Objective: To analyze the urban-rural disparity of childhood stunting and its association with subnational economic growth among Chinese Han students aged 7-18 years. Methods: We used the data from 2014 Chinese National Survey on Students′ Constitution and Health. 213 940 Chinese Han students aged 7-18 years with complete height records were included in this study. Stunting was defined according to the Screening Criteria of Malnutrition for School-age Children and Adolescents(2014 version, in Chinese). We divided students into two groups (economically developed and underdeveloped areas) according to the provincial GDP per capita. Spearman correlation coefficient was used to explore the association between the difference of urban-rural stunting prevalence and the provincial GDP per capita. Logistic regression models were established to assess the risk of stunting in rural children compared with urban children. Results: Among 213 940 students, 107 033 (50.0%) were from urban areas. The average height of 7-18 years old and 18 years old [(152.9±15.7) and (166.1±8.7) cm] of urban students were both higher than those of rural students [(150.7±16.0) and (165.1±8.6) cm] (P<0.001). The stunting prevalence of Chinese urban students (0.4%) was statistically significant lower than that of rural students (1.1%) (P<0.001), which was consistent in all age groups (P<0.05). The urban-rural disparity was found in 60% (18/30) of Chinese provinces. The difference of urban-rural stunting prevalence was negatively associated with provincial GDP per capita (r=-0.62, P<0.001). In economically underdeveloped areas, the risk of stunting for rural students aged 7-9 years was 4.69 (95%CI: 2.93-7.52) times that for urban children, while for students aged 10-18 years, the odds ratio was 2.44 (95%CI: 2.02-2.96). In economically developed areas, the risk of stunting for rural students aged 7-9 years was 5.43 (95%CI: 3.67-8.03) times that for urban children, while for students aged 10-18 years, the odds ratio was 2.15 (95%CI: 1.85-2.49). Conclusions The urban-rural disparity of childhood stunting existed in most places in China. The difference of growth retardation between urban and rural areas was related to regional economic development.

Objective: To examine the relation between physical fitness and frequency of having breakfast among Chinese Han college students so as to provide proper intervention and theoretical basis for improving college students’ physical fitness. Methods: The data from 2014 Chinese National Survey on Students’ Constitution and Health (CNSSCH) was used. The data of 47 172 Han students were calculated, the chi-square test wasused to compare the differences of the physical fitness passing rate in different subgroups of college students. The Log-binomial model was established to assess the relation between physical fitness and breakfast consumption. Results: The unqualified rate of physical fitness was 22.8%. Boys(24.7%), urban students (25.7%), and those who exercised less than one hour per day (23.3%) had lower physical fitness passing rates than girls(20.9%), rural students (19.9%) and those who exercised more than one hour per day (20.3%)respectively(χ2=101.38, 223.33, 32.20,P<0.01). The unqualified rate of physical fitness increased by age. The unqualified rate of physical fitness in eastern, central and western regions was 21.2%, 21.7% and 25.1% respectively. The unqualified rate of physical fitness for those with normal nutritional status (18.2%) was significantly lower than those who were underweight (26.0%) or overweight/obese(42.6%)(χ2=1 660.50, P<0.01). In this study, 53.2% of college students had breakfast every day,unqualified rate of physical fitness was higher among students with less regular consumption of breakfast(χ2=393.50, P<0.01). The Log-binomial model showed that the college students who had 3-5 breakfasts(PR=1.16, 95%CI=1.11-1.20), 1-2 breakfasts(PR=1.34, 95%CI=1.28-1.40), never had breakfast (PR=1.43, 95%CI=1.32-1.53) per week had higher physical fitness failure rates than those who had breakfast every day. Conclusion There is a significant association between physical fitness and breakfast consumption among college students. Developing the good habit of having breakfast is not only the component of healthy lifestyle but also an indispensable part to the improvement of college students’ physical fitness.

