Publications by authors named "Toshihiro Kawamoto"

148 Publications

Gestational weight gain growth charts adapted to Japanese pregnancies using a Bayesian approach in a longitudinal study: The Japan Environment and Children's Study.

J Epidemiol 2021 Aug 28. Epub 2021 Aug 28.

Japan Environment and Children's Study, UOEH Subunit Center, University of Occupational and Environmental Health.

Background Tracking gestational weight gain (GWG) during pregnancy makes it possible to optimize pregnancy outcomes and GWG growth curves are well suitable for this purpose. The GWG guidelines for Japanese were revised in 2021. However, currently, there are no GWG growth curves to guide women on how to gain weight to meet these guidelines.Methods Using data on 96,631 live births from the Japan Environment and Children's Study (JECS), we created descriptive GWG percentile curves estimated the trajectory of GWG required to meet the GWG guidelines stratified by pre-pregnancy body mass index (BMI) For both analyses, Bayesian mixed models with restricted cubic splines adjusted for maternal characteristics were used.Results GWG curves substantially differed by pre-pregnancy BMI, and were higher among multiparas and those with lower maternal age and with no previous disease. We estimated that underweight, normal weight, overweight and obese women who gain 8.4 to 11.1 kg, 6.4 to 9.1 kg, 3.8 to 6.5 kg, and <1.9 kg at 30 weeks of gestation are on the trajectory to reach the new guidelines at 40 weeks of gestation.Conclusions We provide GWG percentiles curves for Japanese women as well as GWG trajectory curves to meet the new GWG recommendations. These results may help pregnant women monitor weight during their pregnancy.
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http://dx.doi.org/10.2188/jea.JE20210049DOI Listing
August 2021

Association of maternal sleep before and during pregnancy with sleep and developmental problems in 1-year-old infants.

Sci Rep 2021 Jun 4;11(1):11834. Epub 2021 Jun 4.

Regional Center for Japan Environment and Children's Study, University of Occupational and Environmental Health, Kitakyushu, Japan.

This study investigated the association of maternal sleep before and during pregnancy with sleeping and developmental problems in 1-year-old infants. We used data from the Japan Environment and Children's Study, which registered 103,062 pregnancies between 2011 and 2014. Participants were asked about their sleep habits prior to and during pregnancy. Follow-up assessments were conducted to evaluate the sleep habits and developmental progress of their children at the age of 1 year. Development during infancy was evaluated using the Ages and Stages Questionnaire (ASQ). Maternal short sleep and late bedtime before and during pregnancy increased occurrence of offspring's sleeping disturbances. For example, infants whose mothers slept for less than 6 h prior to pregnancy tended to be awake for more than 1 h (risk ratio [RR] = 1.49, 95% confidence interval [CI] 1.34-1.66), sleep less than 8 h during the night (RR = 1.60, 95% CI 1.44-1.79), and fall asleep at 22:00 or later (RR = 1.33, 95% CI 1.26-1.40). Only subjective assessments of maternal sleep quality during pregnancy, such as very deep sleep and feeling very good when waking up, were inversely associated with abnormal ASQ scores in 1-year-old infants.
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http://dx.doi.org/10.1038/s41598-021-91271-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8178306PMC
June 2021

Influence of physical activity before and during pregnancy on infant's sleep and neurodevelopment at 1-year-old.

Sci Rep 2021 Apr 14;11(1):8099. Epub 2021 Apr 14.

Japan Environment and Children's Study, UOEH Subunit Center, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan.

The aim of this study was to investigate the association between maternal physical activity (PA) before and during pregnancy and sleep and developmental problems in 1-year-old infants. We used data from a nationwide cohort study in Japan that registered 103,062 pregnancies between 2011 and 2014. Participants were asked about their PA before and during pregnancy, and the sleep and development of their children at the age of 1 year. Maternal PA was estimated using the International Physical Activity Questionnaire and was expressed in METs per week. We defined scores below the cut-off points of the Ages and Stages Questionnaire (ASQ) as abnormal for infant development. Based on the levels of PA before or during pregnancy, the participants were divided into five groups. In mothers with higher PA levels, the risk ratio for bedtime after 22:00 or abnormal ASQ scores in their 1-years-old infants were lower. These associations were observed for PA before and during pregnancy. Higher levels of maternal PA, both before and during pregnancy, may reduce sleep and developmental problems in infants.
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http://dx.doi.org/10.1038/s41598-021-87612-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8046980PMC
April 2021

Study design and participants' profile in the Sub-Cohort Study in the Japan Environment and Children's Study (JECS).

J Epidemiol 2020 Dec 26. Epub 2020 Dec 26.

Centre for Health and Environmental Risk Research, National Institute for Environmental Studies.

Background: The Japan Environment and Children's Study (JECS) is a nationwide birth cohort study investigating environmental effects on children's health and development. A Sub-Cohort Study has begun, conducting extended exposure and outcome measurements by targeting a subgroup randomly selected from the JECS Main Study. We report the Sub-Cohort Study methodology and participants' baseline profiles.

Methods: Of 100,148 children in the JECS Main Study, children born after 1 April 2013 who met eligibility criteria ([1] all questionnaire and medical record data from children and their mothers collected from the first trimester to 6 months of age, [2] biospecimens [except umbilical cord blood] from children and their mothers collected at first to second/third trimester and delivery) were randomly selected for each Regional Centre at regular intervals. Face-to-face assessment of neuropsychiatric development, body measurement, paediatrician's examination, blood/urine collection for clinical testing and chemical analysis, and home visits (ambient and indoor air measurement and dust collection) are conducted. Participants are followed up at 1.5 and 3 years old for home visits, and 2, 4, 6 and 8 years old for developmental/medical examination. The details of protocols after age 10 are under discussion.

Results: Of 10,302 selected children, 5,017 participated. The profiles of the participating mothers, fathers and children did not substantially differ between the Main Study and Sub-Cohort Study.

Conclusion: The JECS Sub-Cohort Study offers a platform for investigating associations between environmental exposure and outcomes.
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http://dx.doi.org/10.2188/jea.JE20200448DOI Listing
December 2020

Non-reassuring foetal status and sleep problems in 1-year-old infants in the Japan Environment and Children's Study: a cohort study.

Sci Rep 2020 07 10;10(1):11432. Epub 2020 Jul 10.

Japan Environment and Children's Study, UOEH Subunit Center, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan.

