The effects of smoking on steroid metabolism and fetal programming

Maternal Passive Smoking, Vitamin D Deficiency and Risk of Spontaneous Abortion

Background: Maternal passive smoking and vitamin D deficiency might elevate risk of spontaneous abortion. The study aimed to investigate the association of co-exposure to passive smoking and vitamin D deficiency with the risk of spontaneous abortion. Methods: A population-based case-control study was performed among non-smoking women in Henan Province, China, with 293 spontaneous abortion cases and 496 liveborn controls with term, normal birthweight. Results: Compared to women without exposure to passive smoking nor vitamin D deficiency, women with deficient vitamin D alone and women with exposure to passive smoking alone had increased risk of spontaneous abortion (OR = 1.76, 95%CI: 1.08~2.89; OR = 1.73, 95%CI: 1.11~2.69, respectively). The risk of spontaneous abortion was even higher for those with co-exposure to passive smoking and vitamin D deficiency (OR = 2.50, 95%CI: 1.63~3.84). A dose-response relationship was found of an incremental risk of spontaneous abortion with rising numbers of exposures to passive smoking and vitamin D deficiency (p < 0.001). Conclusion: Co-exposure to passive smoking and vitamin D deficiency was associated with an elevated risk of spontaneous abortion, and the risk of spontaneous abortion rose with rising numbers of exposures. Intervention programs need to specifically target the vulnerable groups of pregnant women with both malnutrition and unfavorable environmental exposure.

A Pilot Study of Exposure to Nicotine in Human Pregnancy and Maternal and Fetal Testosterone Levels at Birth

Nicotine exposure in pregnant rats and sheep has shown a more than 50% increase in female fetal testosterone (FFT) levels. Increased testosterone levels have also been linked to infertility, increased anogenital distance (AGD), and reduced second to fourth digit (2D:4D) finger length ratios (FLR). In humans, we hypothesized that maternal total testosterone (MTT) levels would increase in smoking mothers and would cause increased FFT levels, increased AGD, and decreased 2D:4D FLR. This prospective study separated women expecting a female fetus into nonsmoking and smoking cohorts. Maternal cotinine (MC) was tested at 3rd trimester and delivery to assess nicotine exposure. MTT levels were drawn at delivery, and FFT levels were collected from cord blood. The AGD and 2D:4D FLRs were measured at birth. Data were analyzed using parametric and nonparametric tests. The data of 36 smokers and 28 nonsmokers were analyzed. Smoking mothers had higher parity, drug abuse history and were more likely white race. No statistical differences were seen among the primary outcomes of MTT and FFT. MTT was higher among nonsmokers versus smokers (144 versus 107 ng/dL). No correlations were noted between MC levels at delivery, MTT, and FFT levels. No statistical differences were noted among secondary outcomes of AGD and FLR. Although animal studies showed increased FFT levels after nicotine exposure, this was not seen in our human study. Placental differences in animals and humans may be at work. Our pilot study reveals a need for research on the effects of smoking in pregnancy on fetal hormones.

DNA methylome perturbations: an epigenetic basis for the emergingly heritable neurodevelopmental abnormalities associated with maternal smoking and maternal nicotine exposure†

Maternal smoking during pregnancy is associated with an ensemble of neurodevelopmental consequences in children and therefore constitutes a pressing public health concern. Adding to this burden, contemporary epidemiological and especially animal model research suggests that grandmaternal smoking is similarly associated with neurodevelopmental abnormalities in grandchildren, indicative of intergenerational transmission of the neurodevelopmental impacts of maternal smoking. Probing the mechanistic bases of neurodevelopmental anomalies in the children of maternal smokers and the intergenerational transmission thereof, emerging research intimates that epigenetic changes, namely DNA methylome perturbations, are key factors. Altogether, these findings warrant future research to fully elucidate the etiology of neurodevelopmental impairments in the children and grandchildren of maternal smokers and underscore the clear potential thereof to benefit public health by informing the development and implementation of preventative measures, prophylactics, and treatments. To this end, the present review aims to encapsulate the burgeoning evidence linking maternal smoking to intergenerational epigenetic inheritance of neurodevelopmental abnormalities, to identify the strengths and weaknesses thereof, and to highlight areas of emphasis for future human and animal model research therein.

