Prenatal secondhand smoke exposure and infant birth weight in China

Revealing the clinical effect and biological mechanism of acupuncture in COPD: A review

BACKGROUND

To provide new ideas for the clinical and mechanism research of acupuncture in the treatment of chronic obstructive pulmonary disease (COPD), this study systematically reviews clinical research and the progress of basic research of acupuncture in the treatment of COPD.

METHODS

PubMed and Web of Science databases were searched using acupuncture and COPD as keywords in the last 10 years, and the included literature was determined according to exclusion criteria.

FINDINGS

Acupuncture can relieve clinical symptoms, improve exercise tolerance, anxiety, and nutritional status, as well as hemorheological changes (blood viscosity), reduce the inflammatory response, and reduce the duration and frequency of COPD in patients with COPD. Mechanistically, acupuncture inhibits M1 macrophage activity, reduces neutrophil infiltration, reduces inflammatory factor production in alveolar type II epithelial cells, inhibits mucus hypersecretion of airway epithelial cells, inhibits the development of chronic inflammation in COPD, and slows tissue structure destruction. Acupuncture may control pulmonary COPD inflammation through the vagal-cholinergic anti-inflammatory, vagal-adrenomedullary-dopamine, vagal-dual-sensory nerve fiber-pulmonary, and CNS-hypothalamus-orexin pathways. Furthermore, acupuncture can increase endogenous cortisol levels by inhibiting the HPA axis, thus improving airway antioxidant capacity and reducing airway inflammation in COPD. In conclusion, the inhibition of the chronic inflammatory response is the key mechanism of acupuncture treatment for COPD.

The Impact of Prenatal Environmental Tobacco Smoking (ETS) and Exposure on Chinese Children: A Systematic Review

Background: There is considerable evidence to support the association between exposure to environmental tobacco smoke (ETS) and children's burden of disease. However, the literature on the health outcomes of prenatal ETS exposure among Chinese children has not yet been comprehensively reviewed. Objective: This systematic review examines the currently available evidence and identifies gaps for further research on the health consequences of prenatal ETS exposure on Chinese children. Methods: Following the JBI systematic-scoping review methodological framework, we conducted a computer-aided search of three electronic databases-PubMed, EBSCOhost, and ProQuest to include studies from January 2011 to May 2023 that addressed the health outcomes of Chinese children whose mothers were exposed to ETS at any stage of pregnancy. Furthermore, a methodological quality assessment of the selected articles was conducted using JBI critical appraisal checklists. Results: A total of 30 articles were reviewed, including eleven high-quality studies and nineteen moderate-quality studies. Five main themes, including hypertension, fetal and children's development, behavioural disorders, respiratory outcomes, and "other health outcomes", were encompassed. The majority of the studies showed a positive link between prenatal ETS exposure and an increased risk of preterm birth, and moderate risk of fetal growth restriction. A few studies explored other potential adverse outcomes of ETS, including hypertension, respiratory morbidity, lung function, and asthma in children. Conclusions: The currently available evidence on prenatal ETS exposure in Chinese children has unveiled a wide range of health outcomes, including preterm birth, fetal development, behavioural disorders, and much more. However, Chinese studies in this area are still lacking and a gap still exists in relation to the strength of association between prenatal ETS exposure and some health risks. Efficient anti-smoking policies and smoking cessation programs should be developed to promote maternal and child health. Further research is also needed to provide better evidence in this field.

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.

