Background: Socioeconomic status (SES) as a determinant of obesity has received scant attention in Japan. This study examined the association between SES and overweight among Japanese children and adolescents. Methods: Cross-sectional analyses of a representative sample of Japanese children (6–11 years: n = 397) and adolescents (12–18 years: n = 397) were performed, with measured heights and weights from the 2010 National Health and Nutrition Examination Survey and the 2010 Comprehensive Survey of Living Conditions. Overweight, including obesity, was defined by International Obesity Task Force cut-offs. SES indicators included household income, equivalent household expenditure, parental educational attainment, and parental occupational class. Results: Overweight prevalence was 12.3% in children and 9.1% in adolescents. Adolescents living in middle-income households were more likely to be overweight than those living in high-income households (OR 2.26, 95% CI, 1.01–5.67) after adjustment for age, sex, and parental weight status. Similarly, adolescents living in households with low expenditure levels were more likely to be overweight than those living in households with high expenditure levels (OR 3.40, 95% CI, 1.20–9.60). In contrast, no significant association was observed among children. Conclusions: Our results indicated that low household economic status was associated with being overweight, independent of parental weight status, among Japanese adolescents.
Background: The association between diabetes mellitus (DM) and low secretory immunoglobulin A (s-IgA) secretion rates is one mechanism suspected of influencing susceptibility to infections among DM patients. However, several studies have shown contradictory results. We examined these two factors to seek evidence of an association among older people. Methods: We analyzed a prospective cohort of 2306 subjects (1209 men and 1097 women) around 64 years old from the New Integrated Suburban Seniority Investigation (NISSIN) Project in Nisshin, Japan. DM statuses were ascertained from levels of fasting plasma glucose and HbA1c, and s-IgA secretion rates were obtained from 5-min saliva samples. We used an analysis of covariance adjusted for possible confounders to compare s-IgA secretion rates according to DM status. Results: s-IgA secretion rates in DM participants were lower than in those classified as normal (18.6 µg/min vs 15.0 µg/min, P = 0.03), even after elimination of the effects of possible confounders. Conclusions: DM was associated with lower s-IgA secretion rates. This suggests that lower s-IgA levels may be a mechanism of susceptibility to infection in individuals with DM.
Objective: This survey explored prevalence of overweight and obesity and their associations with socio-demographic variables in a Nigerian population. Methods: This cross-sectional survey involved 1521 adults in Nnewi. Age, sex, educational and occupational status, and BMI were recorded. Results: Prevalence of overweight was higher in males (32.3%; 95% CI, 29.5%–35.2%) than in females (29.8%; 95% CI, 26.8%–33.0%); the reverse was the case for prevalence of obesity (19.6%; 95% CI, 17.3%–22.2% in males and 36.0%; 95% CI, 32.8%–39.4% in females). Higher odds ratios (ORs) for overweight and obesity were observed in participants aged 41–60 years (OR 2.03; 95% CI, 1.57–2.61 for overweight and OR 4.29; 95% CI, 3.25–5.67 for obesity) and those >60 years (OR 1.72; 95% CI, 1.21–2.43 for overweight and OR 4.21; 95% CI, 2.86–6.19 for obesity) compared to those aged 18–40 years. Female sex was associated with higher ORs for overweight (OR 1.20; 95% CI, 0.96–1.51) and obesity (OR 2.21; 95% CI, 1.73–2.83). Participants with secondary education had marginally higher ORs for overweight (OR 1.15; 95% CI, 0.88–1.51) and obesity (OR 1.17; 95% CI, 0.86–1.59) than those with tertiary education, and so were those with primary education for obesity (OR 1.19; 95% CI, 0.74–1.89) but higher OR for overweight (OR 1.44; 95% CI, 0.98–2.13). Unskilled participants had about the same OR for overweight and obesity as professionals, and while skilled participants had about the same OR for overweight as professionals, their OR for obesity (OR 1.27; 95% CI, 0.67–2.43) was fairly higher than that for professionals. Conclusions: Prevalence of overweight is higher in males than in females, but the reverse is the case for prevalence of obesity. Older age and female sex are associated with increased risk of overweight and obesity, while working at a skilled occupation is associated with obesity, and tertiary educational attainment is associated with overweight.
