Socioecological approach for identifying the determinants of objectively measured physical activity: A prospective study of the UK Biobank.

The socioecological approach emphasises that health promotion should focus on a variety of factors that surround individuals simultaneously, yet there is little evidence on how these factors relatively affect physical activity (PA). The main objective was to identify relevant determinants of PA by examining the associations between factors within multilayered socioecological categories and PA. A prospective analysis was conducted with 84,052 participants participating in the accelerometer measurement from the UK Biobank. Time spent in moderate-to-vigorous PA (MVPA) was calculated from participants who wore a wrist-worn accelerometer for seven days; a questionnaire-based self-reported leisure-time physical activity was also assessed. A categorical principal component analysis was conducted to reduce the dimensions of 184 variables. The associations between principal components (PCs) and PA were evaluated using general linear models. A network of PCs was constructed to assess the comprehensive association with PA. PCs related to body composition and chronic diseases were suggested as key determinants of objectively measured MVPA and found to be clustered in the network. PCs related to body composition and socio-economic status were proposed as the key regulatory hubs in the network because they exhibited the highest level of indirect linkages with other components. In the environmental category, PCs related to greenness and air pollution were revealed to be key factors in the self-reported walking for pleasure. Using a socioecological approach, it was discovered that obesity and disease-related factors were the most important determinants, and they had an integrative influence with other factors in different categories.

Relative Effects of Demographic, Psychological, Behavioral, and Social Factors on the Initiation and Maintenance of Leisure-time Physical Activity: Results From a Confirmatory Path Analysis in a Longitudinal Study.

BACKGROUND: There is a lack of evidence of the complicated pathways of underlying determinants in the phases of physical activity. The purpose of this study was to evaluate simultaneously a set of potential determinants on the initiation and maintenance phases of leisure-time physical activity (LTPA). METHODS: The longitudinal data of 54,359 Korean adults aged 40-69 years from the Health Examinees study were used. The median follow-up duration was 4.2 years. The self-reported durations per week of LTPA was repeatedly assessed. Based on previous longitudinal studies, the potential determinants were selected, and hypothetical models were constructed that consider the complex associations between the determinants. The standardized coefficients for direct and indirect effects were estimated using path analysis to differentiate contributions of mediation from the total effects. RESULTS: In the total population, age, education, chronic diseases, smoking, depression symptoms, and self-rated health were significantly associated with both initiation and maintenance phases. Income (B = 0.025) and social supports (B = 0.019) were associated only with the initiation phase. Waist-to-hip ratio (B = -0.042) and stress (B = -0.035) were associated only with the maintenance phase. After stratifying by sex, the significant effects of education, chronic diseases, and smoking were found only in men. The initiation phase-specific effects of income and social supports and the maintenance phase-specific effects of stress were found only in women. It was estimated that indirect effects contributed approximately 15% of the total effect. CONCLUSION: The findings suggested that there were initiation- or maintenance-specific determinants of leisure-time physical activity according to sex.

Gender differences in factors influencing smoking, drinking, and their co-occurrence among adolescents in South Korea.

INTRODUCTION: This study aimed to examine gender differences in the influence of social, attitudinal, and intrapersonal factors on the onset of smoking, drinking, and the co-occurrence of tobacco and alcohol use among adolescents in South Korea. METHODS: Using time-dependent Cox regression, the study analyzed the Korean Youth Panel Study conducted by the Korean National Youth Policy Institute. The study sample was middle-school second-graders (n = 3,188) in South Korea. RESULTS: This study found gender differences between Korean male and female adolescents in models of smoking and alcohol uptake; the co-occurrence model was identical, however. At first, parental supervision, attachment to friends, drinking friends, self-control, and aggression were common factors in the onset of drinking among Korean adolescents. Stress was shown to be significantly correlated with the onset of male adolescent drinking, whereas family income was a significant factor just for females. In the smoking model, attachment to friends, smoking friends, stigma, and self-control were identified as common factors related to the onset of smoking in both male and female adolescents. Attachment to parents was found to be a significant factor for male adolescents and aggression for females. CONCLUSIONS: The study findings indicate influences on the commencement of smoking, drinking, and concurrent tobacco and alcohol use among Korean male and female adolescents. Culturally sensitive interventions focusing on common risk factors with several differentiated strategies for both boys and girls should be developed and provided for Korean adolescents.

Fine particulate matter and depressive symptoms in children: A mediation model of physical activity and a moderation model of family poverty.

