Secondhand tobacco smoke, does it have an impact on the neurobehavioral performance of the exposed children?

Effect of children secondhand smoke exposure associated with GABA concentration: Influence from parents who are extremely heavy smokers in urban households

BACKGROUND

Secondhand smoke (SHS) poses the most considerable health risk to children in urban households. However, limited evidence exists regarding the impact of children exposure to SHS on gamma-aminobutyric acid (GABA) levels. This study aimed to investigate the level of cotinine and GABA and their association with variables related to children exposed to SHS.

METHODS

A cross-sectional analysis was conducted to assess urinary cotinine and GABA levels in respondents. The study involved 85 participants aged 2-4 years who resided with parents exhibiting heavy smoking habits in urban households in Bangkok, Thailand. Urinary cotinine and GABA concentrations were utilized as biomarkers and measured using an enzyme-linked immunosorbent assay kit. An independent t-test was employed to compare contributing factors with urinary cotinine metabolites. Spearman's correlation test was utilized to assess the relationship between cotinine metabolites and GABA concentration.

RESULTS

The study found a correlation between urinary cotinine metabolites and GABA concentration among children's (r = 0.260, p-value = 0.016), particularly influenced by parents exhibiting extreme heavy smoking in urban households. Male children exhibited significantly higher urinary cotinine metabolite concentrations than females (p-value = 0.040). Moreover, significantly elevated levels of cotinine metabolites (57.37 ± 10.27 ng/ml) were observed in households where parents engaged in extreme heavy smoking.

CONCLUSIONS

This research establishes a link between urinary cotinine metabolite levels and GABA concentration among children exposed to extreme heavy smoking by their parents in urban households. Consequently, smoking might impact neurobehavioral effects, potentially leading to insomnia. The study emphasizes the importance of promoting and safeguarding non-smokers from exposure to SHS in indoor workplaces, public spaces, and households, advocating for the implementation of smoke-free public health regulations.

Low level of urinary cotinine in pregnant women also matters: variability, exposure characteristics, and association with oxidative stress markers

China has relatively high indoor contamination of nicotine, according to recent publications. Therefore, nicotine exposure risks for sensitive populations such as pregnant women in China are of concern. The variability of its internal exposure levels across three trimesters among pregnant women is not well documented. Factors related with nicotine exposure across pregnancy and its associations with oxidative stress markers are also understudied. Based on a birth cohort, we measured concentrations of cotinine (a major metabolite of nicotine) and oxidative stress markers including 8-OHdG, 8-OHG, and HNE-MA in urine samples collected at three trimesters from 1,155 pregnant women enrolled between January 2014 and June 2017 in Wuhan, China. The variability of urinary cotinine across the trimesters, potential factors associated with it, as well as the relationships between urinary cotinine and oxidative stress markers were assessed in pregnant women with cotinine concentrations of < 50 ng/mL (the cutoff value to distinguish smokers and non-smokers). Urinary specific gravity adjusted median concentrations of cotinine (ng/mL) in the entire pregnancy, first, second, and third trimester were 3.04, 3.32, 3.36, and 2.50, respectively, which exhibited fair reliability (intraclass correlation coefficient: 0.47) across pregnancy. Most participants had an estimated daily intake of nicotine higher than the acceptable value (100 ng/kg-bw/day) recommended by the UK and the USA. Maternal age, education level, pre-pregnancy body mass index, and sampling seasons were related to urinary concentrations of cotinine. After adjusting for confounding factors, significant positive relationships (β; 95% confidence interval) were observed between urinary cotinine concentrations and 8-OHdG (0.28; 0.25, 0.30), 8-OHG (0.27; 0.25, 0.29), and HNE-MA (0.27; 0.21, 0.32), respectively (p < 0.01). These results lend insight into the major factors associated with nicotine exposure of pregnant women at environmentally relevant levels and its potential effect on oxidative stress with a large sample size, and warrant the necessity of reducing the exposure in sensitive populations.