Abnormal autonomic function may cause false-positive non-reassuring foetal status (fpNRFS) and may also cause sleeping problems after birth. However, an association between fpNRFS and sleeping problems in infants has not been reported. We previously showed an association of NRFS with temperament, including bad mood and frequent crying for long durations in 1-month-old infants. In the present study, we aimed to assess this association in 1-year-old infants. A total of 62,612 single pregnant women were included in the analysis. fpNRFS was identified from medical records. Sleep problems, such as short sleep duration or crying at night, were investigated in 1-year-old infants using a questionnaire for mothers. We used a log-binominal regression model to explore the association of fpNRFS with each sleep problem and to estimate risk ratios (RRs). The number of fpNRFS cases was 2,071, with a frequency of 3.3%. We observed an association of fpNRFS with shorter sleep duration of less than 8 h a night (RR 1.30, 95% confidence intervals [CI] 1.10-1.54), crying at night (RR 1.19, 95% CI 1.03-1.39), and bedtime after 22:00 (RR 1.09, 95% CI 1.00-1.18). fpNRFS may be associated with sleep problems in 1-year-old infants.
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http://dx.doi.org/10.1038/s41598-020-67856-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7351771PMC
July 2020

Association of maternal sleep before and during pregnancy with preterm birth and early infant sleep and temperament.

Sci Rep 2020 07 6;10(1):11084. Epub 2020 Jul 6.

Japan Environment and Children's Study, UOEH Subunit Center, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan.

This study aimed to investigate the association of maternal sleep before and during pregnancy with preterm birth, infant sleep and temperament at 1 month of age. We used the data of the Japan Environment and Children's Study, a cohort study in Japan, which registered 103,099 pregnancies between 2011 and 2014. Participants were asked about their sleep before and during pregnancy, and the sleep and temperament of their newborns at 1 month of age. Preterm birth data were collected from medical records. Maternal sleep was not associated with preterm birth, but subjective sleep quality during pregnancy was associated with late preterm birth (birth at 34-36 weeks of gestation). For example, participants with extremely light subjective depth of sleep were more likely to experience preterm birth (RR = 1.19; 95% confidence interval [CI] = 1.04-1.35). Maternal sleep both before and during pregnancy seemed to be associated with infant sleep and temperament at 1 month of age. Infants, whose mothers slept for less than 6 hours before pregnancy, tended to cry intensely (RR = 1.15; 95% CI = 1.09-1.20). Maternal sleep problems before and during pregnancy were associated with preterm birth and child sleep problems and temperament.
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http://dx.doi.org/10.1038/s41598-020-67852-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7338358PMC
July 2020

The failure of two major formaldehyde catabolism enzymes (ADH5 and ALDH2) leads to partial synthetic lethality in C57BL/6 mice.

Genes Environ 2020 3;42:21. Epub 2020 Jun 3.

Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC USA.

Background: Exogenous formaldehyde is classified by the IARC as a Category 1 known human carcinogen. Meanwhile, a significant amount of endogenous formaldehyde is produced in the human body; as such, formaldehyde-derived DNA and protein adducts have been detected in animals and humans in the absence of major exogenous formaldehyde exposure. However, the toxicological effects of endogenous formaldehyde on individuals with normal DNA damage repair functions are not well understood. In this study, we attempted to generate C57BL/6 mice deficient in both and , which encode two major enzymes that metabolize endogenous formaldehyde, in order to understand the effects of endogenous formaldehyde on mice with normal DNA repair function.

Results: Due to deficiencies in both ADH5 and ALDH2, few mice survived past post-natal day 21. In fact, the survival of pups within the first few days after birth was significantly decreased. Remarkably, two mice survived for 25 days after birth, and we measured their total body weight and organ weights. The body weight of mice decreased significantly by almost 37% compared to the and mice of the same litter. In addition, the absolute weight of each organ was also significantly reduced.

Conclusion: Mice deficient in both formaldehyde-metabolizing enzymes ADH5 and ALDH2 were found to develop partial synthetic lethality and mortality shortly after birth. This phenotype may be due to the accumulation of endogenous formaldehyde. No serious phenotype has been reported in people with dysfunctional, dominant-negative alleles, but it has been reported that they may be highly susceptible to osteoporosis and neurodegenerative diseases. It is important to further investigate these diseases in individuals with alleles, including an association with decreased metabolism, and thus accumulation, of formaldehyde.
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http://dx.doi.org/10.1186/s41021-020-00160-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7268536PMC
June 2020

Maternal intake of one-carbon metabolism-related B vitamins and anorectal malformations in the Japan Environment and Children's Study.

Br J Nutr 2020 10 29;124(8):865-873. Epub 2020 May 29.

Centre for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki305-8506, Japan.

The occurrence of anorectal malformations (ARM) is thought to be reduced with sufficient folate intake. However, there is no apparent evidence. We focused on enzyme cofactors for one-carbon metabolism, including folate (vitamin B9), vitamin B6 and vitamin B12, and explored the association between maternal combined intake of these B vitamins and the risk of ARM. Using baseline data from a Japanese nationwide birth cohort study between 2011 and 2014, we analysed data of 89 235 women (mean age at delivery = 31·2 years) who delivered singleton live births without chromosomal anomalies. Information on dietary intake was obtained via a FFQ focused on early pregnancy and used to estimate B vitamin intake. We also collected information on the frequency of folic acid supplement use. ARM occurrence was ascertained from medical records. We identified forty-three cases of ARM diagnosed up to the first month after birth (4·8 per 10 000 live births). In terms of individual intake of the respective B vitamins, high vitamin B6 intake was non-significantly associated with reduced odds of ARM. Compared with women in the low combined B vitamin intake group, the OR of having an infant with ARM was 0·4 (95 % CI 0·2, 1·0) in the high intake group (folate ≥400 μg/d, and upper half of vitamin B6 and/or vitamin B12). In conclusion, our cohort analysis suggested an inverse association between the combined intake of one-carbon metabolism-related B vitamins in early pregnancy and ARM occurrence.
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http://dx.doi.org/10.1017/S0007114520001816DOI Listing
October 2020

Acetaldehyde dehydrogenase 2 deficiency increases mitochondrial reactive oxygen species emission and induces mitochondrial protease Omi/HtrA2 in skeletal muscle.