Association between environmental tobacco smoke before and during pregnancy and the risk of adverse birth outcomes: a birth cohort study in Wuhan, China

Associations between environmental tobacco smoke (ETS) and the risk of adverse birth outcomes may be confounded. We aimed to clarify the associations of ETS before and during pregnancy with the risk of adverse birth outcomes and determine whether the associations were modified by key potential confounders. A total of 7147 non-smoking mothers from the Tongji Maternal and Child Health Cohort (TMCHC) in Wuhan, China, were included in the final analyses. ETS status was self-reported by pregnant women at their first antenatal care visit before 16 gestational weeks. Information on birth outcomes was extracted from delivery records. Poisson regression was used to identify the association between ETS before and during pregnancy and the risk of adverse birth outcomes. Exposures to ETS before and during pregnancy were reported by 645 (9.0%) and 464 (6.5%) mothers, respectively. Compared with no ETS, continued ETS during pregnancy was associated with an increased risk of preterm birth (PTB) (RR: 1.55, 95% CI: 1.07, 2.25) after adjustment for potential confounders. The association remained consistent in medically indicated PTB and late PTB. The risk of PTB associated with continued ETS during pregnancy was significantly increased in mothers more educated (P for interaction < 0.05). However, the increased risk of low birth weight (LBW) or small for gestational age (SGA) births by ETS during pregnancy was not observed. Exposure to ETS during pregnancy was associated with a higher risk of PTB, but not LBW or SGA births in a Chinese birth cohort.

Interactions between Prepregnancy Overweight and Passive Smoking for Macrosomia and Large for Gestational Age in Chinese Pregnant Women

INTRODUCTION

Previous analysis showed that passive smoking and overweight were associated with an increased risk of gestational diabetes mellitus (GDM) in a synergistic manner, while GDM increased the risk of macrosomia/large for gestational age (LGA). This study aimed to examine any interactive effects between passive smoking and overweight/obesity on risk of macrosomia/LGA.

METHODS

From 2010 to 2012, 22,302 pregnant women registered for pregnancy at a primary hospital in Tianjin, China. Data were collected longitudinally; that is, from their first antenatal care visit, at the glucose challenge test (GCT) time (24-28 weeks of gestation) and at delivery. Passive smoking was self-reported. Macrosomia was defined as birth weight ≥4,000 g. Binary logistic regression was used to obtain odds ratios (ORs) and 95% confidence intervals (CIs). Additive interaction was used to test the synergistic effect.

RESULTS

Passive smokers accounted for 57.4% of women (n = 8,230). Using nonpassive smoking and prepregnancy body mass index (BMI) <24.0 kg/m2 as the reference, the adjusted ORs of overweight alone and passive smoking alone for macrosomia were 2.39 (95% CI: 2.11-2.71) and 1.17 (95% CI: 1.04-1.32). Copresence of passive smoking and prepregnancy BMI ≥24.0 kg/m2 increased the OR to 2.70 (95% CI: 2.28-3.20), with a significant additive interaction. After further adjustment for GDM or GCT, the OR of copresence of both risk factors was slightly attenuated to 2.52 (2.13-3.00) and 2.51 (2.11-2.98), with significant additive interaction. However, the additive interaction between prepregnancy overweight/obesity and passive smoking for LGA was nonsignificant.

CONCLUSIONS

Prepregnancy overweight/obesity was associated with an increased risk of macrosomia in Chinese women synergistically with passive smoking during pregnancy, and most of the association was not modified by hyperglycemia during pregnancy.

Developmental Timing Determines the Protective Effect of Maternal Electroacupuncture on Perinatal Nicotine Exposure-Induced Offspring Lung Phenotype

Introduction. Environmental exposure of the developing offspring to cigarette smoke or nicotine is an important predisposing factor for many chronic respiratory conditions, such as asthma, emphysema, pulmonary fibrosis, and so forth, in the exposed offspring. Studies showed that electroacupuncture (EA) applied to maternal "Zusanli" (ST36) acupoints during pregnancy and lactation protects against perinatal nicotine exposure- (PNE-) induced lung damage. However, the most effective time period, that is, prenatal vs. postnatal, to attain this effect has not been determined.

OBJECTIVE

To determine the most effective developmental timing of EA's protective effect against PNE-induced lung phenotype in the exposed offspring.

