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Association of Bisphenol A Exposure with Breastfeeding and Perceived Insufficient Milk Supply in Mexican Women
Abstract
Introduction Estrogen inhibits lactation and bisphenol A (BPA) is a high production environmental estrogen. We hypothesize an inhibitory effect of BPA on lactation and aim to analyze the association between third trimester pregnancy urinary BPA and breastfeeding rates 1 month postpartum. Methods Odds ratios (OR) and 95 % confidence intervals (95 % CI) of breastfeeding and perceived insufficient milk supply (PIM) in relation to maternal peripartum urinary BPA concentrations were calculated in 216 mothers. Results 97.2 % of mothers in the lowest BPA tertile were breastfeeding at 1 month postpartum, compared to 89.9 % in highest (p = 0.01). Adjusted ORs (95 % CI) for not breastfeeding at 1 month were 1.9 (0.3, 10.7) and 4.3 (0.8, 21.6) for second and third BPA tertiles, respectively, compared to the lowest (p = 0.06, trend). 4.2 % reported PIM in the lowest BPA tertile, compared to 8.7 % in the highest (p = 0.03). Adjusted ORs (95 % CI) for PIM were 1.8 (0.4, 7.7) and 2.2 (0.5, 9.5), for the second and third BPA tertiles, respectively, compared to the lowest (p = 0.29, trend). Discussion These results suggest an association between maternal BPA exposure and decreased breastfeeding.
... Duplicate measurements were collected by trained research staff for body weight to the nearest 0.1 kg using a digital scale (BAME Model 420; Catálogo Médico) and In-Body 230 (Biospace Co, Ltd, Seoul, Republic of Korea), height to the nearest 0.5 cm, and waist circumference to the nearest 0.1 cm using a non-stretchable measuring tape SECA (model 201, Hamburg, Germany) [84]. The average of the two measurements was used for the analysis [85]. These measurements were conducted at Time 1 and Time 2. ...
... Triglycerides were quantified via an enzymatic colorimetric method using a Cobas Mira automated chemistry analyzer (Roche Diagnostics, Indianapolis, IN, USA). The level of high-density lipoprotein cholesterol was obtained by using direct highdensity lipoprotein cholesterol (Roche Diagnostics) [85]. All serum markers were above the limit of detection (LOD). ...
DNA methylation (DNAm) is a plausible mechanism underlying cardiometabolic abnormalities, but evidence is limited among youth. This analysis included 410 offspring of the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) birth cohort followed up to two time points in late childhood/adolescence. At Time 1, DNAm was quantified in blood leukocytes at long interspersed nuclear elements (LINE-1), H19, and 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD-2), and at Time 2 in peroxisome proliferator-activated receptor alpha (PPAR-α). At each time point, cardiometabolic risk factors were assessed including lipid profiles, glucose, blood pressure, and anthropometry. Linear mixed effects models were used for LINE-1, H19, and 11β-HSD-2 to account for the repeated-measure outcomes. Linear regression models were conducted for the cross-sectional association between PPAR-α with the outcomes. DNAm at LINE-1 was associated with log glucose at site 1 [β = −0.029, p = 0.0006] and with log high-density lipoprotein cholesterol at site 3 [β = 0.063, p = 0.0072]. 11β-HSD-2 DNAm at site 4 was associated with log glucose (β = −0.018, p = 0.0018). DNAm at LINE-1 and 11β-HSD-2 was associated with few cardiometabolic risk factors among youth in a locus-specific manner. These findings underscore the potential for epigenetic biomarkers to increase our understanding of cardiometabolic risk earlier in life.
... Maternal endogenous factors include age, general physiological status, uncommon auto-immune properties, thyroid disorder and dietary habits, history of smoking in the year before pregnancy, consumption of alcohol during the first trimester of pregnancy, number of pregnancies, history of previous deliveries and lactation, duration of lactation and the number of children being breastfed at one time (Sai et al., 2013;Tateoka, 2015). A woman with a higher body mass index (BMI), which reflects adiposity, will tend to accumulate more chemicals in her body than her leaner counterparts, even if she has the same serum concentration of that chemical or received the same chemical dosage (Zimmers et al., 2014;Kasper et al., 2016). In addition, a rapid change in body weight during or after pregnancy, or a difference in metabolic clearance may also contribute to increased amounts of chemicals in persons at increased age. ...
... Global environmental conditions (temperature, pressure) and individual exposure conditions (degree and duration of maternal exposure, presence and levels of xenobiotic) may also alter uptake, distribution, biotransformation, and excretion of bisphenols. In addition, breast milk may carry mixtures of estrogenic and pro-estrogenic EDs and combine adverse effects (Xu et al., 2013;Kasper et al., 2016;Kolatorova et al., 2017). For example, in human milk the levels of the phthalate metabolites were positively associated with maternal diet, water consumption and use of cosmetics (Katsikantami et al., 2016). ...
Bisphenol A (BPA), widely used as additive in food packaging, is an environmental and food contaminant that
shows a weak estrogenic activity in general population and toxicity in the infant population. A temporary tolerable daily intake (t-TDI) of 4 μg/kg bw/day and a migration limit of 0.6 mg/kg in food from plastic materials,
intended to come in contact with food, were fixed. Dietary milk is important in the human diet.
The review investigated the contamination levels in human milk and along the dairy supply chain. Despite the reported levels are generally below the fixed limits, breast milk is considered a continuous low level exposure to endocrine-active compounds for infants. In addition, BPA residues are detected in milk and dairy products posing a risk to human health. BPA enters into milk chain via multiple pathways at various points during milk production (e.g., PVC tubing used during the milking process, transfer from bulk milk to storage tanks, during milk processing). To prevent or mitigate this hazard, a specific TDI for infants is recommended and evaluation of risk factors at each phase of the dairy supply chain, in the quality systems, is recommended.
... Maternal endogenous factors include age, general physiological status, uncommon auto-immune properties, thyroid disorder and dietary habits, history of smoking in the year before pregnancy, consumption of alcohol during the first trimester of pregnancy, number of pregnancies, history of previous deliveries and lactation, duration of lactation and the number of children being breastfed at one time (Sai et al., 2013;Tateoka, 2015). A woman with a higher body mass index (BMI), which reflects adiposity, will tend to accumulate more chemicals in her body than her leaner counterparts, even if she has the same serum concentration of that chemical or received the same chemical dosage (Zimmers et al., 2014;Kasper et al., 2016). In addition, a rapid change in body weight during or after pregnancy, or a difference in metabolic clearance may also contribute to increased amounts of chemicals in persons at increased age. ...
... Global environmental conditions (temperature, pressure) and individual exposure conditions (degree and duration of maternal exposure, presence and levels of xenobiotic) may also alter uptake, distribution, biotransformation, and excretion of bisphenols. In addition, breast milk may carry mixtures of estrogenic and pro-estrogenic EDs and combine adverse effects (Xu et al., 2013;Kasper et al., 2016;Kolatorova et al., 2017). For example, in human milk the levels of the phthalate metabolites were positively associated with maternal diet, water consumption and use of cosmetics (Katsikantami et al., 2016). ...
Bisphenol A (BPA), widely used as additive in food packaging, is an environmental and food contaminant that shows a weak estrogenic activity in general population and toxicity in the infant population. A temporary tolerable daily intake (t-TDI) of 4 μg/kg bw/day and a migration limit of 0.6 mg/kg in food from plastic materials, intended to come in contact with food, were fixed. Dietary milk is important in the human diet. The review investigated the contamination levels in human milk and along the dairy supply chain. Despite the reported levels are generally below the fixed limits, breast milk is considered a continuous low-level exposure to endocrine-active compounds for infants. In addition, BPA residues are detected in milk and dairy products posing a risk to human health. BPA enters into milk chain via multiple pathways at various points during milk production (e.g., PVC tubing used during the milking process, transfer from bulk milk to storage tanks, during milk processing). To prevent or mitigate this hazard, a specific TDI for infants is recommended and evaluation of risk factors at each phase of the dairy supply chain, in the quality systems, is recommended.
