Objective To analyze the district differences of height among Chinese Han population aged 7 to 18 years,and to divide the levels of heights into several regions accordingly,to provide basis for evaluation the development of height in the above said population.Methods Standard Deviation was used to compare the relative lavels of height in different provinces and to divide them into several regions.The results were then showed in map through the Geographic Information System (GIS).Results All the 30 provinces in China were divided into three regions:high,medium and short regions according to the stature.Region with high stature was mainly located in northern,while medium stature was in central and northwest parts and short stature was in southwest parts of China.The differences of height appeared to be significant among regions in every age group.The differences of height were 1-3 cm between adjacent regions,and were even lager between the regions with high or short stature which appeared to be 4-5 cm.Conclusion Overall,heights among the Chinese Han children and adolescents were taller in the northern and shorter in the southern areas.The highest and lowest levels of heights were in the Northern and the Southwest areas respectively.It was observed that the levels of height in the coastal areas were higher than that of the inland.There were no absolute boundaries between different regions because of the gradual transition in the levels of heights in various districts.

Objective To develop the reference on height among children and adolescents aged 7 to 18 years of Chinese Han ethnicity in different administrative districts of China and to use this height reference for screening stunting.Results from the national screening program were compared with the WHO references.Methods Data from the Chinese National Survey on Students Constitution and Health in 2005 was used to develop the height references through LMS method.Results Differences among the references on height for children and adolescents in different districts ( Ⅰ - Ⅳ ) were remarkable.The highest was seen in the Second Districts while the lowest was seen in the First Districts among those at the age of 18,with differences as 3.18 cm for boys and 2.92 cm for girls.The heights from the inland were shorter than that of the WHO references,with the differences ranging from 0.31 cm to 5.07 cm for boys,and from 0.98 cm to 4.22 cm for girls.The prevalence rates of stunting were 2.22％,2.29％,5.25％,respectively according to local references,national references and the WHO references.Conclusion Universal height references from the whole nation could not discriminate the variations caused by geographic conditions and hereditory factors related to socio-economie situations.Height references should be developed locally,to evaluate height levels of the areas.

OBJECTIVETo analyze the trend of overweight and obesity in students in China during 1985 - 2010.

METHODSThe data were from Chinese National Survey on Students Constitution and Health in 1985, 1995, 2000, 2005 and 2010, and the sample sizes were 204 977, 216 786, 234 421, 215 319, respectively. BMI was calculated with height and weight. The prevalence of overweight and obesity as well as the rates of increase were described based on the BMI percentile criteria of Working Group on Obesity in China (WGOC).

RESULTSIn 2010, the prevalence of overweight and obesity in four groups students (urban boys, urban girls, rural boys, and rural girls aged 7 - 18 years) were 23.23% (12 503/53 830), 13.76% (7 414/53 857), 12.72% (6 839/53 744), 8.56% (4 612/53 888), respectively, which were higher in boys and urban, and reached the peak 17.14% (18 463/107 741) in students aged 7 - 12 years. The prevalences of obesity were 0.44% (8/1800) - 21.67% (390/1800) among children aged 7 - 18 years in different provinces. The prevalence of overweight and obesity during 1985 - 1995, 1995 - 2000, 2000 - 2005 and 2005 - 2010 increased 0.10%, 0.30%, 0.23%, 0.23%, respectively, and the increase rate was higher in urban than in rural during 1985 - 2005. During 1985 - 1995, the increase rate of obesity in four groups students were 0.20%, 0.13%, 0.05% and 0.03%, respectively. During 2005 - 2010, the increase rates of obesity in four groups of students were 0.30%, 0.10%, 0.34%, 0.17%, respectively, and the increase rate was higher in rural than in urban.

CONCLUSIONThe prevalence of obesity among 7 - 18 years-old children increased rapidly during the 1985-2000, and the increase rate of obesity in rural exceeded that in urban during 2005 - 2010.

Adolescent ; Body Mass Index ; Child ; China ; epidemiology ; Female ; Health Surveys ; Humans ; Male ; Obesity ; epidemiology ; Overweight ; epidemiology ; Rural Population ; Students ; Urban Population

Objective To discuss characteristics of height growth such as Peak Height Velocity (PHV) and Age at Peak Height Velocity (PHA) during adolescence,and to compare the results with other research findings.Methods Primary and middle school students' annual physical examination data of Zhongshan in 2005-2010 was used.The height velocity by age,PHV,PHA,height velocity by PHA were calculated.Results The average peak height velocity boys was ( 10.03 ± 1.67 ) cm/yr.and that of the girls was ( 8.39 ± 1.05 ) cm/yr.Both findings were close to the results from previous similar findings.The average age at which peak height velocity reached 12.28± 1.30 years for boys and 10.78 ± 1.04 years for girls,both lower than the previous findings.The correlation coefficients,between height level and PHA were -0.357 (P＜0.001) for boys and -0.338 (P＜0.001) for girls.Conclusion The height levels were positively related to the height velocity before PHA.The Zhongshan students' PHA was lower than the Beijing,Shanghai and Shenyang students,also lower than American and Britain students',but their PHVs were similar.