METHODS

Pregnant rats were given (1) saline ("S" group); (2) nicotine ("N" group); (3) nicotine + EA, exclusively prenatally ("Pre-EA" group); (4) nicotine + EA, exclusively postnatally ("Post-EA," group); and (5) nicotine + EA, administered both prenatally and postnatally ("Pre- and Post-EA" group). Nicotine was injected once daily (1 mg/kg, 100 μl) and EA was administered to bilateral ST36 acupoints once daily during the specified time-periods. At the end of the experimental periods, key hypothalamic pituitary adrenal (HPA) axis markers in pups and dams, and lung function, morphometry, and the central molecular markers of lung development in the offspring were determined.

RESULTS

After nicotine exposure, alveolar mean linear intercept (MLI) increased, but mean alveolar number (MAN) decreased and lung PPARγ level decreased, but glucocorticoid receptor (GR) and serum corticosterone (Cort) levels increased, in line with the known PNE-induced lung phenotype. In the nicotine exposed group, maternal hypothalamic corticotropin releasing hormone (CRH) level decreased, but pituitary adrenocorticotropic hormone (ACTH) and serum Cort levels increased. In the "Pre- and Post-EA" groups, PNE-induced alterations in lung morphometry, lung development markers, and HPA axis were blocked. In the "Pre-EA" group, PNE-induced changes in lung morphometry, GR, and maternal HPA axis improved; lung PPARγ level decreased, but glucocorticoid receptor (GR) and serum corticosterone (Cort) levels increased, in line with the known PNE-induced lung phenotype. In the nicotine exposed group, maternal hypothalamic corticotropin releasing hormone (CRH) level decreased, but pituitary adrenocorticotropic hormone (ACTH) and serum Cort levels increased. In the "Pre- and Post-EA" groups, PNE-induced alterations in lung morphometry, lung development markers, and HPA axis were blocked. In the "Pre-EA" group, PNE-induced changes in lung morphometry, GR, and maternal HPA axis improved; lung PPAR.

CONCLUSIONS

Maternal EA applied to ST36 acupoints during both pre- and postnatal periods preserves offspring lung structure and function despite perinatal exposure to nicotine. EA applied during the "prenatal period" affords only limited benefits, whereas EA applied during the "postnatal period" is ineffective, suggesting that the EA's effects in modulating PNE-induced lung phenotype are limited to specific time-periods during lung development.

Antenatal exposure to second hand smoke of non-smoking mothers and growth rate of their infants

Objectives

There is limited evidence on the effect of exposure to second hand smoke (SHS) in non-smoking pregnant mothers and infant health. We assessed the effects of maternal antenatal exposure to SHS on infant growth rate, and secondarily, on birth weight, birth length and head circumference at birth.

Methods

In this prospective cohort, 305 mother-infant pairs were studied. Mothers filled out questionnaires about exposure to SHS in pregnancy at the 3^rd trimester of pregnancy. Infant anthropometry was performed at birth, day 7, and months 1, 2, 4, and 6, postnatally. Linear mixed modeling and linear regression were used to calculate growth rates over the first 6 months. The association between SHS-exposure with growth rate and birth sizes was assessed using multivariate linear regression adjusted for confounders, with SHS as both number of cigarettes and as groups (no exposure, SHS < 23 cigarettes, SHS ≥ 23 cigarettes).

Results

Seventy-three mothers were not exposed and 232 were exposed. SHS exposure (per cigarette) was not related to gain in weight, length, head circumference, and weight for length. However, infants born to mothers exposed to ≥ 23 cigarettes/d had lower head circumference gain (-0.32 mm/m, 95% CI -0.60, -0.03) than those born to non-exposed mothers. SHS exposure (per cigarette) was not related to birth weight, length, and head circumference, but exposure to ≥ 23 cigarettes was related to lower head circumference at birth (-11.09 mm, -20.03, -2.16).