... Besides POPs, emerging evidence suggests that nonpersistent chemicals may also influence milk production ( Table 2). Recent observational studies have found a link between high exposure to bisphenol A (BPA) during pregnancy and shorter breastfeeding duration [132,133]. Rodent studies have revealed that offspring of BPA-exposed rats experienced delayed mammary gland differentiation and alveolar maturation as well as alterations in milk protein and fat compositions [134,135]. Similarly, pups treated with bisphenol S were less likely to initiate lactation [136]. ...
Low milk supply (LMS) poses a significant challenge to exclusive and continued breastfeeding, affecting ∼10% to 15% of mothers. Milk production is intricately regulated by both endocrine and autocrine control mechanisms, with estrogens and progesterone playing pivotal roles in this process. In addition to endogenously produced hormones, external substances capable of interfering with normal hormonal actions, including phytoestrogens, mycoestrogens, synthetic estrogens, and hormonal contraceptives, can influence milk production. The effects of these extrinsic hormones on milk production may vary based on maternal body mass index. This comprehensive review examines the multifaceted causes of LMS, focusing on the involvement of estrogens, progesterone, and related external factors in milk production. Furthermore, it investigates the interplay between hormonal factors and obesity, aiming to elucidate the endocrine mechanisms underlying obesity-associated LMS. Insights from this review provide valuable perspectives for developing interventions to improve milk production and address the challenges associated with LMS.
... Associations similar to those found in this review have been observed for other environmental chemicals, the pesticide metabolite dichlorodiphenyldichloroethylene (DDE) was linked to the shorter duration of breastfeeding in the 1980s and 90s [57,58], and, more recently, maternal Bisphenol A (BPA) exposure has also been linked to the reduced duration of breastfeeding, although the imprecision in the BPA studies did not allow for definitive conclusions [59,60]. ...
Milk formation in the breast during breastfeeding is a complex hormonally regulated process, potentially sensitive to the effects of endocrine-disrupting chemical exposures. The environmental chemicals, per-and polyfluoroalkyl substances (PFAS) are known endocrine disruptors. PFAS exposure have been associated with insufficient mammary gland development in mice and reduced breastfeeding duration in humans. The aim of this review was to gather the epidemiological evidence on the association between PFAS exposure and breastfeeding duration. Using PubMed and Embase, we performed a systematic literature search (on 23 January 2023) to identify epidemiological studies examining the association between maternal PFAS exposure and breastfeeding duration. Animal studies, reviews, and non-English studies were excluded. The risk of bias was assessed using the risk of bias in non-randomized studies of exposures tool. Estimates describing the association between PFAS exposure and the duration of breastfeeding were identified, and the data were synthesized separately for each type of PFAS and for the duration of exclusive and total breastfeeding. Six studies with between 336 and 2374 participants each were identified. PFAS exposure was assessed in serum samples (five studies) or based on residential address (one study). Five out of six studies found shorter total duration of breastfeeding with higher PFAS exposure. The most consistent associations were seen for perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA). The finding of a potential causal association between PFAS exposure and breastfeeding duration is in agreement with findings from experimental studies.
... After childbirth, mothers reported household and demographic information, including their ages, marital status (married or other -free union, single, separated, or divorced), parity status (< 1, ≥2), and years of education (continuous), gestational age in weeks (continuous) estimated by a registered nurse, and mode of delivery (vaginal or C-section childbirth), enrollment at the RCT for calcium supplementation (not enrolled or enrolled). The newborns were followed until 5 years of age, and information about self-reported breastfeeding duration (continuous) was quantified across the visits [31]. ...
Background
Sedentary behavior is a modifiable risk factor for cardiometabolic health; however, the assessment of total sedentary time may not capture youth’s highly active and interrupted activity patterns. This study examined the associations between sedentary activity patterns and cardiometabolic risk factors among Mexican youth, who have a disproportionate burden of metabolic diseases, using a repeated measure design out of a longitudinal data.
Methods
570 subjects in the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) birth cohort, who were followed up to three-time points during adolescence, were included. Bout duration, and frequency and percentages of waking time spent in specific intensities of activity, were quantified using ActiGraph wGT3X-BT wrist accelerometers. Self-reported questionnaires were used to query the usual duration of different sedentary behaviors. Outcomes were fasting lipid profile, markers for glucose homeostasis, anthropometry, and blood pressure. Associations were modeled using linear mixed-effects models, and isotemporal substitution approach was additionally used to assess the effect of replacing objectively assessed sedentary activity with other activity intensities, adjusting for potential confounders.
Results
Each hour of self-reported screen-based time was positively associated with diastolic blood pressure (mm Hg) [β = 0.30, 95% confidence interval (95% CI) = 0.10, 0.51], and an hour of other sedentary time was associated with log serum glucose (mg/dL) [β = 0.01, 95% CI = 0.004, 0.017]. Substitution models showed that replacing 5% of sedentary time with moderate to vigorous physical activity (MVPA) was associated with lower waist circumference (cm) [β = − 1.35, 95% CI = − 1.91, − 0.79] and log serum triglycerides (mg/dL) [β = − 0.11, 95% CI = − 0.18, − 0.03]. Substituting one uninterrupted sedentary bout with light activity was associated with lower insulin (μIU/mL) [β = − 0.06, 95% CI = − 0.10, − 0.02].
Conclusions
Sedentary time was associated with cardiometabolic risk factors in Mexican youth in a context-specific manner. Replacing sedentary time with higher intensities was associated with improvements in some cardiometabolic markers.
... gestational age estimated by a registered nurse, mode of delivery (vaginal, or C-section childbirth), and enrollment in the calcium supplementation RCT (not enrolled, or enrolled). The newborns were followed until 5 years of age, and information reported by mothers about breastfeeding duration was quantified across the visits [55]. ...
There is limited evidence for the effects of diet on cardiometabolic profiles during the pubertal transition. We collected repeated measures of diet quality and cardiometabolic risk factors among Mexican youth. This analysis included 574 offspring of the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) birth cohort followed up to three time points. Dietary Approaches to Stop Hypertension (DASH), alternate Mediterranean Diet (aMedDiet), and Children’s Dietary Inflammatory Index (C-DIITM) scores were computed from food frequency questionnaires. Higher DASH and aMedDiet scores reflect a higher diet quality, and lower C-DII scores reflect an anti-inflammatory diet. Cardiometabolic risk factors were lipid profile, glucose homeostasis, blood pressure, and waist circumference. Linear mixed models were used between quartiles of each diet score and outcomes. Compared to the first quartile, the fourth DASH quartile was inversely associated with log serum insulin (μIU/mL) [β = −0.19, p = 0.0034] and log-Homeostatic Model Assessment of Insulin Resistance [β = −0.25, p = 0.0008]. Additionally, log serum triglycerides (mg/dL) was linearly associated with aMedDiet score [β = −0.03, p = 0.0022]. Boys in the highest aMedDiet quartile had higher serum high-density lipoprotein cholesterol (mg/dL) [β = 4.13, p = 0.0034] compared to the reference quartile. Higher diet quality was associated with a better cardiometabolic profile among Mexican youth.
... Normally after delivery when lactating launches, estrogen level starts to decrease (35), but BPA's concentration may inhibit lactation. Kasper et al. (36) demonstrated an association between maternal BPA exposure and decreased breastfeeding at one month postpartum. As presented in Figure 1, we determined a strong uphill (positive) linear relationship between infants' BPA exposure and infants' BPA risk index. ...
Objective:
Bisphenol A exposure is crucial for lactating women and exclusively breastfed infants. Bisphenol A transfers directly by breastfeeding and may cause adverse health outcomes. We conduct this study to determine maternal human milk bisphenol A level and exclusively breastfed infants' bisphenol A exposure. We investigated the effect of exposure according to participants' nutritional habits.
