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

Self-reported smoking, urine cotinine, and risk of type 2 diabetes: Findings from the PREVEND prospective cohort study

BACKGROUND

Smoking is a major risk factor for type 2 diabetes (T2D), but the evidence has mostly relied on self-reports. We aimed to compare the associations of smoking exposure as assessed by self-reports and urine cotinine with T2D.

METHODS

Using the PREVEND prospective study, smoking status was assessed at baseline by self-reports and urine cotinine in 4708 participants (mean age, 53 years) without a history of diabetes. Participants were classified as never, former, light current and heavy current smokers according to self-reports and analogous cut-offs for urine cotinine. Hazard ratios (HRs) with 95% CIs were estimated for T2D.

RESULTS

During a median follow-up of 7.3 years, 259 participants developed T2D. Compared with self-reported never smokers, the multivariable adjusted HRs (95% CI) of T2D for former, light current, and heavy current smokers were 1.02 (0.75-1.4), 1.41 (0.89-2.22), and 1.30 (0.88-1.93), respectively. The corresponding adjusted HRs (95% CI) were 0.84 (0.43-1.67), 1.61 (1.12-2.31), and 1.58 (1.08-2.32), respectively, as assessed by urine cotinine. Urine cotinine-assessed but not self-reported smoking status improved T2D risk prediction beyond established risk factors.

CONCLUSION

Urine cotinine assessed smoking status may be a stronger risk indicator and predictor of T2D compared to self-reported smoking status.

Urinary Metabolites of Polycyclic Aromatic Hydrocarbons of Rural Population in Northwestern China: Oxidative Stress and Health Risk Assessment

Polycyclic aromatic hydrocarbon (PAH) exposure is suspected to be linked to oxidative damage. Herein, ten PAH human exposure biomarkers [hydroxylated PAH metabolites (OH-PAHs)] and five oxidative stress biomarkers (OSBs) were detected in urine samples collected from participants living in a rural area (n = 181) in Northwestern China. The median molar concentration of ΣOH-PAHs in urine was 47.0 pmol mL-1. The 2-hydroxynaphthalene (2-OHNap; median: 2.21 ng mL-1) was the dominant OH-PAH. The risk assessment of PAH exposure found that hazard index (HI) values were <1, indicating that the PAH exposure of rural people in Jingyuan would not generate significant cumulative risks. Smokers (median: 0.033) obtained higher HI values than nonsmokers (median: 0.015, p < 0.01), suggesting that smokers face a higher health risk from PAH exposure than nonsmokers. Pearson correlation and multivariate linear regression analysis revealed that ΣOH-PAH concentrations were significant factors in increasing the oxidative damage to deoxyribonucleic acid (DNA) (8-hydroxy-2'-deoxyguanosine, 8-OHdG), ribonucleic acid (RNA) (8-oxo-7,8-dihydroguanine, 8-oxoGua), and protein (o, o'-dityrosine, diY) (p < 0.05). Among all PAH metabolites, only 1-hydroxypyrene (1-OHPyr) could positively affect the expression of all five OSBs (p < 0.05), suggesting that urinary 1-OHPyr might be a reliable biomarker for PAH exposure and a useful indicator for assessing the impacts of PAH exposure on oxidative stress. This study is focused on the relation between PAH exposure and oxidative damage and lays a foundation for the study of the health effect mechanism of PAHs.

The Effects of Black Raspberry as a Whole Food-Based Approach on Biomarkers of Oxidative Stress in Buccal Cells and Urine of Smokers

Cigarette smoke is a rich source of free radicals that can promote oxidative stress and carcinogenesis, including head and neck squamous cell carcinoma (HNSCC) development; importantly, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-iso-prostaglandin F2α (8-isoprostane) are biomarkers of oxidative stress. Several mechanisms, including the antioxidant properties of black raspberry (BRB), account for their chemopreventive effects. In the present clinical trial, we tested the hypothesis that BRB administration reduces biomarkers levels of oxidative stress in buccal cells and urine of smokers. One week after enrolling 21 smokers, baseline buccal cells and urine samples were collected before the administration of BRB lozenges for 8 weeks (5/day, 1 gm BRB/lozenge). Buccal cells and urine samples were collected at the middle and the end of BRB administration. The last samples were collected after the BRB cessation (washout period). We analyzed levels of 8-oxodG and 8-isoprostane (LC/MS-MS), urinary cotinine (ELISA), and creatinine (spectrophotometry). BRB significantly reduced the levels of 8-oxodG by 17.08% (P = 0.00079) in buccal cells and 12.44% (P = 0.034) in urine at the middle of BRB administration as compared with baseline; the corresponding values at the end of BRB administration were 16.46% (P = 0.026) in buccal cells and 25.72% (P = 0.202) in urine. BRB had no significant effect on the levels of urinary 8-isoprostane. BRB's capacity to inhibit 8-oxodG formation of smokers' buccal cells and urine is clearly evident and the reduction in 8-oxodG suggests that antioxidant abilities are central to BRB's HNSCC chemopreventive properties.

PREVENTION RELEVANCE

Cigarette smoke contains highly active components namely free radicals that can promote oxidative stress and oral cancer. We found that black raspberry (BRB) inhibited the formation of oxidative stress markers in the oral cavity and urine of smokers suggesting the antioxidant abilities of BRB in preventing oral cancer.

Rural Indonesian adolescents' smoking behaviours during the COVID-19 pandemic: rapid survey and cotinine test of school-attend adolescents in Gunung Kidul, Yogyakarta

The COVID-19 pandemic is predicted to affect adolescent smoking behaviours. We aim to map profiles of adolescents' smoking behaviours in a rural district in Indonesia during the COVID-19 pandemic and validate their smoking exposures using cotinine tests. This study applied an online survey followed by cotinine tests for high-school students in Gunung Kidul, Yogyakarta. The participants were asked to complete the survey and participate in a cotinine test. Univariate and multivariate regressions were performed to seek potential determinants of the smoking status and diagnostic accuracy of the cotinine test. A total of 281 participants completed the survey, with 19.6% (n = 55) and 22.8% (n = 64) being ever-smokers and current smokers. The impacts of the pandemics on their smoking behaviours were found in the urgency and numbers of daily smoked cigarettes. Univariate regression analysis revealed age, gender, learning mode, and whether father/friend smokes correlate with the adolescents' smoking behaviours. Multivariate regression analysis revealed that the odds of planning to stop smoking were 0.01 (95% CI 0.001-0.22, p-value 0.003) for having positive attitudes towards cigarettes compared to none. Of the 65 cotinine tests, 19 tested positive, with the sensitivity and specificity of the cotinine test at 94.7% and 95.6%. The prevalence of adolescent smoking during the COVID-19 pandemic in Gunung Kidul is high, with the impacts of the pandemic on the urgency and number of cigarette smoke. There are opportunities to help them stop smoking by providing reliable quit-tobacco access and advocacy in collaboration with schools, parents, and health providers.

Association between environmental chemical exposure and albumin-to-creatinine ratio is modified by hypertension status in women of reproductive age

Chemicals have been identified as a potential risk factor of renal dysfunction. However, studies that consider both multiple chemicals and non-chemical risk factors, such as hypertension, are rare. In this study, we assessed the associations between exposure to several chemicals, including major metals, phthalates, and phenolic compounds, and the albumin-to-creatinine ratio (ACR). A group of Korean adult women in reproductive age (n = 438, aged between 20 and 49 years), who had previously been studied for association of several organic chemicals, was chosen for this purpose. We constructed multivariable linear regression models for individual chemicals and weighted-quantile sum (WQS) mixtures, by hypertension status. Among the study population, approximately 8.5% of the participants exhibited micro/macro-albuminuria (ACR ≥30 mg/g), and 18.5% and 3.9% exhibited prehypertension and hypertension, respectively. Blood cadmium and lead levels showed a stronger association with ACR only among women with prehypertension or hypertension. Among organic chemicals, depending on the statistial model, benzophenone-1 (BP-1) and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) showed a significant association regardless of hypertension status, but most associations disappeared in the (pre)hypertensive group. These findings clearly indicate that hypertension status can modify and may potentiate the association of environmental chemicals with ACR. Our observations suggest that low-level environmental pollutant exposure may have potential adverse effects on kidney function among general adult women. Considering the prevalence of prehypertension in the general population, efforts to reduce exposure to cadmium and lead are necessary among adult women to minimize the risk of adverse kidney function.

Urinary arsenic and spontaneous pregnancy loss - a hypothesis-generating case-control investigation in western Romania

Arsenic occurs as a natural contaminant of drinking water supplies in arsenic endemic areas, posing a threat to public health. Our aim was to evaluate the relationship between urinary arsenic concentrations and spontaneous pregnancy loss in a population with low-moderate level drinking water arsenic exposure (mostly <10 μg/L). We enrolled 150 women with incident spontaneous pregnancy losses and 150 controls with ongoing pregnancies matched by gestational age. We measured arsenic species in urine using high performance liquid chromatography paired to inductively coupled plasma mass spectrometry. Urinary arsenic was not related to spontaneous pregnancy loss in conditional logistic regression models adjusted for confounding factors. However, a 10 μg/L increase in urinary arsenic (III + V) salt concentrations was associated with 8.00-fold (95% CI: 0.68, 3.35 × 10⁵) greater odds of spontaneous loss among women using prenatal vitamins in an interaction model (P for interaction = 0.07), although the effect estimate was imprecise. In an additional interaction model, prenatal vitamin use was associated with lower odds of loss (OR = 0.30; 95% CI: 0.13, 0.66), although the association was diminished in the presence of a 10 μg/L increase in urinary inorganic arsenic (OR = 0.44; 95% CI: 0.70, 3.22). Total urinary arsenic was associated with 1.48-fold (95% CI: 0.20, 11.35) greater odds for loss among women with urinary cotinine >50 μg/L in another interaction model (P for interaction = 0.07). These results suggest a potential modest increase in the odds of pregnancy loss associated with increased urinary arsenic (III + V) salts and a greater risk with increased total urinary arsenic among women smoking during pregnancy (urinary cotinine >50 μg/L). Prenatal vitamin use may act as a protective factor for arsenic exposure associated pregnancy loss, but appears to be less protective with increasing urinary inorganic arsenic concentrations.