Global, regional, and national deaths, disability-adjusted life years, years lived with disability, and years of life lost for the global disease burden attributable to second-hand smoke, 1990-2019: A systematic analysis for the Global Burden of Disease Study

BACKGROUND

Smoke-free policies have led to a decline in smoking prevalence. Nevertheless, as the global population grows, more non-smokers are exposed to second-hand smoke (SHS) hazards. Mitigating SHS hazards requires a systematic analysis of the global disease burden attributable to SHS.

METHODS

Data on SHS was extracted from the Global Burden of Disease Study 2019. First, we measured the disease burden of SHS by the number of cases and age-standardized rates of deaths, disability-adjusted life years (DALYs), years lived with disability (YLDs), and years of life lost (YLLs) from 1990 to 2019. Second, trends in the disease burden of SHS in different periods were estimated based on the annual percentage change (APC) by joinpoint regression analysis. Finally, using histogram plots, world maps, Pearson correlation analysis, and population attributable fraction (PAF), we conducted a stratified analysis of SHS exposure by sex, age, geographic location, sociodemographic index (SDI) level, and disease.

RESULTS

The number of deaths caused by SHS remained stable between 1990 and 2019, and the number of YLDs more than doubled in three decades. In contrast, the number of DALYs and YLLs caused by SHS decreased. The declining trend in deaths (APC = -1.42 % [95 % UI -1.79 %, -1.05 %]), DALYs (APC = -1.91 % [95 % UI -2.15 %, -1.67 %]), and YLLs (APC = -1.28 % [95 % UI -1.93 %, -0.64 %]) had slowed down in recent years, while SHS-related YLDs were still increasing (APC = 1.84 % [95 % UI 0.74 %, 2.96 %]). From 2010 to 2019, we found that SHS exposure increased the risk of tracheal, bronchus, and lung cancer (PAF increased by 11.75 %), breast cancer (PAF increased by 5.36 %), diabetes mellitus (PAF increased by 8.24 %), and ischemic heart disease (PAF increased by 4.46 %). In addition, the disease burden caused by SHS was highest in middle SDI and low-middle SDI countries.

CONCLUSION

The global disease burden attributable to SHS is still severe, and policymakers need to implement more effective measures to reduce the harm of SHS.

Association between Environmental Tobacco Smoke Exposure and Adaptive Behavior in Individuals with Autism Spectrum Disorder

The study focuses on current issues of adaptive behavior in individuals with autism spectrum disorder (ASD) and on the possible risk factor of environmental tobacco smoke (ETS). Children examined at the Academic Research Center for Autism (ARCA) in Bratislava were involved in the study. The study sample included 84 children (71 boys) with ASD (average age 5.35 years) and a non-ASD group of 24 children (20 boys; average age 8.10 years). The “ETS Questionnaire” focused on the detection of parental smoking habits and other ETS exposures. The concentrations of cotinine in urine were measured by ELISA kit. A significant delay in adaptive behavior of children with ASD in comparison with the non-ASD group was identified. The significant differences were in adaptive behavior, communication, and everyday skills. Children with ASD were more likely to be exposed to ETS, especially in the household. Good agreement was found between objective and subjective ETS exposure indicators (kappa = 0.613). Self-reported exposure to ETS corresponded significantly with the median levels of urinary cotinine. In addition to evaluation and assessment of the quality of adaptive behavior, an important goal of further research should be to identify, investigate, and eliminate environmental factors that interfere with adaptive behavior.