Am J Physiol Regul Integr Comp Physiol 2020 04 12;318(4):R677-R690. Epub 2020 Feb 12.

Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan.

Acetaldehyde dehydrogenase 2 (ALDH2) is an enzyme involved in redox homeostasis as well as the detoxification process in alcohol metabolism. Nearly 8% of the world's population have an inactivating mutation in the gene. However, the expression patterns and specific functions of ALDH2 in skeletal muscles are still unclear. Herein, we report that ALDH2 is expressed in skeletal muscle and is localized to the mitochondrial fraction. Oxidative muscles had a higher amount of ALDH2 protein than glycolytic muscles. We next comprehensively investigated whether ALDH2 knockout in mice induces mitochondrial adaptations in gastrocnemius muscle (for example, content, enzymatic activity, respiratory function, supercomplex formation, and functional networking). We found that ALDH2 deficiency resulted in partial mitochondrial dysfunction in gastrocnemius muscle because it increased mitochondrial reactive oxygen species (ROS) emission (2',7'-dichlorofluorescein and MitoSOX oxidation rate during respiration) and the frequency of regional mitochondrial depolarization. Moreover, we determined whether ALDH2 deficiency and the related mitochondrial dysfunction trigger mitochondrial stress and quality control responses in gastrocnemius muscle (for example, mitophagy markers, dynamics, and the unfolded protein response). We found that ALDH2 deficiency upregulated the mitochondrial serine protease Omi/HtrA2 (a marker of the activation of a branch of the mitochondrial unfolded protein response). In summary, ALDH2 deficiency leads to greater mitochondrial ROS production, but homeostasis can be maintained via an appropriate stress response.
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http://dx.doi.org/10.1152/ajpregu.00089.2019DOI Listing
April 2020

Does overweight before pregnancy reduce the occurrence of gastroschisis?: the Japan Environment and Children's Study.

BMC Res Notes 2020 Jan 30;13(1):47. Epub 2020 Jan 30.

Centre for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.

Objective: For several observational studies that have reported the factors related to gastroschisis, the target population in these studies was mainly residents of Europe or the US, and there is little data on the Asian population. In this study, we summarised characteristics of Japanese women who delivered infants with gastroschisis, particularly focusing on the pre-pregnancy body mass index (BMI), which was found to be inversely associated with gastroschisis in past studies, because the distribution of BMI is clearly different in Asia and the West.

Results: We used data from a nationwide birth cohort study which recruited pregnant women between 2011 and 2014. Among 92,796 women who delivered singleton live births, the frequency of underweight (pre-pregnancy BMI < 18.5 kg/m) was 16.2%, reference weight (18.5-24.9 kg/m) 73.1%, and overweight (≥ 25.0 kg/m) 10.6%. We identified only 9 infants with gastroschisis, 2 of whose women were underweight (frequency of gastroschisis = 0.01%), 5 were in the reference group (0.01%), and 2 were overweight (0.02%). Of these 9 women, none were aged < 20 years, 2 were aged 20-29 years (frequency = 0.01%), and 7 were aged 30-39 years (0.01%). No reduction in the occurrence of gastroschisis was apparent among Japanese women who were overweight before pregnancy.
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http://dx.doi.org/10.1186/s13104-020-4915-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6990474PMC
January 2020

Aldh2 Attenuates Stem Cell Factor/Kit-Dependent Signaling and Activation in Mast Cells.

Int J Mol Sci 2019 Dec 10;20(24). Epub 2019 Dec 10.

Mast Cell Biology Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD 20892, USA.

Mitochondrial aldehyde dehydrogenase (ALDH2) metabolizes endogenous and exogenous aldehydes and protects cells against oxidative injury. Inactivating genetic polymorphisms in humans are common and associate with alcohol flush reactions. However, whether mast cell Aldh2 activity impacts normal mast cell responses is unknown. Using bone marrow-derived mast cells from knockout mice, we found evidence for a role of mast cell Aldh2 in Kit-mediated responses. Aldh2-deficient mast cells showed enhanced Kit tyrosine kinase phosphorylation and activity after stimulation with its ligand (stem cell factor) and augmentation of downstream signaling pathways, including Stat4, MAPKs, and Akt. The activity of the phosphatase Shp-1, which attenuates Kit activity, was reduced in mast cells, along with an increase in reactive oxygen species, known to regulate Shp-1. Reduced Shp-1 activity concomitant with sustained Kit signaling resulted in greater proliferation following Kit engagement, and increased mediator and cytokine release when mast cells were co-stimulated via Kit and FcεRI. However, FcεRI-mediated signaling and responses were unaffected. Therefore, our findings reveal a functional role for mast cell intrinsic Aldh2 in the control of Kit activation and Kit-mediated responses, which may lead to a better understanding of mast cell reactivity in conditions related to ALDH2 polymorphisms.
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http://dx.doi.org/10.3390/ijms20246216DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6940998PMC
December 2019

Impact of sleep duration during pregnancy on the risk of gestational diabetes in the Japan environmental and Children's study (JECS).

BMC Pregnancy Childbirth 2019 Dec 9;19(1):483. Epub 2019 Dec 9.

Research Center for Environmental and Developmental Medical Sciences, Kyushyu University, Fukuoka, Japan.

Background: Gestational diabetes mellitus (GDM) has serious effects on both mother and child. Like Type 2 Diabetes Mellitus, it is increasing in prevalence world-wide. In addition to obesity, sleep duration has been named an important risk factor. Using a large cohort study, including data from 48,787 participants of the Japan Environment and Children's Study (JECS), we examined the association between sleep duration and both random blood glucose levels and GDM rates during pregnancy.

Methods: Random blood glucose levels were measured during pregnancy. GDM diagnosis was based on the results of 75 g oral glucose tolerance test. Additional anthropometric data was collected from questionnaires for statistical analysis.

Results: Compared to mothers averaging 7 to < 10 h sleep (reference group), women receiving < 5 h or ≥ 10 h sleep exhibited significantly elevated random blood glucose levels. This was associated with an elevated risk for positive GDM screening (< 5 h sleep: OR 1.17 (0.96-1.44) p = 0.126; ≥10 h sleep: OR 1.13 (1.03-1.25) p = 0.006). Calculating the risk for GDM, women sleeping < 5 h or ≥ 10 h exhibited elevated risks of 1.31-fold and 1.21 respectively. However, this trend was not found to be significant.