Latent Trajectories of Haematological, Hepatic, and Renal Profiles after Oil Spill Exposure: A Longitudinal Analysis

Exposure to polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) in crude oil has carcinogenic effects on various organ systems. This longitudinal cohort study examined the effects of oil spill exposure on the haematological, hepatic, and renal profiles of Rayong oil spill clean-up workers. The sample included 869 clean-up workers from the Rayong oil spill. Latent class mixture models were used to investigate and classify the longitudinal trajectories and trends of the haematological, hepatic, and renal indices. Subgroup analysis was used to evaluate the association between the urinary metabolites of PAHs and VOCs and haematological, hepatic, and renal parameters. Most clean-up workers (97.6%) had increasing levels of white blood cells (WBCs) (0.03 × 103 cells/µL), 94.90% of the workers had a significantly increasing trend of blood urea nitrogen (0.31 mg/dL per year), and 87.20% had a significantly increasing trend of serum creatinine (0.01 mg/dL per year). A high-decreasing trend of WBCs was seen in 2.42% (-0.73 × 103 per year). Post-exposure changes in haematological, renal, and hepatic profiles are present in workers exposed to the Rayong oil spill. This indicates possible long-term health complications and worsening renal function after exposure to PAHs and VOCs in crude oil.

Prenatal exposure to tobacco and adverse birth outcomes: effect modification by folate intake during pregnancy

BACKGROUND

Fetal exposure to tobacco increases the risk for many adverse birth outcomes, but whether diet mitigates these risks has yet to be explored. Here, we examined whether maternal folate intake (from foods and supplements) during pregnancy modified the association between prenatal exposure to tobacco and with preterm delivery, small-for-gestational age (SGA) births, or neonatal adiposity.

METHODS

Mother-child pairs (n = 701) from Healthy Start were included in this analysis. Urinary cotinine was measured at ~ 27 weeks gestation. Diet was assessed using repeated 24-h dietary recalls. Neonatal adiposity (fat mass percentage) was measured via air displacement plethysmography. Interaction was assessed by including a product term between cotinine (< / ≥ limit of detection [LOD]) and folate (< / ≥ 25th percentile [1077 µg/day]) in separate logistic or linear regression models, adjusting for maternal age, race, ethnicity, education, pre-pregnancy body mass index, and infant sex.

RESULTS

Approximately 26% of women had detectable levels of cotinine. Folate intake was significantly lower among women with cotinine ≥ LOD as compared to those with cotinine < LOD (1293 µg/day vs. 1418 µg/day; p = 0.01). Folate modified the association between fetal exposure to tobacco with neonatal adiposity (p for interaction = 0.07) and SGA (p for interaction = 0.07). Among those with lower folate intake, fetal exposure to tobacco was associated with lower neonatal adiposity (mean difference: -2.09%; 95% CI: -3.44, -0.74) and increased SGA risk (OR: 4.99; 95% CI: 1.55, 16.14). Conversely, among those with higher folate intake, there was no difference in neonatal adiposity (mean difference: -0.17%; 95% CI: -1.13, 0.79) or SGA risk (OR: 1.15; 95% CI: 0.57, 2.31).

CONCLUSIONS

Increased folate intake during pregnancy (from foods and/or supplements) may mitigate the risk of fetal growth restriction among those who are unable to quit smoking or cannot avoid secondhand smoke during pregnancy.

Secondhand tobacco smoke exposure, urine cotinine, and risk of incident atrial fibrillation: The multi-ethnic study of atherosclerosis

BACKGROUND

Secondhand tobacco smoke (SHS) exposure may reduce heart rate variability and lead to atrial fibrillation (AF); however prior study findings have not been confirmed using objective measures for both SHS and AF events.

METHODS

We prospectively examined the association between SHS exposure and incident AF in 5731 participants, ages of 45-84 years and free of known AF and other cardiovascular diseases (CVD) at baseline (2000-2002), who were followed through 2015 in the Multi-Ethnic Study of Atherosclerosis (MESA). SHS weekly exposure time was identified by self-report. Urine cotinine was collected in a cohort subset of 3237 current non-smoking cohort participants. AF events were identified using Medicare claims, hospital records, and 12‑lead electrocardiographic findings. A multivariable Cox proportional hazards regression analysis was used with simultaneous adjustment for demographic factors, educational level, health insurance status, active smoking status, tobacco pack-years, traditional CVD risk factors, depressive symptoms and medications.

RESULTS

During a median follow-up of 14.0 years, 856 and 452 AF events were identified in the overall and the cohort subset, respectively. No association of SHS exposure time or urine cotinine with incident AF was observed. However, a higher AF risk with greater urine cotinine (8.53-442.0 ng/mL) compared with lower urine cotinine (≤7.07 ng/mL) was observed in never smokers [hazard ratios (HR) and 95% confidence intervals: 1.60 (1.16, 2.19)], but not in former smokers [HR: 0.88 (0.63, 1.23)] (p-value for multiplicative interaction: 0.009 and for additive interaction: 0.017, respectively).

CONCLUSION

Objectively measured greater SHS exposure expressed by urine cotinine might be associated with 1.6-fold higher risk of incident AF in never smokers.

Effect of Second-Hand Smoke Exposure on Establishing Urinary Cotinine-Based Optimal Cut-Off Values for Smoking Status Classification in Korean Adults

Regulations for banning smoking in indoor public places and workplaces have increased worldwide in recent years. A consecutive Korean National Health and Nutrition Examination Survey (KNHANES) between 2008 and 2018 showed a trend toward significant decreases in self-reported tobacco smoke exposure and measured urinary cotinine concentrations. We established and compared each optimal cut-off value for assessing the effect of second-hand smoke (SHS) exposure on establishing urinary cotinine-based cut-off values for smoking status classification in a population setting controlled for racial and cultural diversity, using four KNHANES datasets consisting of the 2008, 2011, 2014, and 2018 surveys. A total of 18,229 Korean participants aged >19 years with measured urinary cotinine concentrations were enrolled. Self-reports of current smoking status showed that the prevalence of current smokers decreased from 22.9% to 18.2% between 2008 and 2018. During this period, the median value of urinary cotinine in nonsmokers decreased from 5.86 µg/L to 0.48 µg/L, whereas the median value showed no remarkable decrease in current smokers. The AUC-based optimal cut-off values of urinary cotinine concentration for distinguishing current smokers from nonsmokers decreased from 86.5 µg/L to 11.5 µg/L. Our study showed that decreased SHS exposure would result in decreased optimal cut-off values for distinguishing current smokers from nonsmokers. In addition, the study suggests that the range of urinary cotinine concentration to define SHS exposure for the trend monitoring of populationof SHS exposure is appropriate between 0.30 µg/L and 100 µg/L. In addition, our study showed the importance of determination of cotinine concentration, which would have allowed us to avoid mistakes in qualification to the study group in an increased use of e-cigarette setting.

Associations between differences in anemia-related blood cell parameters and short-term exposure to ambient particle pollutants in middle-aged and elderly residents in Beijing, China

Anemia is a highly prevalent disease among older populations, with multiple adverse health outcomes, and particles exposure is a potential risk factor for anemia. However, evidence on associations of exposure to particles with small size with anemia-related blood cell parameters levels in the elderly is limited, and the underlying mechanisms are unclear. Based on a panel study in Beijing, we found that in 135 elderly participants, mass concentrations of particle with an aerodynamic diameter ≤ 2.5 μm (PM_2.5), black/elemental carbon (BC/EC, particle size range: 0-2.5 μm), and number concentrations of ultrafine particles (UFPs, particle size range: 5.6-93.1 nm) and accumulated mode particles (Acc, size range: 93.1-560 nm) were significantly associated with levels of red blood cell count (RBC), hemoglobin (HGB), hematocrit (HCT), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC). The mean ± SD for PM_2.5, UFPs, Acc, BC, OC, and EC were 69.7 ± 61.1 μg/m³, 12.5 ± 4.3 × 10³/cm³, 1.6 ± 1.2 × 10³/cm³, 3.0 ± 2.0 μg/m³, 8.7 ± 6.7 μg/m³, and 2.1 ± 1.6 μg/m³, respectively. Cotinine (higher than 50 ng/mL) is used as an indicator of smoking exposure. The association between MCHC difference and per interquartile range (IQR) increase in average UFPs concentration 14 d before clinical visits was -0.7% (95% CI: -1.1% to -0.3%). Significant associations of UFPs and Acc exposure with MCHC and MCH levels remain robust after adjustment for other pollutants. Furthermore, 25.2% (95% CI: 7.4% to 64.8%) and 29.8% (95% CI: 5.3% to 214.4%) of the difference in MCHC associated with average UFPs and Acc concentrations 14 d before clinical visits were mediated by the level of tumor necrosis factor α (TNF α), a biomarker of systemic inflammation. Our findings for the first time provide the evidence that short-term UFPs and Acc exposure contributed to the damage of anemia-related blood cell in the elderly, and systemic inflammation was a potential internal mediator.

Susceptibility of patients with chronic obstructive pulmonary disease to heart rate difference associated with the short-term exposure to metals in ambient fine particles: A panel study in Beijing, China

Susceptibility of patients with chronic obstructive pulmonary disease (COPD) to cardiovascular autonomic dysfunction associated with exposure to metals in ambient fine particles (PM_2.5, particulate matter with aerodynamic diameter ≤2.5 µm) remains poorly evidenced. Based on the COPDB (COPD in Beijing) panel study, we aimed to compare the associations of heart rate (HR, an indicator of cardiovascular autonomic function) and exposure to metals in PM_2.5 between 53 patients with COPD and 82 healthy controls by using linear mixed-effects models. In all participants, the HR levels were significantly associated with interquartile range increases in the average concentrations of Cr, Zn, and Pb, but the strength of the associations differed by exposure time (from 1.4% for an average 9 days (d) Cr exposure to 3.5% for an average 9 d Zn exposure). HR was positively associated with the average concentrations of PM_2.5 and certain metals only in patients with COPD. Associations between HR and exposure to PM_2.5, K, Cr, Mn, Ni, Cu, Zn, As, and Se in patients with COPD significantly differed from those in health controls. Furthermore, association between HR and Cr exposure was robust in COPD patients. In conclusion, our findings indicate that COPD could exacerbate difference in HR following exposure to metals in PM_2.5.