RATIONALE: Exposure to fine particulate matter has adverse effects on mental health outcomes. However, no empirical study has yet been conducted on mechanisms of how and why exposure to fine particulate matter can affect mental health outcomes, especially focusing on children. In addition, children living in poverty may be more vulnerable to fine particulate matter. OBJECTIVE: This study aims to examine whether physical activity can explain the impact of ambient fine particulate matter on depressive symptoms among Korean children and whether family poverty moderates the associations between fine particulate matter, physical activity, and children's depressive symptoms. METHODS: Children and their primary caregiver data were drawn from the Children's Happiness Life Time Survey data collected by Child Fund Korea, and fine particulate matter data were derived from Air Korea, collected by the Korea Environment Corporation. Individual-level data were linked to a nationwide neighborhood-level data on air quality. Multilevel structural equation modeling was used to consider the hierarchical data structure. The analytical sample consisted of 4,161 children living in 79 neighborhoods. RESULTS: The findings suggest that living in neighborhoods with higher levels of fine particulate matter is associated with a decrease in physical activity, which in turn increases children's depressive symptoms. Physical activity fully mediates the association between fine particulate matter and children's depressive symptoms. However, family poverty does not have a significant moderating role for the associations between fine particulate matter, physical activity, and children's depressive symptoms. CONCLUSIONS: The results of this study indicate the importance of physical activity in relation to fine particulate matter and children's depressive symptoms.

The influence of parent and peer disapproval on youth marijuana use mediated by youth risk perception: Focusing on the state comparison.

BACKGROUND: The prevention of youth marijuana use has become a national priority in the United States. This study examined the influence of parent and peer disapproval on youth marijuana use, mediated by youth risk perception. Because the legal status of marijuana use can influence individual perceptions of the drug, this study investigated differences in the mediating mechanism between youth living in states with medical marijuana legalization (MML) and those living in non-MML states. METHODS: The 2019 National Survey of Drug Use and Health was used with a youth population aged 12-17 years (N = 2293). Structural equation modeling and bias-corrected bootstrapping were used to examine hypothesized path models and to evaluate the mediating effect of youth risk perception. RESULT: Findings demonstrated that parent and peer disapproval significantly increased youth risk perception of marijuana and reduced youth marijuana use. Second, youth risk perception significantly mediated the association between parent and peer disapproval and youth marijuana use. Third, parent disapproval had a more significant direct effect on youth marijuana use, while peer disapproval had a more significant indirect effect on youth marijuana use via youth risk perception. Finally, the results showed a similar pattern in the mechanism between youths living in MML states compared with those in non-MML states in terms of significance and direction. CONCLUSION: The findings suggested a need for improvements in marijuana related policies for both MML and non-MML states. Moreover, parent and peer focused strategies for education and prevention concerning marijuana use among youth are emphasized.

Understanding the link between exposure to fine particulate matter and internalizing problem behaviors among children in South Korea: Indirect effects through maternal depression and child abuse.

Exposure to air pollution is known to have detrimental effects on health. Previous studies have also found that exposure to fine particulate matter can cause adverse mental health outcomes. However, the link between exposure to fine particulate matter and children's mental health outcomes remains largely unknown. Thus, this study aimed to understand the mechanisms of the effects of exposure to fine particulate matter on children's mental health outcomes, particularly focusing on internalizing problem behaviors. Using fine particulate data from the Ministry of Environment's Air Korea initiative and data from the Panel Study on Korean Children in 2018, this study employed structural equation models to examine the associations between exposure to fine particulate matter, maternal depressive symptoms, child abuse, and children's internalizing problems. Findings suggest that living in neighborhoods with higher exposure to fine particulate matter is positively associated with maternal depressive symptoms, increasing emotional abuse and neglect, which in turn is positively associated with children's internalizing problem behavior. However, physical abuse was not a significant mediator of children's internalizing problem behaviors. It may be necessary for policies that provide interventions for primary caregivers to reduce depression and child abuse to promote mental health outcomes for children, even in the presence of severe fine particulates.

Co-occurring patterns of smoking and alcohol consumption among Korean adolescents.

