Toyama Birth Cohort Study Research Articles

Short-term and long-term associations with sleep onset latency in school children in Japan.

This study aims to examine the relationships between sleep onset latency and multiple sleep-related factors of seventh and tenth graders during the transition from childhood to adolescence. Regarding sleep onset latency, we examined the short-term associations in Phase IV (2002) and long-term associations in Phase V (2005) of the Toyama Birth Cohort Study. In total, 4,673 boys and 4,694 girls in Phase IV and 2,969 boys and 3,108 girls in Phase V answered the questionnaire items regarding sleep, physical and mental health, lifestyle, socioeconomic status, and family and school factors. Considering sleep onset latency as the outcome and 13 sleep-related factors as independent variables, we calculated the odds ratio using binary logistic regression. The longitudinal study was conducted with 1,703 boys and 1,919 girls whose sleep onset latency was within 30 min in Phase IV. The following factors were found to be related to longer sleep onset latency in the short term: sleep duration, physical activity, game time, and self-esteem in boys and sleep duration, bedroom environment, game time, abdominal pain, long-standing illness, onset of puberty, mental health difficulties, and school avoidance feelings in girls. Regarding its long-term effects, having a single parent and self-esteem in boys and breakfast, game time, long-standing illness, obesity, onset of puberty, and school avoidance feelings in girls were associated with longer sleep onset latency. Education of adolescent health and sleep hygiene at home and school should include both short-term and long-term associations between sleep and a healthy lifestyle by gender.

Lifestyle, psychological stress, and incidence of adolescent constipation: results from the Toyama birth cohort study

BackgroundWe aimed to clarify the predisposing factors for adolescent constipation in a longitudinal study, because while factors associated with childhood constipation have been reported, prospective studies on the incidence of constipation are lacking.MethodsWe enrolled 5540 adolescents aged 12 to 13 years from the Toyama Birth Cohort Study—a community-based prospective study examining children’s health. The incidence of constipation, defined as bowel movement frequency of less than once every 2 days, was surveyed during the three-year period from baseline (grade 4) to follow-up (grade 7). Multivariate logistic regression analyses were performed to explore the association between the incidence of adolescent constipation and their lifestyle variables.ResultsA total of 261 adolescents (4.7%) developed constipation during the three-year period. Female sex (odds ratio [OR] = 2.62,) overweight (OR = 0.60), and infrequent intake of fruits (OR = 1.50) at baseline were associated with the incidence of constipation. Furthermore, factors related to lifestyle changes and psychological status such as skipping breakfast (OR = 1.73), becoming physically inactive (OR = 1.55), and being persistently irritated (OR = 1.80) were significantly associated with the incidence of constipation.ConclusionOur prospective study demonstrated that female sex, insufficient fruit intake, and deteriorating lifestyles such as skipping breakfast and becoming inactive during the 3-year period were associated with the incidence of adolescent constipation. Beyond anecdotal, maintaining a healthy lifestyle is recommended to reduce the incidence of adolescent constipation.

The Relationship Between Quality of Life and Pubertal Timing in Adolescence: The Toyama Birth Cohort Study, Japan

PurposeAlthough pubertal timing is gradually becoming earlier in Japan, support as for physical and mental health among children experiencing earlier puberty than their peers is inadequate. To better understand health and life satisfaction in seventh grade students (age 12–13 years), examination of relationships between health outcomes and pubertal timing, socioeconomic status, and lifestyle factors is necessary. MethodsParticipants of the Toyama Birth Cohort Study (4,752 males and 4,740 females) answered questions regarding school year of onset of voice break for boys and menarche for girls, sleep quality, mental health difficulties, overall health, quality of life (QOL), and lifestyle. Relationship between health outcomes and pubertal timing was examined using binary logistic regression analysis. ResultsEarlier pubertal timing was associated with four health-related outcomes. For poor sleep quality, the adjusted odds ratio (OR) of fourth grade males and crude OR of fifth grade females were statistically significant. Regarding mental health difficulties, the crude OR of fifth grade males and adjusted OR of fourth, fifth, and sixth grade females were statistically significant. Associations between poor overall health and fourth grade males and fourth or fifth grade females were observed. For poor QOL, the adjusted OR of fourth grade males and females was statistically significant. ConclusionsRelationships between earlier pubertal timing and poor sleep quality, mental health difficulties, poor physical health, and poor QOL were observed. To improve children's quality of life, support from teachers and school doctors and nurses is needed—especially for children with earlier pubertal timing.