Conclusions

Heavy antenatal exposure to SHS in non-smoking mothers results in reduced neonatal head circumference at birth and head circumference gain over the first 6 months of life. Our findings show no clear relations between exposure to SHS during pregnancy and other markers of neonatal growth and birth size.

Exposure to secondhand smoke in Iranian pregnant women at home and the related factors

INTRODUCTION

Fetus health is of high importance in pregnant women and exposure to secondhand smoke (SHS) endangers maternal and fetal health. Therefore, in this study we examined the prevalence of exposure to SHS in pregnant women at home and the related factors.

METHODS

This cross-sectional study was conducted with 255 pregnant women who were referred to the Isfahan health care center from July to September 2018. A questionnaire that was designed by the research team was applied to collect data about the participants' prevalence of exposure, attitude-emotional dimension, perceived susceptibility, perceived severity, and perceived barriers. The questionnaire used was self-administered. The validity and reliability of the questionnaire were confirmed by a panel of experts. Cronbach's alpha of attitude-emotional dimension, perceived susceptibility, perceived severity, and perceived barriers were also calculated as 0.81, 0.91, 0.92, and 0.89, respectively. Statistically significant differences were examined using chi-squared test and Mann-Whitney test.

RESULTS

We found that the prevalence of exposure to SHS in pregnant women was 23.1%. The age of the husband (p=0.041), education level of the smoking husband (p=0.005), the education level of the pregnant woman (p=0.002), employment status of husband (p=0.010), and whether the pregnancy was planned (p=0.010) had significant association with the participant prevalence of exposure to SHS. Thus, older age of husbands, lower education levels of husbands and wives, unwanted pregnancies, and unemployment of husbands resulted in higher exposure to SHS. The mean scores of knowledge and perceptions were lower in women exposed to smoke than in non-exposed women (p<0.05).

CONCLUSIONS

The rate of SHS exposure was high in pregnant women. The knowledge and perception scores of exposed women to SHS were lower than those of non-exposed women. Low levels of education of husbands and women, unemployment and higher age of husbands, and unwanted pregnancies were considered as health risk factors. Therefore, effective training programs should be designed to educate pregnant women and their husbands.

Environmental tobacco smoke exposure during pregnancy has limited effect on infant birthweight and umbilical vein endothelial nitric oxide synthase

INTRODUCTION

Women who smoke, deliver significantly smaller infants. These infants have reduced levels of the vasodilator endothelial nitric oxide synthase (eNOS) levels in the umbilical vessels, which may reduce fetal growth. Serum cotinine, the degradation product of nicotine, can be used to determine the level of tobacco exposure. Newborns of environmental smokers are suggested to be smaller and shorter in weight, length, and head circumference. eNOS levels have not yet been studied in these infants. We investigated the existence of a relation between maternal environmental tobacco smoke exposure, eNOS activity, concentration, and birthweight.

MATERIAL AND METHODS

We included 263 healthy singleton pregnancies categorized into three groups according to measured cotinine levels: 175 nonsmokers, 38 smokers, and 50 environmental smokers. Cotinine was quantified by mass spectrometry with a detection limit of .2 ng/mL; eNOS activity and concentration were measured in endothelial cells (ECs) of the umbilical vein.

RESULTS

Infants born to environmental smokers had similar weights to infants born to nonsmokers (47 g heavier, P = .48). Cotinine concentrations were .06/.09/.12 ng/mL (quartiles) in infants born to nonsmokers, .27/.37/.81 ng/mL in infants born to women exposed to environmental tobacco smoke, and 43.0/63.8/108.1 ng/mL in infants born to smokers. The eNOS concentration was 1.65 ± .92 ng/10⁶ ECs (mean ± SD) in nonsmokers and 1.71 ± 1.00 ng/10⁶ ECs in environmental smokers. The eNOS activity was 52.0 ± 20.6 pmol l-citrulline/min/10⁶ ECs in nonsmokers and 48.7 ± 19.8 pmol l-citrulline/min/10⁶ ECs in environmental smokers.

