Association between prenatal tobacco exposure and attention-deficit/hyperactivity disorder related characteristics at 6 and 8 years: a birth cohort in Japan.

Objectives: To examine the association between maternal plasma cotinine concentrations during pregnancy and attention-deficit/hyperactivity disorder (ADHD) related characteristics in children.

Design: Prospective birth cohort study from the Hokkaido Study on Environment and Children's Health.

Setting: Hokkaido, Japan.

Organophosphate flame retardants associated with increased oxidative stress biomarkers and elevated FeNO levels in general population of children: The Hokkaido study.

Our previous study found that exposure to higher organophosphate flame retardants (PFRs) was associated with increased prevalence of wheeze and type 2 inflammation among school-aged children. It remains unclear whether PFR exposure elevates oxidative stress in these general pediatric population, thereby potentially contributing to the development of allergic diseases. This study examined the associations between individual and mixture exposure to PFRs and oxidative stress in children aged 9-12 years (n = 423).

Association between small for gestational age and motor coordination difficulties in children aged 5-6 years: Insights from the Hokkaido Study on Environment and Children's Health.

Background: Developmental coordination disorder (DCD) presents motor skill delays in early childhood and has been associated with later maladaptation, necessitating early intervention. However, research on the potential risk factors, particularly in preschool-aged children, remains scarce.

Aims: We aimed to explore the association between small for gestational age (SGA) and other factors and motor coordination problems in 5-6-year-olds from the Hokkaido Study on Environment and Children's Health Cohort.

Impact of wheat sensitization on wheeze and T2 phenotypes in general population of children.

Background: The association between sensitization to specific aeroallergens and outcomes in patients with asthma is well researched; however, the association between childhood-onset wheeze/asthma and sensitization to various aeroallergens and food allergens in the general pediatric population remains poorly understood.

Objective: We sought to investigate the association between sensitization to common aeroallergens and food allergens with wheeze and type 2 (T2) inflammation in the general pediatric population.

Methods: Specific IgEs against 9 aeroallergens and 4 food allergens were measured in the prospective Hokkaido birth cohort of 428 school-age children (age ∼10 years).

Determination of plasma lysophosphatidylethanolamines (lyso-PE) by LC-MS/MS revealed a possible relation between obesity and lyso-PE in Japanese preadolescent children: The Hokkaido study.

Background: Lysophosphatidylethanolamines (lyso-PEs) are the partial hydrolysis products of phosphatidylethanolamine. Although lyso-PEs are important biomarkers in various diseases, their determination is limited by the lack of simple and efficient quantification methods. This study aims to develop an improved quantitative method for the determination of lyso-PEs and its application to an epidemiological study.

Quantitative determination of plasma cholesteryl ester levels in Japanese preadolescents from the Hokkaido study using liquid chromatography/tandem mass spectrometry.

Cholesteryl esters (CE) are sterols comprising various fatty acyl chains attached to a cholesterol hydroxyl moiety. CEs are often considered plasma biomarkers of liver function; however, their absolute concentrations in the plasma of Japanese preadolescents have not been well explored. This study aimed to determine the plasma CE levels in Japanese preadolescents of different sexes, ages, and body weights living in Hokkaido, Japan using targeted liquid chromatography/tandem mass spectrometry.

Association between maternal multimorbidity and neurodevelopment of offspring: a prospective birth cohort study from the Japan Environment and Children's Study.

Objectives: To investigate the association between multimorbidity during pregnancy and neurodevelopmental delay in offspring using data from a Japanese nationwide birth cohort study.

Design: This study was a prospective birth cohort study.

Setting: This study population included 104 059 fetal records who participated in The Japan Environment and Children's Study from 2011 to 2014.

Link between Wi-Fi, cordless devices, mobile phone usage patterns, and behavioral problems among Japanese children: A prospective cohort study.

Background: With the recent advent of technology, it is important to confirm the health and safety of the youth. This study aimed to prospectively evaluate the relationship between Wi-Fi, cordless phones, and mobile phone usage patterns and behavioral problems.

Methods: This study involved 2465 children aged 8-17 years from the Hokkaido Study on Environment and Children's Health from October 2020 to January 2021, with a follow-up from September 2021 to March 2022.

The association between flooring materials and childhood asthma: A prospective birth cohort in the Japan Environment and Children's Study.

Background: Childhood asthma is known to be affected by a range of factors, including conditions in the indoor environment. While flooring material influences indoor air conditions, the potential association between flooring materials and childhood asthma remains poorly understood in Japan.

Objective: The present study aims to assess the association between childhood asthma incidence and the primary flooring material with the ongoing prospective nationwide birth cohort data of the Japan Environment and Children's Study (JECS).

Heavy metals and trace elements in maternal blood and prevalence of congenital limb abnormalities among newborns: the Japan Environment and Children's Study.

Background: Heavy metals such as lead (Pb) and cadmium (Cd) have been associated with adverse pregnancy and developmental outcomes, including congenital abnormalities. This study investigated the association between exposure to heavy metals and trace elements during fetal life and congenital limb abnormalities in infants.

Methods: This study is based on a prospective ongoing nationwide birth cohort from the Japan Environment and Children's Study (JECS).

Alterations in plasma short-chain fatty acids in preadolescence children: The Hokkaido study.

The purpose of this study is to explore the plasma short-chain fatty acid (SCFA) concentrations in 9-12-year-old Japanese children collected in the Hokkaido study, focusing on how factors such as age, sex, and body mass index (BMI) correlate with these levels. The Hokkaido Study on Children's Health is an ongoing longitudinal study since 2002, encompassing 20,926 pregnant women in Hokkaido Prefecture, Japan, between 2003 and 2012. We contacted 1881 children aged 9-12 born between April 2006 and January 2010, and 342 non-fasting plasma samples (boys = 181, girls = 161) were obtained from this cohort, alongside assessments of their height and weight.

Hokkaido birth cohort study in Japan on the growth trajectory of children born with low birth weight until 7 years of age.

Background: Low birth weight (LBW) is a significant global health concern with potential health risks and developmental implications for infants. Catch-up growth, an accelerated growth following an inhibition period, may partially compensate for growth deficits in LBW children.

Aims: This study investigated the prevalence of LBW and catch-up growth in height, weight, and body mass index (BMI) among LBW children in Japan, identified factors associated with LBW, and explored the potential for catch-up growth at different ages up to seven years.

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.

Exposure to organophosphate flame retardants and plasticizers is positively associated with wheeze and FeNO and eosinophil levels among school-aged children: The Hokkaido study.

Exposure to organophosphate flame retardants and plasticizers (PFRs) increases the risk of asthma and allergies. However, little is known about its association with type 2 inflammation (T2) biomarkers used in the management of allergies. The study investigated associations among urinary PFR metabolite concentrations, allergic symptoms, and T2 biomarkers.