml^?1 min^?1 among the groups. In this small study, no significant differences by gender or race were seen in the mean increases observed in cotinine, NNAL or 4-AB adducts following 4?h of exposure. Thus, our results are most consistent with a relatively uniform response in tobacco biomarker concentrations following short-term exposure to ADSS tobacco smoke, and suggest that biomarker measurements are capable of effectively indicating increases in exposure among groups of non-smokers.     

Effect of maternal tobacco smoking or exposure to second-hand smoke on the levels of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) in urine of mother and the first urine of newborn

Tobacco smoking during pregnancy is associated with a variety of negative consequences not only for the mother, but also for the developing fetus. Many studies have shown that carcinogens contained in tobacco smoke permeate across the placenta, and are found in fetus. The aim of the study was to determine the prenatal exposure to tobacco-specific carcinogenic N-nitrosamines on the basis of measurements of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) in urine of smoking and second-hand smoke (SHS) exposed women and in the first urine of their newborns. A questionnaire documenting demographics and socio-economical data, smoking habits and exposure to SHS was completed by 121 delivering women near or at term. Maternal concentrations of cotinine and NNAL were measured in urine of the mother and the first urine of her newborn infant by liquid chromatography tandem mass spectrometry (LC/MS/MS). The mean concentration of cotinine was 439.2 ng/mg creatinine and NNAL concentration in urine of smoking women was 74.0 pg/mg creatinine, and for her newborn 78.6 pg/mg creatinine. Among mothers exposed to SHS, cotinine and NNAL mean concentration were 23.1 ng/mg creatinine, and 26.4 pg/mg creatinine. In newborns of SHS exposed mothers during pregnancy the mean concentration of NNAL was 34.1 pg/mg creatinine, respectively. Active tobacco smoking as well as passive exposure to smoking during pregnancy is an important source of tobacco specific N-nitrosamines to the fetuses as evidenced by increased concentrations of this carcinogen. Determination of NNAL in maternal urine samples can be a useful biomarker of prenatal exposure of newborn to carcinogenic nitrosamines.     

Duration and recurrence of otitis media with effusion in children from birth to 3 years: prospective study using monthly otoscopy and tympanometry.

OBJECTIVE: To monitor the natural course of otitis media with effusion. DESIGN: Prospective, longitudinal assessment of the state of the middle ear by otoscopy and tympanometry at monthly intervals from birth to 3 years. SETTING: Domiciliary visits to family homes. SUBJECTS: 95 full term infants born between August 1991 and November 1993. MAIN OUTCOME MEASURES: Observed and simulated data (Monte Carlo) for the duration of single episodes of otitis media with effusion. RESULTS: 17 of the children had unilateral or bilateral otitis media with effusion for more than half of their first three years of life. Thirty three of the 95 children had tympanograms suggestive of otitis media with effusion at more than a third of observations; the remaining 62 had such tympanograms at less than a third of observations. The data of each group were described by a first order Markov model, yielding a mean duration of unilateral effusion episodes of 5-6 weeks in both groups; the mean duration of bilateral effusion was 6 and 10 weeks in the low and high incidence groups, respectively. However, the main difference between the groups was the time spent between episodes of effusion: effusion free periods were, on average, three times longer in the children who experienced less otitis media with effusion. CONCLUSION: Children who are susceptible to otitis media with effusion tend to have more separate episodes of effusion rather than an increased overall duration of episodes. Such children are primarily distinguished by the likelihood with which they acquire the disease than by their ability to recover from it.     