Methods:
We enrolled voluntarily, healthy postnatal, exclusively breastfeeding women (n=80) and collected hindmilk samples. Human milk-free bisphenol A concentration was analyzed using a competitive ELISA method. Free (unconjugated) BPA has been detected in human samples indicating that humans are internally exposed to estrogenically active BPA. Participants' demographic properties, nutritional habits were questioned with an elaborated survey face-to-face by the researcher.
Results:
Human milk median free bisphenol A level is 0.63 µg/L. There was no statistically significant association between maternal body mass index, birth type, parity, infant birth week, infant birth weight, and human milk bisphenol A concentration. Nevertheless, we only found a statistically significant association between human milk bisphenol A level and fast-food, carbonated drinks consumption (p=0.022 and p=0.018, respectively). Exclusively breastfed infants' bisphenol A exposure was 0.0099±0.0079 µg/kg bw/day. There was a negative moderate statistically significant correlation between infant bisphenol A exposure and infant current body weight (r= 0.327, p=0.003).
Conclusion:
Exclusively breastfed infants bisphenol A exposure was under the tolerable bisphenol A level (4 µg/kg bw/day), and infants' current dietary exposure level was safe.
... Preterm birth is known to negatively affect breastfeeding [32]. Moreover, BPA exposure negatively affects breastfeeding [33] by lowering thyroid hormone levels, which are necessary for lactation [34]. Exclusive breastfeeding (EB) is the most effective protection against infant mortality in the first six months of life and should be continued until two years of age and beyond. ...
Bisphenol A (BPA) is an artificial chemical, and one of the significant external routes of daily BPA exposure is diet. Dietary BPA exposure can be calculated by urinary BPA concentration and dietary recall data. This cross-sectional study investigates exclusively breastfeeding women's BPA exposure by urinary total BPA concentration and nutritional records, including the 24Hour Dietary Recall (HDR) and Food Frequency Questionnaire (FFQ). In this study, we included exclusively breastfeeding, healthy women volunteers (n = 80; 18–40 years), collected spot-morning urine samples and conducted a comprehensive face-to-face survey. Moreover, the women's urine BPA concentration was adjusted according to their urine creatinine concentrations. We assessed dietary BPA intake with the 24HDR and FFQ. Estimated daily BPA exposure according to urinary output volume and urinary creatinine concentration median values were 0.0507 and 0.06 µg/kg bw/day, respectively. Moreover, dietary BPA daily intake was found to be 0.17 and 0.95 µg/kg bw/day according to 24HDR data and FFQ data. The milk and dairy product group’s and soft drinks group's contributions to the daily intake of BPA were 55.9% and 25.92%, respectively. The hazard ratio for BPA exposure was within limits according to references, including US EPA, Health Canada, and EFSA. This study indicates that BPA exposure, based on both total urinary BPA concentration and dietary recall data, was within the recommended daily intake level (4 µg/kg bw/day). However, further studies are required to understand the influence of seasonal, multicentre, and socioeconomic differences on BPA exposure.
Nutritional exposures during critical periods of development can result in structural and metabolic alterations that have lasting influences on mental and physical well-being. This notion is supported by numerous animal experiments, human epidemiological studies, and some human intervention trials. In this chapter, we focus on nutritional and dietary needs around time of conception, during gestation, and first few months following delivery. The body of text is divided into three timeframes: (1) around the time of conception (periconceptional), (2) during gestation (pre-natal), and (3) after delivery (post-natal). Each of these sections comprises a summary of evidence regarding nutritional needs during each developmental window and their relations to later life non-communicable disease risks. The chapter closes with gaps in knowledge, suggestions for future research, and recommendations for practice.
Introduction
Bisphenol A (BPA) is frequently used in the production of plastics. It is an endocrine disruptor, and BPA exposure in mice has been associated with reduced offspring growth due to insufficient milk production. However, human studies of associations between BPA exposure and duration of breastfeeding are sparse.
Methods
Pregnant women from the Odense Child Cohort (n = 725) donated a third trimester morning urine sample, which was analyzed for BPA by LC-MS/MS. Information about duration of exclusive and any breastfeeding was obtained through questionnaires three and 18 months postpartum, and a subgroup of women responded to weekly text messages about breastfeeding. Associations between pregnancy BPA exposure and duration of breastfeeding were analyzed using Cox regression adjusting for potential confounders.
Results
The median urine BPA concentration was 1.29 ng/mL. Compared to women within the lowest tertile of BPA exposure, women in the second and third tertile were slightly more likely to terminate breastfeeding at any given time; HRs (95% CI) were 1.05 (0.87; 1.26) and 1.06 (0.89; 1.27), respectively, and to terminate exclusive breastfeeding at any time up to 20 weeks after birth, HRs (95% CI) were 1.07 (0.88; 1.28) and 1.06 (0.88; 1.27), respectively. However, confidence intervals were also compatible with no effect or even a protective effect.
Discussion
This study indicated that high BPA exposure in pregnancy was associated with shorter duration of breastfeeding. Although our findings were not statistically significant, all estimates were above one suggesting increased risk of early breastfeeding termination with high exposure. Using a single spot morning urine sample to measure BPA has likely caused imprecision as it might not adequately reflect long term exposure. Future studies should consider measuring BPA more than once, including other timepoints during pregnancy and after birth.
Objective:Bisphenol A (BPA) is a known endocrine disruptor and free BPA will interact with estrogen. BPA is also fat soluble and will therefore contaminate breast milk. The European Food Safety Authority has set a limit for temporary tolerable daily intake of 4 μg/kg body weight/day in breastfeeding infants. The aim of this study was to measure human milk BPA concentrations in Turkish women and thus exclusively breastfed infants’ exposure to BPA.Methods:Healthy, postnatal, exclusively breastfeeding women were recruited and breast milk samples were collected. Free BPA concentration was analyzed in the milk samples using competitive enzyme-linked immunosorbent assay. Participants’ demographic characteristics and nutritional habits were investigated through face-to-face interviews using a detailed questionnaire.Results:Eighty women participated. Median milk free BPA level was 0.63 μg/L. There was no statistically significant association between maternal body mass index, birth type, parity, infant birth week, infant birth weight, and human milk BPA concentration. Nevertheless, there was a significant association between human milk BPA level and consumption of fast-food and carbonated drinks (p=0.022 and p=0.018, respectively). Exclusively breastfed infants’ mean BPA exposure was 0.0099±0.0079 μg/kg bw/day. There was a moderate negative significant correlation between infant BPA exposure and infant current body weight (r=0.327, p=0.003).Conclusion:BPA exposure in exclusively breastfed infants was within accepted limits and the current dietary exposure level of infants in this cohort was safe.
Development of the mammary gland requires coordination of hormone signaling pathways including those mediated by estrogen, progesterone, androgen and prolactin receptors. These hormones play important roles at several distinct stages of life including embryonic/fetal development, puberty, pregnancy, lactation, and old age. This also makes the gland sensitive to perturbations from environmental agents including endocrine disrupting chemicals (EDCs). Although there is evidence from human populations of associations between EDCs and disruptions to breast development and lactation, these studies are often complicated by the timing of exposure assessments and the latency to develop breast diseases (e.g., years to decades). Rodents have been instrumental in providing insights—not only to the basic biology and endocrinology of the mammary gland, but to the effects of EDCs on this tissue at different stages of development. Studies, mostly but not exclusively, of estrogenic EDCs have shown that the mammary gland is a sensitive tissue, that exposures during perinatal development can produce abnormal mammary structures (e.g., alveolar buds, typically seen in pregnant females) in adulthood; that exposures during pregnancy can alter milk production; and that EDC exposures can enhance the response of the mammary tissue to hormones and chemical carcinogens. Other studies of persistent organic pollutants have shown that EDC exposures during critical windows of development can delay development of the gland, with lifelong consequences for the individual. Collectively, this work continues to support the conclusion that EDCs can harm the mammary gland, with effects that depend on the period of exposure and the period of evaluation.
