Prevalence and associated factors of school physical violence behaviors among middle school students in Beijing / 中华流行病学杂志

Objective To described the prevalence of school physical violence behaviors and to explore its associated factors among middle school students in Beijing. Methods In 2009, a randomly selected cross- sectional survey was conducted among 5718 students in grades 7 to 12 in Beijing. A self-report anonymous questionnaire involving physical violence at school and sociodemographic variables, such as sex, grades, family economic status and family structure, peer relationships, and communication with their parents etc. were completed by students themselves.Logistic regression was used to estimate the association between physical violence and sociodemographic variables. Results Among the students, 14.3% reported that they had had physical violence behavior in school during the past 12 months. Male students had been more likely to have physical violence behaviors than female students (Male 25.2%, Female 5.1% ). For both male and female students, poor school cohesion were the risk factors of physical violence behaviors (Male OR=1.060, Female OR=1.065). For male students, factors as father' s lower education level (OR=1.653 ), remarried/single-parent families ( OR = 1.834 ), low-grade ( grade 7 OR = 5.291; grade 11 OR =1.526) , poor school performance (OR=1.470) etc were the risk factors of physical violence behaviors; while better-off family economic status (OR=0.546), good peer relationships (OR=0.618) , and easy to communicate with the father (OR=0.756) were the protective factors of physical violence behaviors. For female students, easy to communicate with her mother (OR = 0.358)were the protective factors of physical violence behaviors. Conclusion For male and female students, the prevalence of school physical violence and its related factors were different. Actions on prevention against physical violence behaviors should be fully considered, including factors as gender, personal characteristics, family, school and peers etc.

Comparison of changes in body composition during puberty development of obese and normal-weight children in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To compare the changes in body composition, including fat mass index (FMI) and fat free mass index (FFMI) during puberty development of obese and normal-weight children in China, and to explore the effect of age and gender on body composition.</p><p><b>METHODS</b>A total of 356 children at the age of 7-15 years were enrolled in this study. Body composition of 10 normal-weight and obese children in each age group was measured by dual-energy x-ray absorptiometry (DEXA). FFMI and FMI were calculated according to the following formula: FFMI (kg x m(-2)) = FFM(kg) / height2 (m2) and FMI (kg x m(-2)) = FM (kg) / height2 (m2).</p><p><b>RESULTS</b>The fat mass and fat free mass of obese children were significantly higher than those of normal-weight children (P < 0.05). The FMI and FFMI of obese children increased significantly with age and were higher than those of the same sex, gender, and age normal-weight children (P < 0.05).</p><p><b>CONCLUSION</b>The levels of fat mass, fat free mass, FMI, and FFMI are different in obese and normal-weight children, and gender effects are significant in boys having higher levels of these indicators than in girls. FFMI and FMI can be used as monitoring indexes in weight control of obese children.</p>

Association of the common genetic variant upstream of INSIG2 gene with obesity related phenotypes in Chinese children and adolescents / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the association between the rs7566605 variant of INSIG2 and obesity-related phenotypes in Chinese children and adolescents.</p><p><b>METHODS</b>The study sample consisted of two independent cohorts of Chinese children and adolescents. Anthropometric indices, lipids, blood pressure, fasting glucose, insulin and percentage of fat mass were determined. PCR with restriction fragment length polymorphism analysis was performed for genotyping the rs7566605 variant.</p><p><b>RESULTS</b>In each of the two independent cohorts, no significant association was observed between rs7566605 and obesity under additive, dominant or recessive model. We also did not detect any difference in the genotype frequency between all the obese children and controls. Furthermore, we did not find evidence of an association between body composition indices and metabolic phenotypes in all children. However, the triglyceride level of CC homozygotes was significantly higher than that of GG+GC genotypes in obese children (P=0.022). Additionally, we observed a non-significant trend of severe obesity in a post-hoc test.</p><p><b>CONCLUSION</b>INSIG2 rs7566605 variant is not associated Chinese childhood obesity in two independent cohorts. Further study is needed to verify the effect of rs7566605 on triglyceride in obese children.</p>

Report on childhood obesity in China (6) evaluation of a classroom-based physical activity promotion program / 生物医学与环境科学（英文）

<p><b>OBJECTIVES</b>To evaluate the effect of Happy 10 program on the promotion of physical activity, physical growth and development of primary-school students, and on obesity control and prevention.</p><p><b>METHODS</b>Two similar primary schools from one district of Beijing, China were selected, one as an intervention school and the other as a control school. Happy 10 program was implemented at least once every school day in the intervention school for two semesters, whereas no intervention was adopted in the control school. The information on energy expenditure and duration of physical activity was collected by a validated 7-day physical activity questionnaire. Height and weight were measured by trained investigators following the standardized procedure. Energy expenditure and intensity of each Happy 10 session was measured by a physical activity monitor.</p><p><b>RESULTS</b>The average energy expenditure and duration of total physical activity per day among students in the intervention school increased significantly from 15.0 to 18.2 kcal/kg, and 2.8 to 3.3 h respectively, whereas the figures significantly decreased in the control school. There was a significant difference in change of weight and BMI between girls in the intervention and control school (2.4 kg vs 4.6 kg, -0.47 kg/m2 vs 0.66 kg/m2). The prevalence of overweight and obesity in the intervention school decreased by 0.4%-5.6%, as compared to the increase by 0.6%-4.5% in the control school. The average energy expenditure and intensity per 10-minute session ranged from 25.0-35.1 kcal, 4.8-6.2 kcal/kg/h respectively in grades 1-5.</p><p><b>CONCLUSION</b>Happy 10 program provides a useful strategy to promote physical activity among school children and also plays a positive role in building up physical growth and development of girls.</p>

Study on the relation between anthropometric parameters and lipids profiles / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the relations between anthropometric parameters [body mass index (BMI), percent of body fat, waist circumference] and blood lipids of urban children in Beijing and to compare the ability of prediction effect of waist circumference, percent body fat and BMI on lipid profiles.</p><p><b>METHODS</b>852 children aged 9-10 were recruited with multi-stage sampling. Serum lipids of children were measured using automatic biochemical instrument. Fisher's exact test, trend test and median regression were used to analyze the data from 847 subjects with valid information.</p><p><b>RESULTS</b>(1)With the rise of the BMI, percent body fat and waist circumference, total triglycerides (TG), total cholesterol (TC) and low density lipoprotein choleasterol (LDL-C) showed increasing trends while high density lipoprotein choleasterol (HDL-C) had a decreasing trend(P < 0.01). (2)TG was mainly influenced by waist circumference (t = 6.86), sex (t = 3.96) and percent of body fat (t = 1.85); TC was influenced by percent of body fat (t = 5.31); LDL-C was influenced by waist circumference (t = 4.65), height (t = -2.79) and percent age of body fat (t = 2.77); HDL-C was influenced by waist circumference (t = -12.24), sex (1= -5.83).</p><p><b>CONCLUSION</b>With the aggravation of children's fatness (BMI, WC and PBF), serum lipids would increase and WC seemed to be the best predictor for lipids among BMI, WC and PBF.</p>