Psychological Stress, Family Environment, and Constipation in Japanese Children: The Toyama Birth Cohort Study.

BackgroundChildhood constipation is prevalent and negatively affects quality of life. Although psychological stress and family environment have been identified as risk factors, few epidemiological studies have examined this issue. We aimed to clarify associations of psychological stress and family environment with childhood constipation in a large-scale epidemiological study.MethodsIn total, 7,998 children aged 9–10 years from the Toyama Birth Cohort Study completed questionnaires. Constipation was defined as bowel movements “less frequently than once every 2 days”. Children’s lifestyles, including food frequency, psychological stress, family environment, frequency of irritability, unwillingness to attend school, and frequency of interaction with their parents, were analyzed via multivariate logistic regression analysis. Parental employment status and presence at dinner were also examined.ResultsIn total, 312 children (3.9%) experienced constipation. Girls were more likely to experience constipation than boys (5.1% vs 2.8%). In addition, constipation was significantly associated with girl (odds ratio [OR] 1.97; 95% confidence interval [CI], 1.55–2.51), physical inactivity (OR 1.41; 95% CI, 1.01–1.95), overweight (OR 0.58; 95% CI, 0.40–0.85), infrequent fruit (OR 1.94; 95% CI, 1.42–2.66) and vegetable (OR 1.46; 95% CI, 1.03–2.05) consumption, frequent irritability (OR 1.76; 95% CI, 1.24–2.50), unwillingness to attend school (OR 1.66; 95% CI, 1.13–2.43), and infrequent interaction with parents (OR 1.48; 95% CI, 1.06–2.07). Children whose parents were absent at dinner were more likely to experience constipation compared to those whose parents were present at dinner; however, this differences were not statistically significant.ConclusionPsychological stress and infrequent interaction with parents were as strongly associated with childhood constipation as conventional risk factors. Psychological stress and family environment should be more prioritized in caring childhood constipation.

Mo1551 – Lifestyle, Psychological Stress, and Incidence of Constipation Among Japanese Adolescents: Toyama Birth Cohort Study

Mo1551 – Lifestyle, Psychological Stress, and Incidence of Constipation Among Japanese Adolescents: Toyama Birth Cohort Study

Lifestyle and overall health in high school children: Results from the Toyama birth cohort study, Japan

The aim of this study was to investigate the relationship between lifestyle and overall health in high school children. Subjects were from the Toyama Birth Cohort Study, a prospective, longitudinal study of children born between 1989 and 1990, and who lived in Toyama Prefecture, Japan, at the time of the survey. This investigation used data from phase 5 of the Birth Cohort Study, which was conducted in 2005, when the children were in high school. Participants included 4,966 children (2,449 boys and 2,517 girls) aged 15-16years old. A questionnaire was designed to measure lifestyle factors such as eating habits, physical activity, sedentary behavior, and sleeping pattern. A question from a validated Japanese version of the Dartmouth Primary Care Cooperative Information Project was used to evaluate overall health in children. Logistic regression analysis was used to determine if lifestyle factors are associated with overall health in high school children. Boys who skipped breakfast and had short night-time sleep duration (≤6h per night) were more likely to have poor health status. Girls who skipped breakfast, and had night-time eating patterns, personal computer use >4h per day, and short night-time sleep duration (≤6h/night) were more likely to have poor health status. Undesirable lifestyle was associated with poor health status in high school boys and girls. Further understanding of these relationships is needed to facilitate the development of interventions that will help children with poor health status.

Lifestyle and bowel movements in school children: Results from the Toyama Birth Cohort Study.