Purpose of review:
The purpose of this review is to describe epidemiologic and toxicological literature investigating how endocrine-disrupting chemicals (EDCs) affect mammary gland development and function, thereby impacting lactation duration.
Recent findings:
Perfluoroalkyl and polyfluoroalkyl substances appear to reduce breastfeeding duration through impaired mammary gland development, lactogenesis, and suppressed endocrine signaling. Halogenated aromatic hydrocarbons have differing associations with lactation duration, likely because of the variety of signaling pathways that they affect, pointing to the importance of complex mixtures in epidemiologic studies. Although epidemiologic literature suggests that pesticides and fungicides decrease or have no effect on lactation duration, toxicology literature suggests enhanced mammary gland development through estrogenic and/or antiandrogenic pathways. Toxicological studies suggest that phthalates may affect mammary gland development via estrogenic pathways but no association with lactation duration has been observed. Bisphenol A was associated with decreased duration of breastfeeding, likely through direct and indirect action on estrogenic pathways.
Summary:
EDCs play a role in mammary gland development, function, and lactogenesis, which can affect breastfeeding duration. Further research should explore direct mechanisms of EDCs on lactation, the significance of toxicant mixtures, and transgenerational effects of EDCs on lactation.
Bisphenol A (BPA) and phthalates are endocrine disruptors possibly linked to adverse reproductive and neurodevelopmental outcomes. These chemicals have commonly been measured in urine in population surveys; however, such data are limited for large populations of pregnant women, especially for the critical first trimester of pregnancy. The aim of the study was to measure BPA and phthalate metabolites in first trimester urine samples collected in a large national-scale pregnancy cohort study and to identify major predictors of exposure. Approximately 2000 women were recruited in the first trimester of pregnancy from ten sites across Canada. A questionnaire was administered to obtain demographic and socio-economic data on participants and a spot urine sample was collected and analyzed for total BPA (GC-MS/MS) and 11 phthalate metabolites (LC-MS/MS). The geometric mean (GM) maternal urinary concentration of total BPA, uncorrected for specific gravity, was 0.80 (95% CI 0.76-0.85) μg/L. Almost 88% of the women had detectable urinary concentrations of BPA. An analysis of urinary concentrations of BPA by maternal characteristics with specific gravity as a covariate in the linear model showed that the geometric mean concentrations: (1) decreased with increasing maternal age, (2) were higher in current smokers or women who quit during pregnancy compared to never smokers, and (3) tended to be higher in women who provided a fasting urine sample and who were born in Canada, and had lower incomes and education. Several of the phthalate metabolites analyzed were not prevalent in this population (MCHP, MMP, MiNP, MOP), with percentages detectable at less than 15%. The phthalate metabolites with the highest measured concentrations were MEP (GM: 32.02μg/L) and MnBP (GM: 11.59μg/L). MBzP urinary concentrations decreased with maternal age but did not differ by time of urine collection; whereas the DEHP metabolites tended to be higher in older women and when the urine was collected later in the day. This study provides the first biomonitoring results for the largest population of pregnant women sampled in the first trimester of pregnancy. The results indicate that exposure among this population of pregnant women to these chemicals is comparable to or even lower than that observed in a Canadian national population-based survey.
Objective. To present data on lnfant and young child feeding practices (IYCFP) in Mexico from the 2012 Nacional Health and Nutrition Survey (ENSANUT 2012) to support the development of public policy. Materials and methods. Population: Women 12-49y and children <2y. lndicators of IYCFP suggested by WHO were analyzed by geographic, socioeconomic, participation In food programs and health insurance variables. Results. Median duration of breastfeeding: I0.2mo and 14.4% with exclusive breastfeeding (EBF) <6m. Breastfeeding deteriorated In most vulnerable groups. Decline in EBF<6m 2006-2012 was explained by increases in consumption of formula and other milks (4%) and water (4%). Three-quarters (74%) of 6-11 mo infants had
mínimum food diversity, and it was lower In the most vulnerable. Conclusions. Complementary feeding improved but breastfeeding declined in Mexico. Promotion actions must be integral, coordinated, financed and evaluated, with Federal government leadership and should include the participation of various stakeholders.
Objective:
To present data on infant and young child feeding practices (IYCFP) in Mexico from the 2012 National Health and Nutrition Survey (ENSANUT 2012) to support the development of public policy.
Materials and methods:
Population:
Women 12-49y and children <2y. Indicators of IYCFP suggested by WHO were analyzed by geographic, socioeconomic, participation in food programs and health insurance variables.
Results:
Median duration of breast-feeding: 10.2mo and 14.4% with exclusive breastfeeding (EBF) <6m. Breastfeeding deteriorated in most vulnerable groups. Decline in EBF<6m 2006-2012 was explained by increases in consumption of formula and other milks (4%) and water (4%). Three-quarters (74%) of 6-11mo infants had minimum food diversity, and it was lower in the most vulnerable.
Conclusions:
Complementary feeding improved but breastfeeding declined in Mexico. Promotion actions must be integral, coordinated, financed and evaluated, with Federal government leadership and should include the participation of various stakeholders.
Background
There is increasing evidence suggesting that Bisphenol A (BPA), one of the highest volume chemicals produced worldwide, can interfere with the body’s natural weight control mechanisms to promote obesity. However, epidemiological studies for this are limited, especially for children.
Methods
A cross-sectional study was conducted to investigate the association between BPA exposure and body mass index (BMI) in school children. Three primary and three middle schools were randomly selected from 26 primary and 30 middle candidate schools in Changning District of Shanghai City in China. According to the BMI-based criteria by age and sex for screening of overweight or obese children, we randomly chose 20 obese, 10 overweight, and 30 normal weight children aged 8-15 years of age from each selected school. First morning urine was collected and total urine BPA concentrations were determined by ultra-performance liquid chromatography tandem mass spectrometry. Multiple linear regression analysis was conducted to examine the association of urine BPA concentrations and daily intake estimates with BMI.
Results
BPA was detected in 84.9% of urine samples with a geometric mean of 0.45 ng/mL. The daily intake estimates ranged from 0.03 μg/day to 1.96 μg/day with a geometric mean of 0.37 μg/day. The average urine BPA concentrations and daily intake estimates were similar for boys and girls, but significantly higher in older children than younger ones, and showed an increasing trend with BMI. Multiple linear regression analyses showed that urine BPA concentrations were significantly associated with increasing BMI values in all subjects after adjustment for age and sex and the results were similar before and after corrected by urine specific gravity. When stratified by age or sex, the associations remained significant in females and in those 8-11 years of age before corrected by specific gravity. Similar results were shown for the association between BMI and daily intake estimates.
Conclusions
There is a possibility that BPA exposure increases BMI in school children. Given the cross-sectional nature of this study, longitudinal studies are warranted to confirm BPA exposure as a contributor to increased BMI in children.
Bisphenol A (BPA), a manufactured chemical, is found in canned food, polycarbonate-bottled liquids, and other consumer products. In adults, elevated urinary BPA concentrations are associated with obesity and incident coronary artery disease. BPA exposure is plausibly linked to childhood obesity, but evidence is lacking to date.
To examine associations between urinary BPA concentration and body mass outcomes in children.
Cross-sectional analysis of a nationally representative subsample of 2838 participants aged 6 through 19 years randomly selected for measurement of urinary BPA concentration in the 2003-2008 National Health and Nutrition Examination Surveys.
Body mass index (BMI), converted to sex- and age-standardized z scores and used to classify participants as overweight (BMI ≥85th percentile for age/sex) or obese (BMI ≥95th percentile).
