Nutrition in Chinese-Korean Children and Adolescents / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the nutrition habits among Chinese-Korean children and adolescents in Yanbian Autonomous Prefecture, Jilin, China.</p><p><b>METHODS</b>Data were obtained from the Chinese National Survey on Students' Constitution and Health in 1995, 2000, 2005, and 2010 for Chinese-Korean children and adolescents aged 7-18 years. The number of the subjects included was 4789, 4704, 5875, and 5315, respectively.</p><p><b>RESULTS</b>The rate of the occurrence of stunting showed a declining trend from 1995 to 2010 (for boys: urban, 6.3%; rural, 12.7% in 1995 and 3.5% for both in 2010. For girls: urban, 7.8%; rural, 13.4% in 1995 and 4.2% and 5.5%, respectively, in 2010). Although the ratio of wasting did not show significant differences between the urban and rural children and adolescents in 1995, 2000, 2005, and 2010 respectively, the ratio of occurrence of overweight or obesity increased (for boys: urban, 7.3% and 1.3% in 1995, 17.6% and 12.9% in 2010; rural, 7.0% and 1.3% in 1995, 14.6% and 12.8% in 2010, respectively. For girls: urban, 8.1% and 1.0% in 1995, 17.3% and 8.6% in 2010; rural 5.7% and 0.7% in 1995, 16.4% and 7.4% in 2010, respectively).</p><p><b>CONCLUSION</b>The ratio of malnutrition in children and adolescents in Chinese-Korean areas declined from 1995 to 2010, and the distinction in malnutrition between the urban and rural areas was negligible in 2010. Further, the ratio of overweight and obesity increased over this period.</p>

Relationship between Migration and HIV Risky Behavior: a Comparative Study of Returning Migrants and Non Migrants Based on Rural Out-of-school Youth in Jilin, China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To estimate the relationship between migration and HIV risky behavior when controlling for gender, age, and educational levels and to evaluate the gender differences in migration, HIV knowledge, and HIV risky behaviors among rural youth in China.</p><p><b>METHODS</b>A cross-sectional, anonymous, investigative questionnaire for 1710 unmarried, out-of-school rural youth, aged between 15 and 24 years, was handed out in Gongzhuling county of Jilin province, China.</p><p><b>RESULTS</b>58.5% of participants had a history of migration, irrespective of gender. There were gender differences observed in other factors such as drug abuse (4.3% for males and 5.5% for females, P<0.01), multiple sexual partners (24.1% for males and 44.1% for females, P<0.01), and HIV knowledge rate (35.2% for males and 25.5% for females, P<0.001). While controlling for gender, age, and educational levels, the relationships between migration and drug abuse, selling sex, and non usage of condoms during last instance of sexual activity were found to be significant. The cases of premarital sex and multiple sexual partners were both not found to be related to migration.</p><p><b>CONCLUSION</b>Among rural youth, the HIV risky behavior such as drug abuse, selling sex, and lack of condom use, is significantly related to migration, while premarital sex and multiple sexual partners seem unrelated to migration.</p>

Secular changes of stature in rural children and adolescents in China, 1985-2010 / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To analyze and assess secular change in stature in rural children and adolescents in China from 1985 to 2010.</p><p><b>METHODS</b>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 7-18 years in rural areas of provincial capitals.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Malnutrition prevalence in lasa xizang children and adolescents / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To assess the prevalence of malnutrition among children and adolescents in Xizang (Tibet).</p><p><b>METHODS</b>We analyzed data from the Chinese National Survey on Students' Constitution and Health for the years 1995, 2000, 2005, and 2010 pertaining to Tibetan children and adolescents in lase (Lhasa), aged 7-18 years old. Numbers of survey subjects for these years were: 2393, 2754, 2397, and 2643, respectively.</p><p><b>RESULTS</b>Our results indicated that the rate of occurrence of stunting in Tibet has evidenced a gradual decline: for boys, from 26.8% in 2000 to 9.3% in 2010; and for girls, from 25.8% in 2000 to 10.8% in 2010. In general, the wasting rate for both boys and girls in Tibet has gradually decreased over time: for boys, from 17.7% in 1995 to 4.6% in 2005; and for girls from 12.5% in 1995 to 2.3% in 2005. The stunting rates of boys aged 7-13 years old and of girls aged 7-11 years old were 67.5% and 53.1%, respectively, while these rates for boys aged 14-18 years old and girls aged 12-18 years old were 32.5% and 46.9%, respectively.</p><p><b>CONCLUSION</b>Stunting and wasting rates of Tibetan children and adolescents indicate a gradual declining trend over time. The stunting rates of both boys and girls during early puberty were significantly higher than those during late puberty.</p>

