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

The prevalence of smoking among soldiers of the gendarmerie in a provincial center and affecting factors: A cross-sectional study from Turkey. ARCHIVES OF ENVIRONMENTAL & OCCUPATIONAL HEALTH 2023;78:347-356. [PMID: 37788125 DOI: 10.1080/19338244.2023.2262923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Determining the smoking rates and nicotine dependency levels of soldiers can be a guide in smoking cessation interventions and developing a policy for smoking prevention for soldiers serving in military units. The cross-sectional study was conducted with a total of 313 soldiers stationed in gendarmerie units in a city center in the Central Anatolian Region of Turkey. Data were collected between 01.06.2021 and 31.07.2021 by face-to-face interview technique using Personal Information Form and Fagerström Nicotine Addiction Test. It was determined that 54.6% of the participants smoked, 87.1% had low-moderate nicotine addictions, and 94.9% were smokers in their friends' circle. It was revealed that the prevalence of smoking among the participants was high, and the nicotine addiction levels of the participants working in the "Prison" unit were higher.

Fathers' preconception smoking and offspring DNA methylation

BACKGROUND

Experimental studies suggest that exposures may impact respiratory health across generations via epigenetic changes transmitted specifically through male germ cells. Studies in humans are, however, limited. We aim to identify epigenetic marks in offspring associated with father's preconception smoking.

METHODS

We conducted epigenome-wide association studies (EWAS) in the RHINESSA cohort (7-50 years) on father's any preconception smoking (n = 875 offspring) and father's pubertal onset smoking < 15 years (n = 304), using Infinium MethylationEPIC Beadchip arrays, adjusting for offspring age, own smoking and maternal smoking. EWAS of maternal and offspring personal smoking were performed for comparison. Father's smoking-associated dmCpGs were checked in subpopulations of offspring who reported no personal smoking and no maternal smoking exposure.

RESULTS

Father's smoking commencing preconception was associated with methylation of blood DNA in offspring at two cytosine-phosphate-guanine sites (CpGs) (false discovery rate (FDR) < 0.05) in PRR5 and CENPP. Father's pubertal onset smoking was associated with 19 CpGs (FDR < 0.05) mapped to 14 genes (TLR9, DNTT, FAM53B, NCAPG2, PSTPIP2, MBIP, C2orf39, NTRK2, DNAJC14, CDO1, PRAP1, TPCN1, IRS1 and CSF1R). These differentially methylated sites were hypermethylated and associated with promoter regions capable of gene silencing. Some of these sites were associated with offspring outcomes in this cohort including ever-asthma (NTRK2), ever-wheezing (DNAJC14, TPCN1), weight (FAM53B, NTRK2) and BMI (FAM53B, NTRK2) (p < 0.05). Pathway analysis showed enrichment for gene ontology pathways including regulation of gene expression, inflammation and innate immune responses. Father's smoking-associated sites did not overlap with dmCpGs identified in EWAS of personal and maternal smoking (FDR < 0.05), and all sites remained significant (p < 0.05) in analyses of offspring with no personal smoking and no maternal smoking exposure.

CONCLUSION

Father's preconception smoking, particularly in puberty, is associated with offspring DNA methylation, providing evidence that epigenetic mechanisms may underlie epidemiological observations that pubertal paternal smoking increases risk of offspring asthma, low lung function and obesity.

Verifying the accuracy of self-reported smoking behavior in female volunteer soldiers

Smoking rates in the military are evaluated through questionnaire surveying. Because the accurate identification of smokers facilitates the provision of smoking cessation services, this study conducted urine cotinine concentration testing to verify the accuracy of self-reported smoking behavior by female volunteer soldiers and analyzed the effects of second-hand smoking on urine cotinine concentrations. This study is a cross-sectional study conducted using purposive sampling on female volunteer soldiers receiving training at the Taichung Recruit Training Center in May 2014. This study simultaneously collected questionnaires and urine samples, and urine samples were analyzed with an enzyme-linked immunosorbent assay. The self-reported smoking rate of female volunteer soldiers was 19.3%, whereas the smoking rate as determined by urine cotinine concentration testing was 26.3%, indicating an overall underestimation of 7.0%. Chi-square (χ2) goodness of fit test results indicated that the distribution of self-reported smoking behaviors and that verified from urine cotinine concentration testing were significantly different. The sensitivity of self-reported smoking behavior was 66.7% with a specificity of 97.6%. There was no significant association between second-hand smoking and urine cotinine concentrations. Questionnaire survey self-reporting methods could underestimate the smoking behavior of female volunteer soldiers and routine testing with biochemical verification is necessary.