Objective: To describe the subnational disparity of anemia among Chinese Han students aged 7-14 years, and to provide a reference for making intervention measures to improve anemia among Chinese children. Methods: A total of 71 115 Chinese Han students aged 7-14 years were selected from the project ‘2014 Chinese National Survey on Students’ Constitution and Health'. Anemia and its severity were defined according to the diagnosis criteria of World Health Organization (WHO). The rank sum test was used to compare anemia distribution of different subgroups. Logistic regression models were established to analyze the influencing factors of anemia and moderate-to-severe anemia. Results: In the 71 115 students with measured hemoglobin concentrations in the 2014 CNSSCH, the overall prevalence rate of anemia was 8.9%, with 5.8% to be mild anemia and 3.1% to be moderate-to-severe anemia. For boys aged 7-14 years, the hemoglobin concentration increased with age; Boys aged 7 years had the highest anemia prevalence (9.8%) and moderate-to-severe anemia prevalence(4.4%). For girls aged 7-12 years, the hemoglobin concentration increased with age, but the concentration decreased a little when girls reached 14 years of age; 14-year-old girls had the highest prevalence of anemia(13.3%), and 7-year-old girls had the highest prevalence of moderate-to-severe anemia(4.8%). The highest prevalence rates of anemia were found in Hainan (24.1%) and Gansu(19.6%), while the lowest was in Beijing(2.0%). Logistic regression models revealed that, for children aged 7 and 9 years, when comparing to those lived in urban areas, living in rural areas appeared to be a risk factor for anemia (OR=1.34) and moderate-to-severe anemia(OR=1.48); when comparing to living in cities of upper socio-economic status, living in cities of intermediate socio-economic status appeared to be a risk factor for anemia (OR=1.43) and moderate-to-severe anemia(OR=1.41), and living in cities of lower socio-economic status also appeared to be a risk factor for anemia (OR=1.26) and moderate-to-severe anemia(OR=1.35). For students aged 12 and 14 years, girls were at higher risks for anemia and moderate-to-severe anemic(OR=2.41，2.20). Conclusion The overall prevalence of anemia was low in Chinese school-aged children, but substantial subnational disparity and subgroup disparity exists. Our data called for setting up context-specific measures, such as deworming and iron supplementation, to deal with child anemia. Intervention programs need to be implemented among adolescent girls and those with relatively low socioeconomic status.

Objective To analyze the secular trends and geographic disparities of all-cause mortality among Chinese adolescents aged 10-24 years over the period of 1953-2010.Methods Data were extracted from the Chinese National Census in 1953-2010.We calculated the all-cause mortality and annualized rates of the changes.Using the provincial gross domestic product (GDP) per capita as an indicator of regional socio-economic development level,we calculated the Wagstaff normal concentration indices for adolescent mortality.Results Over the period of 1953-2010,the general patterns of Chinese adolescent mortality appeared higher in males than those in females,higher in the 20-24-year-old than those in the 15-19 year-old and in the 10-14 year-old groups,higher in adolescents from the western than those in the eastern regions.The mortality of adolescents decreased from 554.6/100 000 in 1953-1964 to 55.7/100 000 in 2010 in males and decreased from 488.4/100 000 to 26.7/100 000 in females,respectively.The percentage of decrease for females (94.5％) was higher than that for males (90.0％).In 1981-2010,the highest annualized rate of decline for males was seen in Beijing (4.4％),with the lowest seen in Qinghai (0.1％).For girls,Hubei showed the highest annualized rate of decline (6.4％) while Qinghai the lowest (0.8％).Provinces that with higher mortality tended to have lower annualized rate of decline.The concentration indices for boys were-0.07 (95％ CI:-0.11--0.03),-0.13 (95 ％ CI:-0.18--0.08),and-0.16 (95 ％ CI:-0.22--0.10) in 1990,2000,and 2010,respectively,and were-0.07 (95％CI:-0.13--0.02),-0.18 (95％CI:-0.24--0.12),and-0.18 (95％CI:-0.26--0.09) respectively in girls.The indices among 1990,2000,and 2010 did not show statistically significantly differences,both for boys and girls (P＞0.05).Conclusions Over the half century,the mortality of Chinese adolescents showed dramatic decreasing trend.However,in terms of death rates,gender and geographic disparities were consistently seen in the adolescents.

Objective:To compare the probability of physical activity (PA) time ≥1 hour at school and influencing factors in students in China between 2010 and 2014.Methods:We used the data of 2010 and 2014 Chinese National Survey on Students’ Constitution and Health (CNSSCH). The surveys covered the Han students aged 9-22 years and Tibetan students aged 9-18 years (Tibet). The participants were primary school students (9-12 years old), junior high school students (13-15 years old), senior high school students (16-18 years old) and college students (19-22 years old). The probability of PA time ≥1 hour at school was compared using χ2 tests between 2010 and 2014 survey years. Log-binomial Regression was used to estimate the relative risk ( RR) for the probability of PA time ≥1 hour at school in different age groups. Results:The overall probability of PA time ≥1 hour at school in students aged 9-22 years was 20.5 % in 2010, and 23.8 % in 2014. The difference between 2010 and 2014 was significant ( P<0.001). On the whole, the probability of PA time ≥1 hour at school increased in the eastern, central and western areas in 2014 compared with 2010 ( P<0.05), and the increase range was highest in eastern area, followed by western area and central area ( P<0.05). The probability of PA time of 1 hour at school in all age groups increased in 2014 compared with 2010 ( P<0.05). The increase in the probability of PA time ≥1 hour at school was larger in primary school students than that in high school students and college students ( P<0.05). The probability of PA time ≥1 hour at school increased in all age groups in three areas, except in junior and senior high school students in the central area where the probability of PA time ≥1 hour at school decreased. The probability of PA time ≥1 hour at school in primary and junior/senior high school students in the eastern area had the greatest increase, but in college students it had the smallest increase in the three areas. From 2010 to 2014, the changes in the probability of PA time ≥1 hour at school in students in different provinces were quite different, especially in primary school students. The probability of PA time ≥1 hour at school in four age groups increased in only three provinces. With the probability of PA time ≥1 hour at school in primary school students as the reference, the RR in junior high students had no significant change between 2010 and 2014. The RR in senior high school increased from 0.34 (0.33-0.35) in 2010 to 0.36 (0.36-0.37) in 2014, and the RR in college students increased from 0.33 (0.32-0.34) in 2010 to 0.43 (0.42-0.44) in 2014. Conclusions:The probability of PA time ≥1 hour at school in all age groups increased in 2014 compared with 2010, but there were great differences among provinces. The findings of our study suggests that although the national policy played a certain role, the provinces should take specific measures to improve the probability of PA time ≥1 hour at school in students according to their own conditions. In addition, more attention should be paid to PA of older students.

