Higher Cotinine Concentrations Research Articles

Associations between smoke exposure and kidney stones: results from the NHANES (2007-2018) and Mendelian randomization analysis.

It is currently controversial whether smoke exposure is associated with the risk of kidney stones. Herein, publicly available databases were combined to explore relationships with the risk of nephrolithiasis in terms of smoking status and serum cotinine concentrations. First, we conducted an observational study using data from 2007 to 2018, based on the National Health and Nutrition Examination Survey (NHANES) database. Univariate analysis, multivariate logistic regression, trend testing, restricted cubic spline (RCS), and multiple imputation (MI) were the main analytical methods of our study. Then, A Mendelian randomization (MR) analysis was performed to explore the causal relationship between serum cotinine and nephrolithiasis. Genetic instruments for serum cotinine and pooled data for kidney stones were derived from publicly available large-scale genome-wide association studies (GWAS). Inverse-variance weighting (IVW) was the primary method for our MR analysis. A total of 34,657 and 31,352 participants were included in the observational study based on smoking status and serum cotinine concentrations, respectively. Under full adjustment of covariates, current smokers had an increased risk of kidney stones compared to non-smokers [OR = 1.17 (1.04-1.31), P = 0.009, P for trend = 0.010]. Compared with serum cotinine of <0.05 ng/ml, serum cotinine levels of 0.05-2.99 ng/ml [OR = 1.15 (1.03-1.29), P = 0.013] and ≥3.00 ng/ml [OR = 1.22 (1.10-1.37), P < 0.001] were observed to have a higher risk of nephrolithiasis (P for trend < 0.001). In addition, a non-linear relationship between log2-transformed serum cotinine and the risk of nephrolithiasis was found (P for non-linearity = 0.028). Similar results were found when serum cotinine (log2 transformation) was used as a continuous variable [OR = 1.02 (1.01-1.03), P < 0.001] or complete data was used to analyze after MI. In the MR analysis, genetically predicted high serum cotinine was causally related to the high risk of nephrolithiasis [IVW: OR = 1.09 (1.00-1.19), P = 0.044]. Current smoking and high serum cotinine concentrations may be associated with an increased risk of kidney stones. Further research is needed to validate this relationship and explore its underlying mechanisms.

Urinary cotinine and exposure to passive smoke in children and adolescents in Germany – Human biomonitoring results of the German Environmental Survey 2014–2017 (GerES V)

Passive smoking is a preventable and significant cause of many serious health problems, with children being particularly at risk. In the fifth German Environmental Survey (GerES V), conducted from 2014 to 2017, information reflecting the extent of passive smoke exposure in children and adolescents was collected by interview-based questionnaires and human biomonitoring (HBM) analyses of cotinine in urine from 2260 participants, aged 3–17 years. Based on these population-representative data, we describe current passive smoke exposure stratified by different subgroups and identify specific exposure determinants using multivariate logistic regression. The questionnaire data revealed that 42% of children and adolescents lived with at least one smoker in the household. Quantifiable concentrations of cotinine could be detected in 56% of the participants. The overall median concentration of cotinine was 0.2 μg/L, with children and adolescents of low socioeconomic status found to be a group particularly affected by passive smoke with higher cotinine concentrations (median = 1.2 μg/L). In the multiple analysis, the most significant predictor of cotinine levels derived from the questionnaire was passive smoking at home (odds ratio (OR) 13.07 [95CI: 4.65, 36.70]). However, parental smoking and passive smoking among friends and relatives could also be identified as independent factors influencing elevated cotinine levels. The comparison between the previous cycle GerES IV (2003–2006) on 3–14-year-olds and GerES V shows that tobacco smoke exposure of children decreased significantly. This decrease is likely an effect of extensive non-smoker protection laws being enforced 2007–2008 on federal and state level. This is reflected by a halving of urinary cotinine concentrations. Nevertheless, our results indicate that passive smoke is still a relevant source of harmful pollutants for many children and adolescents in Germany, and thus support the need for further efforts to reduce passive smoke exposure, especially in the private environment.

