中国学龄儿童肥胖和超重性别差异的25年趋势：应用世界卫生组织和国际肥胖工作组标准进行的多次横断面研究

Twenty-five-year trends in gender disparity for obesity and overweight by using WHO and IOTF definitions among Chinese school-aged children： a multiple-cross-sectional study

目的探索1985—2010年中国城乡儿童肥胖和超重率性别差异的长期趋势。方法研究对象来自全国学生体质与健康调研，该调研是中国最大的可代表全国学龄儿童的调研，包括1280239名7～18岁儿童。按照世界卫生组织（wH0）和国际肥胖工作组（[OTV）的标准对肥胖和超重进行判定。使用Logistic回归对不同年度超重、肥胖率的性别差异进行估计。结果过去25年以来，中国城乡儿童肥胖率迅速增长（WHO标准：从0．10％上升到4．3％；IOTF标准：从0．03％上升到2．2％），在每一调查年男生肥胖率均高于女生（P〈0．01）。各年龄组均出现增长趋势（P〈0．01）。尽管肥胖率在男女生中都出现增长，但是男生的增长速度快于女生。肥胖率的男女生性别比有随时间增加的趋势，在每一调查年，城市地区肥胖率的男女生性别比都高于乡村地区。结论在城乡地区逐步增加的性别差异显示男生的肥胖和超重，特别是城市男生的肥胖和超重，导致了儿童肥胖和超重的比例不断增加。

Objectives: We sought to explore 25-year trends of gender disparity in the prevalence of obesity and overweight both in urban and rural areas among Chinese children from 1985 to 2010. Methods: Data included 1 280 239 children aged 7-18 years enrolled in the Chinese National Survey on Students's Constitution and Health (CNSSCH), which is the largest nationally representative sample of school-aged children in China. Obesity and overweight were defined according to both WHO and the International Obesity Task Force (IOTF) definitions. Logistic regression was used to estimate the prevalence OR (POR) of gender for obesity and overweight prevalence in different surveys. Results: The prevalence of obesity increased (WHO definition: from 0.10% to 4.3%; IOTF definition: from 0.03% to 2.2%) over the past 25 years in urban and rural areas among Chinese children and it was much higher among boys than girls at each survey point (p<0.01). The increasing trend was significant in all age subgroups (p<0.01). Although the prevalence of obesity continuously increased in boys and girls, the changing pace was more rapid in boys than in girls. PORs of boys versus girls for obesity also increased over time, and the estimates of PORs were higher in urban areas than in rural areas at each survey point. Conclusions: The gradually increasing gender disparity in urban and rural areas suggests that the prevalence of obesity and overweight in boys, and especially in urban boys, contributes to a large and growing proportion of obese and overweight children.