Impact of COVID-19 pandemic on physical health amongst children: Difference-in-differences analyses of nationwide school health checkup database.

INTRODUCTION: The COVID-19 pandemic posed tremendous challenges for children. However, the long-term effects of the pandemic on various aspects of physical health at a national level remain unclear. METHODS: In this retrospective cohort study, we analysed data from nationwide health checkup records amongst children aged 7-15 years. The dataset comprised 3 544 146 records from 393 794 individuals who graduated from junior high school during fiscal years 2007 to 2022. Difference-in-differences (DID) analyses with multiple time periods were used to examine the impact of COVID-19 on physical health outcomes. RESULTS: Compared with the pre-pandemic period, the COVID-19 pandemic was associated with excess increases in obesity for boys and girls, persisting over the 3 years (+0.42%; [95% CI, 0.23-0.61]). Also, it was associated with excess increases in underweight (+0.28% [0.25-0.32]) and poor visual acuity amongst boys in the 3rd year (+1.80% [1.30-2.30]). There were excess reductions in dental caries (-1.48% [-2.01 to -0.95]), glucosuria (-0.55 [-0.88 to -0.23]) and hematuria (-0.43% [-0.73 to -0.13]) during the 3rd year of the pandemic. CONCLUSIONS: These findings underscore the multifaceted impact of the pandemic on various health indicators for school-aged children. This information could be valuable for public health policy and paediatric healthcare planning in the post-pandemic era.

The effect of parental age on child development at 36 months: Insights from the Japan environment and children's study.

BACKGROUND: The impact of parent-childbearing age on child development at 36 months of age is controversial. AIMS: We used data from a large cohort study with multiple imputation and mediation analyses of variables. METHODS AND PROCEDURES: A total of 72,606 parent-child pairs from the Japan Environment and Children's Study were included in the study. Parents' ages were categorized into five groups. We used five domains of the Japanese translation of the Ages and Stages Questionnaire, Third Edition (J-ASQ-3). Scores below the cutoff value at 36 months were defined as developmental delays in each domain. We used three logistic analysis models. In Model 3, we analyzed maternal and paternal age using other variables and covariates. OUTCOMES AND RESULTS: The outcome was a developmental delay in the five domains of J-ASQ-3. In Model 3, ORs for the developmental delay scores regarding parental age were significantly associated with all five domains of J-ASQ-3. The mediation analysis showed a significant mediation interaction effect for mothers but localized for fathers. CONCLUSION: Advanced paternal and maternal ages were associated with developmental delay in children. Awareness of the risks of childbearing at an advanced age is crucial. WHAT'S THE PAPER ADDS: This manuscript used data from a large cohort study with multiple imputation and mediation analyses. With these analyses, we identified the pure effect of advanced parental age on their children's development at 36 months.

Early childhood neurodevelopmental milestones in children with allergic diseases: the Japan Environment and Children's Study (JECS).

This study investigated the potential link between early childhood allergic diseases and neurodevelopmental milestone attainment during the first 3 years of life. Utilizing data from a large-scale prospective birth cohort study in Japan, encompassing 87,986 children, we examined physician-diagnosed and caregiver-reported allergic conditions, including atopic dermatitis (AD), asthma, and food allergy (FA). Neurodevelopmental milestones were assessed using the Ages and Stages Questionnaires at 1, 1.5, 2, 2.5, and 3 years of age. Stabilized inverse probability-weighted generalized estimating equation models were employed to estimate odds ratios (ORs). Our analysis revealed no significant association of AD and asthma with delay in communication, gross motor, fine motor, problem-solving, and personal-social skills during the initial 3 years of life. However, children with FA showed an increased likelihood of experiencing gross motor delay compared with that shown by those without FA (weighted adjusted OR: 1.14). Despite this, no significant association of FA with other developmental domains was observed. Early childhood allergies may not influence neurodevelopmental delays. However, there is a potential association between FA and delays, specifically in gross motor skills, that warrants routine developmental monitoring and additional investigations.

Guardians' food literacy and breakfast skipping among Japanese school children.

