Secular trends and urban-rural disparities in the median age at menarche among Chinese han girls from 1985 to 2019.

Background: Menarche is a substantial milestone of female puberty. Timing of age at menarche is considered the key to understanding the potential linkages with women's health outcomes later in life. This study aimed to explore the secular trends and urban‒rural disparities in the median age at menarche among Chinese Han girls from 1985 to 2019.

Reducing Anemia Among School-Aged Children in China by Eliminating the Geographic Disparity and Ameliorating Stunting: Evidence From a National Survey.

The aim of this study was to assess the geographic disparity in anemia and whether stunting was associated with anemia in different geographic groups among school-aged children in China. 71,129 Han children aged 7, 9, 12, and 14 years old were extracted from the 2014 cycle of Chinese National Surveys on Children Constitution and Health. Anemia, anemia severity, and stunting were defined according to WHO definitions.

[Secular trends of height among Chinese students aged 17 in 18 ethnic minorities from 1985 to 2010].

Objective: To analyze the secular trends of height among Chinese students aged 17 in different ethnic minorities from 1985 to 2010.

Methods: A total of 18 Chinese ethnic minorities' students, including Mongolian, Hui, Uygur, Zhuang, Korean, Tibetan, Miao, Buyi, Dong, Bai, Tujia, Hani, Dai, Lisu, Wa, Nakhi, Tu and Qiang as subjects were sampled from the 1985, 1995, 2000, 2005 and 2010 Chinese National Surveys on Students' Constitution and Health. The heights of 17 years old people by gender in various ethnic minorities were analyzed and compared.

[Current situation and comparison of age at menarche in 26 ethnic minority groups in Chinese girls in 2010].

Objective: To analyze the current situation of age at menarche (AAM) in Chinese ethnic minority girls aged 9-18 years, and compare the AAM with that of Chinese Han girls from the same province or autonomous region.

Methods: Probit analyses were used to calculate the AAM in various ethnic minority groups of Chinese girls who participated in 2010 National Physical Fitness and Health Surveillance. The sample size of ethnic minority girls was 31 711, and the ethnic minorities were Mongolian, Hui, Tibetan, Uighur, Miao, Yi, Zhuang, Buyi, Korean, Dong, Yao, Bai, Tujia, Hani, Kazak, Dai, Li, Lisu, Wa, Shui, Dongxiang, Naxi, Kirgiz, Tu, Qiang and Sala.

[Association between early menarche and physical fitness among adolescent girls in China].

Objective: To explore the association between early menarche and physical fitness among adolescent girls in China.

Methods: Research material was selected from the data of "2010 National Physical Fitness and Health Survey". Probability unit regression method was used to calculate the age of 10th percentile at menarche and menarche age before the 10th percentile was defined as early menarche(9.

[Analysis of influencing factors on physical endurance of Chinese primary and middle school students aged 10 to 17].

Objective: To explore the influencing factors on physical endurance among Chinese primary and middle school students aged 10-17.

Methods: Data was used from "2010 National Physical Fitness and Health Surveillance", from which 68 458 primary and middle school students with complete information were selected. Good physical endurance was defined as endurance running time ≤ P 25 of same gender and age, poor physical endurance as ≥ P 75 of same gender and age.

[Comparative study of sexual behaviors of high school students between urban and rural China].

Objective: To analyze the situation of sexual behavior in urban and rural Chinese high school students, and to make suggestions for providing appropriate sexual education in the future.

Methods: An anonymous questionnaire survey was conducted in 224 770 high school students selected by using multi-stage stratified cluster sampling method in 28 provincial units of China.

Results: Overall, 5.

[Influence of diet behaviors on height among children and adolescents in China: a multiple level analysis].

Objective: To categorize growth and development stages among children and adolescents based on height, and to explore the influences of diet behaviors on height during different growth and development stages.

Methods: Children and adolescents (7 to 18 years) with normal weights were selected using "Reference Norm for Screening Overweight and Obesity in Chinese Child and Adolescent" set up by WGOC in 2003 and "Reference Norm for Screening Underweight in Chinese Child and Adolescent" from the "2010 National Physical Fitness and Health Surveillance" data, and the variables of height and diet behaviors sorted. The growth and development stages were categorized using the hierachical cluster analysis, and the multilevel model was used to analyze influences of diet behaviors on height at different growth and development stages.