Risk factors in air pollution exposome contributing to higher levels of TNFα in COPD patients

BACKGROUND

Air pollutants are found associated with various health effects in chronic obstructive pulmonary patients. Given the complicate chemical components of air pollutants, it is not clear which components are the main risk factors for these health effects.

OBJECTIVES

Based on the COPD in Beijing (COPDB) study and exposome concept, we examined comprehensively the air pollution components to screen out high-risk factors for systemic inflammation of COPD patients.

METHODS

Concentrations of PM with aerodynamic diameter ≤ 2.5 μm (PM_2.5), ultrafine and accumulated-mode particles (UFPs and Acc), PM_2.5-contained carbonaceous components/elements/water soluble ions, gaseous pollutants, temperature, and relative humidity (RH) were continuously monitored around participants. Urinary polycyclic aromatic hydrocarbons (PAHs) and cotinine, and serum tumor necrosis factor α (TNFα) were measured from 53 COPD and 82 non-COPD participants. Lifestyle variables were recorded using follow-up questionnaire. Linear mixed effects (LME) models were used to assess the associations of TNFα differences with exposure to air pollutants, meteorological variations, and lifestyle.

RESULTS

In COPD patients, the associations of TNFα differences with exposure to ozone, Cd, UFPs, Acc, 2-hydroxydibenzofuran, temperature and RH parameters, and several elements in PM_2.5 were significant in certain time-windows. For example, per interquartile range (IQR) increase in average ozone concentration 14 d before visits was associated with 17.3% (95% confidence interval: 6.8%, 27.7%) TNFα difference. Associations between ozone, Cd, UFPs, Acc, the maximum value of RH, and 2-hydroxydibenzofuran exposure and TNFα differences remained robust in two-pollutant models, and contributed to 19.0%, 10.5%, 2.2%, 1.6%, 2.1%, and 1.5% TNFα differences, respectively. Among the high-risk factors for COPD patients, the responses to UFPs, Acc, and 2-hydroxydibenzofuran were not robust in non-COPD participants.

DISCUSSION

Ozone, Cd, UFPs, Acc, PAHs exposure and RH variation were high-risk factors of systemic inflammation for COPD patients, and the profile of high-risk factors were different from those in general population.

Urinary cotinine assessment of maternal smoking and environmental tobacco smoke exposure status and its associations with perinatal outcomes: a cross-sectional birth study

Tobacco consumption and environmental tobacco smoke (ETS) exposure remains an important public health concern. Pregnant women require particular attention as active and passive smoking during pregnancy are associated with multiple adverse perinatal outcomes. This study aimed to biochemically validate self-reported smoking and ETS exposure status among pregnant women, to more precisely ascertain its association with adverse perinatal outcomes. Data refers to 595 pregnant women who sought prenatal care in a public hospital in Porto, Portugal. A standard questionnaire on smoking and ETS-related variables was completed. Urinary cotinine (UC) concentrations were assessed by solid-phase competitive ELISA, in maternal urine samples collected on the day of delivery. The results showed that the optimal UC cut-off value to distinguish smokers from non-smokers and within non-smokers those who were exposed to ETS from those non-exposed in the third trimester of pregnancy was 74.1 ng/mL (sensitivity and specificity of 96.7% and 98.0%, respectively) and 1.6 ng/mL (sensitivity of 66.2% and specificity of 75.7%, respectively). The agreement between maternal self-reported and UC-based smoking status was very good (κ=0.919, p<0.001), but much lower for ETS exposure (κ=0.386, p<0.001). Maternal active smoking in the third trimester of pregnancy was associated with a significant decrease in birth weight, length and head circumference of 157.66 g (95% CI: -245.81, -69.52; p<0.001), 0.78 cm (95% CI: -1.22, -0.34; p=0.001) and 0.39 cm (95% CI: -0.70, -0.07; p=0.016), respectively. Maternal ETS exposure in the third trimester of pregnancy was associated with a non-significant increase in birth weight of 38.37 g (95% CI: -28.91, 105.64; p=0.263). Furthermore, maternal smoking cessation was associated with the increase of approximately 172 g in birth weight (95% CI: 50.00, 293.19). As such, there is an urgent need for increased public health awareness campaigns to encourage smoking cessation during pregnancy, in order to improve perinatal outcomes.

Exposure to fire smoke in fire training structures: A prospective observational study

The aim of this study was to assess the level of exposure to and contamination by smoke within a population of firefighter instructors. We performed a prospective observational study from September 17 to September 26, 2018, using environmental samples and urinary biomarker analysis. Occupational exposure limits (OELs) were never exceeded, except for carbon monoxide for the fire attack training chamber and formaldehyde and carbon monoxide for the fire box. As regards to urinary biomarkers, we observed that 1OHP and 1-naphtol did accumulate. The pre-post analysis showed an acute exposure exceeding the BRVs of benzene, 1-hydroxypyrene and naphtol, except for 3-benzo[a]pyrene which was undetectable in half of the cases. Even if values were reassuring, an effort could be made to improve the working conditions and reduce contamination by rethinking the respiratory protection and improving PPE quality.

Susceptibility of individuals with lung dysfunction to systemic inflammation associated with ambient fine particle exposure: A panel study in Beijing

BACKGROUND

The underlying mechanism on the susceptibility of chronic obstructive pulmonary disease (COPD) patients to air pollution has yet to be clarified.

OBJECTIVES

Based on the COPD in Beijing (COPDB) study, we examined whether lung dysfunction contributed to pollutant-associated systemic inflammation in COPD patients.

METHODS

Proinflammatory biomarkers including interleukin-8 (IL-8) and tumor necrosis factor α (TNFα) were measured in serum samples collected from 53 COPD and 82 healthy participants. Concentrations of particulate matter with aerodynamic diameter ≤ 2.5 μm (PM_2.5), carbonaceous components in PM_2.5, and PM size distribution were continuously monitored. Linear mixed effects models were used to examine the associations of biomarker differences with particle exposure, between COPD and healthy participants, and across subgroups with different levels of lung dysfunction.

RESULTS

COPD patients showed higher differences in IL-8 and TNFα levels associated with exposure to measured pollutants, comparing to healthy controls. In advanced analysis, particle-associated differences in IL-8 and TNFα levels were higher in participants with poorer lung ventilation and diffusion capacity, and higher ratio of residual volume. For example, an interquartile range increase in average PM_2.5 concentration 2 weeks before visits was associated with a 15.7% difference in IL-8 level in participants with the lowest ratio of measured value to predicted value of forced expiratory volume in 1 s (FEV1%pred) (65.2%), and the association decreased monotonically with increasing FEV1%pred. Associations between differences in TNFα level and average ultrafine particle concentration 1 week before visits increased gradually with increasing ratio of measured value to predicted value of residual volume/total lung capacity.

CONCLUSIONS

COPD patients, especially those with poorer lung function, are more susceptible to systemic inflammation associated with fine particle exposure.

Trends in the Socioeconomic Inequalities Related to Second-Hand Smoke Exposure as Verified by Urine Cotinine Levels Among Nonsmoking Adults: Korea National Health and Nutrition Examination Survey 2008-2018

INTRODUCTION

The expansion of smoke-free policies has reduced the prevalence of second-hand smoke (SHS) exposure; however, declines differ according to socioeconomic positions. We evaluated the trends in socioeconomic inequalities related to SHS exposure in nonsmoking Korean adults from 2008 to 2018.

METHODS

We analyzed 30,027 nonsmoking adults from the Korea National Health and Nutrition Examination Survey 2008 to 2018. We evaluated trends in urine cotinine levels, self-reported prevalence of SHS exposure at workplaces and homes, and people exhibiting nonmeasurable urine cotinine levels between 2008 and 2018. To evaluate the yearly decline differences of urine cotinine levels according to socioeconomic positions, we calculated the interaction effects of year and education, household incomes, and occupation from linear regression analysis.

RESULTS

In the last 11 years, the geometric means of urine cotinine levels decreased from 3.53 (95% CI 2.96-4.19) ng/mL to 0.60 (0.57-0.64) ng/mL in males, and from 2.36 (2.03-2.73) ng/mL to 0.53 (0.51-0.56) ng/mL in females. The prevalence of SHS exposure at workplaces and homes also declined. In the multivariate model, the interaction effects between education and years were significant; therefore, indicating a substantial yearly decline of urine cotinine levels in higher educated individuals. The interaction effects between household incomes and years were only significant among males; the interaction effects between occupations and years were not significant.

CONCLUSIONS

SHS exposure in nonsmoking Korean adults has consistently decreased; however, socioeconomic inequalities related to SHS exposure by education level have widened. Policies targeting socioeconomically disadvantaged populations should be implemented to decrease the disparities of SHS exposure.

IMPLICATIONS

Along with tobacco control policies, the prevalence of self-reported and urinary cotinine verified SHS exposure has decreased in the last 11 years. In contrast, the socioeconomic inequalities related to SHS exposure by education level have increased over time. This study emphasizes the need for implementing tobacco control policies to reduce disparities of SHS exposure.