Changes in the salivary cotinine cut-offs to discriminate smokers and non-smokers before and after Spanish smoke-free legislation

IntroductionHigh levels of cotinine in non-smokers indicate passive exposure to tobacco smoke. This study aims to evaluate variations in salivary cotinine cut-offs to discriminate smokers and non-smokers before and after the implementation of smoke-free legislation (Law 28/2005 and Law 42/2010) in a sample of the adult population of Barcelona, Spain.MethodsThis longitudinal study analyzes salivary cotinine samples and self-reported information from a representative sample (n = 676) of the adult population from Barcelona before and after the approval of smoke-free legislation. We calculated the receiver operating characteristic (ROC) curves, to obtain optimal cotinine cut-off points to discriminate between smokers and non-smokers overall, by sex and age, and their corresponding sensitivity, specificity, and area under the curve. We used linear mixed-effects models, with individuals as random effects, to model the percentage change of cotinine concentration before and after the implementation of both laws.ResultsThe mean salivary cotinine concentration was significantly lower post-2010 law (−85.8%, p < 0.001). The ROC curves determined that the optimal cotinine cut-off points for discriminating non-smokers and smokers were 10.8 ng/mL (pre-2005 law) and 5.6 ng/mL (post-2010 law), with a post-2010 law sensitivity of 92.6%, specificity of 98.4%, and an area under the curve of 97.0%. The post-2010 law cotinine cut-off points were 5.6 ng/mL for males and 1.9 ng/mL for females.ConclusionThe implementation of Spanish smoke-free legislation was effective in reducing secondhand smoke exposure and, therefore, also in reducing the cut-off point for salivary cotinine concentration. This value should be used to better assess tobacco smoke exposure in this population.     

Cytogenetic effects of tobacco smoke exposure among involuntary smokers

Tobacco smoke is highly genotoxic and produces chromosomal damage in several experimental systems. Active smokers have been shown to have an increased prevalence of somatic chromosome damage in their peripheral blood lymphocytes: this is seen in most cases as an increased sister-chromatid exchange (SCE) frequency and often also as increased structural chromosome aberrations (CAs). Among passive smokers, in association with exposure to environmental tobacco smoke, no such induction of chromosomal damage has been documented. In the present paper we report negative results on induction of chromosomal damage in 2 separate groups of intensive involuntary exposure to tobacco smoke, non-smoking restaurant personnel and newborn children of smoking mothers. While significant exposure in these groups is clearly seen in biochemical intake markers, e.g. cotinine and thiocyanate values in plasma, the conventional cytogenetic parameters, structural chromosome aberrations and sister-chromatid exchanges, are unable to detect the low exposures of involuntary smokers.     

Simple, rapid and sensitive assay method for simultaneous quantification of urinary nicotine and cotinine using gas chromatography-mass spectrometry

Nicotine is a major addictive compound in cigarette. Its smoke is rapidly and extensively metabolized to several metabolites in human. Cotinine as a major metabolite of nicotine is commonly used as a biomarker to determine active and passive smokers. Cotinine has a longer half-life ( approximately 20 h) compared to nicotine ( approximately 2h). A simple, sensitive, rapid and high throughput GC-MS method was developed for simultaneous quantification of urinary nicotine and cotinine in passive and active smokers. In the sample preparation method, the analytes and internal standard were first basified and followed by liquid-liquid extraction. Upon completion, anhydrous sodium sulphate was added to the solvent mixture to trap moistures. The clear extract obtained was directly injected into GC-MS, operating under selective ion monitoring (SIM) mode. Calibration curves in the range of 0.5-5000 ng/mL of the analytes in urine matrix were established with linear correlation coefficients (r(2)) greater than 0.997. The limit of detection for both nicotine and cotinine were 0.20 ng/mL. The mean recoveries for nicotine and cotinine were 93.0 and 100.4%, respectively. The within- and between-assay accuracies were between 2.1 and 7.9% for nicotine and between 0.7 and 11.1% for cotinine. Within- and between-assay precisions of 3.3-9.5% for nicotine and 3.4-9.8% for cotinine were also achieved. The method can be used in routine assessment and monitoring of active smoking and exposure to environmental tobacco smoke. The applicability of the assay was demonstrated in a small-scale comparison study between smokers and non-smokers.     

Study of middle ear disease using tympanometry in general practice.