Smoking intensity and urinary nicotine metabolites by socioeconomic status in the Heinz Nixdorf Recall study

BackgroundSmoking intensity, which is generally based on self-reported average cigarettes per day (CPD), is a major behavioural risk factor and strongly related to socioeconomic status (SES). To assess the validity of the CPD measure, correlations with objective markers of tobacco smoke exposure – such as urinary nicotine metabolites – were examined. Yet, it remains unclear, whether this correlation is affected by SES, which may indicate imprecise or biased self-reports of smoking intensity.MethodsWe investigated the role of SES in the association between CPD and nicotine metabolites in current smokers among the participants of the population-based, prospective Heinz Nixdorf Recall Study. We determined urinary cotinine and additionally trans-3′-hydroxy-cotinine. SES was assessed by the International Socio-Economic Index of occupational status, and education. We calculated correlations (Pearson’s r) between logarithmised CPD and cotinine in subgroups of SES and analysed SES and further predictors of cotinine in multiple linear regression models separately by gender.ResultsMedian reported smoking intensity was 20 CPD in male and 19 CPD in female smokers. Men showed higher cotinine concentrations (median 3652 μg/L, interquartile range (IQR) 2279–5422 μg/L) than women (3127 μg/L, IQR 1692–4920 μg/L). Logarithmised CPD correlated moderately with cotinine in both, men and women (Pearson’s r 0.4), but correlations were weaker in smokers with lower SES: Pearson’s r for low, intermediate, and high occupational SES was 0.35, 0.39, and 0.48 in men, and 0.28, 0.43, and 0.47 in women, respectively. Logarithmised CPD and urinary creatinine were main predictors of cotinine in multiple regression models, whereas SES showed a weak negative association in women. Results were similar for trans-3′-hydroxy-cotinine.ConclusionsDecreasing precision of self-reported CPD was indicated for low SES in men and women. We found no strong evidence for biased self-reports of smoking intensity by SES.

Plasma Cotinine Is Positively Associated with Homocysteine in Smokers but Not in Users of Smokeless Tobacco.

Plasma total homocysteine (tHcy) is a risk marker, and smoking is an established risk factor for cardiovascular disease. It is unclear if the effect of smoked tobacco on homocysteine is mediated by nicotine or other combustion products in smoked tobacco. Snus (moist smokeless tobacco) is high nicotine-containing tobacco, and little is known about the effect of snus on plasma homocysteine. Therefore, we studied, in a cross-section of subjects (n = 1375) from the Northern Sweden Health and Disease Study, with strictly defined current smokers (n = 194) and snus users (n = 47), the impact of tobacco exposure on tHcy, assessed by self-reported tobacco habits and plasma cotinine concentrations. The snus users had higher cotinine concentrations than the smokers. Cotinine, creatinine, methylmalonic acid, and the methylenetetrahydrofolate reductase genotype (MTHFR) T allele were positively associated with tHcy among the smokers, but not among the snus users. No association was observed between tHcy and the number of cigarettes/day. There was a positive association between cotinine and tHcy in the smokers, but not among the snus users. This indicates that substances other than nicotine in tobacco smoke could be responsible for the differential effects on homocysteine status. Self-reported smoking should be complemented by a cotinine assay whenever possible.

Comparative analysis of the concentrations of serum cotinine and hydroxycotinine for US children, adolescents, and adults: impact of exposure to environmental tobacco smoke at home and other indoor environments.