Children and adolescents who regularly skip breakfast are at a greater risk of obesity than those who regularly eat breakfast. Guardian's food literacy, defined in this study as a collection of a guardian's knowledge, skill, and attitude towards healthy food practices, may directly influence their child's dietary habits. Thus, this study utilized a food literacy scale to assess the relationship between guardians' food literacy and breakfast skipping among school-attending Japanese children and adolescents and the most commonly reported reasons for skipping breakfast. This was a cross-sectional study using survey data collected from a nationally representative sample of households in Japan (n = 1520). Our results show that 13.0% of children self-reported skipping breakfast at least once a week. Children in households where guardians reported higher knowledge and attitude scores had significantly lower odds of skipping breakfast (odds ratios = 0.90 [95% confidence interval: 0.83-0.98] and 0.81 [0.74-0.90], respectively). These findings suggest that a guardian's attitude and knowledge towards healthy food practices influence the frequency at which their child eats breakfast. Moreover, lower parental attitude scores were associated with children skipping due to not having enough time for breakfast in the morning. Improving guardians' food literacy may provide an avenue by which to decrease the rate of breakfast skipping among children and adolescents, thereby decreasing the risk of obesity and other adverse health outcomes.

The Population-Attributable Fractions of Small-for-Gestational-Age Births: Results from the Japan Birth Cohort Consortium.

A fetal growth restriction is related to adverse child outcomes. We investigated risk ratios and population-attributable fractions (PAF) of small-for-gestational-age (SGA) infants in the Japanese population. Among 28,838 infants from five ongoing prospective birth cohort studies under the Japan Birth Cohort Consortium, two-stage individual-participant data meta-analyses were conducted to calculate risk ratios and PAFs for SGA in advanced maternal age, pre-pregnancy underweight, and smoking and alcohol consumption during pregnancy. Risk ratio was calculated using modified Poisson analyses with robust variance and PAF was calculated in each cohort, following common analyses protocols. Then, results from each cohort study were combined by meta-analyses using random-effects models to obtain the overall estimate for the Japanese population. In this meta-analysis, an increased risk (risk ratio, [95% confidence interval of SGA]) was significantly associated with pre-pregnancy underweight (1.72 [1.42-2.09]), gestational weight gain (1.95 [1.61-2.38]), and continued smoking during pregnancy (1.59 [1.01-2.50]). PAF of underweight, inadequate gestational weight gain, and continued smoking during pregnancy was 10.0% [4.6-15.1%], 31.4% [22.1-39.6%], and 3.2% [-4.8-10.5%], respectively. In conclusion, maternal weight status was a major contributor to SGA births in Japan. Improving maternal weight status should be prioritized to prevent fetal growth restriction.

Teenage and young adult pregnancy and depression: findings from the Japan environment and children's study.

Teenage pregnancy increases the threat of depression because of its many factors. Pregnancy during young adulthood may also have several risk factors for depression compared to older pregnancies. However, data on depression in young adult pregnancies are lacking. This study investigated the association between teenage and young adult pregnancy and depression. Data from the Japan Environment and Children's study was used as a nationwide multicenter prospective cohort study. A multivariate logistic regression was performed to investigate the association between age groups (14-19, 20-24, 25-29, 30-34, ≥ 35 years) and depression, adjusted for behavioral and sociodemographic characteristics. Depression was assessed using the Kessler Psychological Distress Scale. In total, 96,808 pregnant women responded to the questionnaire. Teenage (14-19 years) and young adult (20-24 years) pregnancy were associated with an increased risk of depression compared to older pregnancy (≥ 35 years) (teenage: OR 4.28, 95% confidence interval, CI [3.24-5.64]; young adult: OR 3.00, 95% CI [2.64-3.41]). After adjusting for covariates, the magnitude of the risk of depression was attenuated. However, teenage and young adult pregnancy remained at a significantly increased risk of depression compared to older pregnancy (teenage: OR 2.38, 95% CI [1.77-3.21]; young adult: OR 2.14, 95% CI [1.87-2.46]). Our findings indicate that teenage and young adults' pregnancy are at an increased risk of depression compared to older pregnancy. These findings suggest prioritizing teenage and young pregnant women for prevention and interventions related to depression.

Association between maternal fish consumption during pregnancy and preterm births: the Japan Environment and Children's Study.