Conclusions: Sleep is a critical factor in glucose metabolism, with both abnormally long and short sleep duration increasing random blood glucose levels in pregnant women. Moreover, the risk for positive GDM screening increases significantly with elevated sleep, ≥10 h per night. These findings are promising because they support the idea that sleep duration is a modifiable risk factor, and can be focused upon to improve health and pregnancy outcome.
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http://dx.doi.org/10.1186/s12884-019-2632-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6902452PMC
December 2019

Maternal dietary intake of vitamin A during pregnancy was inversely associated with congenital diaphragmatic hernia: the Japan Environment and Children's Study.

Br J Nutr 2019 12 4;122(11):1295-1302. Epub 2019 Nov 4.

Centre for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.

The pathogenesis of congenital diaphragmatic hernia (CDH) is largely unknown; however, vitamin A seems to play a role in diaphragmatic development. Previous case-control studies reported that maternal dietary vitamin A intake was inversely associated with the risk of CDH. To our knowledge, however, there is no prospective evidence regarding this association. Our aim was to examine whether maternal intake of vitamin A was associated with CDH occurrence. Baseline data, from the Japan nationwide birth cohort study (2011-2014) of 89 658 mothers (mean age at delivery = 31·2 years) who delivered singleton live births, were analysed. We assessed dietary habits using an FFQ focused on the first trimester and estimated the daily intake of total vitamin A (retinol activity equivalents), retinol, provitamin A carotenoids and vegetables. The occurrence of CDH was ascertained from medical records. A total of forty cases of CDH were documented. The adjusted OR of CDH occurrence for the high total vitamin A intake category (median = 468 μg/d) was 0·6 (95 % CI 0·3, 1·2) with reference to the low intake category (230 μg/d). When we restricted to mothers with a prepregnancy BMI of 18·5-24·9 kg/m2, vitamin A intake was inversely associated with the risk of their children being born with CDH (OR 0·5, 95 % CI 0·2, 1·0). Even given the limited number of cases in the study, our findings provide additional evidence to link vitamin A with CDH.
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http://dx.doi.org/10.1017/S0007114519002204DOI Listing
December 2019

Associations between metal concentrations in whole blood and placenta previa and placenta accreta: the Japan Environment and Children's Study (JECS).

Environ Health Prev Med 2019 Jun 7;24(1):40. Epub 2019 Jun 7.

Department of Environmental Health, University of Occupational and Environmental Health, Kitakyushu, Japan.

Background: Placenta previa and placenta accreta associate with high morbidity and mortality for both mothers and fetus. Metal exposure may have relationships with placenta previa and placenta accreta. This study analyzed the associations between maternal metal (cadmium [Cd], lead [Pb], mercury [Hg], selenium [Se], and manganese [Mn]) concentrations and placenta previa and placenta accreta.

Methods: We recruited 17,414 women with singleton pregnancies. Data from a self-administered questionnaire regarding the first trimester and medical records after delivery were analyzed. Maternal blood samples were collected to measure metal concentrations. The subjects were classified into four quartiles (Q1, Q2, Q3, and Q4) according to metal concentrations.

Results: The odds ratio for placenta previa was significantly higher among subjects with Q4 Cd than those with Q1 Cd. The odds ratio for placenta previa was significantly higher for subjects with Q2 Pb than those with Q1 Pb.

Conclusion: Participants with placenta previa had higher Cd concentrations. However, this study was cross-sectional and lacked important information related to Cd concentration, such as detailed smoking habits and sources of Cd intake. In addition, the subjects in this study comprised ordinary pregnant Japanese women, and it was impossible to observe the relationship between a wide range of Cd exposure and placenta previa. Therefore, epidemiological and experimental studies are warranted to verify the relationship between Cd exposure and pregnancy abnormalities.
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http://dx.doi.org/10.1186/s12199-019-0795-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6556030PMC
June 2019

Blood mercury, lead, cadmium, manganese and selenium levels in pregnant women and their determinants: the Japan Environment and Children's Study (JECS).

J Expo Sci Environ Epidemiol 2019 09 18;29(5):633-647. Epub 2019 Apr 18.

Japan Environment and Children's Study Programme Office, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.

The Japan Environment and Children's Study (JECS) is a birth-cohort study of 100,000 mother-child dyads that aims to investigate the effect of the environment on child health and development. Mercury (Hg), lead (Pb), cadmium (Cd), manganese (Mn) and selenium (Se) are considered to be important co-exposures when examining the effect of other chemical substances on child development. The levels of these elements in the blood of 20,000 randomly selected mid/late-term pregnant women from the whole JECS cohort were analysed using inductively coupled plasma-mass spectrometry. The median concentrations (interquartile ranges) for Pb, Hg, Cd, Mn and Se were 0.63 (0.51-0.78) µg dl, 3.83 (2.70-5.43) µg l, 0.70 (0.52-0.95) µg l, 16.1 (13.2-19.6) µg l and 178 (165-192) µg l, respectively. Hg and Se correlated positively with each other (Spearman's ρ = 0.287), as did Pb and Cd (ρ = 0.239) and Cd and Mn (ρ = 0.267). The blood Pb levels decreased by 5-10-fold over the past 25 years. The main predictors of the blood levels of each element were fish consumption for Hg, maternal age and non-alcoholic beverage consumption for Pb, maternal age and smoking for Cd, gestational age at sampling for Mn and serum protein levels for Se. These results revealed the historical trends and current predictors of the blood levels of these elements in pregnant Japanese women.
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http://dx.doi.org/10.1038/s41370-019-0139-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6760604PMC
September 2019

Associations Between Metal Levels in Whole Blood and IgE Concentrations in Pregnant Women Based on Data From the Japan Environment and Children's Study.

J Epidemiol 2019 Dec 12;29(12):478-486. Epub 2019 Jan 12.

Department of Environmental Health, School of Medicine, University of Occupational and Environmental Health.

Background: Metal exposures could possibly affect allergic responses in pregnant women, although no studies have yet shown a clear relationship between the two, and such exposures might also affect the development of allergic diseases in children.

