Discrepancy between Self-Reported and Urine Cotinine-Verified Environmental Tobacco Smoke Exposure among Rural Pregnant Women in China

Plasma nicotine and its metabolite as biomarkers of tobacco exposure and their relevance to pulmonary nodule

Aim: Explore the optimal cut-off values for plasma nicotine and its metabolites in assessing smoking status and quantify the association between individual tobacco exposure and pulmonary nodules (PNs).Materials & methods: A total of 2245 plasma samples were included for the determination of nicotine (Nic), cotinine (Cot) and trans-3'-hydroxycotinine (OHCot) concentrations. The receiver operating characteristic curve was used to determine the optimal biomarkers reflecting smoking status. Binary logistic regression, restricted cubic spline and generalized linear model were used to analyze the association of nicotine and its metabolites with PNs. Quantile g-computation was used to investigate the mixed effects between them.Results: Cot was found to be the best biomarker of self-reported active-passive smoking, with optimal thresholds of 9.06 and 1.26 ng/ml, respectively. Except for OHCot, increased concentrations of Cot, Nic, total nicotine equivalent (TNE2) and TNE3 were significantly positively associated with the risk of PNs, whereas nicotine metabolite ratio presented a negative association. The mixed effects of OHCot, Cot and Nic were associated with PNs, with an odds ratio of 1.17 and a 95% CI of 1.05-1.30.Conclusion: Nicotine and its metabolites as potential biomarkers of tobacco exposure were significantly associated with PNs.

A Comparison of Measured Airborne and Self-Reported Secondhand Smoke Exposure in the MADRES Pregnancy Cohort Study

INTRODUCTION

Secondhand smoke (SHS) exposure during pregnancy is linked to adverse birth outcomes, such as low birth weight and preterm birth. While questionnaires are commonly used to assess SHS exposure, their ability to capture true exposure can vary, making it difficult for researchers to harmonize SHS measures. This study aimed to compare self-reported SHS exposure with measurements of airborne SHS in personal samples of pregnant women.

METHODS

SHS was measured on 48-hour integrated personal PM2.5 Teflon filters collected from 204 pregnant women, and self-reported SHS exposure measures were obtained via questionnaires. Descriptive statistics were calculated for airborne SHS measures, and analysis of variance tests assessed group differences in airborne SHS concentrations by self-reported SHS exposure.

RESULTS

Participants were 81% Hispanic, with a mean (standard deviation [SD]) age of 28.2 (6.0) years. Geometric mean (SD) personal airborne SHS concentrations were 0.14 (9.41) µg/m3. Participants reporting lower education have significantly higher airborne SHS exposure (p = .015). Mean airborne SHS concentrations were greater in those reporting longer duration with windows open in the home. There was no association between airborne SHS and self-reported SHS exposure; however, asking about the number of smokers nearby in the 48-hour monitoring period was most correlated with measured airborne SHS (Two + smokers: 0.30 µg/m3 vs. One: 0.12 µg/m3 and Zero: 0.15 µg/m3; p = .230).

CONCLUSIONS

Self-reported SHS exposure was not associated with measured airborne SHS in personal PM2.5 samples. This suggests exposure misclassification using SHS questionnaires and the need for harmonized and validated questions to characterize this exposure in health studies.

IMPLICATIONS

This study adds to the growing body of evidence that measurement error is a major concern in pregnancy research, particularly in studies that rely on self-report questionnaires to measure SHS exposure. The study introduces an alternative method of SHS exposure assessment using objective optical measurements, which can help improve the accuracy of exposure assessment. The findings emphasize the importance of using harmonized and validated SHS questionnaires in pregnancy health research to avoid biased effect estimates. This study can inform future research, practice, and policy development to reduce SHS exposure and its adverse health effects.

Association between secondhand smoke exposure in pregnant women and their socioeconomic status and its interaction with age: a cross-sectional study

Background

Existing evidence highlights that exposure to secondhand smoke (SHS) is a risk factor for pregnant women’s health and is possibly affected by individual characteristics. This study aimed to explore the effect of individual socioeconomic status (SES) on SHS exposure among pregnant women in the third trimester and the interaction effect of age.

Methods

A total of 678 nonsmoking pregnant women with a median age of 29.0 years from 14 communities in a medium-sized city were recruited for this survey. Exposure to SHS was defined as the self-reported smoking habit of a spouse/partner. Individual SES characteristics consisted of marital status, educational attainment, employment and per capita monthly income.