BACKGROUND: Fish are a rich source of essential nutrients that protect against preterm birth. However, as fish can absorb environmental pollutants, their consumption can also increase the risk of preterm birth. This study aimed to assess whether maternal fish consumption during pregnancy is associated with preterm birth in a nationwide large Japanese cohort that consumed relatively high amounts and many types of fish. METHODS: This study included 81,428 mother-child pairs enrolled in a nationwide prospective Japanese birth cohort study. Fish consumption was assessed using a validated food frequency questionnaire. Multivariate logistic regression was used to investigate the association of total consumption of fish, fatty fish and lean fish, fish paste, and seafood and clams with preterm birth, adjusted for potential confounders. RESULTS: There was no association between overall fish consumption and preterm births. However, the highest quintile of fish paste consumption was significantly associated with an increased risk of preterm birth (odds ratio [OR]: 1.11; 95% confidence interval [CI: 1.04, 1.17]). The consumption of baked fish paste at least three times per week was significantly associated with preterm birth (OR: 1.20; 95% CI: 1.03, 1.40). Consumption of other types of fish, except fish paste, was not significantly associated with preterm birth risk. CONCLUSIONS: Fish paste consumption may increase the risk of preterm birth. Further studies are required to confirm this association.

Health-related quality of life of mothers and developmental characteristics of very low birth weight children at 2.5 years of age: results from the Japan Environment and Children's Study (JECS).

BACKGROUND: The level of child development may be associated with the risk of poor maternal health-related quality of life (HRQoL). The objective of this study was to describe the developmental characteristics of very low birth weight (VLBW) children at 2.5 years of age and to examine associations between maternal HRQoL and the degree of child development based on the Japanese version of Ages and Stages Questionnaire (J-ASQ-3). METHODS: A cross-sectional study was performed using the data from a nationwide prospective birth cohort study in Japan. Among a total of 104,062 fetal records, the VLBW infants (birth weight ≤ 1500 g) were analyzed using linear regression models, adjusted for potential covariates. Subgroup analysis was also conducted to assess the association between social connection or cooperation of the partner and maternal HRQoL by the level of child development. RESULTS: The final study subjects included 357 VLBW children and mothers. The suspected developmental delays (SDDs) in at least two domains was significantly associated with lower maternal mental HRQoL regression coefficient -2.314 (95%CI: -4.065 to -0.564). There was no association between the status of child development and maternal physical HRQoL. After adjusting for child and maternal covariates, the maternal HRQoL was not significantly associated with child development. Amongst women who indicated having some social support, having a child with a SDD in two or more domains was negatively associated with mental HRQoL compared with women whose child was less developmental delay, regression coefficient -2.337 (95%CI: -3.961 to -0.714). Amongst women who indicated having partner's cooperation to child-rearing, having a child with a SDD in two or more domains was negatively associated with mental HRQoL compared with women whose child was less developmental delay, regression coefficient -3.785 (95%CI: -6.647 to -0.924). CONCLUSIONS: Our findings indicate that the lower maternal mental HRQoL was independently associated with the SDDs evaluated by the J-ASQ-3, whereas there was no association after adjusting for covariates. Further research is warranted to elucidate the impact of social connection and partner's cooperation on maternal HRQoL and child development. This study urges that particular attention should be paid to mothers of VLBW children with SDDs and also to provide early intervention and continued support.

Association between pre-pregnancy weight status and dietary patterns during pregnancy: results from the Japan Environment and Children's Study.

OBJECTIVE: Pre-pregnancy weight status is related to offspring health and may influence dietary patterns during pregnancy. We aimed to evaluate the link between pre-pregnancy weight status and dietary patterns during pregnancy. DESIGN: Dietary data were collected using a FFQ during middle or late pregnancy. Dietary patterns were identified using principal component analysis. Anthropometric data were extracted from medical charts. Multiple linear regression was used to assess associations between pre-pregnancy weight status (severely or moderately underweight, mildly underweight, normal weight, overweight and obese) and dietary patterns during pregnancy after adjusting for socio-demographic characteristics. SETTING: Nationwide Japan. PARTICIPANTS: Pregnant Japanese women enrolled in the Japan Environment and Children's Study, a prospective birth cohort study (n 90 765). RESULTS: We identified three dietary patterns. Compared with women with pre-pregnancy normal weight, those with pre-pregnancy obesity were less likely to habitually consume 'fruits and vegetables' pattern (coefficient, -0·18; 95 % CI, -0·21, -0·14) and 'confectionery' pattern (coefficient, -0·18; 95 % CI, -0·21, -0·14) and more likely to consume 'white rice and soy products' pattern (coefficient, 0·08; 95 % CI, 0·04, 0·11), and those with severely or moderately pre-pregnancy underweight were more likely to consume 'confectionery' pattern (coefficient, 0·06; 95 % CI, 0·03, 0·09) during pregnancy, after adjusting for confounders. CONCLUSION: We found that moderately and severely pre-pregnancy underweight women and those with obesity had unhealthy dietary patterns compared to those with pre-pregnancy normal weight. Our findings suggest that prenatal dietary advice is important and should be based on the pre-pregnancy weight status.