This study was carried out to investigate how serum cotinine and hydroxycotinine concentrations compare and vary by age, gender, race/ethnicity, smoking, and exposure to environmental tobacco smoke (ETS) at home and other indoor environments. Data from NHANES for 2013-2018 for US children aged 3-11years (N = 3834), nonsmoker (N = 1963) and smoker (N = 247) adolescents aged 12-19years, and nonsmoker (N = 10,334) and smoker (N = 3264) adults aged ≥ 20years were analyzed by fitting regression models with log10 transformed values of serum cotinine and hydroxycotinine as dependent variables. Models stratified by age and smoking status were fitted. Those reporting using tobacco products during the last 5days were classified as smokers. For cotinine, males had higher cotinine concentrations than females for children, adolescent smokers, and nonsmoker adults. Non-Hispanic Blacks were found to have lower concentrations of both cotinine and hydroxycotinine than non-Hispanic Whites for adult smokers (p < 0.01) only. The ratio of concentrations of those exposed to ETS at home to those not exposed to ETS at home for hydroxycotinine was 6.3 for nonsmoker adults and as low as 1.39 for adult smokers.

High Cotinine and Healthcare Utilization Disparities Among Low-Income Children

This study assesses the associations of child salivary cotinine, parent-reported smoking, and child tobacco smoke exposure with the number of child healthcare visits and hospital admissions over a 6-month period. This study also assesses the relationships between participant characteristics and child cotinine. Longitudinal data were evaluated from a sample of 313 clinically ill children aged 0-9 years who lived with a smoker and presented to a pediatric emergency department or urgent care in 2016-2018. In 2020, cotinine measurements were log transformed, and Poisson and linear regression were performed. The majority of the children came from low-income homes (66.1%) and had public insurance/self-pay (95.5%). Child cotinine concentrations ranged from 0.1 to 332.0 ng/mL (geometric mean=4.8 ng/mL, 95% CI=4.1, 5.5). Poisson regression results indicated that each 1-unit increase of log-cotinine concentration was associated with an increase in pediatric emergency department visits over a 6-month period after the baseline visit, with an adjusted RR of 1.16 (95% CI=1.01, 1.34). Each 1-unit increase of log-cotinine concentration was associated with an increase in the frequency of hospital admissions over the 6-month period, with an adjusted RR of 1.50 (95% CI=1.08, 2.09). No differences were found between parent-reported smoking or child tobacco smoke exposure and healthcare utilization. Linear regression results indicated that children who were younger (β= -0.227, p=0.049), were White (geometric mean=5.5 ng/mL), had a medical history of prematurity (geometric mean=8.1 ng/mL), and had a winter baseline visit (geometric mean=6.5 ng/mL) had higher cotinine concentrations. Children living in apartments (geometric mean=5.5 ng/mL) and multiunit homes (geometric mean=5.5 ng/mL) had higher cotinine concentrations than those in single-family homes (geometric mean=3.6 ng/mL). Routine biochemical screening could identify children who are in need of intensive tobacco smoke exposure reduction interventions.

The Association Between E-Cigarette Use Behaviors and Saliva Cotinine Concentration Among Healthy E-Cigarette Users in Malaysia.

Electronic cigarettes (e-cigarettes) have rapidly increased in popularity within the last 2 years in Malaysia. The study aims to understand the association between e-cigarette use behaviors and salivary cotinine (a CYP2AA metabolite of nicotine) concentration to inform the development of future e-cigarette control policies. A convenience sample of saliva from 144 e-cigarette users was obtained between November and December 2015. The study participants used refill liquid containing between 0 and 12 mg/ml of nicotine. The overall median cotinine concentration of the study participants was 81.1 ng/ml (interquartile range = 8.5-195.8). Among the zero-nicotine and single e-cigarette users, the median cotinine level was 51.1 (interquartile range = 8.20-125.35) ng/ml. Factors significantly associated with a higher salivary cotinine concentration were dual use of e-cigarettes and tobacco cigarettes, regular and daily e-cigarette use, a longer duration of e-cigarette use, using a higher amount of e-liquid, and a shorter duration to finish a refill. Multivariate analysis revealed that e-cigarette use of 1-6 and 6-12 months (but not 1 month and below) was significantly associated with a higher cotinine concentration. Cotinine found in zero-nicotine e-liquids implies the importance of stringent regulatory governance for the consistency of labeled nicotine content of e-cigarette liquid in the market. Zero-nicotine e-cigarette users should also be informed of the likelihood of environmental exposure to tobacco smoke. Future studies conducted on larger samples are warranted to validate the association between duration of e-cigarette use and salivary cotinine concentration as well as to investigate underlying mechanisms.