Differences in transcriptome response to air pollution exposure between adult residents with and without chronic obstructive pulmonary disease in Beijing: A panel study

Ambient air pollution is a major risk factor for the prevalence and exacerbation of chronic obstructive pulmonary disease (COPD). Based on the COPDB (COPD in Beijing) panel study, whole-blood transcriptomes were repeatedly measured in 48 COPD patients and 62 healthy participants. Ambient mass concentrations of fine particulate matter (PM_2.5), temperature, and relative humidity were continuously monitored at a monitoring station. The linear mixed-effects models were applied to estimate the associations between logarithmically transformed transcript levels and 1-day (d), 7-d, and 14-d average concentrations of PM_2.5 before the start of follow-up visits. MetaCore™ was used to conduct the pathway enrichment analyses. Exposure to 1-, 7-, and 14-d average concentrations of PM_2.5 was significantly associated with the transcriptome responses in both groups. The top 10, top 100, and top 1000 PM_2.5-associated transcripts differed greatly between the two groups. Among COPD patients, role of alpha-6/beta-4 integrins in carcinoma progression, Notch signaling in breast cancer, and ubiquinone metabolism were the most significantly enriched PM_2.5-associated biological pathways in the three time windows, respectively. In healthy participants, pro-opiomelanocortin processing was the most significant PM_2.5-associated biological pathway in all three time windows. Our findings provide novel insights into the adverse health effects of air pollution exposure.

Prenatal Exposure to Cigarette Smoke and Anogenital Distance at 4 Years in the INMA-Asturias Cohort

Smoking by women is associated with adverse pregnancy outcomes such as spontaneous abortion, preterm delivery, low birth weight, infertility, and prolonged time to pregnancy. Anogenital distance (AGD) is a sensitive biomarker of prenatal androgen and antiandrogen exposure. We investigated the effect of smoking and passive smoke exposure during pregnancy on anogenital distance in offspring at 4 years in the INMA-Asturias cohort (Spain). Women were interviewed during pregnancy to collect information on tobacco consumption, and anogenital distance was measured in 381 children: Anoscrotal distance in boys and anofourchetal distance in girls. We also measured maternal urinary cotinine levels at 32 weeks of pregnancy. We constructed linear regression models to analyze the association between prenatal smoke exposure and anogenital distance and adjusted the models by relevant covariates. Reported prenatal smoke exposure was associated with statistically significant increased anogenital index (AGI), both at week 12 of pregnancy (β = 0.31, 95% confidence interval: 0.00, 0.63) and at week 32 of pregnancy (β = 0.31, 95% confidence interval: 0.00, 0.63) in male children, suggesting altered androgenic signaling.

Susceptibility of individuals with chronic obstructive pulmonary disease to respiratory inflammation associated with short-term exposure to ambient air pollution: A panel study in Beijing

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide. There is no clear evidence of whether COPD patients are more susceptible to respiratory inflammation associated with short-term exposure to air pollutants than those without COPD.

OBJECTIVES

This study directly compared air pollutant-associated respiratory inflammation between COPD patients and healthy controls.

METHODS

This study is based on the COPDB panel study (COPD in Beijing). Fractional exhaled nitric oxide (FeNO) was repeatedly measured in 53 COPD patients and 82 healthy controls at up to four clinical visits. Concentrations of carbon monoxide (CO), nitrogen monoxide, nitrogen dioxide (NO₂), sulfur dioxide (SO₂), fine particulate matter (PM_2.5), black carbon (BC), ultrafine particles (UFPs), and accumulated-mode particles (Acc) were monitored continuously at a fixed-site monitoring station. Linear mixed-effects models were used to compare the associations between ln-transformed FeNO and average 1-23 h concentrations of air pollutants before the clinical visits.

RESULTS

FeNO was positively associated with interquartile range (IQR) increases in average concentrations of CO, NO₂, SO₂, BC, UFPs, and Acc in all participants, with the strongest associations in different time-windows (range from 6.6% for average 1 h NO₂ exposure to 32.1% for average 7 h SO₂ exposure). Associations between FeNO and average 13-23 h PM_2.5 exposure differed significantly according to COPD status. Increases in FeNO associated with average 1-2 h NO exposure were significant in COPD patients (range 8.9-10.2%), while the associations were nonsignificant in healthy controls. Associations between FeNO and average 1-23 h CO and SO₂ exposure tended to be higher in COPD patients than in healthy controls, although the differences were not significant. UFPs-associated respiratory inflammation was robust in both subgroups.

CONCLUSIONS

COPD patients are more susceptible to respiratory inflammation following PM_2.5, NO, CO, and SO₂ exposure than individuals without COPD.

Self-reported and cotinine-verified smoking and increased risk of incident hearing loss

We examined the associations of smoking status and urinary cotinine levels, an objective measure of smoking, with the development of new-onset HL. This cohort study was performed in 293,991 Korean adults free of HL who underwent a comprehensive screening examination and were followed for up to 8.8 years. HL was defined as a pure-tone average of thresholds at 0.5, 1.0, and 2.0 kHz ≥ 25 dB in both ears. During a median follow-up of 4.9 years, 2286 participants developed new-onset bilateral HL. Self-reported smoking status was associated with an increased risk of new-onset bilateral HL. Multivariable-adjusted HRs (95% CIs) for incident HL comparing former smokers and current smokers to never-smokers were 1.14 (1.004-1.30) and 1.40 (1.21-1.61), respectively. Number of cigarettes, pack-years, and urinary cotinine levels were consistently associated with incident HL. These associations were similarly observed when introducing changes in smoking status, urinary cotinine, and other confounders during follow-up as time-varying covariates. In this large cohort of young and middle-aged men and women, smoking status based on both self-report and urinary cotinine level were independently associated with an increased incidence of bilateral HL. Our findings indicate smoking is an independent risk factor for HL.

Urinary Cotinine and Cotinine + Trans-3'-Hydroxycotinine (TNE-2) Cut-points for Distinguishing Tobacco Use from Nonuse in the United States: PATH Study (2013-2014)

BACKGROUND

Determine the overall, sex-, and racially/ethnically-appropriate population-level cotinine and total nicotine equivalents (TNE-2, the molar sum of the two major nicotine metabolites) cut-points to distinguish tobacco users from nonusers across multiple definitions of use (e.g., exclusive vs. polytobacco, and daily vs. non-daily).

METHODS

Using Wave 1 (2013-2014) of the U.S. Population Assessment of Tobacco and Health (PATH) Study, we conducted weighted Receiver Operating Characteristic (ROC) analysis to determine the optimal urinary cotinine and TNE-2 cut-points, stratified by sex and race/ethnicity.

RESULTS

For past 30-day exclusive cigarette users, the cotinine cut-point that distinguished them from nonusers was 40.5 ng/mL, with considerable variation by sex (male: 22.2 ng/mL; female: 43.1 ng/mL) and between racial/ethnic groups (non-Hispanic other: 5.2 ng/mL; non-Hispanic black: 297.0 ng/mL). A similar, but attenuated, pattern emerged when assessing polytobacco cigarette users (overall cut-point = 39.1 ng/mL, range = 5.5 ng/mL-80.4 ng/mL) and any tobacco users (overall cut-point = 39.1 ng/mL, range = 4.8 ng/mL-40.0 ng/mL). Using TNE-2, which is less impacted by racial differences in nicotine metabolism, produced a comparable pattern of results although reduced the range magnitude.

CONCLUSIONS

Because of similar frequency of cigarette use among polytobacco users, overall cut-points for exclusive cigarette use were not substantially different from cut-points that included polytobacco cigarette use or any tobacco use. Results revealed important differences in sex and race/ethnicity appropriate cut-points when evaluating tobacco use status and established novel urinary TNE-2 cut-points.

IMPACT

These cut-points may be used for biochemical verification of self-reported tobacco use in epidemiologic studies and clinical trials.

EXPOSURE ASSESSMENT OF RAYONG OIL SPILL CLEANUP WORKERS

Background

In July of 2013, a pipeline connecting an offshore oil platform to a tanker caused crude oil to spill into the Sea of Rayong off the coast of Thailand. The resulting oil slick, estimated to be between 50 and 190 cubic meters (336-1,200 barrels), washed ashore one day later on the island of Samet. We conducted a study to quantify internal dose of polycyclic aromatic hydrocarbons (PAHs) and benzene in 1,262 oil spill cleanup workers, and to examine factors related to their dose.

Methods

Frozen stored urine samples (n=1343) collected from the workers during the one month cleanup period were used to measure the concentration of 1-hydroxypyrene-glucuronide (1-OHPG), cotinine and creatinine. Data from questionnaires and urinary trans,trans-muconic acid (t,t-MA), a benzene metabolite, measured previously as part of a worker health surveillance plan, were linked with the laboratory data.

Results

The internal dose of urinary 1-OHPG was highest in individuals who worked during the first 3 days of cleanup work (median: 0.97 pmol/ml) and was 66.7% lower (median: 0.32 pmol/ml) among individuals who worked in the final week of the study (days 21-28). After adjusting for age, cotinineand creatinine by regression analysis, the decline in urinary 1-OHPG concentration with days of cleanup remained significant (P-trend <0.001). A decreasing trend by days of cleanup was also observed for detectable urinary t,t-MA percentage (P-trend <0.001).

Conclusion

Rayong oil spill cleanup workers exhibited evidence of elevated levels of PAH and benzene exposure during the early weeks of cleanup, compared to near background levels 4 weeks after cleanup began. Long-term health monitoring of oil spill cleanup workers is advised.

