Koshu GRoup Activity, Active Play and Exercise (GRAPE) Study: A Cluster Randomised Controlled Trial Protocol of a School-Based Intervention among Japanese Children.

School-based programmes need to be effective, easy for all, easy to perform within a short duration, and inexpensive. However, no studies have reported whether voluntarily and very short-time active play programmes contribute to improved health outcomes. This study aims to describe the GRoup activity, Active Play and Exercise (GRAPE) cluster randomised controlled trial that examined whether active play interventions of very short durations contribute to increasing physical activity (PA) and bone mass among school-aged children.

Association between Maternal Smoking during Pregnancy and Missing Teeth in Adolescents.

Tooth agenesis and disturbance of tooth eruption is the most prevalent oral defect, and is possibly caused by the interaction of genetic and environmental factors. We hypothesized that prenatal factors may affect tooth development. The objective of this study was to examine whether smoking during pregnancy was associated with missing teeth in the offspring during adolescence.

Association of objectively measured physical activity and sedentary behavior with bone stiffness in peripubertal children.

Introduction: Physical activity (PA) is a key factor of bone mass acquisition in peripubertal children. Sedentary behavior (SB) has been shown to influence bone outcomes. This study aimed to examine the association between objectively measured PA and SB and bone stiffness in Japanese children.

Problematic Internet use and its associations with health-related symptoms and lifestyle habits among rural Japanese adolescents.

Aim: There have been concerns about the increase in problematic Internet use (PIU) and its impact on lifestyle habits and health-related symptoms, given the rapid spread of smartphones. This study aimed to clarify PIU prevalence over 3 years in the same area and investigate lifestyle and health-related factors related to PIU among junior high-school students in Japan.

Methods: Each year during 2014-2016, a survey was conducted with junior high-school students from a rural area of Japan (2014, n = 979; 2015, n = 968; 2016, n = 940).

Sex Differences in Birth Weight and Physical Activity in Japanese Schoolchildren.

Background: Lower birth weight (BW) is associated with increased chronic disease risk later in life. Previous studies suggest that this may be mediated principally via physical activity (PA). However, the association between BW and PA in children has not been clarified.

Evaluation of the associations between changes in intraocular pressure and metabolic syndrome parameters: a retrospective cohort study in Japan.

Objective: The contributions of highly correlated cardiovascular risk factors to intraocular pressure (IOP) are not clear due to underlying confounding problems. The present study aimed to determine which metabolic syndrome parameters contribute to elevating IOP and to what extent.

Design: Retrospective cohort study.

Association Between Maternal Smoking During Pregnancy and Birth Weight: An Appropriately Adjusted Model From the Japan Environment and Children's Study.

Background: There has been no large nationwide population-based study to examine the effects of maternal smoking status during pregnancy on birth weight that simultaneously controlled for clinical information, socioeconomic status, and maternal weight. Thus, this study aimed to determine the association between maternal smoking status during pregnancy and birth weight, while taking these confounding factors into consideration.

Methods: This study examined the first-year fixed dataset from a large nationwide birth cohort study that commenced in 2011.

Pubertal timing and a family history of hypertension: Prospective cohort study.

Background: Hypertension is heritable, and genetic factors likely exert an effect from childhood. Puberty is an early life milestone that may relate to adult hypertension. Therefore, this study examined whether there is an association between a family history of hypertension and pubertal growth.

Do body mass index trajectories affect the risk of type 2 diabetes? A case-control study.

Background: Although obesity is a well-studied risk factor for diabetes, there remains an interest in whether "increasing body mass index (BMI)," "high BMI per se," or both are the actual risk factors for diabetes. The present study aimed to retrospectively compare BMI trajectories of individuals with and without diabetes in a case-control design and to assess whether increasing BMI alone would be a risk factor.

Methods: Using comprehensive health check-up data measured over ten years, we conducted a case-control study and graphically drew the trajectories of BMIs among diabetic patients and healthy subjects, based on coefficients in fitted linear mixed-effects models.

Childhood growth trajectories according to combinations of pregestational weight status and maternal smoking during pregnancy: a multilevel analysis.

Pregestational weight status and maternal smoking during pregnancy are significantly associated with fetal and childhood growth. However, few studies have examined associations between childhood growth and combinations of these factors using multilevel analysis. This study aimed to describe differences in childhood growth trajectories according to these combinations, using data from a prospective cohort study in Japan.

Maternal smoking during pregnancy and growth in infancy: a covariance structure analysis.

Background: Smoking during pregnancy is related to fetal constraint and accelerated postnatal growth. However, the pathways between these factors have not been clarified. Pathway analyses that link these factors can help us better understand the mechanisms involved in this association.

Association between malocclusion and headache among 12- to 15-year-old adolescents: a population-based study.

Objectives: Headaches are a common problem among adolescents, and malocclusion is a possible risk factor. The purpose of this study was to investigate the association between malocclusion and headache among Japanese adolescents aged 12-15 years using a population-based sample.

Methods: A total of 938 adolescents (94.

Adolescent growth in overweight and non-overweight children in Japan: a multilevel analysis.

Background: A trend towards earlier pubertal growth has been identified along with an increase in childhood obesity rates. The study aimed to identify the differences in growth patterns during adolescence between overweight/obese and non-overweight children in Japan.