The association between lunch composition and obesity in Iranian adults

We aimed to assess the dietary composition of lunch meal using a posteriori-derived dietary patterns and to determine the association of lunch composition with obesity in a sample of Iranian adults. This cross-sectional study was conducted on 850 men and women in Tehran (aged 20-59 years). Dietary intakes were assessed using three 24-h dietary recalls, and dietary patterns were identified via principal component factor analysis. For each identified pattern, scores were calculated for each participant and then classified into tertiles. Central obesity was defined WHO criteria. General obesity was defined as a BMI of more than 30 kg/m2. Three major dietary patterns were identified at lunch meal using twelve food groups: 'Bread, grains and fat', 'Western' and 'Potato and eggs'. After adjustment for potential confounders, participants at the top tertile of the 'Bread, grains and fat' dietary pattern had greater odds for a higher waist-to-hip ratio (WHR), compared with those in the lowest tertile (OR: 1·44, 95 % CI 1·01, 2·07). However, we found no association between 'Western' or 'potato and eggs' patterns and WHR (OR: 0·89, 95 % CI 0·62, 1·28 and OR: 1·16, 95 % CI 0·69, 1·42, respectively). None of the identified dietary patterns was associated when defining obesity with waist circumference or BMI. In conclusion, participants had a greater chance of central obesity defined based on WHR following a lunchtime pattern with a higher and positive loading factor for 'Bread, grains and fat'.

Comparison of the Effect on Fetal Growth of a Mixture of Atrazine and Nitrates in Drinking Water and of Active Tobacco Exposure during Pregnancy

Active tobacco exposure during pregnancy is a known determinant of fetal growth. Nitrates and atrazine metabolites in drinking water may affect fetal growth as a mixture of endocrine disruptors (ED). We aimed to determine whether EDC have an additional effect on fetal growth compared to active tobacco exposure. A historic cohort study was carried out with a sample stratified with regard to the maternity unit, drinking water exposure, and year of birth. The women included were living in Deux-Sèvres, had given birth between 2005 and 2010 in three selected maternity units, and ultrasound data were available in their obstetrical records. Mixed linear models were used to analyze fetal weight evolution from the second trimester to the time of birth according to drinking water exposure to EDC mixture and active tobacco exposure. We included 558 mother-neonate couples, of whom 9% were exposed to high doses of the mixture and 21% to active tobacco smoking. There was no difference in fetal weight evolution according to drinking water mixture exposure (0.97 g; 95% CI [-3.01; 4.94]). We could not show a supplementary effect of mixture exposure in drinking-water on fetal growth as compared to active tobacco exposure. Further research is needed, using more precise methods to estimate EDC exposure.

Influence of Second-Hand Smoke and Prenatal Tobacco Smoke Exposure on Biomarkers, Genetics and Physiological Processes in Children-An Overview in Research Insights of the Last Few Years

Children are commonly exposed to second-hand smoke (SHS) in the domestic environment or inside vehicles of smokers. Unfortunately, prenatal tobacco smoke (PTS) exposure is still common, too. SHS is hazardous to the health of smokers and non-smokers, but especially to that of children. SHS and PTS increase the risk for children to develop cancers and can trigger or worsen asthma and allergies, modulate the immune status, and is harmful to lung, heart and blood vessels. Smoking during pregnancy can cause pregnancy complications and poor birth outcomes as well as changes in the development of the foetus. Lately, some of the molecular and genetic mechanisms that cause adverse health effects in children have been identified. In this review, some of the current insights are discussed. In this regard, it has been found in children that SHS and PTS exposure is associated with changes in levels of enzymes, hormones, and expression of genes, micro RNAs, and proteins. PTS and SHS exposure are major elicitors of mechanisms of oxidative stress. Genetic predisposition can compound the health effects of PTS and SHS exposure. Epigenetic effects might influence in utero gene expression and disease susceptibility. Hence, the limitation of domestic and public exposure to SHS as well as PTS exposure has to be in the focus of policymakers and the public in order to save the health of children at an early age. Global substantial smoke-free policies, health communication campaigns, and behavioural interventions are useful and should be mandatory.

Sociodemographic and Lifestyle Factors in relation to Overweight Defined by BMI and "Normal-Weight Obesity"

Sociodemographic factors and lifestyle habits affect body weight and body composition. A new syndrome, called normal-weight obesity (NWO), is found in individuals with normal weight and excess body fat in contrast to lean and overweight individuals. The aim of the present study was to explore the associations between sociodemographic factors and smoking and alcohol habits and lower versus higher BMI (≥25 kg/m²) and to examine whether categorization into lean, NWO, and overweight leads to further information about sociodemographic and lifestyle associations, compared with the common categorization defined by BMI. A cohort of 17,724 participants (9,936 females, 56.1%) from the EpiHealth study, with a median age of 61 (53-67) years, was examined. The participants answered a questionnaire about lifestyle, and weight and fat percentage were measured. Associations between sociodemographic factors and lifestyle habits and lower versus higher BMI, and lean versus NWO or lean and NWO versus overweight were calculated by binary logistic regression. Male sex, age, sick leave/disability, married/cohabitating, divorced/widowed, former smoking, and a high alcohol consumption were associated with higher BMI, whereas higher education and frequent alcohol consumption were inversely associated (all p < 0.001). The associations were similar to associations with lean versus overweight and NWO versus overweight, except for age in the latter case. Associations with lean versus NWO differed from those of lower versus higher BMI, with an association with retirement, an inverse association with male sex (OR, 0.664; 95% confidence interval, 0.591-0.746), and no associations with marital status, smoking, and alcohol consumption frequency. Associations with age and occupation were sex dependent, in contrast to other variables examined. Thus, sociodemographic and lifestyle habits showed similar associations with lower versus higher BMI as with lean and NWO versus overweight, whereas lean versus NWO showed different directions of associations regarding sex, marital status, occupation, smoking, and frequency of alcohol consumption.