A Simple and High-throughput LC-MS/MS Method for Simultaneous Measurement of Nicotine, Cotinine, 3-OH cotinine, Nornicotine, and Anabasine in Urine and its Application in the General Korean Population

Measuring nicotine metabolites is the most objective method for identifying smoke exposure. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) can measure multiple metabolites and is sensitive enough to detect low concentrations of metabolites. Therefore, we developed a simple and high-throughput method for measuring nicotine, cotinine, trans-3'-hydroxycotinine (3-OH cotinine), nornicotine, and anabasine for population-based studies using LC-MS/MS. Each 30 µl of urine sample was diluted with 90 µL of acetonitrile containing five deuterated internal standards. Chromatographic separation used a C18 column and LC-MS/MS analysis was performed with a multiple reaction monitoring mode. The chromatographic run time for each sample was 6.5 min. The method was validated by evaluating selectivity, interference, limit of detection, lower limit of quantification, precision, accuracy, linearity, extraction recovery, matrix effect, and carry-over according to guidelines. Our methods required a short preparation time (about 20 minutes) while simultaneously measuring five markers for smoking status. No endogenous or exogenous interference was found. Our method showed excellent precision and accuracy: within-run CV 2.9-9.4%, between-run CV 4.8-8.7%, and bias -10.1 to 5.3%. Linear dynamic ranges were 1-10,000 ng/mL for nicotine, nornicotine, and anabasine; 2-5,000 ng/mL for cotinine; and 5-15,000 ng/mL for 3-OH cotinine. Extraction recovery was consistent (87-109%) across concentrations. No significant matrix effect or carry-over was observed. The validated method was applied to 849 urine samples. In samples from the 125 current smokers, nicotine, cotinine, 3-OH cotinine, nornicotine, and anabasine were detected in 97.6%, 99.2%, 98.4%, 96.8%, and 87.2%, respectively. No markers were detected in 93.9% of 609 non-smokers. The overlapping detection of multiple markers made it possible to identify smoking status even in current smokers with low concentration of cotinine. Our LC-MS/MS method using a simple sample preparation technique is sensitive and effective for screening of smoking status in the general population.

Early readmission and its predictors among patients treated for acute exacerbations of chronic obstructive respiratory disease in Ethiopia: A prospective cohort study

Background

Significant numbers of chronic obstructive respiratory disease patients are readmitted for Acute Exacerbation (AE) within 30 days of discharge. And these early readmissions have serious clinical and socioeconomic consequences. The objective of our study was to determine the rate of readmission within 30 days of discharge and it’s predictors among patients treated for acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD).

Methods

A prospective cohort study involving 130 patients (asthma = 59, COPD = 71) was conducted from April-September, 2019, in Jimma Medical Center (JMC), South-West Ethiopia. Socio-demographic, clinical, laboratory, and drug-related data were recorded at admission and during hospital stay. Cox regression analysis was performed to identify risk factors for readmissions following an AE of asthma and COPD.

Results

During the study period, 130 (male, 78(60%)) patients were admitted with AE of asthma and COPD. The median age was 59(IQR, 50–70) years. Of 130 patients, 21(18.10%) had a new AE of asthma and COPD that required hospitalization in the 30 days after discharge. The overall median survival time to 30-day readmission was 20 days (IQR, 16–29). Multivariate analysis revealed prolonged use of oxygen therapy (AHR = 4.972, 95% CI [1.041–23.736] and frequent hospital admissions (AHR = 11.482 [1.308–100.793]) to be independent risk factors for early readmissions.

Conclusion

Early hospital readmission rates for AE of asthma and COPD were alarmingly high. Frequent hospital admission and long-term oxygen therapy during hospital stay were independent predictors of 30-day readmission.

Urinary Cotinine as a Biomarker of Cigarette Smoke Exposure: A Method to Differentiate Among Active, Second-Hand, and Non-Smoker Circumstances

Objective:

To review the literature on the use of urinary cotinine as a biological marker of cigarette smoke exposure.

Methods:

Narrative review of original and review articles on the topic of interest, published in Portuguese or English by June 2018, and selected in the following online databases: PubMed and Virtual Health Library (VHL).

Results:

Urinary cotinine is usually the recommended biomarker to estimate exposure to cigarette smoke, and can be used alone or, preferably, in association with questionnaires. Different analytical techniques can be used to quantify urinary cotinine and are differently performed because of urine sample interfering factors.

Conclusion:

The precise classification of smoking status is essential. It is advisable to use objective measurements regarding smoking habits since self-reported smoking may not always represent the true smoking status of the individual, particularly in groups that are more vulnerable to omitting the information of questionnaries, in addition, it has possible biases of memory. The accurate assessment of smoking is crucial to improve clinical management and counseling for different diseases as well as the establishment of preventive strategies. So, the use of urinary cotinine as a biomarker of cigarette smoke exposure seems to be a suitable assay to distinguish non-smokers from passive and active smokers.

Smoking status and second-hand smoke biomarkers in COPD, asthma and healthy controls

Introduction

Tobacco smoke worsens COPD and asthma. For healthy individuals, quantifying active and second-hand smoke (SHS) exposure clarifies the epidemiology of tobacco consumption and the efficacy of nonsmoking measures. Identifying tobacco exposure biomarkers and cut-offs might allow the creation of sensitive and specific tests.

Aim

We describe the state-of-the-art serum, urinary cotinine and exhaled carbon monoxide (CO) cut-offs for assessing smoking status and SHS exposure in adult patients with COPD or asthma, and healthy controls.

Methodology

After a keyword research in the PubMed database, we included papers reporting on the cut-offs of the investigated biomarkers in one of the populations of interest. Papers published before 2000, not in English, or reporting only data on nonadult subjects or on pregnant women were excluded from the analysis. 14 papers were included in the final analysis. We summarised diagnostic cut-offs for smoking status or SHS exposure in COPD, asthmatic and healthy control cohorts, reporting sensitivity and specificity when available.

Conclusion

Serum and urinary cotinine and exhaled CO are easy-to-standardise, affordable and objective tests for assessing smoking status and SHS exposure. Evidence on cut-offs with good sensitivity and specificity values is available mainly for healthy controls. For COPD and asthmatic patients, most of the currently available evidence focuses on exhaled CO, while studies on the use of cotinine with definite sensitivity and specificity values are still missing. Solid evidence on SHS exposure is available only for healthy controls. An integrated approach with a combination of these markers still needs evaluation.

Reliable cut-off values for smoking status in COPD and asthmatic adults are only available for exhaled COhttps://bit.ly/34lsHhD

Efficacy of a short-term residential smoking cessation therapy versus standard outpatient group therapy ('START-Study'): study protocol of a randomized controlled trial

BACKGROUND

In Germany, evidence-based outpatient smoking cessation therapies are widely available. Long-term abstinence rates, however, are limited. Studies suggest that short-term residential therapy enables a higher level of environmental control, more intense contact and greater support among patients and from therapists, which could result in higher abstinence rates. The aim of the current START-study is to investigate the long-term efficacy of a short-term residential therapy exclusively for smoking cessation, conducted by a mobile team of expert therapists.

METHODS

A randomized controlled trial (RCT) is conducted to examine the efficacy of residential behavior therapeutic smoking cessation therapy compared to standard outpatient behavior therapeutic smoking cessation group therapy. Adult smokers consuming 10 or more cigarettes per day, who are willing to stop smoking, are randomized in a ratio of 1:1 between therapy groups. The primary endpoint is sustained abstinence for 6-month and 12-month periods. Secondary endpoints include smoking status after therapy, 7-day point abstinence after the 6-month and 12-month follow-ups, level of physical dependence, cost-effectiveness, use of nicotine replacement products, health-related quality of life, self-efficacy expectation for tobacco abstinence, motivational and volitional determinants of behavior change, self-reported depressive symptom severity, adverse events and possible side effects. Assessments will take place at baseline, post-therapy, and at 6-month and 12-month intervals after smoking cessation.

DISCUSSION

There is a high demand for long-term effective smoking cessation therapies. This study represents the first prospective RCT to examine the long-term efficacy of a residential smoking cessation therapy program compared to standard outpatient group therapy as an active control condition. The residential therapeutic concept may serve as a new model to substantially enhance future cessation therapies and improve the understanding of therapeutic impact factors on tobacco abstinence. Utilizing a mobile team, the model could be applied efficiently to medical centers that do not have permanent and trained personnel for smoking cessation at their disposal.

TRIAL REGISTRATION

German Register for Clinical Trials (Deutsches Register für Klinische Studien), DRKS00013466. Retrospectively registered on 1 April 2019. https://www.drks.de/drks_web/navigate.do?navigationId=start.

Estimates of cutoffs with specificities and sensitivities for urine cotinine and hydroxycotinine for US adults aged ≥ 20 years to classify smokers and nonsmokers

Data for urine cotinine and hydroxycotinine became available for the first time in the 2013-2014 cycle of the National Health and Nutrition Examination Survey administered by the US Centers for Disease Control and Prevention. Cutoffs to classify smokers and nonsmokers for both cotinine and hydroxycotinine for US adults aged ≥ 20 years were developed by using receiver operating characteristic curve methodology. The optimality criterion used to determine cutoffs simultaneously maximized both specificity and sensitivity. Cutoffs were determined for the total population, males, females, non-Hispanic whites, non-Hispanic blacks, Hispanics, and non-Hispanic Asians. Cutoffs for both cotinine and hydroxycotinine were determined with a minimum sensitivity of 95.5% and with a minimum specificity of 95.4%. For the total population, cutoff for urine cotinine was 91.7 ng/mL estimated with a specificity as well as a sensitivity of 97.1%. The cutoff for the total population for urine hydroxycotinine was 128.0 ng/mL estimated with a specificity as well as a sensitivity of 96.5%. The order in which cutoffs were observed for cotinine was non-Hispanic blacks (283.0 ng/mL) > non-Hispanic whites (111.0 ng/mL) > males (109.0 ng/mL) > females (91.7 ng/mL) > total population (91.7 ng/mL) > Hispanics (20.8 ng/mL) > non-Hispanic Asians (7.39 ng/mL). The order in which cutoffs were observed for hydroxycotinine was non-Hispanic blacks (530.0 ng/mL) > non-Hispanic whites (180.0 ng/mL) > females (97.0 ng/mL) > total population (96.5 ng/mL) > males (95.9 ng/mL) > Hispanics (20.6 ng/mL) > non-Hispanic Asians (13.8 ng/mL). Thus, the largest cutoffs were observed for non-Hispanic blacks and the lowest cutoffs were observed for non-Hispanic Asians.

Prenatal Exposure to Tobacco and Offspring Neurocognitive Development in the Healthy Start Study

OBJECTIVE

To explore the associations between prenatal exposure to tobacco and neurocognitive development, in the absence of prematurity or low birth weight.