Association of COVID-19-related discrimination with subsequent depression and suicidal ideation in healthcare workers.

Previous cross-sectional studies showed that COVID-19-related discrimination against healthcare workers was linked to depression. However, no study has examined the longitudinal association that allows causal interpretations. This prospective cohort study aimed to examine whether COVID-19-related discrimination at baseline is associated with depression and suicidal ideation several months later. Data were collected from October 2020 to July 2021. Multivariable logistic regression was performed. Fixed effects models were used to control for the effect of hospitals (Level 2 variable). Adjustments also included age, sex, living alone, alcohol consumption, exercise, BMI, working hours, comorbidity, and frontline worker status (Level 1 variables). Multiple sensitivity analyses were conducted to examine if the results substantially changed and were robust to unmeasured confounding. Multiple imputation for missing data was conducted via chained equations. As the final sample, 2862 healthcare workers without depression at baseline were studied. A total of 269 individuals (9.4%) experienced COVID-19-related discrimination. Depression was suggested in 205 participants (7.2%), and suicidal ideation in 108 participants (3.8%). In the adjusted models, COVID-19-related discrimination was significantly associated with subsequent depression (OR = 2.18, 95% CI = 1.39 to 2.90) and suicidal ideation (OR = 2.07, 95% CI = 1.22 to 3.50). Multiple sensitivity analyses verified the results. COVID-19-related discrimination results in depression and suicidal ideation in healthcare workers. Interventions to prevent such discrimination against healthcare workers, e.g., anti-discrimination campaigns, are crucial during the COVID-19 pandemic.

COVID-19 vaccine literacy and vaccine hesitancy among pregnant women and mothers of young children in Japan.

BACKGROUND: Delays in the spread of vaccination have been recognized as an urgent public health issue in the context of the COVID-19 pandemic. Vaccine literacy (VL) is a critical determinant of vaccine uptake; however, little is known about VL among pregnant women and mothers of young children. METHODS: We analyzed data from a nationwide, cross-sectional internet survey in Japan on VL and vaccine hesitancy, conducted with 1,639 pregnant women and 5,688 mothers of young children who had given birth after July 2019, between July 24 and August 30, 2021. RESULTS: Vaccine hesitancy was observed in 51.1 % of pregnant women and 31.9 % of mothers of young children. The risk of vaccine hesitancy was significantly higher among pregnant women with lower interactive/critical skills (risk ratio [RR] 2.10, 95 % confidence interval [CI] 1.59, 2.78, p < 0.001), although functional skills did not significantly correlate with vaccine hesitancy. For mothers of young children, we found a significantly higher risk of vaccine hesitancy among those with low VL functional skills (RR 1.38, 95 % CI 1.19, 1.61), p < 0.001) and low interactive/critical skills (RR 1.29, 95 % CI 1.10, 1.50, p = 0.001). CONCLUSIONS: Our findings suggest that aiding individuals to correctly evaluate vaccine-related information is critical for improving vaccine acceptance rates among both pregnant women and mothers of young children. Meanwhile, improving the comprehensibility of communication toolkits may be important for women with children but have a limited effect among pregnant women.

Vaccine Literacy, COVID-19 Vaccine-Related Concerns, and Intention to Recommend COVID-19 Vaccines of Healthcare Workers in a Pediatric and Maternity Hospital: A Cross-Sectional Study.

