Objective This paper aims to study the relationship between body fat and sexual development in Chinese girls with different waist circumference.Methods Six thousand one hundred and fifty six girls aged 6-19 were sampled.Their body weight,height,waist circumference,percentage of body fat and secondary sex characteristics were measured.All the subjects were divided into three groups:low class waist circumference,moderate class waist circumference and high class waist circumference.The menarche percentages were analyzed by using the status method.The menarche ages were analyzed by using the retrospective method.Estimates for mean age at entry into a pubertal stage and menarche were calculated by a probit analysis.Results The incidences of moderate class and high class waist circumstance were 20.94% and 25.27%,respectively.The sexual development of the former was earlier than that of the latter.The percentages of the menarche were detected as high class>moderate class>low class.The menarche ages were expressed as high class
Objective To analyze the change in Body Mass Index (BMI) distribution among Chinese children and adolescents for the development of more effective intervention for childhood obesity. Methods Data on the national students' constitution and health survey between 1985 and 2010 was used for this study. Subjects were students aged 7-18 randomly selected from 30 provinces in China. BMI for-age curves were developed by LMS method, and the trend of BMI distribution was determined by comparing the upper BMI percentiles and analyzing the skew shift of distribution between 1985 and 2010. Results An overall positive swift trend of BMI between 1985 and 2010 was observed among the Chinese school-age children and adolescents. The average median of the BMI increased from 16.8 and 17.0 kg/m2 to 18.2 and 17.9 kg/m2 in 25 years, with increments 0.56 and 0.36 kg/m2 per decade for males and females, respectively. The more obvious increments were found at the high BMI. The total increments of BMI in this period were 4.03 and 2.20 kg/m2 at the 85th, 6.14 and 3.57 kg/m2 at the 95th, and 6.99 and 4.27 kg/m2 at the 97th percentiles, for males and females, respectively. Conclusion Obvious increments were observed at high BMI of the Chinese children and adolescents. More effective interventions should be taken for control and prevention of obesity and its health consequence for these subgroups. It is necessary to establish a risk-complex system consisting of the identification of BMI scope, the screen of the disease risk factors and the assessment of excessive adiposity.
Objective To analyze and assess secular change in stature in rural children and adolescents in China from 1985 to 2010.Methods Data were obtained from the 6 rounds of the Chinese National Survey on Student’s Constitution and Health.The subjects enrolled in the study were children and adolescents aged 7-18years in rural areas of provincial capitals.Results An overall positive secular trend in stature occurred in rural areas of provincial capitals in China from 1985 to 2010.The overall average increase rates were 3.1 and 2.4 cm/decade for boys and girls,respectively.The total body height increases for grown up boys and girls were 3.6 and 2.3 cm and the increase rates were 1.4 and 0.9 cm/decade,respectively.There were differences in body height increase among eastern,central and western regions.The average body height of the children or adolescents in eastern region was highest,followed by central region and western region.The overall increase rates in central region were highest among the three regions.The difference between eastern/central region and western region was obvious.Conclusion Positive secular trend in stature of children or adolescents has occurred in rural area of China,and rural boys and girls showed a great potential for continuous growth.More attention should be paid to the differences in children’s body height between western region and eastern/central region.
Objective Research evidence shows a secular trend in Chinese physical growth in recent years.The aim of this study was to analyze and assess changes in stature of children and adolescents during the 25 years from 1985‐2010,using national data.Methods Data came from successive cycles of the Chinese National Survey on Students' Constitution and Health(CNSSCH).Subjects were 7‐ to 18‐year‐old children and adolescents.Results An overall positive secular trend occurred in urban China during 1985‐2010.The overall average rates of increment were 2.4 and 1.7 cm/decade for boys and girls,respectively.Total increases in adult stature for boys and girls were 2.6 and 1.7 cm,yielding rates of 1.0 and 0.7 cm/decade,respectively.Cities with different socioeconomic levels had different characteristic trends.Mean stature increases in big cities were larger than those in moderate and small cities,and boys and girls in moderate and small cities showed greater potential for growth in stature.Conclusion An overall positive secular growth trend was associated with socioeconomic progress and differed with area socioeconomic levels.School policies and strategies should be developed based on increased stature,and should continue narrowing the inequity between different socioeconomic populations.
