Publications by authors named "Kenji J Tsuchiya"

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.

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Background: We aim to discover which, if any, of the subscales of internalizing and externalizing behavioral problems at age 3 are still associated with screen time (ST) at age 2 after adjusting for behavioral problems scores at age 2.

Methods: This study was conducted under the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Information was gathered prospectively, with 7207 mother-child pairs included in the analysis.

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Objective: Executive functions are important factors that affect the well-being of children with ADHD. Therefore, inclusion of a convenient assessment of executive dysfunction in diagnosis and treatment of ADHD patients is warranted. However, executive dysfunction assessment presently relies on lab-based neuropsychological tests and symptom rating scales.

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Aim: Autism spectrum disorder (ASD) is associated with abnormal lipid metabolism, such as a high total ratio of omega-6 to omega-3 in polyunsaturated fatty acids (PUFAs). PUFAs are metabolized to epoxy fatty acids by cytochrome P450 (CYP); then, dihydroxy fatty acid is produced by soluble epoxide hydrolase. This study examined the association between PUFA metabolites in the cord blood and ASD symptoms and adaptive functioning in children.

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Objectives: Motor planning is the cognitive process of planning necessary steps for achieving a purposeful movement and is specifically reflected through object manipulation. This study aimed to investigate whether fine motor skills, a surrogate of the motor planning ability of object manipulation, in early childhood are associated with later social skills, in a general-population birth cohort.

Methods: A total of 913 children, participating in the Hamamatsu Birth Cohort for Mothers and Children, were enrolled.

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Our previous study, which aimed to understand the early neurodevelopmental trajectories of children with and without neurodevelopmental disorders, identified five classes of early neurodevelopmental trajectories, categorized as high normal, normal, low normal, delayed, and markedly delayed. This investigation involved measurement using the Mullen Scale of Early Learning in a representative sample of Japanese infants followed up from the age of 0 to 2 years (Nishimura et al., 2016).

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Article Synopsis
  • Fetal growth restriction can lead to negative outcomes for children, prompting an investigation into factors like maternal age, weight, and lifestyle choices affecting small-for-gestational-age (SGA) infant rates in Japan.
  • A study involving nearly 29,000 infants analyzed various maternal conditions, revealing that pre-pregnancy underweight, insufficient weight gain during pregnancy, and ongoing smoking significantly raised the risk of SGA births.
  • The findings highlighted that improving maternal weight and health before and during pregnancy could greatly reduce the incidence of SGA infants, with specific recommendations given to prioritize changes in weight status.
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  • The study investigated the relationship between gaze fixation on the eyes and mouth in children at age 6 and the severity of autism spectrum disorder (ASD) symptoms and functioning.
  • Using an eye-tracking device, the research examined 742 participants and measured their gaze fixation during social interactions, linking these metrics to ASD outcomes.
  • Results indicated that higher gaze fixation on the eyes correlated with a lower likelihood of severe ASD symptoms, while gaze fixation on the mouth was linked to better socialization skills, emphasizing the importance of eye contact in understanding ASD.
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  • The study investigates how screen time affects different areas of child development (communication, motor skills, problem-solving, and social skills) in young children, specifically at ages 2 and 4 years.
  • Conducted in Japan with a large sample of over 7,000 mother-child pairs, the study categorizes screen time exposure into four groups based on daily hours of use.
  • Results indicate that higher screen time, particularly exceeding 2 hours per day, is associated with an increased risk of developmental delays in various domains, notably in communication and fine motor skills.
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Whether longer screen time in infancy increases risk of neurodevelopmental disorders (NDDs) such as autism spectrum disorder (ASD) and ADHD has long been debated, but no causal relationship between the two remains has been established. Using ongoing longitudinal cohort data, we found that in children 24 to 40 months of age, the genetic risk of ASD was associated with longer screen time and that of ADHD with an increase in screen time over time. These data suggest that prolonged screen time may not be a cause of the genetic risk for NDD, but an early sign of NDDs.

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Introduction: Neuroimaging studies on attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) have demonstrated differences in extensive brain structure, activity and network. However, there remains heterogeneity and inconsistency across these findings, presumably because of the diversity of the disorders themselves, small sample sizes, and site and parameter differences in MRI scanners, and their overall pathogenesis remains unclear. To address these gaps in the literature, we will apply the travelling-subject approach to correct site differences in MRI scanners and clarify brain structure and network characteristics of children with ADHD and ASD using large samples collected in a multi-centre collaboration.