CONCLUSIONS

Infants born to environmental smokers, as judged by umbilical serum cotinine levels close to .2 ng/mL, are not associated with lower birthweight or reduced eNOS activity, or concentration in the fetal vascular bed.

Urinary level of triclosan in a population of Chinese pregnant women and its association with birth outcomes

Triclosan (TCS) is a suspected endocrine disrupting chemical which is widely used in consumer products as an antibacterial agent. But findings in human studies focusing on the fetal developmental effects of prenatal TCS exposure were rare and inconsistent. This study aimed to determine maternal urinary TCS and investigate its association with birth outcomes. Pregnant women (n = 1006) were randomly selected from the prospective Healthy Baby Cohort (HBC) enrolled in 2014. TCS levels were determined in maternal urine samples collected at delivery and recorded birth outcomes were obtained from the medical records. Multiple linear regressions were applied to evaluate associations of maternal urinary TCS levels with birth outcomes including birth weight, birth length, and gestational age. Logistic regressions were used to evaluate associations with preterm birth, late term birth, and low birth weight. The geometric mean concentrations for TCS and specific gravity (SG) adjusted TCS in maternal urines were 0.73, 0.78 ng/mL, respectively. In the crude model, one ln-unit increase of urinary SG-adjusted TCS concentration was associated with a 0.30-day [95% confidence interval (CI): 0.00, 0.60] increase in gestational age; however, the associations were not statistically significant after adjustment for covariates. No significant associations of SG-adjusted TCS concentrations with birth weight and birth length were observed. Maternal SG-adjusted TCS concentrations were not related to preterm birth, late term birth, and low birth weight (all p > 0.10). Our findings reported a relatively low level of TCS among Chinese pregnant women. With such exposure level, we did not find strong evidence for associations between maternal TCS exposure and birth outcomes. Longitudinal studies concerning about different potential effects of TCS on perinatal health are necessary.

Inhibition of the receptor for advanced glycation end-products (RAGE) protects from secondhand smoke (SHS)-induced intrauterine growth restriction IUGR in mice

Intrauterine growth restriction (IUGR) is a disease affecting 10% of all pregnancies. IUGR is associated with maternal, fetal, or placental abnormalities. Studies investigating the effects of secondhand smoke (SHS) exposure and IUGR are limited. The receptor for advanced glycation end-products (RAGE) is a pro-inflammatory transmembrane receptor increased by SHS in the placenta. We tested the hypothesis that inhibition of RAGE during SHS exposure protects from smoke-induced IUGR. C57BL/6 mice were exposed to SHS or SHS + semi-synthetic glycosaminoglycan ethers (SAGEs) known to inhibit RAGE signaling. Trophoblast cells were treated with cigarette smoke extract (CSE) with or without SAGEs in order to address the effects of RAGE inhibition during trophoblast invasion in vitro. SHS-treated mice demonstrated a significant reduction in fetal weight (7.35-fold, P ≤ 0.0001) and placental weight (1.13-fold, P ≤ 0.0001) compared with controls. Mice co-treated with SHS and SAGEs were protected from SHS-induced fetal weights decreases. SHS treatment of C57BL/6 mice activated placental extracellular signal-regulated kinase (ERK) (3.0-fold, P ≤ 0.05), JNK (2.4-fold, P ≤ 0.05) and p38 (2.1-fold, P ≤ 0.05) and the expression of inflammatory mediators including TNF-α (1.34-fold, P ≤ 0.05) and IL-1β (1.03-fold, P ≤ 0.05). SHS-mediated activation of these molecules was reduced to basal levels when SAGE was co-administered. Invasion of trophoblast cells decreased 92% (P < 0.002) when treated with CSE and CSE-mediated invasion was completely reversed by SAGEs. We conclude that RAGE inhibition protects against fetal weight loss during SHS-induced IUGR. These studies provide insight into tobacco-mediated IUGR development and clarify avenues that may be helpful in the alleviation of placental complications.