Tympanometry was used to provide evidence of middle ear effusions in a prospective study of middle ear disease in 264 children aged 3 months to 6 years in general practice. Adequate measurements on both ears were obtained in 220 children, of whom 68 (31%) had evidence of middle ear effusion in one ear (29 children) or both ears (39 children) at entry to the study. In 28 (42%) of the 68 children persistence of the tympanometric findings was recorded for at least three months. Children of European descent were more likely to have evidence of middle ear effusion at the initial examination compared with African and West Indian children, as were those children whose siblings had a positive history of otitis media compared with those whose siblings had no such history. Children under 3 years were more likely to have evidence of an effusion than older children. Middle ear effusion as shown by tympanometry was not associated with a previous history of otitis media in the child but was associated with recent symptoms of respiratory infection or otalgia. A previous consultation for otitis media was, however, strongly associated with a greater likelihood of a consultation for otitis media during the follow up period. Comparing evidence of effusion by tympanometry with that by pneumatic otoscopy showed that using the appearance of the eardrum alone the sensitivity of otoscopy was 55%; the addition of mobility improved the sensitivity to 76% with little reduction in specificity. Further studies on populations using tympanometry are needed to determine the natural history, aetiology, and indications for referring children with middle ear effusion.     

Determination of urinary and salivary cotinine using gas and liquid chromatography and enzyme-linked immunosorbent assay

The objective of this study was to compare cotinine concentrations in urine and saliva using gas chromatography (GC), high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA). Ninety-four subjects were selected (27 smokers and 67 non-smokers) and interviewed using questionnaire. Of the non-smokers, 39 had been exposed to environmental tobacco smoke (ETS) and 28 had not been exposed to ETS. Cotinine levels among smokers were highest using all three measurements, followed by ETS exposed subjects and non-smokers. Cotinine levels in urine, using HPLC, correlated significantly with levels measured using ELISA (r=0.92) and GC-nitrogen-phosphorus detection (NPD) (r=0.92). Salivary cotinine levels measured using ELISA did not correlate significantly with either HPLC (r=0.37) or GC-NPD (r=0.33) measurements. Multiple regression models were used to adjust for age, gender, drug use and health status, and it was found that cotinine levels in urine and saliva were significantly correlated with smoking pack-year. The authors conclude that urinary cotinine concentration is a more accurate biomarker for ETS than salivary cotinine concentration.     

Quantification of cotinine in dried blood spots as a biomarker of exposure to tobacco smoke

Objective: We present an ultra-sensitive, minimally-invasive method for quantifying cotinine in dried blood spot (DBS) samples as a biomarker of exposure to tobacco smoke that can be collected using a simple heel or finger prick to obtain blood samples.

Methods: Cotinine levels were measured in matched plasma and reconstituted DBS samples from smokers and nonsmokers to evaluate assay parameters. In addition, we applied this new method to finger-prick DBS samples that were collected from infants, children and young adults ages 1–21 to estimate exposure to tobacco smoke. Partitioning of cotinine across red blood cells and haematocrit effects were investigated.

Results: Cotinine levels measured in matched plasma and reconstituted DBS samples from smokers and nonsmokers were found to be highly correlated (R²=0.94), with 100% sensitivity and 94% specificity to differentiate reported smokers from nonsmokers. With this method, the LOQ is <0.25?ng/mL using a single 3.2?mm punch of a DBS, and haematocrit effects are negligible.

Conclusions: This sensitive, high-throughput and minimally-invasive method for quantifying cotinine in DBS samples provides a simple and cost effective means for estimating exposure to tobacco smoke in population based studies, and has particular advantages in studies involving infants and children.     