Results

There were 238 (35.1%) participants who suffered from SHS exposure. Compared to the pregnant women who were employed, those who were unemployed were more likely to suffer from SHS exposure (OR = 1.572, 95% CI: 1.013–2.441). Participants who had a high school or technical secondary school education were more likely to be exposed to SHS than those with a college education or above (OR = 1.601, 95% CI: 1.029–2.449). Advanced age was a protective factor for participants with a college education or above (OR = 0.939, 95% CI: 0.884–0.997), but age increased the risk of SHS exposure among women who had unstable marriages (OR = 1.256, 95% CI: 1.019–1.549).

Conclusion

Exposure to SHS was very common among pregnant women in the third trimester. Pregnant women with a low SES and an older age should be considered a key population for the implementation of public health interventions.

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.

Low birthweight of children is positively associated with mother's prenatal tobacco smoke exposure in Shanghai: a cross-sectional study

INTRODUCTION

Low birthweight (LBW) is a significant public health issue, and maternal smoking is the most prevalent preventable cause of LBW. But there is limited evidence on association of LBW among children and cigarette smoke exposure in mothers in China. In this cross-sectional study, we try to explore if the LBW in children is positively associated with mothers' prenatal cigarette smoke exposure.

METHODS

We selected 8, 586 mothers and their singleton children in 2018 in Songjiang district, Shanghai. Birthweight of children and gestational weeks of mother was identified by birth records in the hospital, we classified mothers' prenatal cigarette smoke status into the first-hand smoke (FHS) exposure and the second-hand smoke (SHS) exposure. We use SAS 9.1.3 software to calculate the prevalence of children's LBW and the prevalence of mothers' prenatal cigarette smoke exposure including FHS and SHS. Chi-square test and logistic regression were used to analyze the difference.

RESULTS

In 8, 586 women, The prenatal FHS and SHS exposure prevalence was 0.9 and 20.8%, respectively. The mean birthweight of children was 3315.5 g with a standard deviation of 497.2 g, the mean birthweight was 167.7 g and 66.1 g lower in children born to mothers with prenatally FHS and SHS exposure compared with those children whose mother were not exposed, respectively. The children's LBW prevalence was 4.7% in this study. By comparing with children whose mother were not exposed, the LBW prevalence was higher among children whose mother were prenatally exposed to FHS [OR (Odds Ratios) = 2.91, 95% confidence interval (CI) (1.49, 5.68)], and SHS [OR = 2.35, 95% CI (1.90, 2.89)].

CONCLUSIONS

Children's LBW is positively associated with mothers' prenatal tobacco smoke exposure both for FHS and SHS. So implementing tobacco control measures is crucial to lower smoking prevalence among women, and decrease smoking prevalence of their family members as well as work fellows.

Mothers' prenatal tobacco smoke exposure is positively associated with the occurrence of developmental coordination disorder among children aged 3-6 years: A cross-sectional study in a rural area of Shanghai, China

INTRODUCTION

Prenatal tobacco smoke exposure is a potential risk factor for developmental coordination disorder (DCD) in children, but evidence on the relationship between DCD in children and tobacco smoke exposure in women is limited in China. We conducted a cross-sectional study to understand the prevalence of prenatal tobacco smoke exposure among mothers and the prevalence of DCD among children and to explore if mothers’ prenatal tobacco smoke exposure is positively associated with the occurrence of DCD among children.

METHODS

During 2018, we sampled 8586 children aged 3–6 years and their mothers in Songjiang district, Shanghai. DCD in children was identified by MABC-2 screening combined with pediatrician confirmation. Prenatal tobacco smoke exposure among mothers was classified into firsthand smoke (FHS) and secondhand smoke (SHS) exposure. SAS 9.2 software was applied to calculate the prevalence of DCD in children, the prevalence of prenatal FHS and SHS exposure in mothers and to analyze the differences by chi-squared test and logistic regression.

RESULTS

Among the 8586 women, the prevalence of prenatal FHS and SHS exposure was 0.94% and 20.79%, respectively. The prevalence of DCD in children was 6.65%, which was significantly higher in boys (7.64%) than in girls (5.51%), and children aged 3 years (9.77%) had a higher prevalence of DCD than children aged 4, 5 or 6 years (7.44%, 5.27% and 4.28%, respectively). In comparison with children whose mother was not exposed to prenatal FHS or SHS, the odds of having DCD was higher in children whose mother was exposed to prenatal FHS (OR=4.42; 95% CI: 2.62–7.44) and SHS (OR=1.77; 95% CI: 1.47–2.14), even after adjustment for potential confounders.

