Self-control and dental caries among elementary school children in Japan

Association between skipping breakfast and prediabetes among adolescence in Japan: Results from A-CHILD study

OBJECTIVE

Adolescents with prediabetes are at high risk of developing type 2 diabetes in later life. It is necessary to identify risk factors for prediabetes in adolescents. This study aimed to examine the association between skipping breakfast and prediabetes among adolescents in Japan.

STUDY DESIGN

We used the population-based cross-sectional data of eighth grade in junior high school students from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study conducted in Adachi City, Tokyo, Japan, in 2016, 2018, and 2020. Skipping breakfast was assessed using self-reported questionnaires (N=1510). Prediabetes was defined as hemoglobin A1c (HbA1c) levels of 5.6-6.4%. The association between skipping breakfast and prediabetes was evaluated using multivariate logistic regression analysis. Stratified analysis was also performed using BMI, 1 SD or more, or less than 1SD, as overweight was defined as 1SD or more.

RESULTS

Students who skipped breakfast were 16.4% (n=248). The prevalence of prediabetes was 3.8% (n=58). Skipping breakfast exhibited a significant association with prediabetes (OR:1.95, 95% CI: 1.03 to 3.69) after adjusting for sex, annual household income, family history of diabetes mellitus, BMI, and survey year. Stratified analysis showed stronger association among students with overweight (BMI ≥1SD) (OR=4.31, 95% CI 1.06-17.58), while non-sigificant among students without overweight (BMI<1SD) (OR=1.62, 95% CI 0.76-3.47).

CONCLUSIONS

Skipping breakfast in Japanese adolescents, especially those with overweight, was associated with prediabetes. The promotion of avoiding skipping breakfast may help to prevent prediabetes.

Impact of exposure to secondhand smoke on the risk of obesity in early adolescence

BACKGROUND

Exposure to secondhand smoke (SHS) might be associated with obesity in children. This study aimed to evaluate whether continuous, quit, or start exposure to SHS was associated with obesity risk in early adolescents.

METHODS

We used population-based longitudinal data of primary school students in Adachi City, Tokyo, Japan, in 2018 (4th grade) and 2020 (6th grade) and studied 3605 students. The association between continuous, quit, start, or never exposed to SHS from 4th to 6th grade and BMI categories (underweight or normal weight, overweight, obesity) in 6th grade was investigated using ordinal logistic regression models.

RESULTS

Continuous SHS group showed a higher risk of being in the high BMI category than no SHS group (OR = 1.51, 95% CI 1.16-1.96). The stratified analyses by sex showed a similar association in boys (OR = 1.74, 95% CI 1.25-2.44) but not in girls (OR = 1.14, 95% CI 0.74-1.76). Quitting SHS group did not show a higher risk of being in the high BMI category than no SHS group (OR = 1.11, 95% CI 0.75-1.66) and the same was true for boys (OR 1.46, 95% CI 0.88-2.41).

CONCLUSIONS

Continuous SHS was a risk factor for obesity in boys in early adolescence; however, quitting SHS may help prevent it.

IMPACT

Continuous secondhand smoke (SHS) was not associated with a higher risk of obesity in early adolescence in girls. Continuous SHS can be a risk factor for obesity in early adolescence in boys. Quitting SHS may help to prevent obesity in early adolescence in boys.

Poor parenting behaviours and dental caries experience in 6- To 7-year-old children

OBJECTIVES

The association between poor parenting and dental caries in children remains unclear. We investigated the association of poor parenting with dental caries and oral health behaviour among children aged 6-7 years in Japan.

METHODS

Two waves of repeated cross-sectional surveys on children and their caregivers in Adachi City, Tokyo, were analysed. Questionnaires on parenting behaviour and the child's oral health behaviour were distributed through schools and completed by 8499 caregivers (response rate = 80.8%). The number of decayed or filled primary teeth (dft) at school dental health check-ups was linked to the survey data (N for complete case analysis = 6309). Factor analysis was performed to identify types of poor parenting: poor involvement, child abuse and lack of supervision of a child's health behaviours. The association between factor scores (z-score), the number of dft and oral health behaviour (not brushing teeth twice a day, not controlling snack eating habits and drinking juice every day) was evaluated by Poisson's regressions adjusted for covariates, including caregiver's socioeconomic status.

RESULTS

Poor involvement and lack of supervision of a child's health behaviours were positively associated with dft (mean ratio, MR [95% confidence interval, CI] =1.05 [1.03, 1.07] and 1.18 [1.16, 1.21], respectively) and unhealthy oral health behaviours. Child abuse was not associated with dft (MR = 0.99 [0.96, 1.01]) but was associated with all three unhealthy oral health behaviours (prevalence ratio, PR [95% CI] were 1.11 [1.06, 1.16], 1.11 [1.06, 1.16] and 1.06 [1.00, 1.11] for not brushing teeth, not controlling snack eating and drinking juice, respectively).