Empirical changes in the prevalence of overweight and obesity among Chinese students from 1985 to 2010 and corresponding preventive strategies / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To determine the extent of the obesity epidemic in school-aged Chinese children in 2010 and track the increasing trend in different socioeconomic regions over the preceding 25 years. Strategies for preventing childhood obesity are suggested.</p><p><b>METHODS</b>We used a dataset provided by the Chinese National Survey on Students' Constitution and Health from 1985-2010. Subjects were 7-18-year-old students randomly selected from urban and rural areas in 30 provinces. Eight subgroups were created according to region and socioeconomic status.</p><p><b>RESULTS</b>Increased rates of the epidemic (overweight and obesity combined) were greatest in large coastal cities-32.6% and 19.1% among males and females, respectively. These rates has neared that of developed countries. Similar increases were found in all other regions, including the once poverty-stricken rural west. The epidemic in most of the rural areas began after 2000, but has spread swiftly over the last decade. In 2010, it was estimated that 9.9% of Chinese school-aged children and adolescents were overweight and that an additional 5.1% were obese, representing an estimated 30.43 million individuals.</p><p><b>CONCLUSION</b>The prognosis for China's childhood-obesity epidemic is dire. To prevent childhood obesity, we suggest several strategies, including reasonable dietary intake, increase physical activity, a change in sedentary lifestyles and corresponding behavioral modifications.</p>

Secular change in stature of urban Chinese children and adolescents, 1985-2010 / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Secular changes on the distribution of body mass index among Chinese children and adolescents, 1985-2010 / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Study on the characteristics of sexual intercourse debut and its influencing factors among college students in 18 provinces in China / 中华流行病学杂志

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 1.9%. Overall, male students (2.8%) were significantly more likely to have initiated sexual intercourse before age 14, than female students (1.1%). The percentage of students who had initiated sexual intercourse from age 15 to 18 was 6.4% in males versus 2.1% in females. while the rates of students who had initiated sexual intercourse after age 19 were 6.9% in males and 2.6% in females. The first sexual intercourse was significantly associated with parental educational attainment, geographic location and family structure. Students whose parents were relatively well educated, living in the western areas of the country China, or with nucleus/extensive families were more likely to have early sex in their puberties. Conclusion Sexual education should be strengthened especially in the western areas, and targeted on the students whose parents with relatively higher educational background or who were from extensive families.

Waist circumference distribution of Chinese school-age children and adolescents / 生物医学与环境科学（英文）

<p><b>BACKGROUND</b>Waist circumference (WC), a proxy measure of central body fat, is a better predictor than overall body fat for cardiovascular risk factors in both adults and children. WC cutoffs have been established in many countries, but the national WC reference has not been developed in China.</p><p><b>OBJECTIVE</b>To study the distribution of WC in a representative group of Chinese children for establishing Chinese WC cutoff points.</p><p><b>METHODS</b>Cross-sectional data obtained from 15 mainland provinces and Hong Kong were collected. There were 160,225 children and adolescents aged 7-18 years old in total. The subjects were divided into five regional groups namely costal city, other city, north rural, south rural, and Hong Kong, for analyzing the distribution of WC.</p><p><b>RESULTS</b>A large variation in WC distribution was found among the five groups for both sexes. Coastal city group had the highest P85 WC values consistently from the early school ages to 18-year-old compared with other groups. In contrast, south rural group had P85 values consistently lagged behind not only the city groups but also the north rural group. Hong Kong group had a high P85 WC at early ages, but because of the smaller increments of WC during adolescence, the P85 curve was gradually exceeded by the north rural groups. Catch-up trend was found in the two rural groups since the peak of puberty. These disparities were caused by not only socioeconomic and urban-rural factors but also north-south differences. Because of the regional variation of WC, a "gradient" prevalence of central obesity was prospected among these groups. Comparisons of WC distributions between the Chinese and the U.S.A. or Netherlands demonstrated the necessary of setting up China's own WC cutoffs. Sex and age-specific percentiles were obtained and smoothed by using LMS method.</p><p><b>CONCLUSION</b>The data obtained from this study could be used to develop national WC cutoff points for Chinese children and adolescents.</p>

Waist circumference reference values for screening cardiovascular risk factors in Chinese children and adolescents / 生物医学与环境科学（英文）