Study of urinary mercapturic acids as biomarkers of human acrylonitrile exposure

Exposure to the vinyl monomer acrylonitrile (AN) is primarily occupational. AN is also found in cigarette smoke. AN can be detoxified to form N-acetyl-S-(2-cyanoethyl)-cysteine (CEMA) or activated to 2-cyanoethylene oxide (CEO) and detoxified to form N-acetyl-S-(1-cyano-2-hydroxyethyl)-cysteine (CHEMA) and N-acetyl-S-(2-hydroxyethyl)-cysteine (HEMA). These urinary mercapturic acids (MAs) are considered to be potential biomarkers of AN exposure. This study assessed personal AN exposure, urinary MAs (CEMA, CHEMA, and HEMA), and cotinine (a biomarker of cigarette smoke) in 80 AN-exposed and 23 non-exposed factory workers from urine samples provided before and after work shifts. Unambiguous linear correlations were observed between levels of urinary CEMA and CHEMA with personal AN exposures, indicating their potential as chemically-specific biomarkers for AN exposures. AN exposure was the dominant factor in MA formation for AN-exposed workers, whereas urinary cotinine used as a biomarker showed that cigarette smoke exposure was the primary factor for non-exposed workers. The CHEMA/CEMA and (CHEMA+HEMA)/CEMA ratios in this human study differ from those in similar studies of AN-treated rats and mice in literature, suggesting a possible dose- and species-dependent effect in AN metabolic activation and detoxification.

Spirometry as a motivator for smoking cessation among patients attending the smoking cessation clinic of Monastir

BACKGROUND

The choice of spirometry, a biomarker of lung health, as a motivator for smoking cessation is based on its fidelity in emphasizing tobacco adverse effects. Yet, there is a paucity of evidence on its efficacy, and the findings are currently inconclusive. The aim of this study was to determine whether a spirometry and lung age communication has an effect on smoking cessation rates.

METHODOLOGY

We conducted a randomized controlled trial among patients who attended the smoking cessation clinic (SCC) at Fattouma Bourguiba University Hospital in Monastir, from June 2017 to February 2020. Participants were assigned into two groups, a control arm receiving standard program and intervention arm receiving a spirometry and lung age announcement along with usual care. The primary outcomes were the smoking cessation rates after one year of follow-up between the intervention arm and the control arm.

RESULTS

At one-year endpoint, a total of 456 were reachable for assessment, 236 in control group and 220 in spirometry group, which leads to a loss rate equal to 8.8%. One-year smoking cessation rate was higher among the intervention group than among control group (25.5% versus 16.5%), with a considerable statistical significance (p = 0.019). Lung age was significantly higher at paired comparison with chronological age.

CONCLUSION

Smoking cessation is still a challenging procedure with a high risk of relapse, making very valuable any approach that may increase motivation in both unmotivated and motivated smokers. This study is an additional evidence for spirometry and lung age announcement as motivators for smoking cessation.

TRIAL REGISTRATION

Pan African Clinical Trial Registry database ( PACTR202110595729653 ), 06/10/ 2021.

Tobacco Smoking during Pregnancy: Women's Perception about the Usefulness of Smoking Cessation Interventions

Tobacco consumption during pregnancy is a serious public health problem due to its negative effects on fetal development and on pregnant women's health and well-being. Thus, it is of utmost importance to plan and implement smoking cessation interventions, to prevent the negative impact of this risk factor, namely on children's health and development. This cross-sectional study aimed at exploring the perceptions and beliefs about the usefulness of smoking cessation interventions during pregnancy, in a sample of pregnant Portuguese women. The smoking use by pregnant women, as well as the risk factors associated with tobacco smoking during pregnancy, were also analyzed. The sample included 247 pregnant Portuguese women aged between 18-43-years-old (M = 30.30, SD = 5.02): 42.5% never smoked, 18.3% quit smoking before pregnancy, 19.0% quit smoking after getting pregnant and 20.2% were current smokers. The pregnant Portuguese women who smoked during pregnancy (current smokers or who quit smoking after getting pregnant) were mostly single or divorced, with lower education levels, showed a higher prevalence of clinically significant anxiety symptoms, and perceived smoking cessation interventions during pregnancy as less useful when compared to women who never smoked or quit smoking prior pregnancy. Daily or weekly smoking cessation interventions, implemented by health professionals such as doctors, nurses, or psychologists are the ones perceived as the most useful for pregnant women. These findings provide important clues for the planning of smoking cessation interventions during pregnancy, highlighting the domains that should be carefully monitored by health professionals. Specific strategies should also be used by health professionals to promote smoking cessation considering the demands of pregnancy and postpartum.