Constipation is a prevalent health disorder. There have been few epidemiological surveys on constipation in Japanese children. The aim of this study was to evaluate the prevalence of non-daily bowel movements (BM) and irregular BM among children and to identify modifiable lifestyle factors relevant to bowel habits. Subjects were from the Toyama Birth Cohort Study in Japan. A total of 7762 children aged 9-10 years were investigated via questionnaire in 1999. We evaluated bowel habit and the relationship between lifestyle and BM. Non-daily BM and totally irregular BM were defined as dependent variables in the present study. Non-daily BM were reported by 21.8% of boys and by 31.6% of girls, while 10.6% of boys and 18.3% of girls had totally irregular BM. Non-daily BM were significantly associated with skipping breakfast (OR, 1.23), slow eating (OR, 1.13), physical inactivity (OR, 1.50) and late wake up (OR, 1.29). Totally irregular BM were significantly correlated with skipping breakfast (OR, 1.30), slow eating (OR, 1.41), physical inactivity (OR, 1.27), long TV viewing (OR, 1.52), late bedtime (OR, 1.43), and short sleep duration (OR, 1.33). More girls had non-daily and totally irregular BM than boys, and these sex differences were not reduced after adjusting for lifestyle variables. Non-daily and totally irregular BM are common in children, and there are many relevant lifestyle factors. Establishing regular lifestyle habits may lessen constipation.

Outdoor physical activity and its relation with self-reported health in Japanese children: results from the Toyama birth cohort study.

Few studies have examined trends in engagement in outdoor physical activity as children grow and whether changes in physical activity at different ages affect children's health. This study determined the preference for and frequency of physical activity among Japanese children from ages 6 to 12 years and investigated the effect of physical activity and of change in physical activity on children's self-reported health. Data were from the prospective, longitudinal Toyama Birth Cohort Study, a total of 5238 children were followed at their age of 12 years. Preference for and frequency of outdoor physical activity were from the self-administered questionnaire. Self-reported health was from the Japanese version of Dartmouth Primary Care Co-operative project charts. Reporting liking and participating in outdoor physical activity at both ages 6 and 12 years were associated with higher likelihood of good self-reported health (Odds ratio 1.24 [95% CI: 1.03-1.50] for liking activity and OR = 1.27[1.08, 1.50] for participating in activity) compared with those who did not like or participate in this at only one or at neither age, after adjustment for lifestyle factors and body pain. The adjusted OR was 1.23 (95% CI: 0.97-1.56) for girls whose preference for liking outdoor physical activity was not changed at both ages compared with those whose preference changed. The OR was 1.47 (95% CI: 1.14-1.89) for boys who persisted in participating in the outdoor physical activity than those who did not persist. There is an association between a persistent expression of liking outdoor physical activity and self- reported health.

Association among number, order and type of siblings and adolescent mental health at age 12.

Although the sibling relationship is a unique one, the effects of the number and type of siblings on mental health among adolescents have not been reported. Japanese children (total, 9276; boys, 4654; girls, 4622), all 12 years old, and from the Japanese Toyama Birth Cohort Study, were followed up until 2002. Subject self-reported mental health was obtained from the Japanese version of the Dartmouth Primary Care Co-operative Project (COOP) charts. The associations between number and type of siblings and self-reported mental health were examined. There was a significant difference in mental health between different sibling pairs, with brother pairs and brother/sister pairs having a positive effect on adolescent mental health, compared with those in sister pairs. Girls with brothers had better self-reported mental health than those without. The adjusted OR of good mental health was 1.44 (95%CI:1.00-2.08) for those with an older brother and 1.67 (95%CI: 1.17-2.38) for those with a younger brother compared with those without. Boys with a younger sister had a higher OR of good self-reported health than those without (OR, 1.62; 95%CI: 1.08-2.43). Children with siblings had better mental health status than those without, which has practical implications for Asian countries and worldwide considering the declining fertility.

Family history of hypertension and the risk of overweight in Japanese children: results from the Toyama Birth Cohort Study.