Maternal smoking during pregnancy and intelligence quotient of offspring aged 18 and 30 years: Evidence from two birth cohorts in southern Brazil

Maternal smoking during pregnancy causes several harmful effects, including deficits in the intelligence quotient (IQ), a measure associated with academic achievements and higher socioeconomic position. We aimed to measure the association between maternal smoking during pregnancy and offspring's IQ in two birth cohorts from Pelotas, Brazil. Data from the 1982 and 1993 birth cohorts were analyzed. Smoking during pregnancy was ascertained at the perinatal follow-up, and IQ was measured at 30 years (1982) and 18 years (1993). Simple and multiple linear regressions were used for crude and adjusted analysis. Mediation analysis was performed using birth weight and breastfeeding as possible mediators. Data analysis was conducted in 2020. There were 3611 and 4050 participants from the 1982 and 1993 cohorts, respectively. After adjustment for potential confounders, the inverse association between smoking during pregnancy and children's IQ remained significant in both cohorts. Offspring of mothers who smoked during pregnancy had an average of 1.32 less IQ points (95%CI: -2.23, -0.242) in the 1982 cohort, and an average of 1.66 less IQ points (95%CI: -2.42, -0.90) in the 1993 cohort. Neither cohort showed association with paternal smoking (negative controls) after adjustment. Breastfeeding's mediated effects accounted for 26.2% and 23.9% of the association in the 1982 and 1993 cohorts, respectively, while birth weight's accounted for 6.8% and 30.1%, respectively; indirect effects were not significant. The inverse association between maternal smoking and IQ and the lack of association with paternal smoking reinforces our findings of a negative association between exposure and outcome.

Association of Prenatal, Early Postnatal, or Current Exposure to Secondhand Smoke With Attention-Deficit/Hyperactivity Disorder Symptoms in Children

IMPORTANCE

Few studies have investigated the association between the exposure window (prenatal, early postnatal, and current period) of secondhand smoke (SHS) and attention-deficit/hyperactivity disorder (ADHD) symptoms and subtypes in children.

OBJECTIVE

To evaluate the associations of prenatal, early postnatal, or current SHS exposure with ADHD symptoms and subtypes among school-aged children.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional study, 48 612 children aged 6 to 18 years from elementary and middle schools in Liaoning province, China, between April 2012 and January 2013 were eligible for participation. Data on SHS exposure and ADHD symptoms and subtypes for each child were collected via questionnaires administered to parents or guardians by school teachers. Data were analyzed from September 14 to December 2, 2020.

MAIN OUTCOMES AND MEASURES

The ADHD symptoms and subtypes (inattention, hyperactivity-impulsivity, and combined) were measured based on a validated tool developed from the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition). Generalized linear mixed models were evaluated to estimate the association of SHS exposure with ADHD symptoms and subtypes.

RESULTS

A total of 45 562 participants completed the questionnaires and were included in this study (22 905 girls [50.3%]; mean [SD] age, 11.0 [2.6] years; 2170 [4.8%] with ADHD symptoms). Compared with their unexposed counterparts, children who were ever exposed (odds ratio [OR], 1.50; 95% CI, 1.36-1.66) or always exposed to SHS (OR, 2.88; 95% CI, 2.55-3.25) from pregnancy to childhood had higher odds of having ADHD symptoms and subtypes (ORs ranged from 1.46 [95% CI, 1.31-1.62] to 2.94 [95% CI, 2.09-4.13]). Compared with their unexposed counterparts, children with SHS exposure had higher odds of having ADHD symptoms when exposed in the prenatal period (OR, 2.28; 95% CI, 2.07-2.51), early postnatal period (OR, 1.47; 95% CI, 1.29-1.68), or current period (OR, 1.20; 95% CI, 1.09-1.31). Compared with their unexposed counterparts, children whose fathers smoked 10 or more cigarettes/d on both weekdays and weekends had higher odds of having ADHD symptoms and subtypes (ORs ranged from 1.48 [95% CI, 1.28-1.70] to 2.25 [95% CI, 1.29-3.93]).

CONCLUSIONS AND RELEVANCE

Being exposed to SHS from pregnancy to childhood was associated with higher odds of having ADHD symptoms and subtypes among school-aged children, and the associations were somewhat stronger for SHS exposure during prenatal and early postnatal periods. Our findings highlight the important public health implications of reducing SHS exposure, which may decrease the health and economic burdens of individuals with ADHD.