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Objective: Genetic and environmental factors contribute to the development of Attention Deficit/Hyperactivity Disorder (ADHD). Perinatal inflammation is one of the promising environmental risk factors for ADHD, but the relationship between the genetic risk for ADHD and perinatal inflammation requires further examination.

Methods: A possible gene-environmental interaction between perinatal inflammation and ADHD polygenic risk score (ADHD-PRS) on ADHD symptoms was investigated in children aged 8-9 from the Hamamatsu Birth Cohort for Mothers and Children (N = 531).

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  • This study investigates developmental delays among Nepalese children aged 3-4 years, focusing on socioeconomic status and maternal education disparities.
  • The research reveals a national prevalence of suspected developmental delays (SDD) at 34.8%, with higher rates in rural and specific provinces, indicating significant inequalities based on income and education levels.
  • The findings suggest that children from poorer households and those with less-educated mothers are much more likely to experience developmental delays, highlighting the need for targeted policies and programs to address these issues.
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Subnational evidence on the level of inequality in receiving complementary feeding practice among Bangladeshi children is lacking. This study estimated inequality in the minimum acceptable diet (MAD) among Bangladeshi children aged 6-23 months, and identified risk factors for and developed projections of the MAD up to 2030. Data from the Bangladesh Demographic and Health Survey 2017-2018 were used in this cross-sectional study.

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Importance: Whether the association between higher screen time in infancy and later suboptimal neurodevelopment can be mitigated by frequency of outdoor play is unknown.

Objective: To investigate whether higher screen time at age 2 years is associated with neurodevelopmental outcomes at age 4 years and whether this association is mediated by frequency of outdoor play at age 2 years 8 months.

Design, Setting, And Participants: Participants were a subsample of the Hamamatsu Birth Cohort Study for Mothers and Children (HBC Study, N = 1258).

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  • The study investigates early signs of autism spectrum disorders (ASD) in females, focusing on cognitive, motor functions, and adaptive behaviors in children with varying levels of autistic traits.
  • Researchers analyzed data from 824 children over several years, identifying two distinct trajectories: males showed a temporary decline in language skills by age 2, while females did not display notable symptoms until after age 3.
  • The findings suggest that males and females with high autistic traits might exhibit different developmental patterns, highlighting the need for tailored diagnostic criteria that consider these sex differences.
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The ability of humans to use rules for organizing action demands a high level of executive control. Situational complexity mediates rule selection, from the adoption of a given rule to the selection of complex rules to achieve an appropriate response. Several rules have been proposed to be superordinate to human behavior in a cognitive hierarchy and mediated by different brain regions.

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Background: Low-birth-weight infants exhibit a high risk for postnatal morbidity. Cytochrome P450 (CYP) and epoxide hydrolase (EH) are involved in the metabolism of factors responsible for low-birth-weight in infants. Both CYPs and EHs have high substrate specificity and are involved in polyunsaturated fatty acid (PUFA) metabolism.

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Background: Recent literature suggest the effect of maternal smoking on risk of hypertensive disorders in pregnancy (HDP) and preeclampsia may differ by ethnicity; however, studies on Asians are limited.

Methods: We investigated the association of maternal smoking with HDP and preeclampsia using a common analysis protocol to analyze the association in six birth cohorts participating in a Japanese consortium of birth cohorts (JBiCC). Results were compared with-published results from cohorts not included in this consortium, and, where possible, we produced a meta-analysis including these studies.

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Little is known about the trajectory patterns and sex differences in adaptive behaviors in the general population. We examined the trajectory classes of adaptive behaviors using a representative sample and examined whether the class structure and trajectory patterns differed between females and males. We further explored sex differences in neurodevelopmental traits in each latent class.

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Background: Prenatal exposure to per- and polyfluoroalkyl substances (PFAS) has been shown to affect offspring behaviors in laboratory animals. Several epidemiological studies investigated associations between prenatal PFAS exposure and child neurodevelopment, but results were inconclusive. We examined associations between cord blood concentrations of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) and cognitive development in children from 4 to 40 months of age.

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It is unclear whether neurodevelopmental progress from infancy to early childhood remains stable. Moreover, little is known about the risk factors, if any, affecting neurodevelopmental descending transition patterns and the relationship between these patterns and later childhood adaptive behaviours. We used data of 875 children from the Hamamatsu Birth Cohort Study in Japan.

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