Median urinary BPA concentration was 2.8 ng/mL (interquartile range, 1.5-5.6). Of the participants, 1047 (34.1% [SE, 1.5%]) were overweight and 590 (17.8% [SE, 1.3%]) were obese. Controlling for race/ethnicity, age, caregiver education, poverty to income ratio, sex, serum cotinine level, caloric intake, television watching, and urinary creatinine level, children in the lowest urinary BPA quartile had a lower estimated prevalence of obesity (10.3% [95% CI, 7.5%-13.1%]) than those in quartiles 2 (20.1% [95% CI, 14.5%-25.6%]), 3 (19.0% [95% CI, 13.7%-24.2%]), and 4 (22.3% [95% CI, 16.6%-27.9%]). Similar patterns of association were found in multivariable analyses examining the association between quartiled urinary BPA concentration and BMI z score and in analyses that examined the logarithm of urinary BPA concentration and the prevalence of obesity. Obesity was not associated with exposure to other environmental phenols commonly used in other consumer products, such as sunscreens and soaps. In stratified analysis, significant associations between urinary BPA concentrations and obesity were found among whites (P < .001) but not among blacks or Hispanics.
Urinary BPA concentration was significantly associated with obesity in this cross-sectional study of children and adolescents. Explanations of the association cannot rule out the possibility that obese children ingest food with higher BPA content or have greater adipose stores of BPA.
Bisphenol A (BPA) is a widely used chemical. We examined the association between urinary BPA levels and obesity in the National Health and Nutritional Examination Survey (NHANES) 2003-2008. The main outcome of interest was obesity defined as (1) body mass index (BMI) ≥ 30 Kg/m(2) and (2) waist circumference (WC) ≥ 102 cm in men and ≥ 88 cm in women. Urinary BPA levels were examined in quartiles. Overall, we observed a positive association between increasing levels of urinary BPA and both measures of obesity, independent of potential confounding factors including, smoking, alcohol consumption, and serum cholesterol levels. Compared to quartile 1 (referent), the multivariate-adjusted odds ratio (95% confidence interval) associated with quartile 4 for BMI-based obesity was 1.69 (1.30-2.20); P-trend < 0.0001 and for WC-based obesity was 1.59 (1.21-2.09); P-trend = 0.0009. This association between BPA and both measures of obesity was consistently present across gender and race-ethnic groups (all P-trend < 0.05). Elevated levels of urinary BPA are associated with measures of obesity independent of traditional risk factors. This association is consistently present across gender and race-ethnic groups. Future prospective studies are needed to confirm or disprove this finding.
Limited animal, in vitro, and human studies have reported that exposure to phthalates or bisphenol A (BPA) may affect thyroid signaling.
We explored the cross-sectional relationship between urinary concentrations of metabolites of di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and BPA with a panel of serum thyroid measures among a representative sample of U.S. adults and adolescents.
We analyzed data on urinary biomarkers of exposure to phthalates and BPA, serum thyroid measures, and important covariates from 1,346 adults (ages ≥ 20 years) and 329 adolescents (ages 12-19 years) from the National Health and Nutrition Examination Survey (NHANES) 2007-2008 using multivariable linear regression.
Among adults, we observed significant inverse relationships between urinary DEHP metabolites and total thyroxine (T4), free T4, total triiodothyronine (T3), and thyroglobulin, and positive relationships with thyroid-stimulating hormone (TSH). The strongest and most consistent relationships involved total T4, where adjusted regression coefficients for quintiles of oxidative DEHP metabolites displayed monotonic dose-dependent decreases in total T4 (p-value for trend < 0.0001). Suggestive inverse relationships between urinary BPA and total T4 and TSH were also observed. Conversely, among adolescents, we observed significant positive relationships between DEHP metabolites and total T3. Mono(3-carboxypropyl) phthalate, a secondary metabolite of both DBP and di-n-octyl phthalate, was associated with several thyroid measures in both age groups, whereas other DBP metabolites were not associated with thyroid measures.
These results support previous reports of associations between phthalates-and possibly BPA--and altered thyroid hormones. More detailed studies are needed to determine the temporal relationships and potential clinical and public health implications of these associations.
Presence of Bisphenol A (BPA) has been documented worldwide in a variety of human biological samples. There is growing evidence that low level BPA exposure may impact placental tissue development and thyroid function in humans. The aim of this present pilot study was to determine urinary concentrations of BPA during the last trimester of pregnancy among a small subset of women in Mexico City, Mexico and relate these concentrations to risk of delivering prematurely.
A nested case-control subset of 60 participants in the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) study in Mexico City, Mexico were selected based on delivering less than or equal to 37 weeks of gestation and greater than 37 weeks of gestation. Third trimester archived spot urine samples were analyzed by online solid phase extraction coupled with high performance liquid chromatography isotope dilution tandem mass spectrometry.
BPA was detected in 80.0% (N = 48) of the urine samples; total concentrations ranged from < 0.4 μg/L to 6.7 μg/L; uncorrected geometric mean was 1.52 μg/L. The adjusted odds ratio of delivering less than or equal to 37 weeks in relation to specific gravity adjusted third trimester BPA concentration was 1.91 (95%CI 0.93, 3.91, p-value = 0.08). When cases were further restricted to births occurring prior to the 37th week (n = 12), the odds ratio for specific-gravity adjusted BPA was larger and statistically significant (p < 0.05).
This is the first study to document measurable levels of BPA in the urine of a population of Mexican women. This study also provides preliminary evidence, based on a single spot urine sample collected during the third trimester, that pregnant women who delivered less than or equal to 37 weeks of gestation and prematurely (< 37 weeks) had higher urinary concentrations of BPA compared to women delivering after 37 weeks.
Research suggests that estrogenic endocrine-disrupting chemicals interfere with lactation.
(1) to determine if estrogenic persistent organic pollutants (POPs) are associated with shortened lactation duration; (2) to determine whether previous breastfeeding history biases associations.
We measured selected organochlorines and polychlorinated biphenyls (p, p'-DDE, p, p'-DDT, o, p'-DDT, beta-hexachlorocyclohexane, hexachlorobenzene, and PCBs 44, 49, 52, 118, 138, 153, and 180) in serum from 366 low-income, Mexican-American pregnant women living in an agricultural region of California and assessed breastfeeding duration by questionnaires. We found no association between DDE, DDT, or estrogenic POPs with shortened lactation duration, but rather associations for two potentially estrogenic POPs with lengthened lactation duration arose (HR [95% CI]: 0.6 [0.4, 0.8] for p, p'-DDE & 0.8 [0.6, 1.0] for PCB 52). Associations between antiestrogenic POPs (PCBs 138 and 180) and shortened lactation duration were attributed to a lactation history bias.
Estrogenic POPs were not associated with shortened lactation duration, but may be associated with longer lactation duration.
In the early 1970s, the largest industrial accident in the United States resulted in widespread contamination of the food supply in Michigan with polybrominated biphenyls (PBBs). The chemical similarity of PBBs to compounds implicated as endocrine disruptors has raised the question of whether PBBs could affect the reproductive system. In the present analysis we examine the relation between serum measurements of PBBs and the frequency and duration of lactation. Persons who lived on or received food from farms exposed to PBBs were enrolled in a registry by the Michigan Department of Public Health. Female members of the cohort were invited to participate in a telephone survey of reproductive outcomes. The three outcomes of interest in the present analysis were a) the decision to breast-feed (yes/no); b) the duration, in months, of breast-feeding as the main source of nutrition; and c) the total duration, in months, of breast-feeding. None of the three outcomes was significantly associated with serum PBB levels, even after controlling for maternal age, previous history of breast-feeding, body mass index, maternal education, household income, history of smoking in the year before pregnancy, consumption of alcohol during the first trimester of pregnancy, history of thyroid disorder, gestational age of the infant in weeks, time to pregnancy, and year of birth.