<p><b>OBJECTIVES</b>To explore the optimal threshold values of waist circumference (WC) for detecting cardiovascular (CV) risk factors among Chinese children and adolescents.</p><p><b>METHODS</b>Association of WC with CV risk factors was studied among 65,898 children aged 7-18 years whose data were pooled from nine previous studies in China. CV risk factors in this study included hypertension (blood pressure above 95 percentile levels), dyslipidemia (with one or more of the following three indexes: TG > or = 1.7 mmol/L, TC > or = 5.18 mmol/L, and HDL-C < or = 1.04 mmol/L) and elevated glucose level (fasting plasma glucose > or = 5.6 mmol/L). Receive-operating characteristic analysis (ROC) and logistic regression were employed to derive optimal age- and sex-specific waist circumference references for predicting CV risk factors.</p><p><b>RESULTS</b>A slight increasing trend of CV risk factors was observed starting from the 75th percentile of waist circumference in the study population, while a remarkable increasing trend occurred from the 90th percentile. The optimal waist circumference thresholds for predicting high blood pressures were at the 75th percentile for both boys and girls, which was at the 90th percentiles for detecting at least two of the above three CV risk factors. In comparison with children with waist circumference below the 75th percentile, the odds ratio of two CV risk factors doubled among children with waist circumference between the 75th and the 90th percentile, and increased by 6 times among children with waist circumference above the 90th percentile. The trend of high blood pressure increasing with waist circumference remained significant after having been stratified by BMI category.</p><p><b>CONCLUSION</b>The 75th and the 90th percentiles of WC are the optimal cut-off points for predicting an increased and a substantially increased risk of CV factors in Chinese children and adolescents, respectively.</p>

Waist circumference distribution of Chinese school-age children and adolescents / 中华流行病学杂志

Objective To study the distribution of waist circumference (WC) in a representative group of Chinese children for establishing the Chinese WC cut-off points. Methods Cross-sectional data obtained from 15 mainland provinces and Hong Kong were collected. There were 178 865 children and adolescents, aged 7-18 years-old in total. All subjects were divided into five regional groups- costal city, non-coastal city, northern rural, southern rural, and Hong Kong, for analyzing the distribution of WC. Results Large variations in WC distribution were found among the five groups for both sexes. The coastal city group had the highest P85 WC values consistently from the early school age to 18-year-old, when comparing with other groups. In contrast, southern rural group had P85 values consistently lagged behind, in both city group and in the north rural group. Hong Kong group had a high P85 WC at early ages, but because of the smaller increments of WC during adolescence, the P85 curve was gradually exceeded by the northern rural groups. Catch-up trend was found in the two rural groups since peak puberty. These disparities were caused not only by factors related to socioeconomic and urban-rural but also to the geographic differences between the noah and the south. Because of the regional variation of WC, a "gradient" prevalence of central obesity was prospected among these groups. Closed associations were found between WC and height, weight and BMI in all age period. Comparison on the WC distributions between people from China, U.S.A or the Netherlands demonstrated the necessity of setting up China's own WC cutoffs.Sex and age-specific percentiles were obtained and smoothed by using the LMS method.Conclusion Data obtained from this study could be used to develop the national WC cutoff points for Chinese children and adolescents.

Waist circumference reference values for screening cardiovascular risk factors in Chinese children and adolescents aged 7-18 years / 中华流行病学杂志

Objective To explore the optimal threshold values of waist circumference (WC) in detecting the risk on cardiovascular (CV) among the Chinese children and adolescents. Methods Association of WC and CV risk factors were studied among 65 898 children and adolescents aged 7-18 years whose data were pooled from nine studies carried out in China. Receive-operating characteristic analysis (ROC) and logistic regression were employed to derive optimal age- and sex-specific waist circumference references for predicting the CV risk factors. Results A slight increasing trend of CV risk factors was observed starting from the 75th percentile of waist circumference in the study population, while a remarkable increasing trend occurred from the 90th percentile. The optimal waist circumference thresholds for predicting high blood pressures were at the 75th percentile for both boys and girls, and at the 90th percentiles it could detect at least two of the above three CV risk factors. In comparison with children whose waist circumference was below the 75th percentile, the odds ratio of two CV risk factors doubled among children with waist circumference between 75th and 90th percentile, and increased by 6 times among children with waist circumference above the 90th percentile. The trend of high blood pressure increasing remained significant with waist circumference after having been stratified by BMI category. Conclusion The 75th and the 90th percentile of WC appeared to be the optimal cut-off points for predicting an increased and a substantially increased risk of CV factors in Chinese children and adolescents.