Maternal smoking during pregnancy, semen characteristics and reproductive hormone levels in men consulting for couple infertility

The aim of our study was to evaluate the relationship between maternal tobacco consumption during pregnancy and sperm parameters and sexual hormonal levels of their sons in adulthood. We conducted a cross-sectional study in four medical institutions in Argentina, between June 1999 and June 2015, among male partners of couples consulting for infertility. At inclusion, a structured interview was conducted to obtain information on the basic demographic, medical, surgical and reproductive history, personal tobacco consumption and that of their parents during pregnancy. Two semen analyses at an interval of 2-4 weeks and a blood hormone evaluation (FSH, LH, prolactin, total testosterone and oestradiol) were then ordered. Analyses using multivariate models adjusted for potential confounders were performed for 537 men. Maternal tobacco consumption during pregnancy was associated with a significantly higher risk of reduced sperm count and elevated total testosterone levels. We did not find any significant association between maternal smoking and other sperm parameters nor other hormone levels. Our study adds evidence concerning the association between maternal tobacco consumption during pregnancy and reduced sperm counts of their sons in adulthood. The results showing an association between elevated total testosterone levels and maternal tobacco consumption need to be replicated.

Changes to Fetal Steroidogenesis Caused by Maternal Smoking

Smoking during pregnancy presents health risks for both the mother and her child. In this study we followed changes in the production of steroid hormones in pregnant smokers. We focused on changes in steroidogenesis in the blood of mothers in their 37th week of pregnancy and in mixed cord blood from their newborns. The study included 88 healthy women with physiological pregnancies (17 active smokers and 71 non-smokers). We separately analyzed hormonal changes associated with smoking according to the sex of newborns. In women with male fetuses, we found higher levels of serum cortisone, dehydroepiandrosterone (DHEA), 7α-OH-DHEA, 17-OH pregnenolone, testosterone, and androstenedione in smokers at the 37th week compared to non-smokers. In women with female fetuses, we found lower serum levels of 7β-OH-DHEA and higher androstenedione in smokers at the 37th week. We found significantly higher levels of testosterone in newborn males of smokers and higher levels of 7α-OH-DHEA in female newborns of smokers. Smoking during pregnancy induces changes in the production of steroids in both the mother and her child. These changes are different for different fetal sexes, with more pronounced changes in mothers carrying male newborns as well as in the newborn males themselves.

Plausible Roles for RAGE in Conditions Exacerbated by Direct and Indirect (Secondhand) Smoke Exposure

Approximately 1 billion people smoke worldwide, and the burden placed on society by primary and secondhand smokers is expected to increase. Smoking is the leading risk factor for myriad health complications stemming from diverse pathogenic programs. First- and second-hand cigarette smoke contains thousands of constituents, including several carcinogens and cytotoxic chemicals that orchestrate chronic inflammatory responses and destructive remodeling events. In the current review, we outline details related to compromised pulmonary and systemic conditions related to smoke exposure. Specifically, data are discussed relative to impaired lung physiology, cancer mechanisms, maternal-fetal complications, cardiometabolic, and joint disorders in the context of smoke exposure exacerbations. As a general unifying mechanism, the receptor for advanced glycation end-products (RAGE) and its signaling axis is increasingly considered central to smoke-related pathogenesis. RAGE is a multi-ligand cell surface receptor whose expression increases following cigarette smoke exposure. RAGE signaling participates in the underpinning of inflammatory mechanisms mediated by requisite cytokines, chemokines, and remodeling enzymes. Understanding the biological contributions of RAGE during cigarette smoke-induced inflammation may provide critically important insight into the pathology of lung disease and systemic complications that combine during the demise of those exposed.

The human placental proteome is affected by maternal smoking

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The effects of maternal smoking on the term placental proteome was studied.

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Maternal smoking significantly affected 18% of protein spots.

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Maternal smoking affects systems controlling the development and function of placenta.

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The observed placental changes may contribute to the lowered birth weights.