Simultaneous determination of nicotine, cotinine, norcotinine, and trans-3'-hydroxycotinine in human oral fluid using solid phase extraction and gas chromatography-mass spectrometry

Nicotine is rapidly and extensively metabolized in humans. We present an analytical method to simultaneously quantify nicotine, cotinine, norcotinine, and trans-3'-hydroxycotinine in human oral fluid. Solid phase extraction (SPE) and GC/MS/EI with selected ion monitoring (SIM) were utilized. Linearity ranged from 5 to 1000 ng/mL of oral fluid; correlation coefficients for calibration curves were >0.99. Recoveries were 90-115% nicotine, 76-117% cotinine, 88-101% norcotinine, and 67-77% trans-3'-hydroxycotinine. Intra-assay precision and accuracy ranged from 1.6 to 5.7% and 1.6 to 17.8%, respectively. Inter-assay precision and accuracy ranged from 4.3 to 10.2% and 0 to 12.8%, respectively. Suitable precision and accuracy were achieved for the simultaneous determination of nicotine and three metabolites in the oral fluid of smokers. This assay is applicable to pharmacokinetic studies of nicotine, cotinine, and trans-3'-hydroxycotinine from tobacco smokers and can be utilized for routine monitoring of tobacco smoke exposure. 3-Hydroxycotinine requires additional investigation to determine its usefulness as a biomarker for tobacco smoke exposure.     

DNA adducts in human placenta exposed to ambient environment and passive cigarette smoke during pregnancy

BACKGROUND: The risk of human diseases and abnormal development under the relatively reduced toxic environmental exposure conditions of passive cigarette smoke and urban pollution is emerging as significant. To assess the genotoxic potential of such exposure, we analyzed the DNA adducts of polynuclear aromatic hydrocarbons (PAH), a proven marker of genotoxicity, in human placental DNA samples of pregnancies monitored for passive cigarette smoke exposure. METHODS: Maternal exposure to active and passive cigarette smoke was evaluated by verbal disclosure and urinary nicotine and cotinine measurements. PAH-DNA adducts were assayed by ELISA using a polyclonal antibody against benzo[alpha]pyrene-diol-epoxide-DNA in placental DNA. Birth weights of infants were recorded in these monitored pregnancies. RESULTS: Urinary nicotine and cotinine values were reduced in the passive smoke-exposed group compared to smokers and similar to those in the nonsmoker ambient exposure group. PAH-DNA and nicotine/cotinine values were not correlated with birth weight of the infant. PAH-DNA adducts were present in approximately 25% of samples exposed to passive cigarette smoke and ambient environment. CONCLUSIONS: The study has revealed that a subpopulation of humans is predisposed to accumulating PAH adducts independent of high levels of PAH sources (e.g., maternal cigarette smoke exposure). Because DNA adducts promote genomic changes, it is likely that this subpopulation is susceptible to diverse changes in the genome that may influence human development.     

Expression of cytochrome CYP2B1/2 in nonpregnant, pregnant and fetal rats exposed to tobacco smoke

Four-month-old female Wistar rats were exposed for 20 days to tobacco smoke obtained from non-filter cigarettes. During the exposure, concentration of tobacco smoke was monitored indirectly by measuring the CO level (1500 mg/m3 air). The efficacy of exposure was assessed by measuring urine nicotine and cotinine levels. Cigarette smoke did not change total cytochrome P450 and b5 protein levels in any of the organs studied, and most of these organs did not show any changes in the activity of reductases associated with these cytochromes. Following exposure to tobacco smoke, fetal rat liver expressed CYP2B1/2 protein; in newborns (day 1) both liver and lung showed CYP2B1/2 protein expression and very low pentoxyresorufin O-dealkylase activity. Western blot analysis of adult liver, lung, heart, but not of brain microsomes, showed that tobacco smoke induced CYP2B1/2 in both nonpregnant and pregnant rats, though its expression was lower in the livers and hearts of pregnant females. In the rat and human placenta, neither rat CYP2B1/2 nor human CYP2B6 showed basal or tobacco smoke-induced expression at the protein level. This study shows clearly that the expression of CYP2B1/2, which metabolizes nicotine and some drugs and activates carcinogens, is controlled in rats by age-, pregnancy-, and tissue-specific regulatory mechanisms.     

Reproductibilité interobservateur d'un tympanomètre portatif,le MicroTymp.