Body mass index cut-offs for overweight and obesity in Chinese children and adolescents aged 2-18 years / 中华流行病学杂志

Objective To study the body cut-offs of mass index (BMI) for the purpose of screening overweight and obesity for Chinese children and adolescents aged 2-18 years. Methods Based on the BMI growth reference values for Chinese children aged 0-18, using the common methods to establish the BMI cut-offs for screening overweight and obesity. These methods were having the same empirical percentile or Z scores and the BMI value at 18 years consistent with adults.Three sets of BMI cut-offs, including (BMI24, BMI28) , (P85, P95) and (Z1, Z2) , were initially identified. Differences were compared on different cut-off points and prevalence rates of overweight and obesity with different BMI reference, different values and "prevalence" of overweight and obesity based on "2004 Beijing Child and Adolescent Metabolic Syndrome Study ". Cut-offs standards which recommended by the Chinese Working Group on Obesity for Children (WGOC) and by the International Obesity Task Force (IOTF) were also used. Finally the appropriate cut-offs were defined. Results Three sets of BMI cut-offs for screening overweight and obesity for Chinese children and adolescents aged 2-18 years were obtained according to the above mentioned methods for selection. The prevalence rates of overweight and obesity defined by those cut-offs appeared not to be significantly different. Compared with the WGOC, the BMI cut-off points for screening overweight and obesity for both boys and girls from our study were very close to the WGOC', but cut-off points for screening overweight for girls aged 8.5-15.5 y was 0.3-1.0 kg/m2 lower than the WGOC'. Going through the database on screening of "2004 Beijing Children's Metabolic Syndrome Survey ", the prevalence of overweight for girls was about 3.4% higher than using the cut-offs of WGOC. Conclusion Results from this study suggested that the BMI cut-offs passed through the cut-off point of BMI24 and BMI28 at 18 years was appropriate for screening overweight and obesity in Chinese children from 2 to 18 years, and achieved the continuity in age and consistency in screening standard when using the BMI indicator in children and adolescents.

Height and weight standardized growth charts for Chinese children and adolescents aged 0 to 18 years / 中华儿科杂志

<p><b>OBJECTIVE</b>To construct the height and weight growth charts for Chinese children and adolescents from birth to 18 years for both clinical and preventive health care uses.</p><p><b>METHODS</b>Data from two national representative cross-sectional surveys which were The National Growth Survey of Children under 7 years in the Nine Cities of China in 2005 and The Physical Fitness and Health Surveillance of Chinese School Students in 2005. The data from 94,302 urban healthy children were used to set up the database of length/height (length was measured for children under 3 years) and weight. The LMS method was used to smooth the growth curves, with estimates of L, M, and S parameters, values of percentile and Z-score curves which were required were calculated, and then generated standardized growth charts.</p><p><b>RESULTS</b>The 3rd, 10th, 25th, 50th, 75th, 90th, 97th smoothed percentiles curves and -3, -2, -1, 0, +1, +2, +3 Z-scores curves of weight-for-age, length/height-for-age for boys and girls aged 0-18 years were made out respectively. Comparison with the new WHO growth charts and 2000 CDC growth charts for the United States, the results showed that there was some big difference in weight and height among the three growth charts. For boys under 15 years of age and girls under 13 years of age, the China curves are slightly higher than WHO and CDC curves, but after those ages, the China curves fall behind and the difference became larger as age progresses. At the age of 18 years, the Chinese children are 3.5 cm shorter in boys and 2.5 cm shorter in girls as compared with the U. S. children. The difference in weights are very large for the school children, especially in girls. The weight of Chinese boys was 5.9 kg less than that of the U. S. boys at 18 years, and the difference was much bigger in girls, the weight of U.S. girls between 8 to 18 years was 4.1-20.5 kg more than that of Chinese girls at the same age range.</p><p><b>CONCLUSION</b>The new growth charts of height and weight were based on national survey data and therefore are recommended as the China national growth standards for use in pediatric clinics and public health service. Application of the charts will promote child growth monitoring, discovering early growth disorder, and will be useful to diagnosis of diseases and assessment of therapeutic effects.</p>

Body mass index growth curves for Chinese children and adolescents aged 0 to 18 years / 中华儿科杂志