BackgroundFamily history can be a useful screening tool in the assessment and management of the risk for noncommunicable disease. However, no data have yet been reported on family history of hypertension and its effect on children’s overweight.MethodsA total of 7249 Japanese children enrolled in the Toyama Birth Cohort Study were followed until 2002 (mean age: 12.3 years). Family history of hypertension was ascertained by asking children’s parents whether children’s biological parents or grandparents had doctor-diagnosed hypertension. Child overweight was defined according to international criteria for age- and sex-specific body mass index.ResultsThe prevalence of child overweight at age 12 was 21.7% for males and 15.9% for females. After adjusting for family structure, parental employment status, and lifestyle factors, we found that a maternal family history of hypertension was positively associated with the risk of child overweight at age 12 (adjusted odds ratio [OR] 1.21, 95% confidence interval [CI] 1.04–1.39). The adjusted OR increased from 1.16 (95% CI 0.99–1.35) to 1.42 (95% CI 1.04–1.92) to 4.75 (95% CI 1.35–16.69) as the number of family members with hypertension increased from 1 to 2 to 3, respectively. There was no significant difference in the prevalence of overweight between children with a paternal family history of hypertension and those without.ConclusionsA maternal family history of hypertension was positively associated with the risk of overweight in children at age 12.

Mother employment status and nutritional patterns in Japanese junior high schoolchildren

To investigate associations between mothers' employment (full, part time and no employment) and nutrition habits (regularity of breakfast, snack, dinner, meal speed and portion size) in a sample of Japanese junior high schoolchildren, 12-13 years of age. A total of 10 453 children aged 12-13 years from the Toyama birth cohort study (fourth phase) participated, of whom 8906 children (89% response rate) responded to all questions related to the examined variables. Nutrition habits consisted of breakfast, snack, dinner, meal speed and meal portion. Children's obesity/overweight was measured by body mass index (BMI). Fathers' employment had no effect on their children's nutrition patterns. Children of full-time employed mothers were the most likely to snack and to skip dinner. Children of part-time employed mothers ate larger meal portions, and those of non-employed mothers reported faster meal speeds. BMI was significantly (P<0.001) higher among children of full-time employed mothers (19.3), and lowest among non-employed mothers (19.00). Children of full-time employed mothers are more likely to be overweight, but not obese compared with other children. There was a strong relationship between mother's employment and nutrition patterns in this cohort of Japanese schoolchildren; special programs focused on children's nutrition patterns should take into account the mothers' employment status.

Lifestyle and overweight among Japanese adolescents: the Toyama Birth Cohort Study.

ObjectiveTo investigate the effects of lifestyle factors on overweight among Japanese adolescents.MethodsWe studied 5753 junior high school students (2842 boys and 2911 girls) aged 12 to 13 years. The students were residents of Toyama prefecture, Japan and completed a questionnaire about their height, weight, and lifestyle factors, in June and July 2002. Subjects with a body-mass index (BMI) higher than age- and sex-specific cut-off points were defined as obese. Parental overweight was defined as a BMI of 25 or higher. Logistic regression analysis was used to examine associations between lifestyle factors and overweight.ResultsSkipping breakfast, eating quickly, excessive eating, physical inactivity, and long hours of TV watching were positively and significantly associated with overweight in both sexes. There was a negative association between snacking and overweight in girls (P < 0.001); no such association was found in boys (P > 0.05). Nighttime snacking was negatively associated with overweight in boys and girls (P < 0.05). Extended video game playing (≥2 hours; OR = 2.00, P = 0.012) and short sleep duration (<7 hours; OR = 1.81, P = 0.004) were significantly associated with overweight in girls only. The respective risks of overweight that derived from the subjects’ fathers and mothers were 2.0 and 2.5 times, respectively, in boys and 1.9 and 3.0 times in girls.ConclusionsParental overweight, skipping breakfast, eating quickly, excessive eating, long hours of TV watching, long hours of video game playing, physical inactivity, and short sleep duration were associated with adolescent overweight. Furthermore, there were significant negative associations between adolescent overweight and snacking in girls and nighttime snacking in both sexes.