STUDY DESIGN

We followed mother-child pairs within Healthy Start through 6 years of age. Children were born at ≥37 weeks of gestation with a birth weight of ≥2500 g. Parents completed the Third Edition Ages and Stages Questionnaire (n = 246) and children completed a subset of the National Institutes of Health Toolbox Cognition Battery (n = 200). The Ages and Stages Questionnaire domains were dichotomized as fail/monitor and pass. Maternal urinary cotinine was measured at approximately 27 weeks of gestation. Separate logistic regression models estimated associations between prenatal exposure to tobacco (cotinine below vs above the limit of detection) and the Ages and Stages Questionnaire domains. Separate linear regression models estimated associations between prenatal exposure to tobacco and fully corrected T-scores for inhibitory control, cognitive flexibility, and receptive language, as assessed by the National Institutes of Health Toolbox. A priori covariates included sex, maternal age, maternal education, daily caloric intake during pregnancy, race/ethnicity, household income, maternal psychiatric disorders, and, in secondary models, postnatal exposure to tobacco.

RESULTS

Compared with unexposed offspring, exposed offspring were more likely to receive a fail/monitor score for fine motor skills (OR, 3.9; 95% CI, 1.5-10.3) and decreased inhibitory control (B: -3.0; 95% CI, -6.1 to -0.7). After adjusting for postnatal exposure, only the association with fine motor skills persisted.

CONCLUSIONS

Prenatal and postnatal exposures to tobacco may influence neurocognitive development, in the absence of preterm delivery or low birth weight. Increased developmental screening may be warranted for exposed children.

Exposure to prenatal secondhand smoke and early neurodevelopment: Mothers and Children's Environmental Health (MOCEH) study

BACKGROUND

The association between exposure to secondhand smoke (SHS) during pregnancy and a child's neurodevelopment has not been established yet. We explored the association between prenatal exposure to SHS and neurodevelopment at 24 months of age considering genetic polymorphism and breastfeeding in 720 mothers and their offspring enrolled in the Korean multicenter birth cohort study (Mothers and Children Environmental Health, MOCEH).

METHODS

We quantified urine cotinine concentrations in mothers once from 12th to 20th gestational weeks and excluded those whose urine cotinine levels exceeded 42.7 ng/ml to represent SHS exposure in early pregnancy. Mental developmental index (MDI) and psychomotor developmental index (PDI) values were measured using the Korean version of the Bayley Scales of Infant Development II (K-BSID-II) at 24 months of age. A general linear model was used to assess the relationship between maternal urinary cotinine level and neurodevelopment.

RESULTS

MDI scores were inversely associated with cotinine [β = - 2.73; 95% confidence interval (CI): - 5.32 to - 0.15] in children whose mothers had early pregnancy urinary cotinine levels >1.90 ng/ml. No association was evident in children whose mothers had cotinine levels ≤1.90 ng/ml. This negative association was more pronounced in children whose mothers had both Glutathione S-transferases mu 1 (GSTM1) and theta 1 (GSTT1) null type [β = - 5.78; 95% CI: -10.69 to - 0.87], but not in children whose mothers had any present type of GSTM1/GSTT1 [β = - 1.64; 95% CI: -4.79 to 1.52]. The association was no longer significant when children received breast milk exclusively for up to 6 months [β = - 0.24; 95% CI: -4.69 to 4.20] compared to others [β = - 3.75; 95% CI: -7.51 to 0.00]. No significant association was found for PDI.

CONCLUSIONS

Maternal exposure to SHS during pregnancy may result in delayed MDI in early childhood. This effect might be modified by genetic polymorphism and breastfeeding behavior.

Smoking and urinary cotinine by socioeconomic status in the Heinz Nixdorf Recall Study

Background

Associations of socioeconomic status (SES) and smoking-related diseases depend on uniform validity of self-reported smoking habits in different SES groups. We investigated the influence of SES on validity of self-reported smoking status by means of urinary cotinine.

Methods

We determined total urinary cotinine in the baseline population of the Heinz Nixdorf Recall Study. Participants with cotinine>200 µg/L were potential current smokers. We defined upper and lower 20% of the gender-specific distribution of the International Socio-Economic Index (ISEI) as high and low SES, respectively, else as intermediate. We analysed the association of self-reported smoking status and cotinine by ISEI and additional SES measures, stratified by gender. In self-reported non-smokers, we estimated age-adjusted ORs with 95% CI to detect differences by SES in the validity of self-reported smoking status.

Results

In 2004 men and 1887 women, 78% and 80%, respectively, reported to be non-smokers. Median cotinine concentrations were 2 µg/L in non-smokers, and 3651 µg/L in male and 3127 µg/L in female smokers. Based on cotinine in non-smokers, 2.0 % of men (n = 32) and 1.8 % of women (n = 27) were potential smokers, with lower proportions in the subgroup of never-smokers (men: 0.7%, women: 0.5%). The validity of self-reported smoking status did not substantially differ by SES. Tendencies for increased underreporting were indicated for women with low ISEI (OR 1.35; 95% CI 0.54 to 3.39) and men in blue-collar jobs (OR 1.39; 95% CI 0.67 to 2.87).

Conclusion

Validity of self-reported smoking status in this elderly German cohort was high and did not depend on SES.

Dose-Dependent Toxic Effect of Cotinine-Verified Tobacco Smoking on Systemic Inflammation in Apparently Healthy Men and Women: A Nationwide Population-Based Study

Chronic exposure to tobacco smoke leads to chronic low-grade systemic inflammation; however, little is known about the dose-dependent toxic effect of objective tobacco smoking on systemic inflammation. We examined the dose-dependent toxic effect of cotinine-verified tobacco smoking on leukocyte count in a representative sample of Korean adults, including 8655 men and 10,432 women aged 19⁻65 years from the Korean National Health and Nutrition Examination Survey. The participants were categorized into five groups by the level of urine cotinine (Ucot) as follows: A non-smoker group (<50.00 ng/mL) and four quartile groups for smokers for both men and women. The odds ratios (ORs) and 95% confidence intervals (CIs) for sex-specific high leukocyte count (≥75th percentile) were calculated across five groups of Ucot concentrations using multiple logistic regression analyses. The mean values of leukocyte count gradually increased according to the grade of Ucot concentration in both sexes. The ORs (95% CIs) for high leukocyte count in the 4th Ucot quartile concentrations versus the non-smokers were 4.09 (3.39⁻4.94) for men and 3.91 (2.82⁻5.41) for women after adjusting for confounding variables. The present study confirmed the dose-response toxic effect of tobacco smoking on chronic low-grade systemic inflammation.

Assessing tobacco use in an African population: Serum and urine cotinine cut-offs from South Africa

BACKGROUND

Cotinine, a nicotine metabolite, is used to measure tobacco use and exposure, but recommended cut-offs to differentiate tobacco users from those exposed through the environment range from 3 to 58 ng/ml in serum, and 2.5 to 550 ng/ml in urine. Cut-offs may differ by ethnicity, sex and age. As data from adults in Africa are scarce, our aim was to evaluate cut-offs for serum and urine cotinine that best predict self-reported tobacco use in South African adults.

METHODS

Two datasets were explored: African-PREDICT (n = 941 black and white healthy young adults, 20-30 years, serum cotinine); and WHO SAGE Wave 2 (n = 604 adults, 18-102 years, urine cotinine). Population specific cut-offs (ROC analyses) were compared with published cut-offs and self-reported tobacco use.

RESULTS

Overall, 19% (293 of 1545) reported current tobacco use. The following cotinine cut-offs showed the highest sensitivity and specificity: serum ≥15 ng/ml in black and white men, and white women; serum ≥10 ng/ml in black women; urine ≥300 ng/ml for black, mixed ancestry, and older adults (50-plus years); urine ≥500 ng/ml for younger adults (18-49 years). Specificity was lower for urine than for serum cotinine.

CONCLUSION

Our study suggests that a serum cotinine level of ≥15 ng/ml and a urine cotinine level of ≥300 ng/ml best distinguish current tobacco users from non-users generally in the South African adult population.

Smoking and Urinary Cotinine Levels Are Predictors of Increased Risk for Gastric Intestinal Metaplasia

Studies on a longitudinal relationship between smoking status and intestinal metaplasia (IM), a premalignant lesion of stomach cancer, are limited. Here we examined the association of smoking status and urinary cotinine levels, an objective measure of smoking, with the development of endoscopic IM. This cohort study included 199,235 Korean adults free of endoscopic IM who underwent upper endoscopy at baseline and subsequent visits and who were followed for up to 6.8 years (median, 3.7 years). Former and current smoking status and pack-years based on self-reports were associated with an increased risk of new-onset IM in men but not in women. However, urinary cotinine levels were positively associated with incident IM in a dose-response manner in both men and women. For men, the multivariable-adjusted HR [95% confidence interval (CI)] for incident IM comparing the urinary cotinine levels of 50 to 99 ng/mL, 100 to 499 ng/mL, and ≥500 ng/mL with <50 ng/mL were 1.20 (0.94-1.55), 1.26 (1.14-1.40), and 1.54 (1.44-1.64), respectively, whereas for women, corresponding HR (95% CI) were 0.75 (0.19-2.99), 1.86 (1.20-2.88), and 1.57 (1.07-2.30), respectively. These associations were observed when changes in smoking status and other confounders were updated during follow-up as time-varying covariates. In this large cohort of young and middle-aged men and women, urinary cotinine levels were independently associated with an increased incidence of endoscopic IM in a dose-response manner. Collectively, these data confirm smoking as an independent risk factor for the development of gastric IM, a precursor lesion of stomach cancer. SIGNIFICANCE: A large-scale cohort study of nearly 200,000 adults associates smoking with increased risk for gastric intestinal metaplasia, a precursor lesion of stomach cancer.

Socioeconomic inequalities in exposure to environmental tobacco smoke in children in Israel

BACKGROUND

Environmental tobacco smoke (ETS) exposure in infants and children causes more frequent and severe asthma attacks, respiratory infections, ear infections, and sudden infant death syndrome. The aim of this study was to measure ETS exposure in children in Israel (ages 4-11 years) using urinary cotinine measurements, in order to compare exposure levels to other international populations, and to assess predictors of ETS exposure in children in Israel.