[Relationship between obesity, overweight and physical function in students of Han nationality aged 7 - 18 years in 2010].

Objective: To study the effects of overweight and obesity on physical function (including systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse, weight vital capacity index) in children and adolescents.

Methods: The data of 2010 Chinese National Survey on Students Constitution and Health was analyzed. The samples of overweight and normal-weight group were randomly selected from the data by matching gender, urban or rural for getting the same number sample size as obese group (10 601 each group).

[Behavioral risk factors for overweight and obesity among Chinese primary and middle school students in 2010].

Objective: To explore the associations between behavioral risk factors and overweight and obesity among Chinese primary and middle school students in 2010.

Methods: A total of 149 912 primary and middle school students aged 9 - 18 were selected from "2010 National Physical Fitness and Health Surveillance" while underweight students excluded. Questionnaires and height, weight and other physical index were performed.

[The trend analysis of overweight and obesity in Chinese students during 1985 - 2010].

Objective: To analyze the trend of overweight and obesity in students in China during 1985 - 2010.

Methods: The 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.

[Current situation of semenarche in boys aged 11-18 of 18 Chinese ethnic minority].

Objective: To analyze the current situation of semenarche in boys aged 11 - 18 of 18 Chinese ethnic minority, and compare the average age of semenarche with Chinese Han boys from the same province or autonomous region.

Methods: The average age of semenarche in various ethnic minority groups of Chinese boys who participated in 2005 National Physical Fitness and Health Surveillance were calculated. The sample size of ethnic minority boys was 16 267, and the ethnic minorities were Mongolian, Hui, Tibetan, Korean, Zhuang, Miao, Buyi, Dong, Shui, Tujia, Bai, Hani, Dai, Lisu, Wa, Naxi, Li and Tu.

[Changes on secular growth among minority girls in China from 1985 to 2005].

Objective: To analyze the trend of secular growth among the minority girls in China from 1985 to 2005 in order to develop national and local intervention strategies and measures to improve their physical fitness and health.

Methods: A total of 19 Chinese minority girls, including Mongolian, Hui, Zhuang, Korean, Tibetan, Miao, Buyi, Dong, Yao, Bai, Tujia, Hani, Dai, Lisu, Wa, Nakhi, Tu, Qiang and Salar were sampled from the 1985 and 2005 Chinese national surveys to study the students' physical fitness and health. Probit analyses were used to calculate age at menarche (AAM), and the heights and weights of 17-years-old girls in various minority groups.

The epidemiology of alcohol consumption and misuse among Chinese college students.

Aims: To understand alcohol-related risk behaviours among Chinese college students.

Methods: As part of the first China National Youth Risk Behaviour Survey, undertaken in 2009, 52,150 students at 119 colleges were randomly sampled. Information was obtained from self-administered questionnaires.

[Study of geographic distribution and 10 years' change of spermarche in Chinese boys of Han-group aged 11 to 18].

Objective: To analyze the geographic distribution and 10 years' change of spermarche in Chinese boys of Hangroup aged 11 - 18.

Methods: Calculate the average age of spermarche of Chinese boys who participated in National Physical Fitness and Health Surveillance in 2005 and 1995. The sample size of boys was 69 320 in 2005, 68 992 in 1995 National Physical Fitness and Health Surveillance, respectively.

[Geographic distribution and secular trend of menarche in 9-18 year-old Chinese Han girls].

Objective: To analyze the characteristics and secular trend of age at menarche (age at menarche, AAM) in Chinese girls aged 9-18.

Methods: Probit analyses were used to calculate AAMs in various populations of Chinese girls who participated in National Physical Fitness and Health Surveillance in 2005 or 1995. The samples of girls were 92 767 in 2005 and 85 433 in 1995 National Physical Fitness and Health Surveillance, respectively.

[Study on the characteristics of sexual intercourse debut and its influencing factors among college students in 18 provinces in China].