Background: We investigated the prevalence and trends of underweight and overweight/obesity in a population-based sample of Japanese schoolchildren from 2003 to 2012, defined by body mass index (BMI) and percentage overweight (POW). Methods: Subjects comprised fourth and seventh graders from the town of Ina, Japan, from 2003 to 2012. The height and weight of each subject were measured. Children were classified as underweight, normal weight, or overweight/obese using two criteria: BMI cutoff points proposed by the International Obesity Task Force and cutoffs based on POW in Japan. Results: Data from 4367 fourth graders and 3724 seventh graders were analyzed. The prevalence of underweight and overweight as defined by POW criteria were lower than those based on BMI criteria. There was a decrease in the prevalence of overweight among fourth-grade boys and girls and seventh-grade girls according to BMI; this decrease was also observed when POW criteria were used for the definition of overweight. Conclusions: The prevalence and trends of both underweight and overweight as defined by POW were underestimated among Japanese schoolchildren compared to those determined using BMI. The results of this study also suggest that trends in underweight and overweight/obesity using POW criteria are similar to those based on BMI criteria among schoolchildren in Japan.
Backgrounds: The association between weight gain and the incidence of type 2 diabetes is well known. The aim of our study was to investigate the relationship between change in waist circumference (WC) and type 2 diabetes incidence. Methods: The participants in the Suita Study, a population-based cohort study in an urban area of Japan, underwent a baseline survey between 1989 and 1994 (Exam 1) and were examined at follow-up every 2 years. We performed a 9.3-year cohort study of 946 men and 1327 women with no history of diabetes who underwent Exam 1 and Exam 2 (between 1997 and 1999). Participants were stratified by sex and median WC at Exam 1, and, in each stratum, participants were further classified into three categories by tertile of WC change per year between Exam 1 and Exam 2. Hazard ratios (HRs) and 95% confidence intervals (CIs) for type 2 diabetes incidence were calculated by Cox proportional hazard models. The endpoints were first diagnosis of type 2 diabetes or March 2011. Results: During follow-up, 287 participants developed type 2 diabetes. In both sexes with median WC or higher, participants in the highest tertile of WC change had a significantly higher risk of developing type 2 diabetes. Multivariable adjusted HRs were 1.84 (95% CI, 1.10–3.08) in men and 2.30 (95% CI, 1.31–4.04) in women. No significant association was observed among participants with WC below median. Conclusions: Preventing WC gain is important in preventing type 2 diabetes in the Japanese population, especially among individuals with a relatively high WC.
Background: Despite being a signatory since 2004, Japan has not yet fully implemented Article 8 of the World Health Organization’s Framework Convention on Tobacco Control regarding 100% protection against exposure to second-hand smoke (SHS). The Japanese government still recognizes designated smoking rooms (DSRs) in public space as a valid control measure. Furthermore, subnational initiatives for tobacco control in Japan are of limited effectiveness. Through an analysis of the Hyogo initiative in 2012, we identified key barriers to the achievement of a smoke-free environment. Methods: Using a descriptive case-study approach, we analyzed the smoke-free policy development process. The information was obtained from meeting minutes and other gray literature, such as public records, well as key informant interviews. Results: Hyogo Prefecture established a committee to propose measures against SHS, and most committee members agreed with establishing completely smoke-free environments. However, the hospitality sector representatives opposed regulation, and tobacco companies were allowed to make a presentation to the committee. Further, political power shifted against completely smoke-free environments in the context of upcoming local elections, which was an obvious barrier to effective regulation. Throughout the approving process, advocacy by civil society for stronger regulation was weak. Eventually, the ordinance approved by the Prefectural Assembly was even weaker than the committee proposal and included wide exemptions. Conclusions: The analysis of Hyogo’s SHS control initiative shed light on three factors that present challenges to implementing tobacco control regulations in Japan, from which other countries can also draw lessons: incomplete national legislation, the weakness of advocacy by the civil society, and the interference of the tobacco industry.