Evaluation of a Newly Developed Smartphone App for Risk Factor Management in Young Patients With Ischemic Stroke: A Pilot Study

Background: Efficient treatment of modifiable vascular risk factors decreases reoccurrence of ischemic stroke, which is of uttermost importance in younger patients. In this longitudinal pilot study, we thus assessed the effect of a newly developed smartphone app for risk factor management in such a cohort. Methods: The app conveys key facts about stroke, provides motivational support for a healthy lifestyle, and a reminder function for medication intake and blood pressure measurement. Between January 2019 and February 2020, we consecutively invited patients with ischemic stroke aged between 18 and 55 years to participate. Patients in the intervention group used the app between hospital discharge and 3-month follow-up. The control group received standard clinical care. Modifiable risk factors (physical activity, nutrition, alcohol consumption, smoking behavior, obesity, and hypertension) were assessed during the initial hospital stay and at a dedicated stroke outpatient department three months post-stroke. Results: The study cohort comprised 21 patients in the app intervention group (62% male; age = 41 ± 11 years; education = 12 ± 3 years) and 21 sex-, age- and education-matched control patients with a comparable stroke risk factor profile. Baseline stroke severity was comparable between groups (intervention: median NIHSS = 3; control: median NIHSS = 4; p = 0.604). Three months post-stroke, patients in the intervention group reported to be physically almost twice as active (13 ± 9 h/week) compared to controls (7 ± 5 h/week; p = 0.022). More intense app usage was strongly associated with higher physical activity (r = 0.60, p = 0.005) and lower consumption of unhealthy food (r = -0.51, p = 0.023). Smoking behavior (p = 0.001) and hypertension (p = 0.003) improved in all patients. Patients in the intervention group described better self-reported health-related quality of life three months post-stroke (p = 0.003). Conclusions: Specifically designed app interventions can be an easily to implement and cost-efficient approach to promote a healthier lifestyle in younger patients with a stroke.

Association between Self-Reported Survey Measures and Biomarkers of Second-Hand Tobacco Smoke Exposure in Non-Smoking Pregnant Women

Second-hand tobacco smoke (SHS) causes adverse health outcomes in adults. Further studies are needed to evaluate psychosocial SHS exposure measures in comparison to SHS exposure biomarkers, particularly in pregnant women. This study aimed to compare self-reported SHS exposure to urinary cotinine levels in pregnant women. A cross-sectional correlation design was conducted using a convenience sample of 70 non-smoking pregnant women. Measures included self-reported questionnaires and laboratory confirmation of cotinine levels in the urinary samples. Multiple regression analysis was used to assess the correlation after controlling for potential confounding variables. The average level of urinary cotinine among non-smoking pregnant women was 6.77 ng/mL. Medium-strength correlations were found among psychosocial SHS exposure measures and urine cotinine levels. Questions regarding ‘instances of smoking in front of the individual’ and ‘subjective perceived frequency of SHS exposure in past 7 days’ are feasible items for pregnant women in clinics (particularly the first question). Hence, we suggest that these simple questions should be used to assist pregnant women in reducing the harm associated with SHS exposure.

Environmental Tobacco Smoke Exposure Among Children by Urinary Biomarkers and Parent Report

OBJECTIVE

The goal of this study was to describe environmental tobacco smoke (ETS) exposure using urinary biomarkers and its correlation with parent report, among children presenting to emergency room.

METHODS

This is a case control study among children aged 3 to 12 years at a tertiary pediatric emergency department in Israel. Children with respiratory (case) or gastrointestinal (control) symptoms were recruited and their accompanying parent completed a short survey. Urine samples were obtained and analyzed for nicotine, cotinine trans-3'-hydroxycotine. Clinical data were extracted from medical records. We compared tobacco exposure using urinary biomarkers, parent report, and Pearson's product-moment correlation, including 95% confidence intervals, between cases and controls.