CONCLUSIONS

The occurrence of DCD among children is positively associated with prenatal tobacco smoke exposure among the mothers. It is crucial to implement tobacco control measures to decrease the prevalence of smoking among pregnant women and SHS exposure at home as well as in the work environment.

ABBREVIATIONS

DCD: developmental coordination disorder, ADHD: attention deficit hyperactivity disorder, FHS: firsthand smoke, SHS: secondhand smoke, MABC-2: movement assessment battery for children-2nd edition, GATS: global adult tobacco survey, SD: standard deviation, OR: odds ratio, CI: confidence interval, DAGs: directed acyclic graphs.

Exposure to tobacco smoke and stillbirth: a national prospective cohort study in rural China

INTRODUCTION

Parental exposure to tobacco smoke has been associated with an increased risk of stillbirth, while only a few studies took the overall parental tobacco exposure status into consideration. We aim to explore the relationship of parental smoking and passive smoking before and during pregnancy with stillbirth in a large Chinese rural cohort.

DESIGN

248 501 couples were enrolled in a national prospective cohort study conducted in rural China. Parental exposure to tobacco smoke before and during pregnancy, along with other risk factors, was ascertained by questionnaires. Pregnancy outcomes were recorded by physicians.

RESULTS

The ORs (Odds Ratios) of maternal active smoking, maternal passive smoking, paternal active smoking and paternal passive smoking were 2.07 (95% CI 1.25 to 3.41), 1.22 (95% CI 1.01 to 1.47), 1.36 (95% CI 1.13 to 1.63) and 1.10 (95% CI 0.87 to 1.39), respectively. The rates of stillbirth increased from 0.31% for the maternal non-smoking group to 0.43% for the smoking cessation during pregnancy group, to 0.64% for the decreased smoking group and 1.28% for the continuing smoking group. A similar pattern was found in the change in paternal smoking status and stillbirth. Stratified by maternal passive smoking, the OR of paternal smoking was 1.35 (95% CI 1.13 to 1.61) in the maternal non-smoking group and 1.67 (95% CI 1.09 to 2.56) in the maternal passive smoking group.

CONCLUSIONS

Parental exposure to tobacco smoke increased the risk of stillbirth, especially for those continuing smoking during pregnancy. Paternal smoking is an independent risk factor for stillbirth despite maternal passive smoking status.

Self-Reported Exposure to ETS (Environmental Tobacco Smoke), Urinary Cotinine, and Oxidative Stress Parameters in Pregnant Women-The Pilot Study

Background: Exposure to ETS (environmental tobacco smoke) is one of the most toxic environmental exposures. Objective: To investigate the association of ETS with physiological, biochemical, and psychological indicators, as well as with urine antioxidant capacity (AC) and oxidative damage to lipids in a pilot sample of healthy pregnant women. Methods: Exposure to ETS was investigated via a validated questionnaire, and urine cotinine and the marker of oxidative damage to lipids via 8-isoprostane concentrations using an ELISA kit. Urine AC was determined by the spectrophotometric Trolox-equivalent antioxidant capacity (TEAC) method. From a sample of pregnant women (n = 319, average age 30.84 ± 5.09 years) in 80, the levels of cotinine and oxidative stress markers were analyzed. Results: Among the 80 pregnant women, 5% (7.4% confirmed by cotinine) reported being current smokers and 25% reported passive smoking in the household (18.8% confirmed by cotinine). The Kappa was 0.78 for smokers and 0.22 for ETS-exposed nonsmokers. Pregnant women in the ETS-exposed group had significantly reduced AC compared to both the nonsmoker (ETS−) and the smoker groups (p < 0.05). Nonsmokers had significantly lower levels of 8-isoprostane than smokers (p < 0.01) and ETS-exposed nonsmokers (p < 0.05). Correlations between urine levels of cotinine and AC were positive in ETS-exposed nonsmokers. Conclusion: A harmful association of active and passive smoking and oxidative stress parameters among pregnant women has been indicated.

Breast-Feeding Protects Children from Adverse Effects of Environmental Tobacco Smoke

In a cross-sectional study on 433 schoolchildren (aged 6⁻9 years) from 9 schools in Austria, we observed associations between housing factors like passive smoking and lung function as well as improved lung function in children who had been breast-fed. The latter findings urged the question of whether the protective effects of breast-feeding act on environmental stressors or if they act independently. Therefore, the effect of passive smoking on lung function was stratified by breast-feeding. The detrimental effects of passive smoking were significant but restricted to the group of 53 children without breast-feeding. Breast-feeding counteracts the effect of environmental stressors on the growing respiratory organs.