The endocrine system coordinates development of the mammary gland with reproductive development and the demand of the offspring for milk. Three categories of hormones are involved. The levels of the reproductive hormones, estrogen, progesterone, placental lactogen, prolactin, and oxytocin, change during reproductive development or function and act directly on the mammary gland to bring about developmental changes or coordinate milk delivery to the offspring. Metabolic hormones, whose main role is to regulate metabolic responses to nutrient intake or stress, often have direct effects on the mammary gland as well. The important hormones in this regard are growth hormone, corticosteroids, thyroid hormone, and insulin. A third category of hormones has recently been recognized, mammary hormones. It currently includes growth hormone, prolactin, PTHrP, and leptin. Because a full-term pregnancy in early life is associated with a reduction in breast carcinogenesis, an understanding of the mechanisms by which these hormones bring about secretory differentiation may offer clues to the prevention of breast cancer.
Breast cancer is the most common non-skin cancer among women in this country. Breast cancer risk is significantly influenced by genetics, but over 70% of the women that are diagnosed have noninherited or sporadic cancer. The risk of breast cancer is thought to be modified by lifestyle and environment. Exposures to certain chemicals and hormone-mimicking or endocrine-disrupting compounds (EDCs) are suspected of contributing to increased breast cancer incidence as well as precocious puberty in the United States. Studies of EDC effects in rodents indicate that multiple toxicants can alter mammary gland development, with or without changing other markers of puberty. EDCs can cause transient and persistent effects on mammary gland development depending on dose, exposure parameters, and whether exposure was during critical periods of gland growth or differentiation. Adverse effects from these abnormal developmental patterns include the presence of carcinogen-sensitive structures in greater numbers or for longer periods in the gland and inhibited functional differentiation leading to malnutrition or increased mortality of their offspring. Developmental toxicants of the mammary gland could lead to an increase in the incidence of mammary tumors if they alter circulating or tissue-localized hormone levels, gland receptor expression patterns, hormone transport, or metabolism that results in altered response to endogenous hormones or growth factors. Environmental disruptors of rodent mammary gland development must be identified for informed decisions in epidemiological studies aimed at identification of environmental factors contributing to breast cancer risk, altered breast development during puberty, or inability to produce sufficient breast milk.
Bisphenol A (BPA) and 4-tertiary-octylphenol (tOP) are industrial chemicals used in the manufacture of polycarbonate plastics and epoxy resins (BPA) and nonionic surfactants (tOP). These products are in widespread use in the United States.
We aimed to assess exposure to BPA and tOP in the U.S. general population.
We measured the total (free plus conjugated) urinary concentrations of BPA and tOP in 2,517 participants > or = 6 years of age in the 2003-2004 National Health and Nutrition Examination Survey using automated solid-phase extraction coupled to isotope dilution-high-performance liquid chromatography-tandem mass spectrometry.
BPA and tOP were detected in 92.6% and 57.4% of the persons, respectively. Least square geometric mean (LSGM) concentrations of BPA were significantly lower in Mexican Americans than in non-Hispanic blacks (p = 0.006) and non-Hispanic whites (p = 0.007); LSGM concentrations for non-Hispanic blacks and non-Hispanic whites were not statistically different (p = 0.21). Females had statistically higher BPA LSGM concentrations than males (p = 0.043). Children had higher concentrations than adolescents (p < 0.001), who in turn had higher concentrations than adults (p = 0.003). LSGM concentrations were lowest for participants in the high household income category (> $45,000/year).
Urine concentrations of total BPA differed by race/ethnicity, age, sex, and household income. These first U.S. population representative concentration data for urinary BPA and tOP should help guide public health research priorities, including studies of exposure pathways, potential health effects, and risk assessment.
Bisphenol A (BPA) is used to manufacture polymeric materials, such as polycarbonate plastics, and is found in a variety of consumer products. Recent data show widespread BPA exposure among the U.S. population.
Our goal in the present study was to determine the temporal variability and predictors of BPA exposure.
We measured urinary concentrations of BPA among male and female patients from the Massachusetts General Hospital Fertility Center.
Between 2004 and 2006, 217 urine samples were collected from 82 subjects: 45 women (145 samples) and 37 men (72 samples). Of these, 24 women and men were partners and contributed 42 pairs of samples collected on the same day. Ten women became pregnant during the follow-up period. Among the 217 urine samples, the median BPA concentration was 1.20 microg/L, ranging from below the limit of detection (0.4 microg/L) to 42.6 microg/L. Age, body mass index, and sex were not significant predictors of urinary BPA concentrations. BPA urinary concentrations among pregnant women were 26% higher (-26%, +115%) than those among the same women when not pregnant (p > 0.05). The urinary BPA concentrations of the female and male partner on the same day were correlated (r = 0.36; p = 0.02). The sensitivity of classifying a subject in the highest tertile using a single urine sample was 0.64.
We found a nonsignificant increase in urinary BPA concentrations in women while pregnant compared with nonpregnant samples from the same women. Samples collected from partners on the same day were correlated, suggesting shared sources of exposure. Finally, a single urine sample showed moderate sensitivity for predicting a subject's tertile categorization.
Breastfeeding and human milk are the normative standards for infant feeding and nutrition. Given the documented short-and long-term medical and neurodevelopmental advantages of breastfeeding, infant nutrition should be considered a public health issue and not only a lifestyle choice. The American Academy of Pediatrics reaffirms its recommendation of exclusive breastfeeding for about 6 months, followed by continued breastfeeding as complementary foods are introduced, with continuation of breastfeeding for 1 year or longer as mutually desired by mother and infant. Medical contraindications to breastfeeding are rare. Infant growth should be monitored with the World Health Organization (WHO) Growth Curve Standards to avoid mislabeling infants as underweight or failing to thrive. Hospital routines to encourage and support the initiation and sustaining of exclusive breastfeeding should be based on the American Academy of Pediatrics-endorsed WHO/UNICEF "Ten Steps to Successful Breastfeeding." National strategies supported by the US Surgeon General's Call to Action, the Centers for Disease Control and Prevention, and The Joint Commission are involved to facilitate breastfeeding practices in US hospitals and communities. Pediatricians play a critical role in their practices and communities as advocates of breastfeeding and thus should be knowledgeable about the health risks of not breastfeeding, the economic benefits to society of breastfeeding, and the techniques for managing and supporting the breastfeeding dyad. The "Business Case for Breastfeeding" details how mothers can maintain lactation in the workplace and the benefits to employers who facilitate this practice. Pediatrics 2012; 129:e827-e841
Phthalates and BPA are known endocrine disruptors and exposure in pregnant mothers and children is ubiquitous. We explored the relationship of prenatal and childhood exposures with pubertal onset and sex hormones in boys (ages 8-14). Phthalate metabolites and BPA were measured in maternal 3(rd) trimester or childhood urine. Sex hormones DHEAS, estradiol, inhibin B, SHBG, and total testosterone were measured in serum. Adrenarche and puberty were assessed by pediatrician. Prenatal exposure to some phthalates was associated with decreased DHEAS and inhibin B levels, and with increased SHBG. Prenatal exposure to most phthalates and BPA was associated with greatly reduced odds of adrenarche (odds ratios [OR]=0.12 to 0.65) and slightly reduced odds of puberty (OR=0.50 to 0.98). Childhood exposure was not associated with adrenarche or puberty, but some phthalates and BPA were associated with increased SHBG levels and decreased total and free testosterone levels.