Methods: The participants were children from a prospective cohort study called Project Koshu, who were born between 1991 and 1998, in Japan.

Effect of maternal smoking cessation before and during early pregnancy on fetal and childhood growth.

Background: Maternal smoking during pregnancy is a major cause of intrauterine growth restriction and childhood obesity, but only a few studies have examined the association of smoking cessation before and during pregnancy with fetal and childhood growth. We examined this association in a prospective cohort study in Japan.

Methods: Our study included children born between 1991 and 2006 and their mothers.

Multilevel longitudinal analysis of sex differences in height gain and growth rate changes in Japanese school-aged children.

Background: Determining standard pubertal growth patterns using longitudinal anthropometric measures is important in growth assessment. We used an appropriate repeated-measurements method to identify height growth patterns in Japanese school-aged girls and boys.

Methods: The participants were children born during the period from 1991 through 1999 who had entered the first grade of elementary school in the Enzan district in Koshu City, Japan.

Differences in the effect of maternal smoking during pregnancy for childhood overweight before and after 5 years of age.

Aim: This study aimed to clarify the association between maternal smoking during pregnancy and childhood overweight during different periods using two cohort studies from the same population: the birth cohort (the 1st cohort) and the non-overweight children at 5 years of age cohort (the 2nd cohort) by sex.

Material And Methods: The study population comprised children born between 1 April 1991 and 31 March 1999 in Koshu City, Yamanashi Prefecture, Japan, and their mothers. The dependent variables were diagnosis of overweight in each cohort.

Developmental trajectories of body mass index among Japanese children and impact of maternal factors during pregnancy.

Background: The aims of this study were to 1) determine the distinct patterns of body mass index (BMI) trajectories in Japanese children, and 2) elucidate the maternal factors during pregnancy, which contribute to the determination of those patterns.

Methodology/principal Findings: All of the children (1,644 individuals) born in Koshu City, Japan, between 1991 and 1998 were followed in a longitudinal study exploring the subjects' BMI. The BMI was calculated 11 times for each child between birth and 12 years of age.

[A survival analysis approach to assess the association between maternal smoking during pregnancy and childhood obesity].

Objectives: It has been suggested that maternal smoking during pregnancy has an effect on childhood obesity. We previously clarified the association between maternal lifestyle habits practiced during pregnancy, including smoking, and childhood obesity and overweight at 9-10 years of age. In this study, we aimed to demonstrate this association through survival analysis.

Maternal smoking during pregnancy and childhood growth trajectory: a random effects regression analysis.

Background: Although maternal smoking during pregnancy has been reported to have an effect on childhood overweight/obesity, the impact of maternal smoking on the trajectory of the body mass of their offspring is not very clear. Previously, we investigated this effect by using a fixed-effect model. However, this analysis was limited because it rounded and categorized the age of the children.

Maternal psychosocial factors determining the concentrations of transforming growth factor-beta in breast milk.

Background: Cytokines in breast milk may play crucial roles in the beneficial effects of breastfeeding in protecting against allergic and infectious diseases in infants. In particular, breast milk-borne transforming growth factor-beta (TGF-β) has an important potential role in developing the mucosal immune system in infants. However, little is known about what factors influence TGF-β expression in human milk.

Recent trends in the prevalence of and factors associated with maternal smoking during pregnancy in Japan.

Aim: To compare the prevalence of maternal smoking during pregnancy and the correlations between maternal smoking and other maternal lifestyle or pregnancy factors between the years 1996-2001 and 2001-2006.

Methods: The participants were pregnant women who responded to questionnaires while registering their pregnancies between 1 April 1996 and 31 March 2001 (Group 1), and between 1 April 2001 and 31 March 2006 (Group 2). The odds ratios were calculated with a 95% confidence interval for maternal smoking during early pregnancy by using a logistic multivariate regression analysis based on maternal factors.

The association between maternal smoking during pregnancy and childhood obesity persists to the age of 9-10 years.

Background: We previously reported that a number of factors related to maternal lifestyle during early pregnancy, including smoking, are associated with childhood obesity at 5 years of age. In the present study, we investigated whether the association with maternal smoking persisted to the age of 9-10 years.

Methods: The study population comprised children born between April 1, 1991 and March 31, 1999, and their mothers.

Confirmatory factor analysis of the Child Feeding Questionnaire (CFQ) in Japanese elementary school children.

The validity of the Child Feeding Questionnaire (CFQ), one of the measures used to assess parental child feeding practices and attitudes, has been confirmed in American populations. We used confirmatory factor analysis to test the validity and factor structure of the translated version of the CFQ among parents of Japanese elementary school children. The structural equation modelling software Linear Structural Relationships (LISREL) was applied to explore the validity of the translated CFQ to examine child feeding behaviours and attitudes in a sample of 920 parents of Japanese elementary schoolchildren from schools in Koshu City in Yamanashi prefecture (grades 4-6), Japan.

Is maternal smoking during early pregnancy a risk factor for all low birth weight infants?

Background: Low birth weight (LBW) infants do not form a homogeneous group; LBW can be caused by prematurity or poor fetal growth manifesting as small for gestational age (SGA) infants or intrauterine growth retardation. We aimed to clarify the relationship of maternal smoking with both SGA and preterm LBW infants.

Methods: The study population comprised pregnant women who registered at the Koshu City between January 1, 1995, and December 31, 2000, and their children.