CONCLUSIONS

Poor involvement and lack of supervision of a child's health behaviours were associated with dental caries, and any type of poor parenting was associated with poor oral health behaviour among children.

Toothbrushing and School Refusal in Elementary School: A Longitudinal Study

The aim of this study was to examine the association between toothbrushing frequency and school refusal among elementary school children. We used data from the Adachi Child Health Impact of Living Difficulty (A-CHILD) longitudinal study conducted between 2015 and 2016 in Adachi City, Tokyo, Japan. A questionnaire was distributed to all first-grade children aged 6 to 7 years (N = 3697, follow-up rate: 86.2%). Propensity score (PS) matching was applied to collapse the known covariates on toothbrushing frequency in grade 1 on the association with school refusal in grade 2. Among the followed children, 2.4% showed school refusal in grade 2 (89 children) and 23.5% (870 children) brushed their teeth once or less than once daily in grade 1. After propensity score matching, children with toothbrushing once or less than once daily in grade 1 were 2.25 (95% CI: 1.25–4.05) times more likely to show school refusal in grade 2, compared with those with toothbrushing twice or more a day. Our findings suggest that toothbrushing once or less than once daily is an independent risk factor for school refusal among children. Oral health promotion to recommend toothbrushing more than once a day could prevent school refusal. Further intervention studies investigating the mechanism and causality are warranted.

Correlation between Oral Hygiene and IL-6 in Children

The aim of this study was to evaluate the correlation between marginal gingivitis, oral hygiene parameters, and interleukin-6 (IL-6) levels in gingival crevicular fluid of 40 children. The marginal periodontal pathology was evaluated by gingival index (GI). The status of oral hygiene was estimated by using patient hygiene performance (PHP), brushing frequency (BF), and plaque index (PI). IL-6 levels in gingival crevicular fluid were measured to evaluate the inflammation in marginal gingiva. PHP score showed a significant correlation with GI, BF, and PI. The groups based on PHP ranges were significantly related to IL-6 concentration in crevicular fluid.

Budget impact analysis reveals walk-in fingertip HbA1c testing in community pharmacies could provide a significant long-term reduction in public expenditure

In Japan, a new opportunistic community-based walk-in HbA1c testing program at pharmacies was enabled in 2014. An economic evaluation of this program from societal perspective has previously been published. This study examines the effect of a subsidy program for walk-in HbA1c-testing at community pharmacies in Japan on public health care expenditure by conducting a budget impact analysis from payer's perspective. The study focused on Adachi Ward in Tokyo, where a pioneering subsidy program was implemented. It examined the budget impact of the subsidy program over a 15 years. The total subsidy paid by the local authority during the first year was 2909 USD. Public expenditure remained positive for the first five years before becoming negative in the sixth year, eventually resulting in savings of 221,000 USD in the 15th year. The cost of treating type 2 diabetes that is detected early is offset by a reduction in expensive treatments for complicated cases. Subsidizing walk-in fingertip HbA1c testing in community pharmacies is likely to result in a significant reduction in public expenditure over the mid-to long term. Our result suggests that a similar strategy in other areas could also have a potentially favorable budget impact.

Oxytocin Response Following Playful Mother-Child Interaction in Survivors of the Great East Japan Earthquake

BACKGROUND

Children who are exposed to natural disasters are at greater risk of developing mental and behavior problems. Prior studies have suggested that positive parenting practices could prevent child mental and behavior problems among those who were exposed to natural disasters. Parent-child interaction increases oxytocin level in parents and infants; however, studies assessing the change in oxytocin level after positive parent-child interaction and its effect on child behavior problems among preadolescents who were exposed to natural disasters are lacking. This study investigated whether playful interaction stimulated oxytocin levels in 34 mother-child dyads who experienced the 2011 Great East Japan Earthquake in Kesennuma City in Miyagi Prefecture, Japan, and the effect of the maternal oxytocin changes on child behavior problems.

METHODS

Participants were recruited in 2012 after the Great East Japan Earthquake. Annual surveys were conducted from 2012 to 2017. Salivary oxytocin level was assessed before and after the playful interaction in 2015. Behavior problems were evaluated by caregivers, using the Child Behavior Checklist (CBCL) in 2017. Fixed effect regression analyses were conducted to determine the effect of playful mother-child interaction on oxytocin level by comparing the change in the 10 min after the interaction with the change in the 10 min before the interaction. We also examined the effect of maternal oxytocin changes before and after the playful interaction on the onset of child behavior problems in 2017.