Vaccine literacy of healthcare workers (HCWs) may affect the COVID-19 vaccine uptake of the general population. This study aimed to clarify the vaccine literacy level of HCWs in Japan and its impacts on their concerns about vaccines and intention to recommend that others receive vaccines. This cross-sectional survey was conducted in July 2021 based on the recruitment of HCWs in a pediatric and maternity hospital and research center in Tokyo, Japan. All HCWs in this center had the chance to receive the COVID-19 vaccine before the survey, and their vaccine coverage was relatively high, at 95%. A total of 1519 workers answered the questionnaire. The results showed that HCWs with lower functional vaccine literacy had 1.5 times as many concerns about the efficacy of vaccines and 1.6 times as many concerns about the future side effects compared with those with higher literacy. Further, HCWs with higher vaccine literacy were more likely to recommend that older people, people with comorbidities, and pregnant women receive vaccines. Our findings suggest that high vaccine literacy alleviates concerns about COVID-19 vaccines and raised the intention to recommend vaccines to others. To achieve high vaccine coverage, countermeasures such as personalized education are essential.

Use of heated tobacco products, moderate alcohol drinking, and anti-SARS-CoV-2 IgG antibody titers after BNT162b2 vaccination among Japanese healthcare workers.

The effect of heated tobacco products (HTPs) use and moderate alcohol drinking on immunogenicity to coronavirus disease (COVID-19) vaccines remain elusive. This study aimed to examine the association of tobacco product use and alcohol consumption with anti-SARS-CoV-2 spike IgG antibody titers after the BNT162b2 vaccine. Participants were 3433 healthcare workers receiving two vaccine doses in the 4 national centers for advanced medical and research in Japan. Smoking status and alcohol consumption were assessed via a questionnaire, and anti-SARS-CoV-2 spike IgG titers were measured with chemiluminescent enzyme immunoassay using serum collected on the median of 64 days after the second vaccination. Multilevel linear regression models were used to estimate the geometric mean titers (GMT) and the ratios of means (RoM) between groups with adjustment for covariates. Compared with never-smokers (GMT = 118), IgG antibody titers were significantly lower among HTPs users (including those who also smoked cigarettes) (GMT = 105; RoM = 0.89 [95%CI: 0.78-0.99]) and exclusive cigarettes smokers (GMT = 98; RoM = 0.81 [95%CI: 0.71-0.92]). Compared with non-drinkers of alcohol (GMT = 123), alcohol drinkers consuming <1 go/day (GMT = 113; RoM = 0.93 [95%CI: 0.88-0.98]), 1-1.9 go/day (GMT = 104; RoM = 0.85 [95%CI: 0.78-0.93]), and ≥ 2 go/day (GMT = 103; RoM = 0.84 [95%CI: 0.74-0.96]) had significantly lower antibody titers (P for trend<0.01). Spline analysis showed a large reduction of antibody until around 1 go/day of alcohol consumption, and then they gradually decreased. Results suggest that in addition to conventional cigarette smoking and heavy alcohol drinking, HTPs use and moderate alcohol drinking may be predictors of lower immunological response to COVID-19 vaccine.

Food and nutrient intake in dietary supplement users: a nationwide school-based study in Japan.

Dietary supplements can be used to compensate for an inadequate diet. However, some studies indicate that supplement users consume healthier diets than non-users, although such data are lacking in Japanese children. The aim of the present study was to investigate the food and nutrient intake of dietary supplement users among school-aged children in Japan. A nationwide school dietary survey was conducted at fourteen elementary schools and thirteen junior high schools in twelve prefectures in Japan. Three-day non-consecutive semi-weighed dietary records were obtained on two weekdays and one weekend day. Analysis of covariance was performed to investigate differences in food and nutrient intake from meals consumed at school and outside of school between dietary supplement users and non-users, adjusted for socio-demographic and health-related characteristics. Of the 910 children included in this analysis, 80 (8⋅8 %) reported supplement use. Based on 3-d dietary records, dietary supplement users consumed higher mean amounts of oils and lower amounts of fruits and vegetables than non-users. In school lunches, users consumed significantly higher amounts of oils and lower amounts of protein than non-users. In meals consumed outside of school, dietary supplement users consumed significantly higher amounts of confectioneries and lower amounts of fruits and vegetables, folate, vitamin C and dietary fibre than non-users. Collectively, our findings indicate that dietary supplement users consumed less healthy diets than non-users. Additional studies are warranted to confirm these results and identify factors contributing to poorer dietary habits in supplement users.

Convenience Food Options and Adequacy of Nutrient Intake among School Children during the COVID-19 Pandemic.