This study seeks to assess the transition probabilities between smoking and alcohol consumption trajectories for ages 13-17 using data from the Korea Youth Panel Survey (KYPS). Four smoking trajectories were identified-noninitiator, late-onsetter, experimenter, and escalator. Similarly, four alcohol consumption trajectories were identified-noninitiator, late-onsetter, experimenter, and chronic user. Those in the chronic group of alcohol consumption were most likely to be smokers. Those who fell into a particular group for use of one substance were most likely to fall into the corresponding group for use of the other substance. Implications for smoking and alcohol prevention are discussed.

A Comparative Study of Cohorts for Children's Body Mass Index Changes.

The purpose of this study is to examine how the body mass index changes over time and to determine whether there is a difference between the cohorts. For these purposes, we used latent growth curve modeling and multi-group analysis involving 2,250 students (first-grade cohort panel data) and 2,094 students (fourth-grade cohort panel data) who participated in the Korean Children and Youth Panel Survey. Major findings are as follows. 1) The trajectories of body mass index were different by the cohort. Specifically, children's body mass index has become more serious in recent generation. 2) Multi-group analysis showed that the trajectories of body mass index and its predictors were varied by the cohort. Specifically, self-esteem, abuse, sedentary lifestyle, and study time explained the cohort effect. These findings suggest that the social environment intervention is needed for the physical health of children.

Predicting Behavior Problems in Korean Preschoolers: Interactions of the SLC6A4 Gene and Maternal Negative Affectivity.

OBJECTIVE: This study aimed to investigate whether maternal negative affectivity (MNA) moderates the effect of genetic polymorphism of SLC6A4 on behavior problems in children. METHODS: Study participants comprised 143 preschoolers and their mothers from South Korea. The Childhood Behavior Checklist and Emotionality, Activity, and Sociability adult scale were used to measure child behavior and maternal affectivity. DNA from saliva was genotyped to determine serotonin transporter polymorphism. RESULTS: MNA appeared to exert effects in externalizing (b =5.78, p＜0.001) and internalizing problems (b =6.09, p＜ 0.001). Interaction between SLCA4 polymorphism and MNA showed effects on externalizing (b =-7.62, p＜0.01) and internalizing problems (b =-9.77, p＜0.01). Children with two short alleles showed considerable differences in both externalizing and internalizing problems according to MNA; however, children with one short allele or none showed relatively few differences in behavior problems due to maternal affectivity. CONCLUSION: The effect of SLC6A4 polymorphism on child behavior seemed to be moderated by MNA. In addition, the impact of MNA was found to vary based on a child’s genetic risk. High MNA may trigger the risk allele while low MNA causes the risk allele to illicit less behavior problems. Children with two short variants of the SLC6A4 gene may benefit from intervention that modulates MNA.

Linking Traumatic Childhood Experiences to the Physical Health of Korean Adolescents in Out-of-Home Care through Depression and Anxiety.

The main purpose of this study is to assess whether the physical health of Korean adolescents in out-of-home care is affected directly by traumatic childhood experiences and/or indirectly through depression and anxiety. Study participants are 460 adolescents who are included in the first and second wave of the Panel Study on Korean Children in Out-of-Home Care. The data are analyzed using structural equation modeling. Our structural model finds no direct effects of traumatic experiences on physical health. Among the two types of trauma experiences, namely, family instability and violence experiences, only violence experiences affect physical health indirectly through depression and anxiety. Based on the results, practice implications for Korean adolescents in care are discussed.

Developmental relationships between adolescent substance use and risky sexual behavior in young adulthood.

PURPOSE: To examine the developmental relationship between adolescent substance use and risky sexual behavior in young adulthood. A gender-balanced, ethnically diverse urban sample of 808 children in Seattle was surveyed at age 10 years in 1985 and followed prospectively to age 21 years in 1996. Semiparametric group-based modeling was used to determine trajectory groups of binge-drinking, cigarette smoking, marijuana use, and the use of other illicit drugs. Negative binomial regressions and logistic regressions were used to examine whether these trajectory groups predicted the number of sex partners and condom use at age 21 years. Specific forms of adolescent substance use significantly predicted risky sexual behavior at age 21 years, after other substance use and early measures of sexual behavior were controlled. Early binge-drinkers had significantly more sex partners than nonbinge-drinkers. Late onset binge-drinkers and marijuana users had significantly more sex partners and were less likely to use condoms consistently than those who did not binge drink or use marijuana. Experimenters in cigarette smoking, who did not escalate smoking, were more likely to use condoms consistently than nonsmokers. In contrast, the use of other illicit drugs in adolescence did not predict risky sexual behavior at age 21 years. The effects of adolescent substance use on risky sexual behavior at age 21 years differed for youths with developmentally different substance use trajectories in this urban sample disproportionately drawn from high crime neighborhoods. To prevent risky sexual behavior among young adults, attention should be paid to binge-drinking and marijuana use during adolescence.