OBJECTIVE: To determine the interobserver reliability of tympanograms obtained with the MicroTymp, a portable tympanometer. SETTING: Family medicine teaching unit in a tertiary care hospital. PATIENTS: Thirty-three patients who presented to the ear, nose and throat clinic in August 1990 for an ear problem. INTERVENTION: Three residents in family medicine independently attempted to record with the MicroTymp one tympanogram for the 66 ears. We excluded the results for seven ears for which tympanograms could not be obtained. MAIN OUTCOME MEASURE: Using objective criteria, two family physicians and two residents in family medicine independently classified the 177 tympanograms into five categories (normal, possible effusion, possible perforation, possible tympano-ossicular dysfunction and unclassifiable). Reliability was estimated by means of the kappa (kappa) coefficient on 161 tympanograms from 59 ears for which the interpretation of the three tympanograms agreed. MAIN RESULTS: The interpretation of the three tympanograms agreed for 34 of the 59 ears (0.58) (kappa = 0.52, 95% confidence limits 0.45 and 0.59). There was no significant difference in interobserver reliability between pairs of observers or between symptomatic and asymptomatic ears. CONCLUSIONS: The interobserver reliability of the MicroTymp is moderate. The tympanograms obtained with the instrument should be interpreted in the context of the clinical findings.     

Simultaneous estimation of nicotine and cotinine levels in biological fluids using high-resolution capillary-column gas chromatography combined with solid phase extraction work-up

A rapid and sensitive capillary gas-chromatographic method with nitrogen-sensitive detection is reported for the simultaneous analysis of nicotine and cotinine levels occurring in the plasma, saliva, and urine of regular tobacco smokers. The proposed assay has a linear output, has satisfactory accuracy over the range of concentrations of both amines encountered in active smokers, and has also been successful in the analysis of the urine samples of passive smokers. Its lower limit of sensitivity is 0.2 ng of nicotine and 0.5 ng of cotinine per ml of plasma or saliva or per 100 l of urine.The beneficial characteristics of the presented method were achieved by the combination of solid phase extraction of 0.1–1.0 ml of fluid specimens, capillary column gas chromatography with splitless injection and nitrogen sensitive detection, and the use of separate, structurally analogous compounds as internal standards for nicotine. The suitability of the assay is shown by plasma concentration-time curves of nicotine and cotinine in a steady smoker during a 24 hours period.     

Steroid hormone levels associated with passive and active smoking

Context

Cigarette tobacco smoke is a potent environmental contaminant known to adversely affect health including fertility and pregnancy.

Objective

To examine the associations between second-hand cigarette tobacco-smoke exposure, or active smoking and serum concentrations of steroid hormones using tandem mass spectrometry.

Design

Healthy women (18-45 y) from the general community in the Metropolitan Washington, DC were recruited at the follicular stage of their menstrual cycle. Participants were assigned to one of three study groups: active smokers (N = 107), passive smokers (N = 86), or non-smokers (N = 100). Classifications were based on a combination of self-reporting and serum cotinine concentrations.

Methods

Serum androgens, estrogens, progestins, androstenedione, aldosterone, cortisol, corticosterone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), 11-deoxycortisol and 25-hydroxy-vitamin D3 (25-OHVitD3) and cotinine were measured by isotope dilution tandem mass spectrometry (LC/MS/MS) (API-5000). Kruskal-Wallis tests were used to assess median differences among the three groups, with Dunn's multiple comparison test for post hoc analysis.

Results

Serum estrone, estradiol, and estriol concentrations were lower in active and passive smokers than in non-smokers. The three study groups differed significantly in serum concentrations of 16-OHE1, aldosterone and 25-OHVitD3, as well as in the ratios of many of the steroids. Pair-wise comparison of the groups demonstrated significant differences in hormone concentrations between (i) smokers and non-smokers for aldosterone: (ii) passive smokers and non-smokers for aldosterone, progesterone and estriol. Moreover, for smokers and passive smokers, there were no significant differences in these hormone concentrations.

Conclusions

Smoke exposure was associated with lower than normal median steroid hormone concentrations. These processes may be instrumental in explaining some adverse effects of tobacco smoke on female health and fertility.     