Lifestyle at 3 years of age and quality of life (QOL) in first-year junior high school students in Japan: results of the Toyama Birth Cohort Study

The aim of this study was to determine whether some effects of childhood lifestyles at 3 years of age are associated with quality of life (QOL) in first-year junior high school students (JHSS). Lifestyles including sleep, physical activity and dietary habits of 9,674 3-year-old children were obtained by questionnaire between 1992 and 1994. Assessments were undertaken with the Dartmouth Primary Care Co-operative Project charts in 9,574 first-year JHSS in 2002. Logistic regression analyses were used to explore the relationship between lifestyle in early childhood and QOL in first-year JHSS for the follow-up subjects. After adjusting for demographic and familial factors at baseline, the results showed that later bedtime [odds ratio (OR) = 1.17, P = 0.043], later waking time (OR = 1.19, P = 0.039), short sleep duration (OR = 1.15, P = 0.061), physical inactivity (OR = 1.48, P = 0.022), skipping breakfast (OR = 1.56, P = 0.003), irregular snacks (OR = 1.43, P < 0.001), and frequent instant noodle consumption (OR = 1.49, P = 0.007) in early childhood increased the risk of poor QOL in first-year JHSS. The relationships were reinforced by a significant linear trend for almost all factors considered at baseline to QOL in first-year JHSS. Early childhood lifestyle factors, especially dietary habits, at 3 years of age have significant effects on QOL in first-year JHSS. This suggests that interventions as early as 3 years of age should be considered.

Sib-size, birth order and risk of overweight in junior high school students in Japan: Results of the Toyama Birth Cohort Study

Objective. To investigate whether there is a relationship between sib-size, birth order and the risk of overweight in junior high school students. Method. Sib-size, birth order, height and weight of subjects and their parents, and other lifestyle factors were obtained through a questionnaire survey conducted between June and July 2002 from 7,959 junior high students in Toyama prefecture, Japan. Logistic regression analysis was performed to examine the associations. Boys and girls were analyzed separately. Results. Boys from three-child families showed a significantly lower risk of overweight than only boys (odds ratio (OR) = 0.66, p = 0.010), and girls from larger families have a significantly lower risk than only girls ( p for trend = 0.001). Compared to middle-born girls, only girls have a significantly higher risk of overweight (OR = 2.22, p < 0.001). The risk of overweight in boys was significantly lower with increasing number of elder sibling or sister. However, increasing of any one sibling almost had the same risk reduction effect on the risk of overweight in girls (OR ranged from 0.74 to 0.76, p <= 0.001). Conclusion. Children without siblings are the ones most at risk for overweight, especially in girls. Birth order and sib-size are possible risk factors for the development of overweight and obesity.

Body Image, Body Satisfaction and Dieting Behavior in Japanese Preadolescents: The Toyama Birth Cohort Study

Body Image, Body Satisfaction and Dieting Behavior in Japanese Preadolescents: The Toyama Birth Cohort Study

Body image, body satisfaction and dieting behavior in Japanese preadolescents: The Toyama birth cohort study

To examine the relationships between body image, body satisfaction and dieting behavior in the context of pubertal changes in Japanese preadolescents. A cross-sectional study of dieting behavior among 5,244 preadolescents (2,452 boys and 2,792 girls aged 12-13) born in Toyama prefecture. The percentages of those who perceived themselves fat, wanted to be thinner, and had tried dieting, which increased with body mass index (BMI), were significantly higher in girls than in boys (34.2% vs. 20.0%, 58.0% vs. 26.0%, and 17.3% vs. 5.7%, respectively). Independent of sex and BMI, those who wanted to be thinner and those who had tried dieting were more frequently observed in those who perceived themselves fat, and those who had tried dieting were more frequently observed in those who wanted to be thinner. Pubertal changes were significantly associated with dieting behavior, but their relationships to body image and body satisfaction differed between sexes; for boys, those who perceived themselves fat were more frequently observed in those without pubertal changes; whereas for girls, those who wanted to be thinner were more frequently observed in those with pubertal changes. Dieting behavior of Japanese preadolescents was associated with whether they perceived themselves fat and wanted to be thinner, sometimes independent of whether they were actually overweight. Pubertal changes might induce a positive perspective of growing fat among boys and a desire to be thinner among girls, with the consequence that dieting behavior would be reinforced in those with pubertal changes.