Methods: We investigated the relationship between metal concentrations in whole blood and immunoglobulin E (IgE; total and specific) in 14,408 pregnant women who participated in the Japan Environment and Children's Study. The subjects submitted self-administered questionnaires, and blood samples were collected from them twice, specifically, during the first trimester and again during the second/third trimester. Concentrations of the metals Cd, Pb, Hg, Se, and Mn, as well as serum total and allergen-specific IgEs for egg white, house dust-mites (HDM), Japanese cedar pollen (JCP), animal dander, and moth, were measured. Allergen-specific IgE(s) were divided based on concentrations <0.35 or ≥0.35 UA/mL, and the metal levels were divided into quartiles.

Results: Multivariable logistic regression analysis showed that there was a significant negative correlation between HDM- and animal dander-specific IgEs and Hg and Mn concentrations. Conversely, there was a significant positive relationship between JCP-specific IgE and Hg and Se concentrations.

Conclusions: Metal exposures may be related to both increases and decreases in allergen-specific IgEs in pregnant women.
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http://dx.doi.org/10.2188/jea.JE20180098DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6859078PMC
December 2019

Association Between Work-Related Factors and Diet: A Review of the Literature.

Workplace Health Saf 2019 Mar 2;67(3):137-145. Epub 2019 Jan 2.

1 University of Occupational and Environmental Health Japan.

The quality of workers' dietary intake could be influenced by their working conditions. This review aimed to summarize the published literature examining the association between work-related factors, such as work hours, shift work, physical strain, mental strain, job strain, support, and diet quality. The literature search, conducted in PubMed, was limited to articles published from 2000 to 2017, written in English, available online, and among workers employed in high-income countries. The search resulted in 16 articles that met the criteria. Although there was some evidence of unhealthy diet among shift workers, data on the diet quality in association with other work-related factors, such as number of hours worked, physical, mental, and job strain, and worksite support were scarce. Further studies are need for purposes better defining the association between work-related factors and quality of workers' diet.
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http://dx.doi.org/10.1177/2165079918812481DOI Listing
March 2019

Association between bisphenol A diglycidyl ether-specific IgG in serum and food sensitization in young children.

Eur J Med Res 2018 Dec 26;23(1):61. Epub 2018 Dec 26.

Department of Environmental Health, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyusyu, Fukuoka Prefecture, 807-8555, Japan.

Background: Recent studies have reported that endocrine-disrupting compound (EDC) exposure is related to food sensitization. Bisphenol A diglycidyl ether (BADGE) is one of the most widespread EDCs and its biological effects are considered to be greater on children than on adults. This study investigated the relationship between serum BADGE-specific immunoglobulin G (IgG) concentrations and food sensitization in young children by measuring food-specific IgE levels.

Methods: In total, 98 young children (59 boys and 39 girls; median age: 7 months; 25th and 75th percentile ages: 6 and 8 months, respectively) were enrolled. Blood samples were collected twice from all children (median sampling interval: 6 months; 25th and 75th percentile: 5 and 7 months). Food sensitization was evaluated based on food-specific IgE titers (egg white, milk, and wheat), which were determined using the capsulated hydrophilic carrier polymer-radioallergosorbent test. Furthermore, a dot-blotting assay for BADGE-specific IgG and quantitative reverse-transcriptase PCR for IL-6, IL-8, IL-10, and COX-2 mRNA expression were conducted.

Results: BADGE-specific IgG was detected in 20% of study subjects. A significant association was observed between the presence of BADGE-specific IgG and elevated wheat-specific IgE levels (OR = 3.56; 95% CI 1.13-11.2; P = 0.031). This relationship was particularly strong in girls (OR = 9.46; 95% CI 1.01-89.0; P = 0.049). A slight but non-significant association was noted between the presence of BADGE-specific IgG and elevated milk-specific IgE levels (OR = 2.77; 95% CI 0.93-8.22; P = 0.067). The expression of IL-6 mRNA among children with BADGE-specific IgG tended to increase, along with wheat-specific IgE levels.

Conclusion: BADGE exposure might enhance food sensitization in early childhood. Therefore, this should be strictly regulated, especially in younger children.
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http://dx.doi.org/10.1186/s40001-018-0358-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6306001PMC
December 2018

Association between time-related work factors and dietary behaviors: results from the Japan Environment and Children's Study (JECS).

Environ Health Prev Med 2018 Dec 14;23(1):62. Epub 2018 Dec 14.

Department of Environmental Health, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, Fukuoka, 807-8555, Japan.

Background: Few studies have examined the association of workhours and shift work (referred to here as "time-related work factors") with dietary behaviors. We aimed to investigate this association, as well as the dietary behaviors among individuals with occupations characterized by time-related work factors.

Methods: A cross-sectional study was performed using data from the Japan Environment and Children's Study. The study included 39,315 working men. Dietary behaviors (i.e., skipping breakfast, eating out, eating instant food, overeating, and eating fast) were assessed with a self-reported information from the Food Frequency Questionnaire. Logistic regression analysis was conducted to examine the associations of time-related work factors with dietary behaviors and dietary behavior tendencies among those in occupations characterized by long workhours and/or shift work.

Results: Long workhours were associated with high frequencies of skipping breakfast, eating out, eating instant food, overeating, and eating fast. The frequency of having shift work was associated with high frequencies of skipping breakfast, eating out, and eating instant food. Several occupations involving long workhours and/or shift work showed specific dietary behaviors; in some occupations, the level of significance changed after adjusting for time-related work factors in addition to other potential confounding factors.

Conclusions: Time-related work factors may help explain workers' dietary behaviors. Long workhours and shift work may lead to poor dietary behaviors. Other factors influenced by occupation itself, such as food environment, may also influence workers' dietary behaviors. Workhours and/or shift work, and these other work factors, should be given attention in workplace health promotion.
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http://dx.doi.org/10.1186/s12199-018-0753-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6293619PMC
December 2018

Inhalation exposure to low levels of ethyl tertiary butyl ether: Its genetic effects were significantly modified by ALDH2 activity.

Environ Mol Mutagen 2019 03 25;60(2):145-153. Epub 2018 Nov 25.

National Institute of Occupational Safety and Health, Kawasaki, Japan.