Bisphenol A (BPA) and phthalates are endocrine disruptors possibly linked to adverse reproductive and neurodevelopmental outcomes. These chemicals have commonly been measured in urine in population surveys; however, such data are limited for large populations of pregnant women, especially for the critical first trimester of pregnancy. The aim of the study was to measure BPA and phthalate metabolites in first trimester urine samples collected in a large national-scale pregnancy cohort study and to identify major predictors of exposure. Approximately 2000 women were recruited in the first trimester of pregnancy from ten sites across Canada. A questionnaire was administered to obtain demographic and socio-economic data on participants and a spot urine sample was collected and analyzed for total BPA (GC–MS/MS) and 11 phthalate metabolites (LC–MS/MS). The geometric mean (GM) maternal urinary concentration of total BPA, uncorrected for specific gravity, was 0.80 (95% CI 0.76–0.85) μg/L. Almost 88% of the women had detectable urinary concentrations of BPA. An analysis of urinary concentrations of BPA by maternal characteristics with specific gravity as a covariate in the linear model showed that the geometric mean concentrations: (1) decreased with increasing maternal age, (2) were higher in current smokers or women who quit during pregnancy compared to never smokers, and (3) tended to be higher in women who provided a fasting urine sample and who were born in Canada, and had lower incomes and education. Several of the phthalate metabolites analyzed were not prevalent in this population (MCHP, MMP, MiNP, MOP), with percentages detectable at less than 15%. The phthalate metabolites with the highest measured concentrations were MEP (GM: 32.02 μg/L) and MnBP (GM: 11.59 μg/L). MBzP urinary concentrations decreased with maternal age but did not differ by time of urine collection; whereas the DEHP metabolites tended to be higher in older women and when the urine was collected later in the day. This study provides the first biomonitoring results for the largest population of pregnant women sampled in the first trimester of pregnancy. The results indicate that exposure among this population of pregnant women to these chemicals is comparable to or even lower than that observed in a Canadian national population-based survey.
Background:
Breastfeeding durations in the United States fall short of public health objectives. We sought to quantify the prevalence and identify risk factors for early, undesired weaning that mothers attribute to physiologic difficulties with breastfeeding.
Methods:
We analyzed data from the Infant Feeding Practices Study (IFPS) II, a longitudinal study of US women. We defined disrupted lactation as early, undesired weaning attributed to at least two of the following three problems: breast pain, low milk supply, and difficulty with infant latch. We used logistic regression to estimate the association maternal body mass index (BMI), postpartum depressive symptoms, and disrupted lactation.
Results:
Of 4,902 women enrolled in the IFPS II, we analyzed 2,335 women who reported prenatal intention and breastfeeding initiation. The prevalence of disrupted lactation was 12 per 100 women (95% confidence interval [CI] 11, 13) during the first year of life. Women in this group weaned earlier (median 1.2 months, interquartile range [IQR] 0.5-2.8) than women without disrupted lactation (median 7.0 months, IQR 2.8-2.0, p<0.01). In multivariable-adjusted (MV-adj.) models, we found increased odds of disrupted lactation among overweight (odds ratio [OR] 1.6, 95% CI 1.1-2.3) or obese (OR 1.7, 95% CI 1.2-2.6) women, compared with women with a normal pregravid BMI. Maternal depressive symptoms at 2 months, defined as Edinburgh Postnatal Depression Scale ≥13, were also associated with disrupted lactation (MV-adj. OR 1.7, 95% CI 1.1-2.7).
Conclusion:
In a longitudinal sample of US women, disrupted lactation affected one in eight mothers who initiated breastfeeding. These findings underscore the need for both improved early breastfeeding support and targeted research to define the underlying pathophysiology and to determine management strategies that will enable more mothers to achieve their breastfeeding goals.
Bisphenol A (BPA) is a high production volume chemical with adverse endocrine and reproductive health effects in toxicological studies. Despite widespread general population exposure to BPA, knowledge of its potential impacts upon reproduction and pregnancy in humans is limited. This paper reviews the current epidemiological literature on fertility and adverse pregnancy outcomes associated with BPA exposure. It also provides relevant resources for health care providers who are in a unique position to provide guidance in reducing exposure to this endocrine disrupting chemical.
Exposure to endocrine disrupting chemicals such as bisphenol A (BPA) and phthalates is prevalent among children and adolescents, but little is known regarding important sources of exposure at these sensitive life stages. In this study, we measured urinary concentrations of BPA and nine phthalate metabolites in 108 Mexican children aged 8-13years. Associations of age, time of day, and questionnaire items on external environment, water use, and food container use with specific gravity-corrected urinary concentrations were assessed, as were questionnaire items concerning the use of 17 personal care products in the past 48-h. As a secondary aim, third trimester urinary concentrations were measured in 99 mothers of these children, and the relationship between specific gravity-corrected urinary concentrations at these two time points was explored. After adjusting for potential confounding by other personal care product use in the past 48-h, there were statistically significant (p<0.05) positive associations in boys for cologne/perfume use and monoethyl phthalate (MEP), mono(3-carboxypropyl) phthalate (MCPP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and in girls for colored cosmetics use and mono-n-butyl phthalate (MBP), mono(2-ethylhexyl) phthalate (MEHP), MEHHP, MEOHP, and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), conditioner use and MEP, deodorant use and MEP, and other hair products use and MBP. There was a statistically significant positive trend for the number of personal care products used in the past 48-h and log-MEP in girls. However, there were no statistically significant associations between the analytes and the other questionnaire items and there were no strong correlations between the analytes measured during the third trimester and at 8-13years of age. We demonstrated that personal care product use is associated with exposure to multiple phthalates in children. Due to rapid development, children may be susceptible to impacts from exposure to endocrine disrupting chemicals; thus, reduced or delayed use of certain personal care products among children may be warranted.
Childhood obesity, a major public health problem, can lead to cardiovascular disease in adulthood. Studies have implicated exposure to bisphenol A (BPA), a commonly used chemical, in the development of obesity in adults. However, literature is limited on this association in children. We examined the association between urinary BPA and obesity in children aged 6-18 years from the National Health and Nutrition Examination Survey (2003-2008). The primary exposure was urinary BPA and the outcome was obesity, defined as the ≥95th percentile of body mass index specific for age and sex. We found a positive association between increasing levels of urinary BPA and obesity, independent of age, sex, race/ethnicity, education, physical activity, serum cotinine, and urinary creatinine. Compared with children in the lowest quartile of BPA (<1.5 ng/mL), children in the highest quartile (>5.4 ng/mL) had a multivariable odds ratio for obesity of 2.55 (95% confidence interval (CI): 1.65, 3.95) (Ptrend < 0.01). The observed positive association was predominantly present in boys (odds ratio = 3.80, 95% CI: 2.25, 6.43) (P trend < 0.001) and in non-Hispanic whites (odds ratio = 5.87, 95% CI: 2.15, 16.05) (Ptrend < 0.01). In a representative sample of children, urinary BPA was associated with obesity, predominantly in non-Hispanic white boys, independent of major risk factors. © 2013 © The Author 2013. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: [email protected]
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Bisphenol A (BPA) is one of the highest volume chemicals produced worldwide. This compound is a building block of polycarbonate plastics often used for food and beverage storage, and BPA is also a component of epoxy resins that are used to line food and beverage containers. Studies have shown that BPA can leach from these and other products in contact with food and drink, and as a result, routine ingestion of BPA is presumed. This compound is also found in an enormous number of other products that we come into contact with daily, and therefore it is not surprising that it has been detected in the majority of individuals examined. BPA is a known endocrine disruptor. Although initially considered to be a weak environmental estrogen, more recent studies have demonstrated that BPA may be similar in potency to estradiol in stimulating some cellular responses. Moreover, emerging evidence suggests that BPA may influence multiple endocrine-related pathways. Studies in rodents have identified adverse effects of BPA at levels at or below the current acceptable daily intake level for this compound. The various reported adverse effects of BPA are reviewed, and potential mechanisms of BPA action are discussed. Much more investigation is needed to understand the potential adverse health effects of BPA exposure in humans and to understand the multiple pathways through which it may act. Although many questions remain to be answered, it is becoming increasingly apparent that exposure to BPA is ubiquitous and that the effects of this endocrine disruptor are complex and wide-ranging.