Environmental Tobacco Smoke Exposure in Relation to Family Characteristics, Stressors and Chemical Co-Exposures in California Girls.

Childhood environmental tobacco smoke (ETS) exposure is a risk factor for adverse health outcomes and may disproportionately burden lower socioeconomic status groups, exacerbating health disparities. We explored associations of demographic factors, stressful life events, and chemical co-exposures, with cotinine levels, among girls in the CYGNET Study. Data were collected from families of girls aged 6–8 years old in Northern California, through clinic exams, questionnaires and biospecimens (n = 421). Linear regression and factor analysis were conducted to explore predictors of urinary cotinine and co-exposure body burdens, respectively. In unadjusted models, geometric mean cotinine concentrations were higher among Black (0.59 ug/g creatinine) than non-Hispanic white (0.27), Asian (0.32), or Hispanic (0.34) participants. Following adjustment, living in a rented home, lower primary caregiver education, and lack of two biologic parents in the home were associated with higher cotinine concentrations. Girls who experienced parental separation or unemployment in the family had higher unadjusted cotinine concentrations. Higher cotinine was also associated with higher polybrominated diphenyl ether and metals concentrations. Our findings have environmental justice implications as Black and socio-economically disadvantaged young girls experienced higher ETS exposure, also associated with higher exposure to other chemicals. Efforts to reduce ETS and co-exposures should account for other disparity-related factors.

Active smoking, secondhand smoke exposure and serum cotinine levels among Cheyenne River Sioux communities in context of a Tribal Public Health Policy

IntroductionAmerican Indians and Alaska Natives face disproportionately high rates of smoking and secondhand smoke (SHS) exposure. The Cheyenne River Sioux Tribe (CRST) is among the few Tribal Nations controlling commercial...

Assessment of salivary cotinine concentration among general non-smokers population: Before and after Spanish smoking legislations

BackgroundIn Spain, two smoke-free laws have been passed (Law 28/2005 and Law 42/2010).This study evaluates the association between Spanish smoking legislations and the second-hand smoke (SHS) exposure in an adult non-smoking population cohort in Barcelona (Spain). MethodsThis is a longitudinal study, before and after the implementation of two national smoking bans, in a representative sample of adults (≥16years old) from Barcelona (Spain) surveyed in 2004–2005 and followed up in 2013–2014 (n=736). We only analyzed non-smokers (n=397). We obtained 9ml of saliva sample for analysis of cotinine, a biomarker of recent tobacco exposure. We calculated geometric means of salivary cotinine concentration and their geometric standard deviation. We used linear mixed effect models, with individuals as random effects, to model the percentage change in salivary cotinine concentration and their 95% confidence intervals. ResultsThe percentage of participants with saliva samples with measurable concentrations of cotinine fell from 92.4% to 64.2% after both Spanish smoking legislations. The geometric mean of salivary cotinine concentration significantly decreased 88% (from 0.98ng/mL to 0.12ng/mL, p<0.001) after the implementation of the two Spanish smoke-free legislations. The decrease of the GM salivary cotinine concentration was statistically significant independently of the sociodemographic variables. ConclusionThere was a large reduction in the salivary cotinine concentration among adult non-smokers and higher cotinine concentrations among those declaring exposure to SHS at home after both legislations. Moreover, after both Spanish smoke-free laws salivary cotinine concentration was homogenized according to sociodemographic variables.