The COVID-19 pandemic has caused changes in the family food environment, resulting in more families relying on convenience food options. This study aimed to investigate diet quality by convenience food options (namely instant, frozen, and take-out foods) among Japanese school children during the COVID-19 pandemic. We examined the relationship between the frequency of consumption of convenience food options and nutritional status of the school children. The participants (671 children, 10-14 years old) were chosen to form a nationally representative sample of the Japanese population. Using questionnaires completed by the participants' guardians, information was collected on the frequency of instant, frozen, and take-out food consumption. Habitual food and nutrient intake were collected using a validated food frequency questionnaire, completed by the children with help from their guardian(s). "Frequent" consumption was defined as consumption of instant, frozen, and/or take-out foods on more than 5 days per week. Using 19 nutrients and their respective dietary reference intake (DRI) values, an index was created to label each child's nutrient intake as "Adequate", "Inadequate", "Excess", or "Deficient." Compared to children with non-frequent consumption, school children with frequent instant food consumption had significantly higher rates of inadequate nutrient intake (risk ratio (RR) = 3.0 [95% CI: 1.6-5.6]) and excess nutrient intake (RR = 2.3 [95% CI: 1.3-4.2]), while school children with frequent take-out food consumption had significantly higher rates of inadequate nutrient intake (RR = 2.1 [95% CI: 1.3-3.3]). There were no significant differences for children with frequent frozen-food intake. These associations did not change when adjusting for sociodemographic factors. Our results suggest that the frequent consumption of instant or take-out foods among school children results in non-adequate nutritional intake.

25-Hydroxyvitamin D levels among 2-year-old children: findings from the Japan environment and Children's study (JECS).

BACKGROUND: The study aim was to obtain epidemiological data on vitamin D levels for the pediatric population in Japan. We assessed the prevalence of vitamin D deficiency and insufficiency in 2-year-old Japanese children using data from a large ongoing birth cohort study. METHODS: Data for analysis was obtained from the Japan Environment and Children's Study (JECS) and a Sub-Cohort Study (SCS) of JECS. We evaluated the children's serum 25(OH) D levels by 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles, and the rates of vitamin D deficiency or insufficiency. We also presented a weighted prevalence rate for vitamin D deficiency or insufficiency among all children in JECS. RESULTS: After excluding children with missing 25(OH)D2 or 25(OH)D3 data, we analyzed 4655 remaining children, of whom 24.7% (95% CI, 23.5-26.0%) had vitamin D deficiency (< 20 ng/mL), and 51.3% (95% CI, 49.8-52.7%) were at risk of vitamin D insufficiency (20-30 ng/mL). The estimated prevalence of vitamin D deficiency and insufficiency among all children in JECS were 25.4% (95% CI, 24.1-26.7%) and 50.9% (95% CI, 49.4-52.4%). Vitamin D deficiency was found in 22.9% of boys and 26.5% of girls. Median serum 25(OH) D concentrations were lower among participants measured during winter and spring than among those measured in summer and autumn. The highest rate of vitamin D deficiency was observed in Hokkaido, the northernmost prefecture of Japan. CONCLUSION: We analyzed data on serum 25(OH) D levels from a birth cohort study and found that vitamin D deficiency and insufficiency are very common among 2-year-old Japanese children. Sex, season, and latitude affect serum 25(OH) D concentrations.

Hypertensive disorders of pregnancy and risk of allergic conditions in children: Findings from the Japan Environment and Children's study (JECS).

BACKGROUND: Hypertensive disorders of pregnancy (HDP) are one of the most common medical conditions that women encounter during pregnancy. Whether or not hypertensive disorders of pregnancy (HDP) are associated with allergic conditions in the offspring is unclear. This study used data from a large Japanese birth cohort to investigate whether HDP contributes to the development of allergic conditions in the offspring at 3 years. We also assessed the effect of blood pressure at different pregnancy trimesters on children's allergies. METHODS: We obtained data from the Japan Environment and Children's Study (JECS), which included 104 062 fetal records. After data selection, we analyzed 77 505 mother-child pairs, using logistic regression models to examine the relationships between HDP or the mother's blood pressure and their children's allergic conditions. In addition, we also evaluated the effect of HDP during pregnancy on allergies with a propensity score matched dataset, using a logistic regression model that predicts the conditional probability of whether a mother belonged to the HDP or non-HDP group. RESULTS: Among the 77 505 mothers eligible for analysis, 2334 (3.0%) had HDP. Percentages of women with hypertension were 1.7% in early gestation, 1.0% in mid-gestation, and 1.6% in late gestation. After adjusting for multiple potential confounders, HDP contributed nothing to allergy development in offspring. Children born to women with hypertension were no more likely than those without to have allergic conditions at 3 years of age. The propensity score matched dataset showed similar findings. CONCLUSION: HDP and high blood pressure during pregnancy are apparently not risk factors for developing allergy in offspring. This information may help clinicians in counseling women who suffered HDP during pregnancy.