Previous experiments showed that high concentrations of ethyl tertiary butyl ether (ETBE) exposure (500-5,000 ppm) significantly resulted in DNA damages in aldehyde dehydrogenase 2 (Aldh2) knockout (KO) mice. This study was aimed to verify the genotoxic effects in three genetic types, Aldh2 KO, heterogeneous (HT), and wild type (WT), of mice exposed to lower concentrations of ETBE (50-500 ppm) by inhalation. Histopathology assessments in the livers, measurements of genotoxic biomarkers in blood and livers, and urinary 8-hydroxydeoxyguanosion (8-OH-dG) for the oxidative DNA damage of whole body were performed. Significant histopathological changes and DNA strand breaks both in hepatocytes and leukocytes were found in HT and KO male mice exposed to ≥200 ppm ETBE, but not in 50 ppm ETBE. 8-OH-dG levels either in liver or urine were higher in the HT and KO male mice exposed to ≥200 ppm ETBE. The pathological and genetic effects of ETBE were almost at the same extents for HT and KO mice. Thus, 50 ppm could be the no observed adverse effect level for ETBE in HT and KO male mice, which was far lower than the 500 ppm in WT mice. These results suggested that decrease and deficiency of ALDH2 activity would significantly increase the sensitivity to ETBE-induced genotoxicity as well as hepatotoxic effects after exposure even to low concentrations of ETBE. Environ. Mol. Mutagen. 60: 145-153, 2019. © 2018 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/em.22256DOI Listing
March 2019

Isoflavone Intake in Early Pregnancy and Hypospadias in the Japan Environment and Children's Study.

Urology 2019 02 15;124:229-236. Epub 2018 Nov 15.

Centre for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan.

Objective: To explore the association between isoflavone intake in early pregnancy (the critical window of masculinisation) and hypospadias. Since oestrogen is likely to contribute to the differentiation of male external genitalia, dietary intake of isoflavone, which has a similar structure to human oestrogen, may be associated with the occurrence of hypospadias. However, there has been little evidence of this association.

Materials And Methods: We used data of a nationwide birth cohort study, which recruited women as early in pregnancy as possible throughout Japan between 2011 and 2014. From the response to a self-administered food-frequency questionnaire, the daily intake of genistein (as a representative for isoflavone) was estimated. Information on hypospadias cases that were diagnosed until the first month after birth was obtained from medical records. Odds ratios (ORs) of hypospadias were estimated using a logistic regression model.

Results: Among 41,578 mothers, who delivered singleton live male births, the median genistein intake was 15.3 mg/day, and a total of 51 cases of hypospadias were identified. Compared with mothers in the reference group (genistein intake 11th-89th percentiles), those in the low intake group (≤10th percentile) had an elevated risk of their sons having hypospadias (multivariable-adjusted OR = 2.8, 95% confidence interval = 1.4-5.8). Adverse or beneficial effects of genistein on hypospadias were not observed in the high intake group (≥90th percentile) (OR = 0.9, 95% confidence interval = 0.4-2.4).

Conclusion: Low maternal intake of isoflavone in early pregnancy was associated with an elevated risk of hypospadias.
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http://dx.doi.org/10.1016/j.urology.2018.11.008DOI Listing
February 2019

Optimal protein intake during pregnancy for reducing the risk of fetal growth restriction: the Japan Environment and Children's Study.

Br J Nutr 2018 12 5;120(12):1432-1440. Epub 2018 Nov 5.

9Department of Pediatrics,School of Medicine,University of Occupational and Environmental Health,1-1, Iseigaoka,Yahatanishi,Kitakyusyu807-8556,Japan.

Clinical trials show that protein supplement increases infant size in malnourished populations; however, epidemiological studies in high-income countries have reported mixed results. Although these findings suggest a non-linear relationship between maternal macronutrient intake and fetal growth, this relationship has not been closely examined. We assessed the association between maternal protein intake and fetal growth among 91 637 Japanese women with singletons in a nation-wide cohort study using validated FFQ. The respondents answered the FFQ twice, once during early pregnancy (FFQ1; 16·3 (sd 6·0) weeks), and second during mid-pregnancy (FFQ2, 28·1 (sd 4·1) weeks). Daily energy intake and percentage energy from protein, fats and carbohydrates were 7477 (sd 2577) kJ and 13·5 (sd 2·0), 29·5 (sd 6·5) and 55·3 (sd 7·8) %, respectively, for FFQ1, and 7184 (sd 2506) kJ and 13·6 (sd 2·1), 29·8 (sd 6·6) and 55·3 (sd 7·9) %, respectively, for FFQ2. The average birth weight was 3028 (sd 406) g, and 6350 infants (6·9 %) were small for gestational age (SGA). In both phases of the survey, birth weight was highest and the risk of SGA was lowest when the percentage energy from protein was 12 %, regardless of whether isoenergetic replacement was with fat or carbohydrates. Furthermore, when protein density in the maternal diet was held constant, birth weight was highest when 25 % of energy intake came from fat and 61 % came from carbohydrates during early pregnancy. We found maternal protein intake to have an inverse U-curve relationship with fetal growth. Our results strongly suggest that the effect of protein on birth weight is non-linear, and that a balanced diet fulfilling the minimum requirement for all macronutrients was ideal for avoiding fetal growth restriction.
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http://dx.doi.org/10.1017/S000711451800291XDOI Listing
December 2018

Fish consumption in early pregnancy and congenital gastrointestinal tract atresia in the Japan Environment and Children's Study.

Br J Nutr 2019 01 29;121(1):100-108. Epub 2018 Oct 29.

1Centre for Health and Environmental Risk Research,National Institute for Environmental Studies,16-2 Onogawa,Tsukuba,Ibaraki 305-8506,Japan.

Current evidence suggests that the aetiology of congenital gastrointestinal (GI) tract atresia is multifactorial, and not based solely on genetic factors. However, there are no established modifiable risk factors for congenital GI tract atresia. We used data from a Japanese nationwide birth cohort study launched in 2011, and examined whether fish consumption in early pregnancy was associated with congenital GI tract atresia. We analysed data of 89 495 women (mean age at delivery=31·2 years) who delivered singleton live births without chromosomal anomalies. Based on the results of the FFQ, we estimated the daily intake of fish and n-3 PUFA consumption in early pregnancy. We defined a composite outcome (oesophageal atresia, duodenal atresia, jejunoileal atresia and/or anorectal malformation) as congenital GI tract atresia. In this population, median fish intake was 31·9 g/d, and seventy-four cases of congenital GI tract atresia were identified. Fish consumption in early pregnancy was inversely associated with the composite outcome (multivariable-adjusted OR for the high v. low consumption category=0·5, 95 % CI 0·3, 1·0). For all the specific types of atresia, decreased OR were observed in the high consumption category, although not statistically significant. Reduced atresia occurrence was observed even beyond the US Food and Drug Administration's recommended consumption of no more than 340 g/week. Also, n-3 PUFA-rich fish and n-3 PUFA consumptions tended to be inversely associated with atresia. Fish consumption in early pregnancy may be a preventive factor for congenital GI tract atresia.
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http://dx.doi.org/10.1017/S0007114518002842DOI Listing
January 2019

Non-reassuring foetal status and neonatal irritability in the Japan Environment and Children's Study: A cohort study.