Occurrences of pharmaceuticals in drinking water sources of major river watersheds, China

Pharmaceuticals in drinking water sources (DWSs) have raised significant concerns for their persistent input and potential human health risks. Currently, little is known about the occurrence of pharmaceuticals in DWSs in China. In this study, a survey for multi-class pharmaceuticals in DWSs of five major river watersheds in China was conducted from 2012 to 2013. Samples were collected from 25 sampling sites in rivers and reservoirs. 135 pharmaceuticals were analyzed using solid-phase extraction and ultra-performance liquid chromatography tandem mass spectrometry. The results showed that a total of 70 pharmaceuticals were present in the samples, and the most frequently detected ones included sulfonamides, macrolides, antiepileptic drugs, anti-inflammatory drugs, and β-blockers, etc. Amongst these, maximum concentrations of lincomycin, sulfamethoxazole, acetaminophen and paraxanthine were between 44ng/L and 134ng/L, and those of metoprolol, diphenhydramine, venlafaxine, nalidixic acid and androstenedione were less than 1ng/L. Concentrations of the two that were most persistent, DEET and carbamazepine, were 0.8–10.2ng/L and 0.01–3.5ng/L, respectively. Higher concentrations of cotinine were observed in warm season than in cold season, while concentrations of lincomycin were the opposite. In a causality analysis, the occurrence of pharmaceuticals in DWSs depends mainly on the detection limits of the methods, their usage and the persistence in the aquatic environment.

Acute effects of chewing tobacco on coronary microcirculation and hemodynamics in habitual tobacco chewers

Background: Long-term adverse cardiovascular effects of smokeless tobacco are well established, however, the effect of chewing tobacco on coronary microcirculation and hemodynamic have not been studied. We intended to analyze the acute effect of chewing tobacco on coronary microcirculation and hemodynamics in habitual tobacco chewers with stable coronary artery disease undergoing elective percutaneous coronary intervention (PCI). Materials and Methods: We prospectively enrolled seven habitual tobacco chewers with stable coronary artery disease with single vessel disease or double vessel disease satisfying the criteria for elective PCI. Patients were instructed to keep 1 g of crushed dried tobacco leaves in the mouth after a successful PCI. Lesion in last stented vessels was evaluated for fractional flow reserve (FFR), coronary flow reserve (CFR), and index of microcirculatory resistance (IMR) post-PCI, after 15 min and 30 min of tobacco chewing along with the measurement of serum cotinine levels. Results: Oral tobacco led to high levels of cotinine in the majority of patients. There was an insignificant rise in heart rate, systolic and diastolic blood pressure following tobacco consumption. Baseline CFR (median 1.6, range 1.1–5.5) was low in tobacco chewers after PCI even after optimum FFR (0.9 ± 0.05) in the majority of patients suggesting abnormal microvascular hemodynamics (high IMR in 3 patients, overall median 14.2, range 7–36.2). However, there was no significant change in the estimated CFR or IMR values following tobacco chewing. One patient had bradycardia and hypotension which may be related to vagal reaction or acute nicotine poisoning. Conclusion: Tobacco chewers have abnormal coronary microcirculation hemodynamics even following a successful PCI. However, the coronary micocirculation and hemodynamics do not change acutely following tobacco chewing despite high serum cotinine concentrations.

Tobacco use vs. helminths in Congo basin hunter-gatherers: self-medication in humans?