Dietary supplement use in elementary school children: a Japanese web-based survey.

BACKGROUND: A variety of dietary supplements are commercially available. However, the efficacy and safety of dietary supplement use in children are not well established. Understanding dietary supplement use is important for developing public health policy regarding dietary supplements. This study aimed to investigate the types of dietary supplements used and characteristics of dietary supplement users among Japanese elementary school children. METHOD: We conducted a cross-sectional web-based questionnaire study. Dietary supplement use, socio-demographics, and health-related behaviors were assessed through mother-reported questionnaire. Types of dietary supplements were identified based on ingredient using product barcodes and brand names. Multivariate logistic regression analysis was conducted to investigate the socio-demographics and health-related behaviors associated with supplement use. RESULTS: Among 4933 children, 333 (6.8%) were identified as dietary supplement users. The most common supplement was amino acids or protein (1.4%), followed by n-3 fatty acids or fish oil (1.0%), probiotics (1.0%), multivitamins (0.9%), multivitamin-minerals (0.8%), and botanicals (0.8%). Overall, any dietary supplement use was significantly associated with the highest frequency of sports participation (odds ratio [OR], 2.58; 95% confidence interval [CI], 1.65-4.02), highest household income (OR, 1.87; 95% CI, 1.13-3.10), highest maternal educational level (OR, 1.82; 95% CI, 1.31-2.52), and male sex (OR, 1.38; 95% CI, 1.09-1.75). The highest frequency of sports participation was significantly associated with higher odds of use of amino acids or protein (OR, 6.06; 95% CI, 1.78-20.6) and multivitamins (OR, 3.56; 95% CI, 1.11-11.5), compared to the lowest frequency of sports participation. CONCLUSION: This study showed that Japanese children primarily use non-vitamin, non-mineral supplements. Non-vitamin, non-mineral supplements should thus be included in future studies aimed at monitoring dietary supplement use. We also found that dietary supplement use in children was associated with sports participation. Guidelines for dietary supplement use for children, in particular sport participants, are needed.

Association of Hemoglobin and Hematocrit Levels during Pregnancy and Maternal Dietary Iron Intake with Allergic Diseases in Children: The Japan Environment and Children's Study (JECS).

Few epidemiologic studies have examined the role of maternal iron status in allergic diseases in offspring and findings have been inconsistent. We used a large birth cohort in Japan to explore the association of the markers for maternal iron status (maternal hemoglobin, hematocrit and dietary iron intake during pregnancy) with allergy development in offspring during early childhood. We analyzed information on children age 0-3 years from the Japan Environment and Children's Study (JECS). We used logistic models and generalized estimating equation models to evaluate the effect of maternal hemoglobin and hematocrit levels and dietary iron intake on allergies in children. Models were also fitted with propensity score-matched datasets. Data were collected for a total of 91,247 mother-child pairs. The prevalence (95% confidence interval) of low hemoglobin and hematocrit was 14.0% (13.7-14.2%) and 12.5% (12.3-12.8%), respectively. After adjusting confounders, low hemoglobin and hematocrit during pregnancy were not associated with childhood allergic outcomes. Findings from models with propensity score-matched datasets also indicated that children born to mothers with low hemoglobin or hematocrit levels during pregnancy did not have a higher risk of developing allergic conditions at 3 years old. We found no meaningful associations between low energy adjusted maternal dietary iron intake and allergies in children. In conclusion, using birth cohort data, we found no evidence supporting an association of low maternal hemoglobin, hematocrit and low dietary iron intake with allergy symptoms during early childhood. Further studies with more suitable proxy markers for blood iron status are needed.