Detrimental effects of maternal smoking on the term placental proteome and steroid-metabolizing activities, and maternal hormone levels, were studied by using seven non-smoker and seven smoker placentae. Smoking significantly affected 18% of protein spots. The functional networks affected were i) cell morphology, cellular assembly and organization, cellular compromise (15 hits) and ii) DNA replication, recombination, and repair, energy production, nucleic acid metabolism (6 hits). Smoking significantly up-regulated such proteins as, SERPINA1, EFHD1 and KRT8; and down-regulated SERPINB2, FGA and HBB. Although maternal plasma steroids were not significantly altered, the catalytic activity of CYP1A1 was increased whereas CYP19A1 activity was reduced by smoking. Furthermore, transcript expression of CYP1A1 and CYP4B1 were induced while HSD17B2, NFKB and TGFB1 were repressed by smoking. The observed smoking induced wide-spread changes on placental proteome and transcript levels may contribute to the lowered birth weights of the new-born child and placenta.

Fetal programming of chronic kidney disease: the role of maternal smoking, mitochondrial dysfunction, and epigenetic modfification

The role of an adverse in utero environment in the programming of chronic kidney disease in the adult offspring is increasingly recognized. The cellular and molecular mechanisms linking the in utero environment and future disease susceptibility remain unknown. Maternal smoking is a common modifiable adverse in utero exposure, potentially associated with both mitochondrial dysfunction and epigenetic modification in the offspring. While studies are emerging that point toward a key role of mitochondrial dysfunction in acute and chronic kidney disease, it may have its origin in early development, becoming clinically apparent when secondary insults occur. Aberrant epigenetic programming may add an additional layer of complexity to orchestrate fibrogenesis in the kidney and susceptibility to chronic kidney disease in later life. In this review, we explore the evidence for mitochondrial dysfunction and epigenetic modification through aberrant DNA methylation as key mechanistic aspects of fetal programming of chronic kidney disease and discuss their potential use in diagnostics and targets for therapy.

Transient and persistent metabolomic changes in plasma following chronic cigarette smoke exposure in a mouse model

Cigarette smoke exposure is linked to the development of a variety of chronic lung and systemic diseases in susceptible individuals. Metabolomics approaches may aid in defining disease phenotypes, may help predict responses to treatment, and could identify biomarkers of risk for developing disease. Using a mouse model of chronic cigarette smoke exposure sufficient to cause mild emphysema, we investigated whether cigarette smoke induces distinct metabolic profiles and determined their persistence following smoking cessation. Metabolites were extracted from plasma and fractionated based on chemical class using liquid-liquid and solid-phase extraction prior to performing liquid chromatography mass spectrometry-based metabolomics. Metabolites were evaluated for statistically significant differences among group means (p-value≤0.05) and fold change ≥1.5). Cigarette smoke exposure was associated with significant differences in amino acid, purine, lipid, fatty acid, and steroid metabolite levels compared to air exposed animals. Whereas 60% of the metabolite changes were reversible, 40% of metabolites remained persistently altered even following 2 months of smoking cessation, including nicotine metabolites. Validation of metabolite species and translation of these findings to human plasma metabolite signatures induced by cigarette smoking may lead to the discovery of biomarkers or pathogenic pathways of smoking-induced disease.

The relationship between umbilical cord estrogens and perinatal characteristics

BACKGROUND

Prenatal estrogen exposure is thought to contribute to later life diseases such as breast cancer. However, few studies have directly measured prenatal estrogens and most have relied on proposed "markers" of estrogen exposure. We used a large population-based birth cohort to directly measure the relationship between prenatal estrogens and perinatal characteristics, including putative markers of estrogen exposure.

METHODS

Total estrone (E1), estradiol (E2), estriol (E3), and estetrol (E4) were assayed by liquid chromatography/tandem mass spectrometry from archived mixed arterial and venous serum from 860 umbilical cord blood samples.

RESULTS

Values for all estrogens were strongly intercorrelated. Cord estrogen concentrations did not differ between males and females. Levels of all estrogens were reduced in twins and concentrations increased with gestational age. Neither E1 nor E2 was correlated with birth weight, but E3 and E4 levels correlated weakly, whereas onset of labor was associated with higher estrogen concentrations. E1 and E2 concentrations were not associated with preeclampsia in the current pregnancy, but E3 and E4 concentrations were lower in pregnancies complicated by preeclampsia and antepartum hemorrhage.

CONCLUSIONS

Umbilical cord estrogen concentrations vary with gestational age, mode of delivery, pregnancy complications, and twinning, but not with infant sex. Putative markers of prenatal estrogen exposure, preeclampsia, and birth weight did not correlate with direct fetal measures of the most potent estrogen (E2) but were associated with weaker estrogens (E3 and E4). Twins had lower concentrations of all estrogens.

IMPACT

This is the largest and best characterized dataset of prenatal estrogen concentrations, measured using highly accurate mass spectrometry/spectroscopy. These observations represent the new "gold standard" for umbilical cord estrogens, and will inform the interpretation of other datasets and the early life origins of health and disease. Cancer Epidemiol Biomarkers Prev; 23(6); 946-52. ©2014 AACR.