We tested a novel hypothesis that recreational use of neurotoxic plants helps defend against parasites. Specifically, we investigated the relationship between smoking and helminthiasis among the Aka, a remote population of Central African foragers who are avid tobacco smokers, suffer high rates of helminthiasis, and have little-to-no access to commercial anthelmintics. Two hundred and six healthy Aka men provided saliva and stool samples. Saliva samples were assayed for cotinine, a nicotine metabolite; a subsample was genotyped for the CYP2A6 enzyme, which metabolizes nicotine. Stool samples were assayed for intestinal helminth eggs as an index of worm burden. After 1year, a subsample of participants was located and provided additional saliva and stool samples. We found (1) an exceptionally high prevalence of tobacco use, (2) a significant negative correlation between cotinine (a nicotine metabolite) and worm burden, (3) that treating helminths with albendazole, a commercial anthelmintic, reduced cotinine concentration two weeks later, compared to placebo controls, (4) among treated participants, higher cotinine concentrations in year 1 predicted less reinfection by year 2, and (5) younger and older participants with slow nicotine-metabolizing CYP2A6 alleles had lower worm burdens compared to those with extensive metabolizing alleles. These results provide the first evidence of a link between helminthiasis and smoking. They also suggest that, in populations where intestinal helminths are endemic, tobacco use might protect against helminth infection and reduce worm burden among infected individuals, and that individuals modulate nicotine exposure in response to infection. The results thus support the hypothesis that substance use helps defend against parasites.

Development and comparison of two competitive ELISAs for estimation of cotinine in human exposed to environmental tobacco smoke

We simultaneously set up two competitive (direct and indirect) enzyme-linked immunosorbent assays (ELISAs) based on the same antibody for estimation of cotinine (COT) in pregnant women especially and population generally exposed to environmental tobacco smoke. The results show that the limits of detection (LODs) for direct competitive ELISA and indirect competitive ELISA were 0.04 μgL(-1) and 0.1 μgL(-1), respectively. Direct competitive ELISA was found to be more sensitive than indirect competitive ELISA. Thereafter, we applied our direct competitive ELISA for the detection of COT from urinary samples taken from 450 volunteers from the Zhejiang Province of China. COT was detected in 100% of participants with concentration ranging from LOD to 5358.0 μgL(-1). The GM and 95th percentile concentration of COT in pregnant women were 6.3 μgL(-1) and 57.2 μgL(-1), respectively. Males had statistically higher COT concentrations than females (P < 0.0001), active smokers had statistically higher COT concentrations than non-smokers (P < 0.0001), whereas, non-pregnant women were found to have higher COT concentration than pregnant women. We conclude that our developed direct competitive ELISA is useful for detecting the COT in urinary concentration of human. The human urinary data obtained in this study indicated that common people generally and pregnant women especially were highly exposed to COT. Further studies are needed to focus on the sources of exposure, potential health effects and risk assessment of exposure to COT.

Determinants of Salivary Cotinine Concentrations Among Smokeless Tobacco Users

Factors associated with cotinine concentrations have been studied in smokers. Based on these studies, cotinine is recommended as a biomarker to assess severity of tobacco dependence. Evidence of association between cotinine concentrations and various factors among smokeless tobacco (ST) users is limited and mostly comes from tobacco cessation studies. The present study describes the relationship of salivary cotinine concentrations to sociodemographic factors, tobacco use characteristics, and ST products among ST users. Data are from a community-based sample of 95 current adult ST users. Study participants provided a saliva sample for cotinine analysis and completed a mail survey that included questionnaires regarding sociodemographic information, tobacco use characteristics, and tobacco dependence measures. Crude and adjusted associations between cotinine and other variables were calculated. Age, years of ST use, cans per week, and swallowing of tobacco juices were significantly associated with salivary cotinine concentrations in the multiple regression model. Fine-cut ST products resulted in higher cotinine concentrations as compared with long-cut ST products when adjusted for age and tobacco use characteristics (p = .029). The Fagerström Test for Nicotine Dependence for ST users (r = .58, p < .0001) and the modified Tobacco Dependence Screener (r = .24, p < .0001) were both correlated with cotinine concentration. The findings suggest some similarities in the determinants of cotinine concentrations in ST users and smokers. Swallowing of tobacco juices and type of ST product are unique to ST users and are associated with higher cotinine concentrations.