Infant feeding decisions affect maternal and child health outcomes, worldwide. Even in settings with clean water and good sanitation, infants who are not breast-fed face an increased risk of infectious, as well as non-infectious morbidity and mortality. The decision not to breast-feed can also adversely affect mothers' health by increasing the risk of pre-menopausal breast cancer, ovarian cancer, type II diabetes, hypertension, hyperlipidemia and cardiovascular disease. Clinicians who counsel mothers about the health impact of infant feeding and provide evidence-based care to maximize successful breast-feeding, can improve the short and long-term health of both mothers and infants.
Overadjustment is defined inconsistently. This term is meant to describe control (eg, by regression adjustment, stratification, or restriction) for a variable that either increases net bias or decreases precision without affecting bias. We define overadjustment bias as control for an intermediate variable (or a descending proxy for an intermediate variable) on a causal path from exposure to outcome. We define unnecessary adjustment as control for a variable that does not affect bias of the causal relation between exposure and outcome but may affect its precision. We use causal diagrams and an empirical example (the effect of maternal smoking on neonatal mortality) to illustrate and clarify the definition of overadjustment bias, and to distinguish overadjustment bias from unnecessary adjustment. Using simulations, we quantify the amount of bias associated with overadjustment. Moreover, we show that this bias is based on a different causal structure from confounding or selection biases. Overadjustment bias is not a finite sample bias, while inefficiencies due to control for unnecessary variables are a function of sample size.
Bisphenol A (BPA) is an environmental chemical with physiological potencies that cause adverse effects, even at environmentally relevant exposures, on the basis of a number of studies in experimental rodents. Thus, there is an increasing concern about environmental exposure of humans to BPA. In the present study, we used experimentally controlled cynomolgus monkeys (Macaca fascicularis) to assess the influence of prenatal exposure to BPA (10 microg/(kg day)) via subcutaneously implanted pumps and examined social behaviors between infants and their mothers during the suckling period. Mother-infant interactions in cynomolgus monkeys had behavioral sexual dimorphism associated with sex of infant from early suckling period. Prenatal exposure to BPA altered the behaviors of male infants significantly; BPA-exposed male infants behaved as female infants. And it also affected some of female infant behaviors. Consequently, gestational BPA exposure altered some behaviors of their mothers, mainly in male-nursing mothers. These results suggest that BPA exposure affects behavioral sexual differentiation in male monkeys, which promotes the understanding of risk of BPA exposure in human.
Bisphenol A (BPA) is a widespread estrogenic chemical used in the production of polycarbonate, and epoxy resins lining food and beverage cans and in dental sealants. During fetal life the intrauterine environment is critical for the normal development, and even small changes in the levels of hormones, such as estradiol or estrogen-mimicking chemicals, can lead to changes in brain function and consequently in behavior. We review here a series of ethological studies on the effects of maternal oral exposure during the last part of gestation (prenatal exposure) or from gestation day 11 to postnatal day 7 (perinatal exposure) to a low, environmentally relevant dose of BPA (10 microg/kg bw/day) on behavioral responses of CD-1 mouse offspring. We examined both male and female offspring and found that maternal exposure to BPA affected: (1) behavioral responses to novelty before puberty and, as adults; (2) exploration and activity in a free-exploratory open field; (3) exploration in the elevated plus maze and (4) sensitivity to amphetamine-induced reward in the conditioned place preference test. A consistent effect of the maternal exposure to BPA is that in all these different experimental settings, while a significant sex difference was observed in the control group, exposure to BPA decreased or eliminated the sex difference in behavior. In addition, exposure of female mice to BPA in both adulthood or during fetal life altered subsequent maternal behavior. These findings, together with those from other laboratories, are evidence of long-term consequences of maternal exposure to low-dose BPA at the level of neurobehavioral development.
Contraception par les steroides, effets des contraceptifs hormonaux sur la composition du lait, effet de la contraception hormonale sur les immunoglobulures du lait. Etude des autres methodes de contraception
Dichlorodiphenyl dichloroethylene (DDE) has been shown to reduce the duration of breast feeding in two studies. In addition to duration, we examined whether DDE lowers the initiation of breast feeding. Between 1973 and 1991, the Michigan Department of Community Health conducted three surveys to assess polychlorinated biphenyls (PCBs) and DDE serum concentrations in Michigan anglers. Through telephone interviews with parents, we retrospectively ascertained information on breast feeding. Based on repeated maternal serum measurements between 1973 and 1991, we arrived at the level of exposure at the time of delivery by extrapolating PCB and DDE serum levels. One mother may have contributed more than one child; however, serum concentrations varied between children from the same mother. The maternal DDE and PCB serum concentrations were categorised as follows: 0 to < 5 µg/L, 5 to < 10 µg/L, ≥ 10 µg/L. Repeated measurement models and survival analyses were used to determine the relationship between DDE and PCBs and characteristics of breast feeding while controlling for cohort effects, maternal age at delivery, education, and smoking during pregnancy. We focused on 176 pregnancies of 91 mothers who had maternal exposure information and gave birth between 1969 and 1995.
Pollutant chemicals that are widespread in the environment can affect endocrine function in laboratory experiments and in wildlife. Although human beings are commonly exposed to such pollutant chemicals, the exposures are generally low and clear effects on endocrine function from such exposures have been difficult to demonstrate. Human data including both exposure to the chemical agent and the endocrine outcome are reviewed here, including age at weaning, age at puberty, anogenital distance, and sex ratio at birth, and the strength of the evidence are discussed. Although endocrine disruption in humans by pollutant chemicals remains largely undemonstrated, the underlying science is sound and the potential for such effects is real.
Theories for the origin of milk have been recorded since the time of Ancient Greeks. In those times it was believed that milk was derived from special vessels that connected the uterus to the breasts. The "chyle theory" on the origin of milk was another prominent theory which persisted well into the nineteenth century before the realisation that milk components were derived from blood and some milk constituents were actually synthesized within the breasts. The demonstration that milk ejection was the expulsion of milk that had already been secreted and that milk secretion was a separate continuous process, set the background for the development for the current understanding of milk synthesis and secretion. Today we know that there are two stages in the initiation of lactation- secretory differentiation and secretory activation. Secretory differentiation represents the stage of pregnancy when the mammary epithelial cells differentiate into lactocytes with the capacity to synthesize unique milk constituents such as lactose. This process requires the presence of a 'lactogenic hormone complex' of the reproductive hormones, estrogen, progesterone, prolactin and some metabolic hormones. Secretory activation on the other hand, is the initiation of copious milk secretion and is associated with major changes in the concentrations of many milk constituents. The withdrawal of progesterone triggers the onset of secretory activation but prolactin, insulin and cortisol must also be present. This review describes the works of pioneers that have led to our current understanding of the biochemical and endocrinological processes involved in the initiation of human lactation.
Deterioro de la lactancia materna: dejoar las fórmulas y apegarse a lo básico
- T González De Cossío
- L Escobar Zaragoza
- L D González Castell
- M Hernández Ávila
González de Cossío, T.; Escobar Zaragoza, L.; González Castell, LD.; Hernández Ávila, M. Deterioro
de la lactancia materna : dejoar las fórmulas y apegarse a lo básico. Centro de Investigación en
Nutrición y Salud, Instituto Nacional de Salud Pública; 2012.
Author manuscript; available in PMC
Matern Child Health J. Author manuscript; available in PMC 2017 August 01.
World Health Organization. Infant and young child nutrition: Global strategy on infant and young child feeding
- R H Weldon
- M Webster
- K G Harley
- A Bradman
- L Fenster
- M D Davis
- B Eskenazi
Weldon RH, Webster M, Harley KG, Bradman A, Fenster L, Davis MD, Eskenazi B. Serum persistent
organic pollutants and duration of lactation among Mexican-American women. Journal of
Environmental and Public Health. 2010; 2010:1-11. http://doi.org/10.1155/2010/861757.
World Health Organization. Infant and young child nutrition: Global strategy on infant and young child
feeding. Fifty Fifth World Health Assembly. 2002; A55/15:13.10. Retrieved from http://
apps.who.int/gb/archive/pdf_files/WHA55/ea5515.pdf.