Factors associated with perceived health among Korean adolescents.

This study examined the influences of personal, social, and environmental-structural factors on the perceived health of Korean adolescents. Using a two-stage generalized hierarchical logistic linear multilevel model, this study found that general high school enrollment, younger age, normal weight, and frequent exercise increased the likelihood of a positive self-perception of health. Higher levels of parental concern and quality of school life also contributed to the likelihood of students perceiving themselves as healthy. In contrast, psychological symptoms and negative self-esteem decreased the likelihood that students perceived themselves as healthy. The results provide implications for disease prevention and health promotion programs.

Developmental trajectories of family management and risk for violent behavior in adolescence.

PURPOSE: To address two questions: (1) Can groups of family management trajectories be identified in early adolescence? (2) How are the different family management trajectories related to trajectories of violent offending for youths aged 13-18 years? METHODS: Analyses used semi-parametric group-based modeling (SGM) to identify groups of family management trajectories. A joint trajectory method was used to predict patterns of youth violence conditional on family management. RESULTS: Analyses identified 3 trajectories of family management from age 11 to 14: (1) stable low, (2) stable high, and (3) increasing family management. Youths from families in the low family management trajectory were more likely than others to follow chronic and late increasing trajectories of violence. In contrast, youths in stable-high positive family management were less likely to engage in violence from age 13 to age 18. Further, youths whose families started low, but increased to high family management, had patterns of adolescent violence similar to those whose parents were consistently high in their use of good parenting practices. CONCLUSIONS: The current study advances knowledge of developmental patterns in family management and youth violence. Although most parents remained stable in family management practices from age 11 to 14 (stable high or stable low), parents who started low, but improved their management practices during middle school, had children with lower levels of chronic and late increasing violence than those who remained low. Findings suggest that interventions developed to enhance family management practices may reduce risk for violence in later adolescence.

Patterns of mental distress following the violent death of a child and predictors of change over time.

We observed 173 parents bereaved by the violent death of an adolescent or young adult child. Data were collected 4, 12, 24, and 60 months postdeath. Using latent growth modeling, we examined how initial levels of mental distress and the rate of change over time are influenced by nine predictors: parents' gender, self-esteem, three coping strategies, perceived social support, negative life stressors, posttraumatic stress disorder (PTSD) symptoms, and an intervention offered in the early bereavement period. The results support a multiple-risk and -protective factor model of loss accommodation. Parents' gender, self-esteem, and affective and repressive coping were predictive of changes in mental distress over time. Although parents' initial levels of PTSD were the best predictor of baseline mental distress, they did not predict reductions in distress 5 years later. Theoretical, empirical, and clinical implications are discussed.

The prevalence of PTSD following the violent death of a child and predictors of change 5 years later.

In this study, we examined the violent death bereavement trajectories of 173 parents by following them prospectively for 5 years after their children's deaths by accident, suicide, homicide, or undetermined causes. Using latent growth curve methodology, we examined how the initial level of PTSD and the rate of change over time were influenced by 9 predictors: the deceased children's causes of death, parents' gender, self-esteem, 3 coping strategies, perceived social support, concurrent levels of mental distress, and an intervention offered in early bereavement. Six of the nine factors predicted initial levels of PTSD; however, only parents' gender and perceived social support predicted change in PTSD over the 5-year time frame. Five years postdeath, 3 times as many study mothers (27.7%) met diagnostic criteria for PTSD and twice as many study fathers (12.5%) met diagnostic criteria for PTSD compared with the normative samples.

Identifying and Predicting Offending Trajectories among Poor Children.

Using data from the Seattle Social Development Project, we identify childhood predictors of offending trajectories among poor children. Five trajectories are identified: nonoffenders, late onsetters, desisters, escalators, and chronic offenders. Among initial nonoffenders, late onsetters are distinguished from nonoffenders by early alcohol drinking. Among youths already delinquent at age 13, escalators are distinguished from desisters by poor family management, family conflict, association with antisocial peers, the presence of troubled children in their neighborhoods, and drug availability. In contrast to prior findings for a general urban sample, family factors significantly predict desistance from offending by age 18 in children from low-income families.