RESULTS

Forty-nine cases with respiratory symptoms and 96 controls with gastrointestinal symptoms were enrolled in the study. Parent-reported ETS exposure in the previous month was higher in the cases compared to control (71.4% vs 57.3%), although the difference was not statistically significant. The mean values of detectable biomarkers did not differ by between cases and controls. However, there was a correlation between urinary biomarkers and reported ETS exposure (0.278-0.460 for various biomarkers) only among cases.

CONCLUSIONS

The majority of children in this study had detectable nicotine urinary biomarkers, regardless of their symptoms. However, correlation between parental report and urinary biomarkers was only found among children with symptoms potentially related to ETS. These findings imply that parents of children without respiratory symptoms may underestimate exposure. Efforts to educate parents and caregivers on the risks associated with exposure to ETS should be intensified, regardless of illness.

Factors Associated With the Differences Between Self-Report Smoking and Urinary Cotinine Criteria

During self-reporting, respondents underreport their smoking status for various reasons. We aimed to evaluate the difference between smoking status self-reporting and urinary cotinine tests in Korea respondents. Logistic regression analyses were performed to identify factors associated with the differences between self-reporting and urinary cotinine criteria. The dependent variable was the underreporting of smoking status; independent variables were sociodemographic, health status, and secondhand smoke (SHS) exposure. Total underreporting was 3.6% when Cot ≥164 and 4.0% when Cot-variable (classified) criteria underreported. Positive associations were found between smoking and age, education, drinking, and SHS. Underreporting in the nonsmoker group (odds ratio [OR] = 2.336; confidence interval [CI] = 1.717-3.179) was significantly associated with SHS, but this difference was nonsignificant in the ex-smoker group (OR = 1.184; CI = 0.879-1.638). Underreporting was 3.6% to 4.0%, and C-statistics was about 0.7, indicating that outcomes could be classified. SHS in nonsmokers was positively associated with underreporting; however, only the nonsmoker group had positive associations, demonstrating unintentional underreporting due to SHS.

Data visualization of the relationship between smoking and periodontal site-specific effects across the lifespan in the US adult population

BACKGROUND

Data visualization techniques were used to ascertain (1) site-specific effects of cigarette smoking on the periodontium compared to never-smokers; (2) patterns of site-specific effects by age among current and never-smokers using contour maps.

METHODS

Data from 10,713 dentate participants aged ≥30 years in NHANES 2009-2014 were used. Pocket depth (PD) and clinical attachment level (CAL) for six sites/tooth were ascertained by smoking status and plotted using contour maps to identify new patterns.

RESULTS

In the overall sample, 19% (n = 2015) were current smokers and 56% (n = 6013) were never-smokers. Contour maps of the overall sample showed teeth/sites most affected with mean PD > 2.1 mm were molars (2,3,15,18,19,30,31) in mesio-lingual (ML) and disto-lingual (DL) sites. Most affected sites for current smokers were interproximal sites of most posterior teeth. Among never-smokers, fewer teeth/sites were affected with PD > 2.1 mm, whereas among smokers, number of affected teeth/sites increased with age. Overall, teeth/sites most affected with mean CAL≥2.1 mm were noted in 2,3(ML), 3(DL), 14(DF, DL), 15(MF, ML), 18(ML), 19(DL, ML), and 30-31(ML, DL) with upper anterior teeth least affected. Among current smokers, several teeth/sites were affected (CAL≥2.1 mm): 2,3(all six sites), 4(ML, DL), 9(ML), 11-21(DL), 13-18(DF, ML, MIL, DL), 19-20(DF, ML, MIL), 14-18(MIF), 21(MIF, ML, DL), 22(MF), 23-27(MIL), 24-26(MIL, MF, DF in 26), 27(MF), 28(MF, ML, DL), 29-31(all 6 sites except MIF 30,31). As age increased, more teeth/sites were affected among smokers and by the 5th decade nearly all teeth/sites had CAL≥2.0 mm.

CONCLUSIONS

Contour mapping identifies patterns and dramatically visualizes the substantial periodontal site-specific differences. Current smokers had more affected teeth and/or periodontal sites with a different contour pattern than never-smokers.