The level of cotinine - marker of tobacco smoking, in patients with hyperthyroidism

INTRODUCTION: Orbitopathy associated with Graves' disease TAO (thyroid associated orbitopathy) is likewise connected with environmental factors including tobacco smoking. Tobacco smoking increases the risk of ophthalmologic pathology and leads to the orbital tissue damage due to the hypoxia. The aim of the study was to correlate the concentration of urinecotinine (marker of tobacco smoking) in Graves' disease patients with TAO with points received on the Fagerstr?m questionnaire. MATERIALS AND METHODS: Thirty women with different degree of exacerbation of TAO in Graves' disease (34.28 +/- 12.04 yr.) were examined. As control we used 29 women with Graves' disease without TAO (29.35 +/- 12.33 yr.). The diagnosis was established according to level of TSH and level of thyrotropin receptor antibodies (TRAb). Measure of tobacco smoking or exposure to second hand tobacco smoke ETS (environmental tobacco smoke) carried out according to the Fagerstr?m questionnaire, and measured cotinine level (the major metabolite of nicotine in urine). The level of clinical ophtalmopathy was measured according to the CAS (Clinical Activity Score) scale and degree of progression of TAO according to American Thyroid Association (NOSPECS scale). Additionally increase of exophthalmus was measured using the Hertl's exophthalmometer. RESULTS: In the group with TAO: 19 (63.3%) persons had mild exophthalmos (according to CAS), medium in 13 (43.3%) patients, and pronounced exophthalmous in 10 (33%) patients. There was statistically significant difference in the level of TRAb (18.4 +/- 8.2 vs. 5.1 +/- 3.4 IU/l; p < 0.0001) between TAO and controls. There was no correlation between TSH (0.6 +/- 0.02 vs. 0.4 +/- 0.04; p = 0.18) and fT4 (38.8 +/- 29.3 vs. 26.1 +/- 17.3; p = 0.026) in both analyzed groups. Smokers and non-smokers with TAO had no statistically significant in level of TRAb (Mann-Whitney test p = 0.16). No correlation was found between smoking tobacco (cotinine level) and the level of TRAb in patients with TAO (Pearson r = 0.28 p = 0.58). There was a statistically significant difference between the level of urine cotinine in smoking patients with TAO in the highest level of ophthalmopathy exacerbation (> 24 mm; > or = 4 points according to CAS) and those without TAO (Mann-Whitney's test p = 0.04). CONCLUSIONS: 1. In patients with Graves' disease with TAO the highest score of tobacco smoking has been found in persons with the highest ophthalmopathy exacerbation. 2. Estimation of cotinine concentration in urine is the most objective and useful method of tobacco smoking.     

Inhalation of mainstream and sidestream cigarette smoke retards embryo transport and slows muscle contraction in oviducts of hamsters (Mesocricetus auratus).

Prior experiments have shown that the functioning of hamster oviducts is impaired by in vitro exposure to cigarette smoke. To determine if cigarette smoke affects oviductal functioning in vivo, an inhalation experiment was done in which hamsters were exposed to doses of smoke similar to those received by human smokers. The effects of mainstream smoke (the bolus of smoke inhaled by active smokers) and sidestream smoke (the main component in environmental tobacco smoke) were compared. Transport of preimplantation embryos through the hamster oviduct was retarded in females inhaling doses of mainstream or sidestream smoke that produced serum cotinine levels within the range reported for women who actively or passively smoke during pregnancy. In addition, hamster oviductal muscle contraction rate decreased significantly during a single exposure of animals to either mainstream or sidestream smoke, and contraction rate failed to return to initial control values during a 25-min recovery period. Both preimplantation embryo transport and muscle contraction were more sensitive to sidestream than mainstream smoke. These data demonstrate that inhalation of doses of mainstream and sidestream cigarette similar to those received by active and passive human smokers adversely affects functioning of the oviduct and may explain the increased incidence of ectopic pregnancies reported in women who smoke.