Factors Associated with Second-Hand Smoke Exposure in Young Inner-City Children with Asthma

Objectives. To examine the association of social and environmental factors with levels of second-hand smoke (SHS) exposure, as measured by salivary cotinine, in young inner-city children with asthma. Methods. We used data drawn from a home-based behavioral intervention for young high-risk children with persistent asthma post-emergency department (ED) treatment (N = 198). SHS exposure was measured by salivary cotinine and caregiver reports. Caregiver demographic and psychological functioning, household smoking behavior, and asthma morbidity were compared with child cotinine concentrations. Chi-square and ANOVA tests and multivariate regression models were used to determine the association of cotinine concentrations with household smoking behavior and asthma morbidity. Results. Over half (53%) of the children had cotinine levels compatible with SHS exposure and mean cotinine concentrations were high at 2.42 ng/ml (SD 3.2). The caregiver was the predominant smoker in the home (57%) and 63% reported a total home smoking ban. Preschool aged children and those with caregivers reporting depressive symptoms and high stress had higher cotinine concentrations than their counterparts. Among children living in a home with a total home smoking ban, younger children had significantly higher mean cotinine concentrations than older children (cotinine: 3–5 year olds, 2.24 ng/ml (SD 3.5); 6–10 year olds, 0.63 ng/ml (SD 1.0); p < .05). In multivariate models, the factors most strongly associated with high child cotinine concentrations were increased number of household smokers (β = 0.24) and younger child age (3–5 years) (β = 0.23; p < .001, R2 = 0.35). Conclusion. Over half of the young inner-city children with asthma were exposed to SHS, and caregivers are the predominant household smokers. Younger children and children with depressed and stressed caregivers are at significant risk of smoke exposures, even when a household smoking ban is reported. Further advocacy for these high-risk children is needed to help caregivers quit and to mitigate smoke exposure.

Decreased Aortic Elasticity in Healthy 11-Year-Old Children Exposed to Tobacco Smoke

The goal was to assess the relationship between passive smoking and arterial elasticity in children. Healthy 11-year-old children (N = 386) from an atherosclerosis prevention trial (Special Turku Coronary Risk Factor Intervention Project for Children) were studied. Aortic and carotid elasticities were determined by using M-mode ultrasound imaging based on measurements of blood pressure and arterial diameter changes during the cardiac cycle. The aortic stiffness index, Young's elastic modulus, and distensibility and the respective indices for the carotid artery were calculated. Exposure to tobacco smoke was measured by using serum cotinine concentrations, and children were classified into 3 groups, that is, the noncotinine group (n = 220; undetectable cotinine levels), the low-cotinine group (n = 127; cotinine levels of 0.2-1.6 ng/mL), and the top-decile cotinine group (n = 39; cotinine levels of > or =1.7 ng/mL). Higher cotinine concentrations were associated with increased aortic stiffness index values. An increase in aortic Young's elastic modulus and a decrease in aortic distensibility were observed across the cotinine groups. In multivariate regression models, the cotinine level remained a significant explanatory variable regarding all aortic elasticity indices. Carotid elasticity indices showed no differences across the cotinine groups. Childhood exposure to tobacco smoke (verified with serum cotinine levels) decreases aortic elastic properties in healthy children.

Nicotine Intake in Cigarette Smokers in England: Distribution and Demographic Correlates

Documenting smoke intake by objective biochemical markers is important for quantification of exposure to toxins. The aim of this report is to show the most definitive distribution of the nicotine metabolite, cotinine, yet available from English smokers in the period before implementation of the legislation banning smoking in indoor public areas. A total of 6,423 cigarette smokers, ages 16 years and above, taking part in the Health Survey for England between 1998 and 2003 provided a saliva cotinine value. Data on cigarette consumption, age, gender, social class, deprivation (as indicated by manual or nonmanual occupation, car ownership, and housing tenure), marital status, and region were collected. Cotinine concentrations showed no overall trend over the study period. The mean value was 289.15 ng/mL (SD 174.43); excluding those who had not smoked in the past 24 hours, the mean value was 302.08 ng/mL (SD 168.78). A higher cotinine concentration was associated with being middle-aged (peaking at 40 years), being male, being single, greater economic deprivation, and not living in London. After adjusting for cigarette consumption, higher values were associated with middle age, being male, and greater deprivation. This study provides the most complete picture yet of the smoke intake of cigarette smokers in England. The fact that cotinine peaks at around the age of 40 years raises the possibility that nicotine intake continues to increase decades after a person starts to smoke. Greater nicotine intake in more deprived smokers could explain why they find it harder to stop smoking.