Body image and body satisfaction play important roles in the path to dieting behavior in Japanese preadolescents: The Toyama birth cohort study

To analyze the path to dieting behavior in Japanese preadolescents. A cross-sectional study of dieting behavior among 5,244 preadolescents (2,452 boys and 2,792 girls aged 12-13) born in Toyama prefecture. While increasing with body mass index (BMI), the percentage of those who had tried dieting was higher in those who perceived themselves fat than in those who perceived themselves thin or average. Of those who wanted to be thinner, 16.1% of boys and 26.8% of girls had tried dieting. Path analysis in nonobese subjects (2,116 boys and 2,334 girls) showed that (1) body image was primarily based on BMI, (2) body image led to body dissatisfaction, and (3) body dissatisfaction led to dieting behavior. Pubertal changes had a significant effect on body image (path coefficient <0)for boys and body satisfaction (path coefficient >0) for girls, in addition to that on BMI. Maternal BMI had a significant effect on BMI but not on body image, body satisfaction, or dieting behavior. Body image and body satisfaction play important roles in the path to dieting behavior in Japanese preadolescents. Pubertal changes may reinforce dieting behavior, but the mechanism may differ by sex.

Associations of lifestyle factors with quality of life (QOL) in Japanese children: a 3‐year follow‐up of the Toyama Birth Cohort Study

To examine the associations between lifestyle factors and quality of life (QOL) among Japanese children. Participants were 7794 children (3869 boys and 3925 girls) aged 9-10. They completed a questionnaire regarding lifestyles at baseline survey and were followed up for 3 years. In the follow-up survey, QOL was evaluated using a Japanese version of the COOP charts. Children rated their QOL as one of five response categories. Subjects rated as 'very well' or 'pretty good' were considered to have good QOL, and the remainder was assumed to have poor QOL. Logistic regression analysis was performed to evaluate the relationship between lifestyles or changes in lifestyles and QOL. In the multivariate analysis model, age, sex, body mass index (BMI), and lifestyle factors were simultaneously entered. During the follow-up period, children became more sedentary. Compared to children participating in physical activity 'very often' at baseline, those who exercised 'almost never' were more likely to have poor QOL [OR (95% CI): 1.92 (1.26-2.93)]. Children who developed or maintained undesirable lifestyles had high OR for poor QOL. Compared to children taking breakfast 'often' during the follow-up period, those changing from 'often' to 'seldom' or those taking breakfast 'seldom' were more likely to have poor QOL [1.61 (1.24-2.07), 2.05 (1.03-4.09), respectively]. When compared with children maintaining their participation in physical activity 'often', those who changed from 'often' to 'seldom' and those who kept 'seldom' were more likely to have poor QOL [2.10 (1.84-2.39), 2.21 (1.88-2.59), respectively]. This study shows that unfavourable lifestyles in childhood are associated with poor QOL in early adolescence. Early intervention could be worth considering to keeping desirable lifestyles during childhood.

Body Image and Body Satisfaction Play Important Roles in the Path to Dieting Behavior in Japanese Preadolescents: The Toyama Birth Cohort Study

Body Image and Body Satisfaction Play Important Roles in the Path to Dieting Behavior in Japanese Preadolescents: The Toyama Birth Cohort Study

Lifestyles and health-related quality of life in Japanese school children: a cross-sectional study

Background Lifestyles are associated with physical and mental health status, as well as health-related quality of life (QOL) in adults. There is little information about relation between lifestyles and QOL in children. This study aims to examine the correlation among Japanese children. Methods Subjects were from the Toyama Birth Cohort Study, a prospective, longitudinal survey of children born between 1989 and 1990 in Toyama Prefecture, Japan. When children were 12–13 years in 2002, a cross-sectional questionnaire-based survey was administered. The questionnaire designed to measure lifestyles included questions on eating, physical activity, sleep, and other factors. For QOL measurement, a validated Japanese version of the COOP Charts was used. Data from 7,887 children were available and logistic regression analyses were used. Results Children with undesirable lifestyles, such as skipping breakfast, less participation in physical activity, longer television viewing, and later bedtime, were more likely to have poor QOL in domains of physical fitness, feelings, overall health, and quality of life. These correlations were independent of sex, BMI, social background, and somatic symptoms. Conclusions Undesirable lifestyles are positively associated with impaired QOL among children. Further understanding of these relationships will facilitate the development of interventions to help children with poor QOL.