METHODS

A subset of children who participated in the National Health and Nutrition Survey (RAV- MABAT) in 2015-2016 were invited to participate in the Second Israel Biomonitoring Survey. We analyzed urinary cotinine and creatinine concentrations in 103 children. Parents of study participants were interviewed in person on children's exposure to ETS at home and in other environments and on sociodemographic variables. We calculated creatinine-adjusted and unadjusted urinary cotinine geometric means in children and analyzed associations in univariable and multivariable analyses, between sociodemographic variables and parental - reported exposure, and urinary cotinine concentrations.

RESULTS

Based on urinary creatinine measurement, over 60% of children are exposed to ETS (compared to <40% based on parental report). Linear regression showed a positive association between urinary cotinine concentration and reported ETS exposure (p = 0.001). Mean cotinine concentration among children whose parents reported that they are exposed to ETS at home (5.1 μg/l) was significantly higher than the concentration among children whose parents reported they are not exposed to ETS at home (1.6 μg/l, p < 0.001). There was an inverse relationship between total family income and urinary cotinine concentration (p < 0.05). In a multivariable model adjusted for ethnicity and other factors, family income was a significant predictor of urinary cotinine level (p = 0.04, slope = -0.49). Geometric mean creatinine adjusted concentrations in children in the current study were higher than in children in Canada and selected European countries.

CONCLUSIONS

We found evidence of widespread exposure to ETS in children in the study. There is an urgent need to protect children in Israel from exposure to ETS.

Fetal exposure to maternal active and secondhand smoking with offspring early-life growth in the Healthy Start study

BACKGROUND

Previous studies have modeled the association between fetal exposure to tobacco smoke and body mass index (BMI) growth trajectories, but not the timing of catch-up growth. Research on fetal exposure to maternal secondhand smoking is limited.

OBJECTIVES

To explore the associations between fetal exposure to maternal active and secondhand smoking with body composition at birth and BMI growth trajectories through age 3 years.

METHODS

We followed 630 mother-child pairs enrolled in the Healthy Start cohort through age 3 years. Maternal urinary cotinine was measured at ~ 27 weeks gestation. Neonatal body composition was measured using air displacement plethysmography. Child weight and length/height were abstracted from medical records. Linear regression models examined the association between cotinine categories (no exposure, secondhand smoke, active smoking) with weight, fat mass, fat-free mass, and percent fat mass at birth. A mixed-effects regression model estimated the association between cotinine categories and BMI.

RESULTS

Compared to unexposed offspring, birth weight was significantly lower among offspring born to active smokers (-343-g; 95% CI: -473, -213), but not among offspring of women exposed to secondhand smoke (-47-g; 95% CI: -130, 36). There was no significant difference in the rate of BMI growth over time between offspring of active and secondhand smokers (p = 0.58). Therefore, our final model included a single growth rate parameter for the combined exposure groups of active and secondhand smokers. The rate of BMI growth for the combined exposed group was significantly more rapid (0.27 kg/m² per year; 95% CI: 0.05, 0.69; p < 0.01) than the unexposed.

CONCLUSIONS

Offspring prenatally exposed to maternal active or secondhand smoking experience rapid and similar BMI growth in the first three years of life. Given the long-term consequences of rapid weight gain in early childhood, it is important to encourage pregnant women to quit smoking and limit their exposure to secondhand smoke.

Self-Reported Smoking, Urine Cotinine, and Risk of Cardiovascular Disease: Findings From the PREVEND (Prevention of Renal and Vascular End-Stage Disease) Prospective Cohort Study

BACKGROUND

We aimed to compare the associations of smoking exposure as assessed by self-reports and urine cotinine with cardiovascular disease (CVD) risk and determine the potential utility of cotinine for CVD risk prediction.

METHODS AND RESULTS

Smoking status by self-reports and urine cotinine were assessed at baseline in 4737 participants (mean age, 53 years) of the PREVEND (Prevention of Renal and Vascular End-Stage Disease) prospective study. Participants were classified as never, former, light current (≤10 cigarettes/day), and heavy current smokers (>10 cigarettes/day) according to self-reports and analogous cutoffs for urine cotinine. During a median follow-up of 8.5 years, 296 first CVD events were recorded. Compared with self-reported never smokers, the hazard ratios (95% confidence interval) of CVD for former, light current, and heavy current smokers were 0.86 (0.64-1.17), 1.28 (0.83-1.97), and 1.80 (1.27-2.57) in multivariate analysis. Compared with urine cotinine-assessed never smokers, the corresponding hazard ratios of CVD for urine cotinine-assessed former, light current, and heavy current smokers were 1.70 (1.03-2.81), 1.62 (1.15-2.28), and 1.95 (1.39-2.73) respectively. The C-index change on adding urine cotinine-assessed smoking status to a standard CVD risk prediction model (without self-reported smoking status) was 0.0098 (0.0031-0.0164; P=0.004). The corresponding C-index change for self-reported smoking status was 0.0111 (0.0042-0.0179; P=0.002).

CONCLUSIONS

Smoking status as assessed by self-reports and urine cotinine is associated with CVD risk; however, the nature of the association of urine cotinine with CVD is consistent with a dose-response relationship. The ability of urine cotinine to improve CVD risk assessment is similar to that of self-reported smoking status.

Urine Cotinine level with smoking history predicts a risk of coronary artery calcification

We investigated whether urine cotinine level, alone or combined with smoking status and cumulative smoking amount, could predict coronary calcium (CAC) score increase over time. The study population included 10,980 subjects. We analysed an association between CAC score increase over time and single or combined smoking-related factors. Urine cotinine level of ≥100 ng/mL, current or ex-smokers, and cumulative smoking amount of ≥1 pack-years (PY) showed significantly higher odds ratios (ORs) for CAC score increase over time. A combination of current smokers with >10 PY and urine cotinine level of ≥100 ng/mL showed the highest OR. Irrespective of smoking status and cumulative smoking amount, all combinations with urine cotinine of ≥100 ng/mL showed higher ORs than other combinations with urine cotinine level of <100 ng/mL. Urine cotinine levels can be useful to predict coronary artery calcification and encourage smokers to quit smoking.

Environmental cadmium exposure is associated with elevated risk of chronic otitis media in adults

Objectives

Chronic otitis media (COM) is caused by an infection of the middle ear, although it may also be associated with environmental pollutants. Recent reports found that cadmium exposure could be toxic to middle ear cell lines, but the role of cadmium in the development of COM in humans has not been examined to date. We hypothesised that environmental cadmium exposure was associated with an increased risk of COM in the general population.

Methods

We analysed cross-sectional data for 5331 adults of 20 years of age or above, obtained from the Korea National Health and Nutrition Examination Survey 2010–2012. We examined the association between blood cadmium levels and COM diagnosed by an otolaryngologist.

Results

The highest quartile group of cadmium blood concentration was associated with an OR of 3.33 (95% CI 1.78 to 7.53) for COM, after adjusting for potential confounding factors. Doubling blood cadmium concentration resulted in an OR of 1.58 (95% CI 1.19 to 2.08) for COM. These associations were robust on sensitivity analyses after excluding current smokers and former smokers and after excluding subjects with a potential history of occupational exposure to cadmium.

Conclusions

The results of our study suggest that environmental cadmium exposure is associated with increased risk of COM, and further studies are warranted to understand the pathogenetic mechanism by which COM is caused by cadmium exposure.

Effect of Secondhand Smoking, Determined by Urinary Cotinine Level on Bone Health

Background:

We evaluated the relationship between secondhand smoke (SHS) inhalation, as verified by urinary cotinine levels, and bone health.

Methods:

We analyzed the nationwide, population-based, cross-sectional health survey. We included 1936 men aged 50 years or older who checked bone mineral density (BMD) from the Korean National Health and Nutrition Examination Survey (2008–2010). Current smokers assessed by urinary cotinine levels higher than 500 ng/mL were excluded (n = 616). Exposure to SHS was determined using a 50 ng/mL urinary cotinine threshold.

Results:

The estimated prevalence of SHS exposure in our cohort was 13.9%. After adjusting for age and body mass index (BMI), T-scores at total femur (P < 0.001), femoral neck (P < 0.001), and lumbar spine (P = 0.004) were lower in SHS exposure versus nonexposure groups. Impaired bone health (osteopenia or osteoporosis) at femoral neck or lumbar spine was evident in 61.7% and 48.6% of SHS exposure and nonexposure cases, respectively (P = 0.004). Moreover, after adjusting for age, BMI, and health habits, the odds ratio for impaired bone health in the SHS exposure group was 1.89 (95% confidence interval: 1.31–2.74).

Conclusions:

Our findings suggest that SHS exposure, determined by urinary cotinine levels, is negatively associated with BMD and is a leading cause of impaired bone health in Korean men.

Validation of Self-reported Smoking with Urinary Cotinine Levels and Influence of Second-hand Smoke among Conscripts

Accurate identification of smoking behaviour is crucial to monitor the smoking rate. This study used urinary cotinine (UC) as a biomarker to verify the effectiveness of self-reported smoking behaviour among conscripts during recruit training. The influence of second-hand smoke (SHS) on the UC concentration was also analysed. A cross-sectional study was conducted from July 2014 to December 2014. The participants comprised a total of 621 military service and basic military training conscripts. A self-administered questionnaire survey and a urine test were performed to verify the participants’ smoking behaviour. The UC concentration of 100 ng/mL was adopted as the baseline to identify smokers. A high level of consistency was observed between the conscripts’ self-reported results and the results validated by the UC concentrations (the overall kappa coefficient was 0.918). Moreover, the overall sensitivity and specificity were 92.9% and 98.1%, respectively. The sensitivity for the military service conscripts was significantly lower than that for the basic military training conscripts (86.1% vs. 97.5%, P-value = 0.002). For the self-reported nonsmokers among the military service conscripts, SHS exposure was related to their UC concentrations. The method of self-reporting through a questionnaire survey can serve as a tool to assess conscripts’ smoking behaviour.