Objective To analyze the urban?rural disparity of childhood stunting and its association with subnational economic growth among Chinese Han students aged 7-18 years. Methods We used the data from 2014 Chinese National Survey on Students′ Constitution and Health. 213 940 Chinese Han students aged 7-18 years with complete height records were included in this study. Stunting was defined according to the Screening Criteria of Malnutrition for School?age Children and Adolescents(2014 version, in Chinese). We divided students into two groups (economically developed and underdeveloped areas) according to the provincial GDP per capita. Spearman correlation coefficient was used to explore the association between the difference of urban?rural stunting prevalence and the provincial GDP per capita. Logistic regression models were established to assess the risk of stunting in rural children compared with urban children. Results Among 213 940 students, 107 033 (50.0%) were from urban areas. The average height of 7-18 years old and 18 years old [(152.9±15.7) and (166.1±8.7) cm] of urban students were both higher than those of rural students [(150.7±16.0) and (165.1±8.6) cm] (P<0.001). The stunting prevalence of Chinese urban students (0.4%) was statistically significant lower than that of rural students (1.1%) (P< 0.001), which was consistent in all age groups (P<0.05). The urban?rural disparity was found in 60% (18/30) of Chinese provinces. The difference of urban?rural stunting prevalence was negatively associated with provincial GDP per capita (r=-0.62, P<0.001). In economically underdeveloped areas, the risk of stunting for rural students aged 7-9 years was 4.69 (95%CI: 2.93-7.52) times that for urban children, while for students aged 10-18 years, the odds ratio was 2.44 (95%CI: 2.02-2.96). In economically developed areas, the risk of stunting for rural students aged 7-9 years was 5.43 (95%CI : 3.67-8.03) times that for urban children, while for students aged 10-18 years, the odds ratio was 2.15 (95%CI: 1.85-2.49). Conclusions The urban?rural disparity of childhood stunting existed in most places in China. The difference of growth retardation between urban and rural areas was related to regional economic development.

Objective To analyze the urban?rural disparity of childhood stunting and its association with subnational economic growth among Chinese Han students aged 7-18 years. Methods We used the data from 2014 Chinese National Survey on Students′ Constitution and Health. 213 940 Chinese Han students aged 7-18 years with complete height records were included in this study. Stunting was defined according to the Screening Criteria of Malnutrition for School?age Children and Adolescents(2014 version, in Chinese). We divided students into two groups (economically developed and underdeveloped areas) according to the provincial GDP per capita. Spearman correlation coefficient was used to explore the association between the difference of urban?rural stunting prevalence and the provincial GDP per capita. Logistic regression models were established to assess the risk of stunting in rural children compared with urban children. Results Among 213 940 students, 107 033 (50.0%) were from urban areas. The average height of 7-18 years old and 18 years old [(152.9±15.7) and (166.1±8.7) cm] of urban students were both higher than those of rural students [(150.7±16.0) and (165.1±8.6) cm] (P<0.001). The stunting prevalence of Chinese urban students (0.4%) was statistically significant lower than that of rural students (1.1%) (P< 0.001), which was consistent in all age groups (P<0.05). The urban?rural disparity was found in 60% (18/30) of Chinese provinces. The difference of urban?rural stunting prevalence was negatively associated with provincial GDP per capita (r=-0.62, P<0.001). In economically underdeveloped areas, the risk of stunting for rural students aged 7-9 years was 4.69 (95%CI: 2.93-7.52) times that for urban children, while for students aged 10-18 years, the odds ratio was 2.44 (95%CI: 2.02-2.96). In economically developed areas, the risk of stunting for rural students aged 7-9 years was 5.43 (95%CI : 3.67-8.03) times that for urban children, while for students aged 10-18 years, the odds ratio was 2.15 (95%CI: 1.85-2.49). Conclusions The urban?rural disparity of childhood stunting existed in most places in China. The difference of growth retardation between urban and rural areas was related to regional economic development.