Exposure to cooking fuels and birth weight in Lanzhou, China: a birth cohort study

BACKGROUND

Early studies have suggested that biomass cooking fuels were associated with increased risk of low birth weight (LBW). However it is unclear if this reduced birth weight was due to prematurity or intrauterine growth restriction (IUGR).

METHODS

In order to understand the relationship between various cooking fuels and risk of LBW and small for gestational age (SGA), we analyzed data from a birth cohort study conducted in Lanzhou, China which included 9,895 singleton live births.

RESULTS

Compared to mothers using gas as cooking fuel, significant reductions in birth weight were observed for mothers using coal (weight difference = 73.31 g, 95 % CI: 26.86, 119.77) and biomass (weight difference = 87.84 g, 95 % CI: 10.76, 164.46). Using biomass as cooking fuel was associated with more than two-fold increased risk of LBW (OR = 2.51, 95 % CI: 1.26, 5.01), and the risk was mainly seen among preterm births (OR = 3.43, 95 % CI: 1.21, 9.74). No significant associations with LBW were observed among mothers using coal or electromagnetic stoves for cooking.

CONCLUSIONS

These findings suggest that exposure to biomass during pregnancy is associated with risk of LBW, and the effect of biomass on LBW may be primarily due to prematurity rather than IUGR.

Exposure to secondhand tobacco smoke and interventions among pregnant women in China: a systematic review

INTRODUCTION

Smoking prevalence is high among men in China. One result is that a large number of nonsmoking Chinese women may be exposed daily to secondhand smoke (SHS). Exposure is particularly problematic for pregnant women because of potential adverse reproductive effects. To determine the extent of this exposure and to summarize existing intervention studies designed to reduce SHS exposure in China, a systematic review of the literature published from 1995 through 2012 was conducted.

METHODS

We searched the PubMed and Wanfang databases for studies published from 1995 through 2012 using various search terms including SHS, pregnant women, and China. Only articles on prevalence of SHS exposure and interventions to reduce exposure to SHS were selected.

RESULTS

We identified 132 studies during the initial searches. Eight of 13 eligible studies reported the prevalence of SHS exposure among pregnant women; estimates ranged from 38.9% to 75.1%. Few SHS prevention interventions among pregnant women in China have been studied; we found only 5 such studies. The interventions primarily focused on changing husbands' smoking behaviors; some interventions focused on women's avoidance behaviors.

CONCLUSION

Prevalence of exposure to SHS among pregnant women is high in China. Information is limited on effective interventions to protect pregnant women from exposure. The results of this review can provide the basis for the design and evaluation of interventions to help pregnant women avoid SHS exposure.

Evaluation of the impact of maternal smoking on ultrasound and endocrinological markers of first trimester placentation

OBJECTIVES

To study the effect of maternal smoking on 2D ultrasound measurements and maternal serum (MS) levels of endocrinologic markers of placentation.

STUDY DESIGN

Prospective population-based cohort study of 32 smokers and 96 non-smoking controls with a normal pregnancy outcome.

MAIN OUTCOME MEASURES

Placental thickness and 2D-volume and MS levels of pregnancy-associated plasma protein A (PAPP-A) and free-beta human chorionic gonadotrophin (fβhCG) at 11-13(+6)weeks of gestation and mid-trimester MS α-fetoprotein (AFP), unconjugated estriol (uE3) and inhibin A levels.

RESULTS

The MS levels of fβhCG and PAPP-A were significantly (P < 0.01 and P < 0.001, respectively) lower in the serum and the level of inhibin A significantly (P < 0.001) higher in the smokers than in controls. There was no significant difference for the MSAFP, MSuE3 placental thickness, basal plate surface and volume between the groups.

CONCLUSION

The placental morphological alterations secondary to maternal smoking are mainly at the level of the villous trophoblast and are not associated with changes in the placental size or utero-placental interface during the first trimester of pregnancy.