Sci Rep 2018 10 26;8(1):15853. Epub 2018 Oct 26.

Japan Environment and Children's Study, UOEH Subunit Center, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan.

The aim of this study was to investigate whether non-reassuring foetal status (NRFS) affected an infant's temperament, or if the temperament formed prenatally resulted in an excessive heart rate reaction that was diagnosed as NRFS. We examined the correlation between NRFS and difficulty in holding a baby, and the amount of crying in the one month after birth, which was considered an indicator of the newborn's temperament. We divided the cases with NRFS into positive NRFS and false positive NRFS. NRFS was associated with bad mood, frequent crying for a long duration, and intense crying. After adjustment for other covariates, NRFS was associated with bad mood (odds ratio, OR = 1.15, 95% confidence interval, CI = 1.00-1.33), and intense crying (1.12, 1.02-1.24). In the multi-variable model, positive and false positive NRFS were not clearly associated with neonatal irritability. When stratified by parity, NRFS and false positive NRFS were likely to be positively associated with neonatal irritability in parous women. The clear association between NRFS and intense crying was observed in parous women (multi-variable adjusted OR = 1.46, 95% CI = 1.16-1.83), but not in nulliparae (1.01, 0.91-1.12) (p for effect modification <0.01). Similarly, increased odds of intense crying associated with false positive NRFS were only found in parous women (multi-variable adjusted OR = 1.40, 95% CI = 1.09-1.81) (p for effect modification = 0.03). There was no association observed between positive NRFS and irritability; therefore, NRFS has no effect on an infant's temperament.
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http://dx.doi.org/10.1038/s41598-018-34231-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6203769PMC
October 2018

[Deterioration of Healthcare Service Quality Provided by Occupational Physicians Due to Dumping by Health Checkup and Switching Health Checkup Organizations].

Nihon Eiseigaku Zasshi 2018 ;73(3):413-420

Faculty of Sustainability Studies, Hosei University.

Introduction: From 2007, competitive bidding for procurement became widely employed by the Japanese Government, and health check providers for government workers are selected every year by this method. Deterioration of health check quality due to excessive price competition is a serious concern. The National Federation of Industrial Health Organization (Zeneiren) conducted an investigative research on the contracting of health check providers and occupational physicians in workplaces in 2015-2016 in an effort to prevent low-cost but low-quality health checks. The report of the research is available on the homepage of Zeneiren. In this paper, we provide a brief overview of the report, and deterioration of health check quality due to dumping by and switching of health check providers is discussed from economic and legal viewpoints.

Method: Information was obtained from articles in print and on the Internet.

Results: A questionnaire survey of health check providers revealed that excessive discounts due to both competitive bidding and demand from companies commissioning health checks occurred on a routine basis, and some providers were concerned about worsening business conditions in the future. In a separate questionnaire survey of occupational physicians, it was discovered that they were able to evaluate the quality of health checks, whereas administrative officials responsible for selecting the providers were seldom able to adequately evaluate the health check quality, resulting in contracting providers of questionable quality, which in turn caused considerable dissatisfaction on the part of occupational physicians. Moreover, when health check providers were switched, the reporting format of health check results changed. The physicians did not favor such a change because of the considerably increased workload involved in coordinating past and current data and the risk of decreased occupational health service quality.

Discussion: Dumping makes the management of health check providers very difficult and is a cause of loss of social capital. If health check providers of good quality withdraw from the market, the supply of high-quality health checks decreases. This corresponds to external diseconomy caused by dumping on the part of the health check providers and loss of social surplus (economic surplus).

Conclusions: To avoid deterioration of occupational health service due to low-quality health checks and changes in the reporting format, occupational physicians must actively engage in the selection of health check providers of good quality.
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http://dx.doi.org/10.1265/jjh.73.413DOI Listing
October 2018

Questionnaire results on exposure characteristics of pregnant women participating in the Japan Environment and Children Study (JECS).

Environ Health Prev Med 2018 Sep 15;23(1):45. Epub 2018 Sep 15.

Japan Environment and Children's Study Programme Office, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, 305-8506, Japan.

Background: The Japan Environment and Children's Study (JECS) is a nation-wide birth cohort study investigating environmental effects on children's health and development. In this study, the exposure characteristics of the JECS participating mothers were summarized using two questionnaires administered during pregnancy.

Methods: Women were recruited during the early period of their pregnancy. We intended to administer the questionnaire during the first trimester (MT1) and the second/third trimester (MT2). The total number of registered pregnancies was 103,099.

Results: The response rates of the MT1 and MT2 questionnaires were 96.8% and 95.1%, respectively. The mean gestational ages (SDs) at the time of the MT1 and MT2 questionnaire responses were 16.4 (8.0) and 27.9 (6.5) weeks, respectively. The frequency of participants who reported "lifting something weighing more than 20 kg" during pregnancy was 5.3% for MT1 and 3.9% for MT2. The Cohen kappa scores ranged from 0.07 to 0.54 (median 0.31) about the occupational chemical use between MT1 and MT2 questionnaires. Most of the participants (80%) lived in either wooden detached houses or steel-frame collective housing. More than half of the questionnaire respondents answered that they had "mold growing somewhere in the house". Insect repellents and insecticides were used widely in households: about 60% used "moth repellent for clothes in the closet," whereas 32% applied "spray insecticide indoors" or "mosquito coil or an electric mosquito repellent mat."

Conclusions: We summarized the exposure characteristics of the JECS participants using two maternal questionnaires during pregnancy.
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http://dx.doi.org/10.1186/s12199-018-0733-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6138908PMC
September 2018

Acetaldehyde administration induces salsolinol formation in vivo in the dorsal striatum of Aldh2-knockout and C57BL/6N mice.

Neurosci Lett 2018 10 20;685:50-54. Epub 2018 Jul 20.

Department of Forensic Medicine, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki, Kita, Kagawa, Japan.

