Objective:Socioeconomic status(SES)is associated with childhood obesity,but the underlying factors remain unknown.This study aimed to identify mediators that may explain SES disparities in childhood obesity in China.Methods:Nationally representative longitudinal data from the China Education Panel Survey of 11 019 chil-dren(13.03±0.79)collected from 2013-2014 to 2016-2017 academic years.Overweight/obesity was de-fined using Chinese national body mass index cut-points.Principal component analysis was used to con-vert the four SES indicators(maternal and paternal education,and occupation)into one comprehensive vari-able.Mediation analysis for SES disparities in childhood obesity was conducted using structure equation models.Results:The prevalence of overweight/obesity was 12.8％,and was higher in boys than in girls(17.8％vs.7.6％,P＜0.001)at baseline.Among boys,relative risk(RR)of obesity was 1.23(95％CI:1.09 to 1.40,P＜0.001)for per unit change in SES.There was no significant association between obesity and SES among girls.Mediation analyses showed that among boys,birth weight,being the only child in the family and children's self-perceived weight status mediated 70.0％of the effects of SES on obesity.No mediation effect was detected in girls.Conclusions:Chinese boys are more likely to be overweight or obese than girls.SES may impact childhood obesity through birth weight,being the only child in the family and children's self-perceived body weight status in boys,but not in girls.More attention should be made to address childhood obesity in high SES families among boys.Interventions targeting at these mediators are needed.

Objective:This study compared the prevalence,awareness,treatment and control of hypertension and associated factors in China and the United States(US).Methods:Adult data from nationally representative samples were derived from the Chronic Disease and Risk Factors Surveillance in 2010 and 2013 in China and the National Health and Nutrition Examination Survey in 2010 and 2013 in the US.Multivariable logistic and Poisson regression analysis were conducted to assess associations of the four outcomes with body weight status and behavioral factors.Results:Age-standardized prevalence rates of hypertension was 35.7％(95％confidence interval[CI]:35.4％to 36.1％)in 2010 and 29.8％(95％CI:29.4％to 30.2％)in 2013 in China,and 35.3％(95％CI:33.6％to 37.1％)in 2010 and 37.9％(95％CI:36.0％to 39.7％)in 2013 in the US.Among hypertensive participants,the age-standardized rates of treatment were 18.4％(95％CI:17.9％to 18.9％)in 2010 and 23.8％(95％CI:23.1％to 24.6％)in 2013 in China and 54.5％(95％CI:50.3％to 58.7％)in 2010 and 50.9％(95％CI:46.5％to 55.3％)in 2013 in the US;the age-standardized hypertension control rates were 3.2％(95％CI:3.0％to 3.5％)and 5.7％(95％CI:5.3％to 6.0％)in 2010 and 2013 in China and 50.6％(95％CI:46.2％to 55.0％)and 55.3％(95％CI:50.3％to 60.3％)in the US.Obesity was significantly associated with prevalence,awareness and control rates in both countries.Different from the US,obesity was negatively associated with hypertension control in China.Conclusion:Hypertension prevalence in China is similar to that in the US,but the control rate in China was significantly lower.Obesity was a critical risk factor for poor hypertension control in China.