Risk assessment of environmental exposure to heavy metals in mothers and their respective infants

Exposure to heavy metals can cause renal injury, which has been well documented in occupational exposure. Studies of low exposure in the general population, however, are still scarce, particularly for vulnerable populations such as mothers and young children. This study evaluated exposure to heavy metals, and biomarkers of renal function and oxidative stress in 944 lactating mothers and their infants and investigated the role of the interaction between heavy metals and oxidative stress in altering renal function. Mother and infant urine samples were analyzed to measure mercury (Hg), cadmium (Cd), and lead (Pb) concentrations for determining body-burden exposure; N-acetyl-β-d-glucosaminidase (NAG), α₁-microglobulin (α₁-MG), albumin (ALB), and creatinine (Cr) concentrations for determining early renal injury; and 8-hydroxy-2-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) concentrations for determining oxidative stress. The median concentrclearlyations in mothers presented as μg/g Cr (infants as μg/l) for Hg, Cd, and Pb were 0.695 (0.716), 0.322 (0.343), and 3.97 (5.306) respectively. The mothers and their infants had clearly been exposed to heavy metals and had levels higher than the reference values reported for the general populations of USA, Germany, and Canada. Multiple regression analyses clearly demonstrated associations between urinary heavy metals in quartiles and several renal and oxidative biomarkers in mothers and to a lesser extent their infants. ß coefficients for urinary excretions of MDA, 8-OHdG, ALB, α₁-MG, NAG, and Cr in mothers were high in the highest quartile of Hg (1.183-51.29μg/g Cr or 1.732-106.95μg/l), Cd (0.565-765.776μg/g Cr or 0.785-1347.0μg/l), and Pb (6.606-83.937μg/g Cr or 9.459-80.826μg/l), except Pb was not associated with ALB. Infants in the highest Pb quartile (9.293-263.098μg/l) had the highest ß coefficients of urinary excretion of MDA, 8-OHdG, ALB, NAG, and Cr. Significant increasing trend in biomarkers across the quartiles of the three metals was seen in both mothers and infants (p_trend <0.001). A receiver operating characteristic analysis supported the predictive abilities of the four renal biomarkers in discriminating between low versus high metal quartiles. The interaction between heavy metals and oxidative stress contributed to the high excretions of renal biomarkers, but the mechanism remains unclear. These findings add to the limited evidence that low exposure to heavy metals in the general population is associated with alterations in renal function that could eventually progress to renal damage if exposure continues and that children are more susceptible due to the immaturity of their body organs.

Nicotine cut-off value in human hair as a tool to distinguish active from passive smokers: A cross-sectional study in Japanese men

BACKGROUND

Nicotine concentration in hair is a useful marker of tobacco exposure. Detection of nicotine in the hair of non-smokers indicates passive smoking. Accurate measurement of nicotine among active and passive smokers can help in smoking cessation programs or programs designed to prevent secondhand smoke exposure.

OBJECTIVE

To establish, using high-performance liquid chromatography-ultraviolet detection (HPLC/UV), a hair nicotine cut-off value to distinguish active from passive smokers.

METHODS

Hair samples were collected from randomly chosen Japanese men (n= 192) between 2009 and 2011. Nicotine and cotinine levels in hair were measured using HPLC/UV with column-switching. T-tests and chi-square tests were performed to compare active and passive smokers, while receiver operating characteristic curves were used to evaluate the effectiveness of the cut-off value.

RESULTS

There were 69 active smokers and 123 passive smokers. The nicotine and cotinine concentrations in hair were significantly higher in active than in passive smokers (p< 0.01). The area under the curve for nicotine was 0.92. A hair nicotine cut-off value of 5.68 ng/mg, with a sensitivity of 94.2% and specificity of 87.0%, was identified as the optimal cut-off value for separating active from passive smokers.

CONCLUSION

Nicotine and cotinine concentrations in hair clearly distinguished active from passive smokers.

The Association between Involuntary Smoking Exposure with Urine Cotinine Level and Blood Cadmium Level in General Non-Smoking Populations

Unintentional environmental exposure to toxicants is associated with an aggravated health status of the general population. Involuntary smoking (IS) exposure is one of the main routes to involuntary toxicants exposure. However, few studies have attempted to understand the environmental cadmium exposure by IS exposure in the general, non-smoking population. The purpose of the current study was to examine the relationship between blood cadmium level and IS level according to gender and age. We used the Korea National Health and Nutrition Examination Survey (KNHANES) IV-VI data that included heavy metal and urine cotinine sampling with IS exposure history. The final analysis comprised 3,493 adults (1,231 males and 2,262 females) and 395 adolescents (210 males and 185 females). Linear regression was performed to estimate the association between self-reported IS exposure with urine cotinine level and blood cadmium level in non-smokers with gender and age group stratification. In final regression model, the effect values (B) (standard errors [SE]) between blood cadmium and urine cotinine level in men was 0.0004 (0.0001) and 0.0006 (0.0002) in adults and adolescents, the B (SE) in women was 0.0006 (0.0002) and 0.0016 (0.0006) in adults and adolescents. Our study revealed, for the first time, a significant association between blood cadmium and IS exposure in non-smokers. Greater efforts are needed to improve environmental justices of the general population from IS, considering the severe harmful effects of involuntary exposure to even a low level of cadmium.

Overview of Cotinine Cutoff Values for Smoking Status Classification

While cotinine is commonly used as a biomarker to validate self-reported smoking status, the selection of an optimal cotinine cutoff value for distinguishing true smokers from true nonsmokers shows a lack of standardization among studies. This review describes how the cutoff values have been derived, and explains the issues involved in the generalization of a cutoff value. In this study, we conducted an English-language literature search in PubMed using the keywords “cotinine” and “cutoff” or “self-reported” and “smoking status” and “validation” for the years 1985–2014. We obtained 104 articles, 32 of which provided (1) sensitivity and specificity of a cutoff value and (2) determination methods for the given cutoff value. We found that the saliva cotinine cutoff value range of 10–25 ng/mL, serum and urine cotinine cutoff of 10–20 ng/mL and 50–200 ng/mL, respectively, have been commonly used to validate self-reported smoking status using a 2 × 2 table or a receiver operating characteristics (ROC) curve. We also found that recent large population-based studies in the U.S. and UK reported lower cutoff values for cotinine in serum (3 ng/mL) and saliva (12 ng/mL), compared to the traditionally accepted ones (15 and 14 ng/mg, respectively).

Estimation of Saliva Cotinine Cut-Off Points for Active and Passive Smoking during Pregnancy-Polish Mother and Child Cohort (REPRO_PL)

A reliable assessment of smoking status has significant public health implications and is essential for research purposes. The aim of this study was to determine optimal saliva cotinine cut-off values for smoking during pregnancy. The analyses were based on data from 1771 women from the Polish Mother and Child Cohort. Saliva cotinine concentrations were assessed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-ESI + MS/MS). The saliva cotinine cut-off value for active smoking was established at 10 ng/mL (sensitivity 96%, specificity 95%) and for passive smoking at 1.5 ng/mL (sensitivity 63%, specificity 71%). About 5% of the self-reported non-smoking women were classified as smokers based on the cotinine cut-off value. Significantly more younger, single, and less educated self-reported non-smokers had a cotinine concentration higher than 10 ng/mL compared to those who were older, married, and who had a university degree. Close to 30% of the non-smokers who indicated that smoking was not allowed in their home could be classified as exposed to passive smoking based on the cut-off value. The study suggests that self-reported smoking status is a valid measure of active smoking, whereas in the case of passive smoking, a combination of questionnaire data and biomarker verification may be required.

Comparison of SemiQuantitative Cotinine Values Obtained by the DRI Immunoassay and Values Obtained by a Liquid Chromatography-Tandem Mass Spectrometry-Based Method: The DRI Immunoassay is Suitable for Screening Purposes Only Because Semiquantitative Values May Be Unreliable

BACKGROUND

DRI cotinine assay is suitable only for screening for cotinine in urine specimens. We studied the reliability of DRI cotinine semiquantitative values by comparing them with the cotinine concentration obtained with a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method.

METHODS

Semiquantitative cotinine concentrations in 39 urine specimens obtained by the DRI immunoassay were compared with cotinine concentrations obtained by LC-MS/MS.

RESULTS

The DRI cotinine assay consistently overestimated cotinine values obtained by the LC/MS/MS method (y = 1.1529 x + 252.24, n = 39, R² = 0.8899) indicating that semiquantitative values obtained using the DRI assay may be unreliable. However, no false-negative results were observed using the DRI assay.

CONCLUSION

DRI cotinine assay is suitable only for screening cotinine in urine specimens.

Can a urine dipstick test be used to assess smoking status in patients undergoing planned orthopaedic surgery? a prospective cohort study

AIMS

Smoking is associated with post-operative complications but smokers often under-report the amount they smoke. Our objective was to determine whether a urine dipstick test could be used as a substitute for quantitative cotinine assays to determine smoking status in patients.

PATIENTS AND METHODS

Between September 2013 and July 2014 we conducted a prospective cohort study in which 127 consecutive patients undergoing a planned foot and ankle arthrodesis or osteotomy were included. Patients self-reported their smoking status and were classified as: 'never smoked' (61 patients), 'ex-smoker' (46 patients), or 'current smoker' (20 patients). Urine samples were analysed with cotinine assays and cotinine dipstick tests.

RESULTS

There was a high degree of concordance between dipstick and assay results (Kappa coefficient = 0.842, p < 0.001). Compared with the quantitative assay, the dipstick had a sensitivity of 88.9% and a specificity of 97.3%. Patients claiming to have stopped smoking just before surgery had the highest rate of disagreement between reported smoking status and urine testing.

CONCLUSION

Urine cotinine dipstick testing is cheap, fast, reliable, and easy to use. It may be used in place of a quantitative assay as a screening tool for detecting patients who may be smoking. A positive test may be used as a trigger for further assessment and counselling. Cite this article: Bone Joint J 2016;98-B:1418-24.