Prevalence and risk factors of obesity among school-aged children in Xi'an, China

The purpose of this study was to examine the prevalence and the risk factors associated with obesity among school-aged children in Xi'an city. The body mass index of 6,740 children aged 7-18 years was compared with the Working Group on Obesity in China cut-off value to estimate the prevalence of obesity. A case-control study of obese and non-obese children was carried out to study risk factors for obesity. A standardized questionnaire was used to collect information on possible risk factors causing obesity. Univariate analysis was performed first to compare the distribution of risk factors between cases and controls. Conditional logistic regression analysis was used to assess independent risk factors of obesity. The results showed that the overall prevalence of obesity among school-aged children was 4.11% (4.63% for males and 3.57% for females). A total of 516 subjects (258 pairs of cases and controls) were included in the final analysis. High maternal education and a longer sleeping time were shown to be protective factors against obesity (odds ratio [OR] 0.148, 95% confidence interval [CI] 0.074-0.296 and OR 0.472, 95% CI 0.342-0.652, respectively). Whereas family history of diabetes (OR 5.498, 95% CI 2.606-11.600), parental overweight (OR 3.720, 95% CI 2.068-6.689), and watching television, playing video games, and using computers (OR 1.564, 95% CI 1.133-2.159) were associated with a higher obesity risk. Conclusion: the prevalence of childhood obesity in Xi'an has become a concern, and sleeping time, sedentary behavior, and family factors have pronounced effects on the prevalence of obesity.