Association between Cigarette Smoking and New-Onset Diabetes Mellitus in 78,212 Koreans Using Self-Reported Questionnaire and Urine Cotinine

BACKGROUND

No study has assessed association between cigarette smoking and new-onset diabetes mellitus (NODM) incidence using two different smoking classification systems: self-reported questionnaire and urine cotinine. The objective of this longitudinal study was to evaluate NODM risk using the above two systems in Korean adults.

METHODS

Among individuals enrolled in Kangbuk Samsung Health Study and Cohort Study who visited between 2011 and 2012 at baseline and 2014 at follow-up, 78,212 participants without baseline diabetes mellitus were followed up for a median of 27 months. Assessment of NODM incidence was made at the end of follow-up period. Cotinine-verified current smoking was having urinary cotinine ≥50 ng/mL.

RESULTS

Percentages of self-reported and cotinine-verified current smokers were 25.9% and 23.5%, respectively. Overall incidence of NODM was 1.5%. According to multivariate regression analyses, baseline self-reported current smoking (relative risk [RR], 1.33; 95% confidence interval [CI], 1.07 to 1.65) and cotinine-verified current smoking (RR, 1.27; 95% CI, 1.08 to 1.49) increased NODM risk compared to baseline self-reported never smoking and cotinine-verified current non-smoking. Higher daily amount and longer duration of smoking were also associated with increased NODM risk (P for trends <0.05). In particular, self-reported current smokers who smoked ≥20 cigarettes/day (RR, 1.62; 95% CI, 1.25 to 2.15) and ≥10 years (RR, 1.34; 95% CI, 1.08 to 1.67) had the highest RRs for NODM. These results remained significant in males, although there was no gender interaction.

CONCLUSION

This longitudinal study showed that baseline self-reported and cotinine-verified current smoking were associated with increased risks of NODM, especially in males.

Effects of smoking habit change on hospitalized fractures: a retrospective cohort study in a male population

We examined effects of smoking habit change on fracture risk in men. Long-term quitters and never smokers showed decreased risk for overall fractures, lumbar fractures, and other site fractures. Short-term quitters did not show decreased risk. Longer time since smoking cessation may lead to decreased fracture risk in men.

PURPOSE

Cigarette smoking is a well-known modifiable risk factor of osteoporosis and fractures. This study investigated the effects of change in smoking habits on risks of all types of fractures in men using a nationwide health claims database.

METHODS

Retrospective study was performed using the Korean National Health Insurance Service-National Sample Cohort Data. Cox proportional hazards regression analyses were performed to estimate risks of all types of hospitalized fractures, hip fractures, lumbar fractures, and other site fractures (all other fractures excluding the lumbar and hip areas).

RESULTS

Compared to continued smokers, long-term quitters and never smokers showed decreased risk for all types of fractures (adjusted hazard ratio (aHR) 0.83, 95% confidence interval (CI) 0.78-0.88 and aHR 0.84, 95% CI 0.80-0.89, respectively). According to skeletal site, long-term quitters and never smokers showed decreased risk for lumbar fractures (aHR 0.82, 95% CI 0.68-0.98 and aHR 0.85, 95% CI 0.73-0.99, respectively) and other site fractures (aHR 0.83, 95% CI 0.78-0.89 and aHR 0.85, 95% CI 0.81-0.90, respectively). Hip fractures were decreased in never smokers (aHR 0.77, 95% CI 0.62-0.94). Short-term quitters did not show decreased risk for fractures.

CONCLUSIONS

Longer time since smoking cessation in men may lead to decreased risk for fractures, especially lumbar and other site fractures. Physicians should counsel patients at risk for fractures both to quit smoking and to maintain abstinence from smoking. Further studies may be required to help comprehend how smoking cessation can affect fracture risk.

Association Between Second-hand Smoke Exposure and Depressive Symptoms Among Japanese Adults: A Cross-sectional Study

Background

Second-hand smoke exposure has been associated with poor mental health. However, among Japanese adults, little is known about the association between second-hand smoking and depressive symptoms. We examined this association in a cross-sectional study among a Japanese general adult population sample.