Objective: To describe the characteristics of sexual debut among college students in China to provide appropriate sex education in that population.

Methods: An anonymous questionnaire survey was conducted among 33 653 college students selected by multi-stage stratified cluster sampling method in 18 provinces and cities of China.

Results: The percentage of students who had initiated sexual intercourse before age 14 was 1.

[Secular growth trends in height and weight of Chinese children aged 7 to 18 year-old from 1985 to 2005].

Objective: To analyze the secular changes in height and weight of Chinese school children in recent 20 years, in order to take effective preventive strategies and measures to improve their physical fitness and health.

Methods: Students aged 7-18 year-old participated in the 1985, 1995 and 2005 National Survey on Students Constitution and Health were used as subjects. The LMS method was applied to draw the 5th, 50th and 95th smoothed percentile curves of height and weight, and comparison was analyzed between different years.

[Changes of physical functions among Chinese minority students from 1985 to 2005].

Objective: To study the changes of physical functions among minority students in China from 1985 to 2005, to provide evidence for health promotion to the minority students in the country.

Methods: Using data from the Chinese national survey on students physical fitness and health from 1985 to 2005, we analyzed the physical functions of 15 minority groups from primary and secondary schools, including Mongolian, Hui, Uygur, Zhuang, Korean, Tibetan, Yao, Li, Qiang, Buyi, Dong, Miao, Tu, Salar, Kirgiz, aged 7 - 18 years old.

Results: Some of the minority students had the higher levels of physiological functions and athletic ability, but some indicators decreased significantly.

[Study on the changing status of morphological development among minority students in China, from 1985 to 2005].

Objective: To identify the changes of morphological development status on minority students in China from 1985 to 2005.

Methods: We selected a total of 15 groups of the Chinese minority students as subjects of the study, including Mongolian, Hui, Uygur, Zhuang, Korean, Tibetan, Yao, Li, Qiang, Buyi, Dong, Miao, Tu, Salar, Kirgiz, with data from the Chinese national survey on students' physical fitness and health condition in 1985, 1995, 2000 and 2005. Height, weight and waist of the subjects were calculated and analyzed.

[Study on the trend of minority students' health status from 1995 to 2005 in China].

Objective: To reveal the trend of minority students' health from 1995 to 2005 in China.

Methods: We selected 15 minority groups wtih data pertaining to students' nutritional status, poor vision and decayed tooth in 1995, 2000 and 2005. The minority groups were Mongolian, Hui, Uygur, Zhuang, Korean, Tibetan, Yao, Li, Qiang, Bouyei, Dong, Hmong, Tu, Salar and Kirgiz.

[Prevalence rates of overweight and obesity in Chinese minority students in 2005].

Objective: To analyze the prevalence rates of overweight and obesity in Chinese minority students in 2005.

Methods: We analyzed data of 24 minority groups aged 7 - 18 years from Chinese national survey on students' physical fitness and health in 2005. Criterion made by the workgroup of obesity in China (WGOC) was used.

[Study on incidences and effect factors of injuries among middle school students in 18 provinces, China].

Objective: To identify the current epidemiological situation of injuries among adolescents in China and to provide basis for prevention and control.

Methods: An anonymous questionnaire survey was conducted among 170 602 middle school students in 18 provinces and cities of China.

Results: The overall incidence of injuries among middle school students was 43.

[Secular growth trends in the Chinese urban youth and its implications on public health].

Objective: To analyze the secular growth trends of the Chinese urban youth from 1979 to 2005, in order to make national intervention strategies and measures to improve their physical fitness and health.

Methods: Subjects were sampled from 16 provincial-capital cities in China. They were all Han primary and secondary school students aged 7 to 18 years.

[Analysis of motor performance status in students of Han nationality in fifteen provinces in China].

Objective: To analyze the motor performance status in students of Han nationality in fifteen provinces in china.

Methods: Totally, 161 804 students of Han nationality aged from 7 to 18 years old were involved in the Chinese Surveillance on Students' Physical Fitness and Health in 2004. Motor abilities were accessed with the aid of gripping power, 50 m dash, standing long jump, and 1-min sit-ups.