Salivary cotinine concentration versus self-reported cigarette smoking: Three patterns of inconsistency in adolescence

The present study examined the extent and sources of discrepancies between self-reported cigarette smoking and salivary cotinine concentration among adolescents. The data are from household interviews with a cohort of 1,024 adolescents from an urban school system. Histories of tobacco use in the last 7 days and saliva samples were obtained. Logistic regressions identified correlates of three inconsistent patterns: (a) Pattern 1-self-reported nonsmoking among adolescents with cotinine concentration above the 11.4 ng/mg cutpoint (n = 176), (b) Pattern 2-low cotinine concentration (below cutpoint) among adolescents reporting having smoked within the last 3 days (n = 155), and (c) Pattern 3-high cotinine concentration (above cutpoint) among adolescents reporting not having smoked within the last 3 days (n = 869). Rates of inconsistency were high among smokers defined by cotinine levels or self-reports (Pattern 1 = 49.1%; Pattern 2 = 42.0%). Controlling for other covariates, we found that reports of nonsmoking among those with high cotinine (Pattern 1) were associated with younger age, having few friends smoking, little recent exposure to smokers, and being interviewed by the same interviewer as the parent and on the same day. Low cotinine concentration among self-reported smokers (Pattern 2) was negatively associated with older age, being African American, number of cigarettes smoked, depth of inhalation, and exposure to passive smoke but positively associated with less recent smoking and depressive symptoms. High cotinine concentrations among self-reported nonsmokers was positively associated with exposure to passive smoke (Pattern 3). The data are consonant with laboratory findings regarding ethnic differences in nicotine metabolism rate. The inverse relationship of cotinine concentration with depressive symptoms has not previously been reported. Depressed adolescent smokers may take in smaller doses of nicotine than nondepressed smokers; alternatively, depressed adolescents may metabolize nicotine more rapidly.

C91 - Étude comparative des facteurs de risque du lentigo malin de Dubreuilh et des autres mélanomes chez les sujets âgés

We tested a novel hypothesis that recreational use of neurotoxic plants helps defend against parasites. Specifically, we investigated the relationship between smoking and helminthiasis among the Aka, a remote population of Central African foragers who are avid tobacco smokers, suffer high rates of helminthiasis, and have little-to-no access to commercial anthelmintics. Two hundred and six healthy Aka men provided saliva and stool samples. Saliva samples were assayed for cotinine, a nicotine metabolite; a subsample was genotyped for the CYP2A6 enzyme, which metabolizes nicotine. Stool samples were assayed for intestinal helminth eggs as an index of worm burden. After 1 year, a subsample of participants was located and provided additional saliva and stool samples. We found (1) an exceptionally high prevalence of tobacco use, (2) a significant negative correlation between cotinine (a nicotine metabolite) and worm burden, (3) that treating helminths with albendazole, a commercial anthelmintic, reduced cotinine concentration two weeks later, compared to placebo controls, (4) among treated participants, higher cotinine concentrations in year 1 predicted less reinfection by year 2, and (5) younger and older participants with slow nicotine-metabolizing CYP2A6 alleles had lower worm burdens compared to those with extensive metabolizing alleles. These results provide the first evidence of a link between helminthiasis and smoking. They also suggest that, in populations where intestinal helminths are endemic, tobacco use might protect against helminth infection and reduce worm burden among infected individuals, and that individuals modulate nicotine exposure in response to infection. The results thus support the hypothesis that substance use helps defend against parasites.