RESULTS

A significant increase in maternal oxytocin level was detected following playful interaction, especially among mothers of first-born boys (2.63 pg/mg protein. 95% CI: 0.45, 4.81). Maternal psychological distress and trauma were also negatively associated with an increase of oxytocin levels. The increase in maternal oxytocin level was significantly associated with lower externalizing problem score of children 2 years later.

CONCLUSION

Our results might suggest a rational for potential preventive intervention for child behavior problems through playful mother-child interaction after natural disasters.

Association between grandparent co-residence, socioeconomic status and dental caries among early school-aged children in Japan: A population-based prospective study

Globally many children are living with grandparents, and it has been suggested that grandparent co-residence may be associated with dental caries in infants and toddlers possibly through passive parenting style, accompanied by children's cariogenic behaviors such as feeding sugary sweets. However, little is known about this association in schoolchildren, adjusted for socioeconomic status. Therefore, this study investigates the association between grandparent co-residence, socioeconomic status, and dental caries among schoolchildren. All caregivers of first-grade children (age 6-7 years) in Adachi City, Tokyo, were administered a questionnaire about children's grandparent co-residence status and oral health-related behaviors, and responses were linked with dental examination records conducted by school dentists (N = 3,578). Multilevel Poisson regression analysis was applied to examine the association between grandparent co-residence, socioeconomic status, and dental caries status for each individual tooth, adjusting for potential covariates. The percentage of dental caries experience was higher among children living with grandparents (48.9%) than among children living without grandparents (44.0%). The risk for caries, however, did not differ according to grandparent co-residence status when tooth type, child's age and sex, and parental socio-economic status and structure were adjusted (PR, 1.13; 95%CI, 0.90, 1.42). The association between grandparent co-residence and dental caries among early school-aged children in urban Japan was confounded by socioeconomic status.

Association between grandparent coresidence and weight change among first-grade Japanese children

BACKGROUND

The prevalence of grandparent coresidence is increasing. However, the impact of grandparent coresidence on weight change among school-age children remains unclear.

OBJECTIVES

The objective of the study is to examine the association between grandparent coresidence and obesity-related behaviours and change in body mass index (BMI) z scores among school-age children.

METHODS

In total, 3422 caregivers of first-grade children in Adachi City, Tokyo, participated in surveys and health checkups in 2016 and 2017 with no change in their grandparent coresidence status (response rate: 80.1% and 81.4%, respectively). Association between grandparent coresidence and obesogenic dietary, physical activity, and screen-based sedentary behaviours was measured using Poisson regression with robust error variance analysis, while change in BMI z scores was determined by linear regression and adjusting for potential covariates.

RESULTS

Grandparent coresidence was associated with increased prevalence rate (PR) of irregular snack foods intake (PR: 1.38, 95% confidential interval (CI): 1.19, 1.61); however, children who live with grandparents showed a lower BMI z scores in the second grade (coefficient: -0.048, 95% CI: -0.094 to -0.0013) after adjustment for BMI z scores in the first grade, family sociodemographics, and obesogenic behaviours.

CONCLUSION

Grandparent coresidence is associated with lower BMI z scores among early primary school-age Japanese children living in urban areas.

Association between social capital and second dose of measles vaccination in Japan: Results from the A-CHILD study

BACKGROUND AND OBJECTIVES

Measles vaccination is important to prevent outbreak, and social capital can be an important preventive factor. However, there have been very few studies that investigated the association between social capital and measles vaccination, especially the second dose, which is more likely to be suboptimal. This study aimed to investigate the association between social capital and second dose of measles vaccine.

METHODS

Data were derived from a population-based study of first-grade elementary school children (6-7 years old) in Adachi City, Tokyo. Caregivers were asked to complete a questionnaire, and 4291 of them provided a valid response (response rate: 80.1%). Among these 4291 valid responses, 69 responses were excluded since variables for social capital measures were missing, which resulted in analytic sample size of 4222. We analyzed the association between measles vaccination and social capital including social ties, social trust and mutual aid by multilevel logistic regression analysis with a random intercept model.

RESULTS

About 8.9% of the children did not receive a second dose of measles-containing vaccines. After covariates adjustments, increase of one-standard-deviation of poor individual-level social ties showed 11% lower odds of receiving measles-containing vaccines (OR: 0.89, 95% CI: 0.80-0.99). By contrast, no significant association between community-level social ties and measles vaccination was found. Regarding social trust, no significant association between individual-level social trust and measles vaccination was found. However, increase of one-standard-deviation of poor community-level social trust showed 11% lower odds of receiving measles-containing vaccines (OR: 0.89, 95% CI: 0.79-0.998). There was no association between mutual aid and measles vaccination.

CONCLUSION

Social ties and social trust were associated with second dose of measles vaccination. Fostering social capital may be effective in raising the low rate of second dose of measles vaccine.