Methods

Japanese adults were recruited from the Japan Multi-Institutional Collaborative Cohort Study in the Okazaki area between 2012 and 2017. Second-hand smoke exposure and smoking status were assessed using a self-administered questionnaire. Based on their frequency of exposure to second-hand smoke, non-smokers and smokers were categorized as “almost never,” “sometimes,” and “almost every day”. Depressive symptoms were defined by a Kessler 6 score ≥5 points. We performed a multivariable Poisson regression analysis to obtain adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs) for depressive symptoms.

Results

Overall, 5,121 participants (4,547 non-smokers and 574 smokers) were included whose mean age was 63.6 (standard deviation [SD], 10.3) years for non-smokers and 59.33 (SD, 10.2) years for smokers. The association between second-hand smoking and depressive symptoms was significant among non-smokers, but not among smokers. Among non-smokers, PRs compared with “almost never” were 1.25 (95% CI, 1.09–1.42) for “sometimes” and 1.41 (95% CI, 1.09–1.84) for “almost every day” (P for trend <0.001); among smokers, PRs compared with “almost never” were 1.30 (95% CI, 0.82–2.06) for “sometimes” and 1.44 (95% CI, 0.90–2.33) for “almost every day” (P for trend = 0.144).

Conclusions

Second-hand smoking and depressive symptoms were associated among non-smokers. Our findings indicate the importance of tobacco smoke control for mental health.

Detoxification effects of aloe polysaccharide and propolis on the urinary excretion of metabolites in smokers

The aim of the present study was to investigate the detoxifying effects of aloe polysaccharide (APS), propolis, and the mixture of APS and propolis on the urinary excretion of major human tobacco carcinogens, BaP and an addictive stimulant alkaloid, nicotine. Smokers (≥20 cigarettes/day) were randomly classified into four subgroups (10 people/group) and were given 600 mg/day of APS, 600 mg/day of propolis, or 600 mg/day of the mixture of APS (420 mg/day) and propolis (180 mg/day) for four weeks. Urinary excretion of BaP and cotinine (a metabolite of nicotine) increased in a time-dependent manner increased after supplementation with APS (BaP, 2.23-fold; cotinine, 2.64-fold), propolis (BaP, 1.30-fold; cotinine, 2.08-fold), and the mixture (BaP, 2.33-fold; cotinine, 2.28-fold) compared with smoker control. Creatinine, glucose, and total bilirubin levels significantly decreased in a time-dependent manner after supplementation with APS (creatinine, 15.24%; glucose, 40.22%; total bilirubin, 48.82%), propolis (creatinine, 16.83%; glucose, 36.25%; total bilirubin, 52.59%), and the mixture (creatinine, 16.36%; glucose, 46.37%; total bilirubin, 39.20%) (p < 0.05). These results suggest that supplementation with APS, propolis, or the mixture could reduce the risk of cancer or other diseases associated with tobacco smoking by enhancing urinary excretion of BaP and nicotine.

Association of exposure level to passive smoking with hypertension among lifetime nonsmokers in Japan: a cross-sectional study

Brief exposure to passive smoking immediately elevates blood pressure. However, little is known about the association between exposure to passive smoking and chronic hypertension. We aimed to examine this association in a cross-sectional study, after controlling multiple potential confounders.Participants included 32,098 lifetime nonsmokers (7,216 men and 24,882 women) enrolled in the Japan Multi-Institutional Collaborative Cohort Study. Passive smoking was assessed using a self-administered questionnaire. The single question about exposure to passive smoking had five response options: "sometimes or almost never," "almost every day, 2 hours/day or less," "almost every day, 2 to 4 hours/day," "almost every day, 4 to 6 hours/day," and "almost every day, 6 hours/day or longer." Hypertension was defined as any of the following: systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, or use of antihypertensive medication. Multivariate-adjusted odds ratio (OR) and 95% confidence interval (CI) for hypertension were estimated by exposure level to passive smoking using unconditional logistic regression models.The multivariate-adjusted OR for hypertension in those exposed almost every day was 1.11 (95% CI: 1.03-1.20) compared with those exposed sometimes or almost never. The OR for a 1-hour per day increase in exposure was 1.03 (95% CI: 1.01-1.06, Pfor trend = .006). This association was stronger in men than in women; the ORs were 1.08 (95% CI: 1.01-1.15, Pfor trend = .036) and 1.03 (95% CI: 1.00-1.05, Pfor trend = .055), respectively.Our findings suggest importance of tobacco smoke control for preventing hypertension.