Sex-specific role of education on the associations of socioeconomic status indicators with obesity risk: A population-based study in South Korea.

BACKGROUND: No study of obesity risk for people in developed countries has conducted a multi-dimensional analysis of the association of socioeconomic status with obesity. In this paper, we investigated if education functions as either a confounder or an effect modifier in the association of another socioeconomic status indicator with obesity. METHODS: This cross-sectional study analyzed data of an adult population sample (10,905 men and 14,580 women) from the Korea National Health and Nutrition Examination Survey (2010-2014). The study performed multivariate logistic regression analyses for three education levels and four indicators of socioeconomic status (i.e., marital status, residential area, occupation, and income). RESULTS: The overall prevalence of obesity was 38.1% in men and 29.1% in women (p < 0.001). In men, while education functioned as an effect modifier in the association between marital status and obesity (p for interaction = 0.006), it functioned as both a confounder (p < 0.001) and an effect modifier (p for interaction < 0.001) in the association between residential area and obesity. In contrast, in women, education functioned as a confounder in the association of residential area with obesity (p = 0.010). However, it functioned as both a confounder (p < 0.001) and an effect modifier (p for interaction = 0.012) in the association between income and obesity. A prediction showed that unlike in women, education was positively associated with obesity risk for some socioeconomic indicator groups in men; for example, in a rural resident group, a higher level of education increased the probability of being obese by 19.7%. CONCLUSIONS: The present study suggests the need to examine sex-specific studies regarding the role of education on the association between other socioeconomic status indicators and obesity. This should be considered in planning education policies to reduce the risk of obesity.

Gender-specific interactions between education and income in relation to obesity: a cross-sectional analysis of the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V).

OBJECTIVES: To identify gender-specific associations between education and income in relation to obesity in developed countries by considering both the interaction-effect terms of the independent variables and their main-effect terms. DESIGN: A cross-sectional study. Education and income levels were chosen as socioeconomic status indicators. Sociodemographics, lifestyles and medical conditions were used as covariates in multivariable logistic regression models. Adjusted ORs and predicted probabilities of being obese were computed and adjusted for a complex survey design. SETTING: Data were obtained from the Fifth Korea National Health and Nutrition Examination Survey (2010-2012). PARTICIPANTS: The sample included 7337 male and 9908 female participants aged ≥19 years. OUTCOME MEASURE: Obesity was defined as body mass index of ≥25, according to a guideline for Asians. RESULTS: In models with no interaction-effect terms of independent variables, education was significantly associated with obesity in both men and women, but income was significant only in women. However, in models with the interaction-effect terms, education was significant only in women, but income was significant only in men. The interaction effect between income and education was significant in men but not in women. Participants having the highest predicted probability of being obese over educational and income levels differed between the two types of models, and between men and women. A prediction using the models with the interaction-effect terms demonstrated that for all men, the highest level of formal education was associated with an increase in their probability of being obese by as much as 26%. CONCLUSIONS: The well-known, negative association between socioeconomic status and obesity in developed countries may not be valid when interaction effects are included. Ignoring these effects and their gender differences may result in the targeting of wrong populations for reducing obesity prevalence and its resultant socioeconomic gradients.

Modifying effects of education on the association between lifestyle behaviors and the risk of obesity: evidence from South Korea.

BACKGROUND: No previous study has explored the interactions between education and lifestyle in relation to obesity. This study hypothesized that education may be obesogenic through its interplay with lifestyle behaviors. METHODS: Data for a nationally representative sample (6937 men and 9333 women) from the Korea National Health and Nutrition Examination Survey (2010-2012) were analyzed. Multivariate logistic regressions were performed for three education levels and six lifestyle behaviors, each of which comprised two groups. RESULTS: Interactions between education and lifestyle behaviors in relation to obesity were observed for all lifestyle behaviors in women (p for interaction <0.001) and for three lifestyle behaviors in men. Education appeared obesogenic for three groups of lifestyle behaviors in men (p for trend <0.05), but was protective against obesity for 11 groups in women. Each one-unit increase in education level in men increased the odds of obesity by 1.29-fold among under-reported energy intake groups (95 % confidence interval: 1.16, 1.44). CONCLUSIONS: Education may be a risk factor for obesity through its interplay with lifestyle behaviors. Further research is required to examine these findings in different socio-cultural settings.

[Estimating the socioeconomic costs of alcohol drinking among adolescents in Korea].

OBJECTIVES: The purpose of this study was to estimate the socioeconomic costs resulting from alcohol drinking among adolescents as of 2006 from a societal perspective. METHODS: The costs were classified into direct costs, indirect costs, and other costs. The direct costs consisted of direct medical costs and direct non-medical costs. The indirect costs were computed by future income losses from premature death, productivity losses from using medical services and reduction of productivity from drinking and hangover. The other costs consisted of property damage, public administrative expenses, and traffic accident compensation. RESULTS: The socioeconomic costs of alcohol drinking among adolescents as of 2006 were estimated to be 387.5 billion won (0.05% of GDP). In the case of the former, the amount included 48.25% for reduction of productivity from drinking and hangover, 39.38% for future income losses from premature death, and 6.71% for hangover costs. CONCLUSIONS: The results showed that the socioeconomic costs of alcohol drinking among adolescents in Korea were a serious as compared with that of the United States. Therefore, the active interventions such as a surveillance system and a prevention program to control adolescents drinking by government and preventive medicine specialist are needed.