Acetaldehyde (AcH) and salsolinol play important roles in the central effects of ethanol. This study aimed to investigate the effect of administration of AcH on dopamine (DA), DA-derived salsolinol and serotonin (5-HT) levels in the dorsal striatum of Aldh2-knockout (Aldh2-KO) and C57BL/6 N (WT) mice. Animals were treated with AcH (50, 100 and 200 mg/kg) intraperitoneally and dialysate levels of DA, 5-HT and salsolinol were determined using in vivo microdialysis coupled with HPLC-ECD. Salsolinol was first detected at 20 min after AcH administration, and reached its peak concentration (WT mice: 0.29 ± 0.22 pg/μl; Aldh2-KO mice: 0.63 ± 0.17 pg/μl) at 25 min in the 200 mg/kg AcH group, before decreasing rapidly and reaching zero at approximately 55-80 min. Treatment with 100 and 200 mg/kg AcH increased levels of salsolinol in both WT and Aldh2-KO mice, with 200 mg/kg AcH inducing a higher level of salsolinol in Aldh2-KO mice than in WT mice. Treatment with 50 mg/kg AcH produced a small increase in salsolinol levels in Aldh2-KO mice, whereas no elevation of salsolinol was detected in WT mice. The increase in salsolinol formation was found to occur a dose-dependent manner in both genotypes. Administration of AcH and the subsequent changes in salsolinol concentrations did not change DA or 5-HT levels in either genotype. Our study suggests that AcH dose-dependently increases the formation of salsolinol in the dorsal striatum of mice, which provides further support for the role of AcH in salsolinol formation in the animal brain.
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http://dx.doi.org/10.1016/j.neulet.2018.07.032DOI Listing
October 2018

The association between whole blood concentrations of heavy metals in pregnant women and premature births: The Japan Environment and Children's Study (JECS).

Environ Res 2018 10 28;166:562-569. Epub 2018 Jun 28.

Department of Environmental Health, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, Fukuoka 807-8555, Japan. Electronic address:

Background: Heavy metals are widely distributed in the environment. Recent reports have demonstrated the risk of preterm birth following heavy metal exposure. Preterm births are classified as early and late, depending on the duration of pregnancy, and are associated with increased risk of congenital illnesses such as heart failure, asthma, etc. Particularly, early preterm births carry a higher risk of mortality; however, the differential effects of heavy metal exposure on early and late preterm births are unknown.

Objectives: To analyze the association between maternal whole blood concentrations of heavy metals, such as cadmium (Cd), lead (Pb), mercury (Hg), selenium (Se), and manganese (Mn) that are common toxicants in Japan, and early and late preterm births.

Methods: The data of 14,847 pregnant women who were participants of the Japan Environment and Children's Study were used. Data of the self-questionnaire pertaining to the first trimester (T1), second/third trimester (T2), and medical records after delivery were analyzed. We divided preterm birth into two groups: early preterm (22 to < 34 weeks) and late preterm (34 to < 37 weeks). Maternal blood samples for measuring heavy metal concentrations were collected in T2 (pregnancy weeks: 14-39). The participants were classified into four quartiles (Q1-Q4) according to increasing heavy metal levels.

Results: The rate of preterm birth was 4.5%. After controlling for confounding factors, such as age, pre-pregnancy body mass index, smoking, partner's smoking, drinking habits, gravidity, parity, number of cesarean deliveries, uterine infections, household income, educational levels, and sex of infant, Cd levels were found, by multivariable logistic regression analysis, to be significantly associated with early preterm birth (p = 0.002), with odds ratio for early preterm birth of 1.91 (95% confidence interval: 1.12-3.27, P = 0.018) in subjects of Q4 compared with in subjects with term birth (≧ 37 weeks).

Conclusion: Maternal blood Cd levels during pregnancy are positively associated with the risk of early preterm birth among Japanese women. Identification of the main source of maternal Cd exposure may contribute to the prevention of early preterm births and health maintenance of mothers and their infants in the future.
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http://dx.doi.org/10.1016/j.envres.2018.06.025DOI Listing
October 2018

Evaluation of chemical-specific IgG antibodies in male workers from a urethane foam factory.

Environ Health Prev Med 2018 Jun 19;23(1):24. Epub 2018 Jun 19.

Department of Environment Health, University of Occupational and Environmental Health, Kitakyushu, Japan.

Background: Plastic resins are complex chemicals that contain toluene diisocyanate (TDI) and/or trimellitic anhydride (TMA), which cause occupational allergies (OA), including respiratory allergies. Serum IgGs against TDI and TMA have been suggested as potential markers of the exposure status and as exploring cause of OA. Although TDI-specific IgG has been examined for suspected OA, TMA-specific IgG is not commonly evaluated in a urethane foam factory. This study therefore investigated both TDI- and TMA-specific IgGs in suspected OA patients and to evaluate the usefulness of the measurement of multiple chemical-specific IgG measurement for practical monitoring.

Methods: Blood samples were collected from two male workers who developed respiratory allergies supposedly caused by occupational exposure to TDI and/or TMA for the presence of TDI- and TMA-specific IgGs. In addition, blood samples from 75 male workers from a urethane foam factory, along with 87 male control subjects, were collected in 2014 and tested for the same IgGs in 2014. The presence and levels of TDI- and TMA-specific serum IgGs were measured using dot blot assays.

Results: We found that controls had mean concentrations of TDI- and TMA-specific IgGs of 0.98 and 2.10 μg/mL, respectively. In the two workers with respiratory allergies, the TDI-specific IgG concentrations were 15.6 and 9.51 μg/mL, and TMA-specific IgG concentrations were 4.56 and 14.4 μg/mL, which are clearly higher than those in controls. Mean concentrations of TDI- and TMA-specific IgGs in the factory workers were 1.89 and 2.41 μg/mL, respectively, and are significantly higher than those of the controls (P < 0.001 and P < 0.026 for TDI- and TMA-specific IgGs, respectively).

Conclusion: The workers suspected of OA showed an evidently high level of TDI- and TMA-specific IgG, and these levels in workers at the urethane foam factory were also significantly higher than those in controls. In conclusion, the measurement of TDI- and TMA-specific IgG among workers using plastic resins is helpful to monitor their exposure status.
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http://dx.doi.org/10.1186/s12199-018-0713-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6010152PMC
June 2018
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