<p><b>OBJECTIVE</b>To construct the body mass index (BMI) reference data and curves for Chinese children and adolescents from birth to 18 years of age.</p><p><b>METHODS</b>Data from two national representative cross-sectional surveys which were The National Growth Survey of Children under 7 years in the Nine Cities of China in 2005 and The Physical Fitness and Health Surveillance of Chinese School Students in 2005. Height (length was measured for children under 3 years) and weight data of 93,702 urban healthy children from nine cities/provinces used to calculate the BMI. The LMS method was used to smooth the BMI, with estimates of L, M, and S parameters, values of percentile and Z-score curves which were required were calculated, and then standardized growth charts were generated. Adult cut-offs for overweight and obesity at 18 years was used to study the cut-offs for children 2 to 18 years of age.</p><p><b>RESULTS</b>The smoothed percentiles and Z-scores reference data and curves of BMI-for-age for boys and girls aged 0-18 years were made out respectively. BMI cut-off values for overweight and obesity for children from 2 to 18 years of age were also defined. At 18 years, the BMI values are equivalent to the overweight cut-off (> or =24 kg/m2) and obesity cut-off (> or =28 kg/m2) for Chinese adults. Comparison with the reference of the WHO and 2000 CDC for the United States, there were some difference among them, at the 97th percentile curve there was a big difference between Chinese and U. S. adolescents. On the whole, the China BMI curve for boys was higher than the new WHO curve and lower than 2000 CDC at 97 percentile curve, but the China BMI curve for girls was lowest among the three curves. There was also significant difference between China and Japan BMI values at 97 percentile curve.</p><p><b>CONCLUSION</b>BMI growth curves are very useful in child growth monitoring and nutritional surveillance, discovering overweight and obesity. The BMI growth charts are recommended for use in pediatric clinic and public health service.</p>

Investigation of HIV/AIDS related knowledge and attitude among 6,487 high school students / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate HIV/AIDS related knowledge and attitude among high school students in China, and to preliminarily evaluate the effects of the special HIV/AIDS prevention education programme.</p><p><b>METHODS</b>A total of 6487 high school students from 24 high schools of Beijing, Zhengzhou and Tangshan were investigated by using questionnaire, among which, 6487 students completed the questionnaire (96.08%). chi(2) test, t test and one way ANOVA were used to test the group differences and logistic regression was employed for further analysis. P < 0.05 was considered as statistically significance.</p><p><b>RESULTS</b>The mean knowledge and attitude scores of the students were separately 14.42 out of 20 and 6.47 out of 10. Students from Tangshan had the significantly (P < 0.001) highest knowledge and attitude level (average score of knowledge = 15.11, average score of attitude = 7.21) followed by Beijing (average score of knowledge = 14.62, average score of attitude = 6.15) and Zhengzhou (average score of knowledge = 13.56, average score of attitude = 6.07). The significant differences were observed in all except the varying attitude between Zhengzhou and Beijing (Knowledge comparison: t(Tangshan vs Beijing) = 0.49, P < 0.001, t(Tangshan vs Zhengzhou) = 1.56, P < 0.001, t(Zhengzhou vs Beijing) = 1.07, P < 0.001; Attitude Comparison: t(Tangshan vs Beijing) = 1.06, P < 0.001, t(Tangshan vs Zhengzhou) = 1.14, P < 0.001, t(Zhengzhou vs Beijing) = 0.08, P = 0.282). Boys had higher knowledge scores (average score of knowledge = 14.61) than those of girls (average score of knowledge = 14.23, t = 4.22, P < 0.001) but no significant difference was found (average knowledge score of boys = 6.47, average knowledge score of girls = 6.48, t = 0.16, P = 0.869). Higher knowledge level (OR = 1.21, P < 0.001) and being a rural student (OR = 1.31, P < 0.001) were significantly associated with higher attitude level, while higher grade (OR = 0.85, P = 0.003) and better academic performance (OR = 0.94, P = 0.003) were negative predictors of attitude.</p><p><b>CONCLUSION</b>The HIV/AIDS related knowledge among high school students in China was relatively limited and instability positive attitude under the pressure of social desirability. It is necessary to tailor the special education strategies for further education effect improvement.</p>

The prevalence of bullying behaviors among urban middle school students in 18 provinces, China / 中华流行病学杂志

Objective To find out the prevalence of bullying behaviors among urban middle school students in China. Methods An anonymous questionnaire survey was conducted among middle school students selected by multiply stage cluster random sampling in 18 provinces in China. 187 328 self- administration questionnaires were finished by students from grade 7 to 12 in urban middle school(male,86 472; female, 91 106), in which 177 578 were valid. Results Bullying was common in urban middle school students in China. Multiple bullying behavior also existed. About 66.1% of boys and 48.8% of girls suffered from one or more kinds of bullying; 8.1% of boys and 2.9% of girls suffered from four or more kinds of bullying. Boys were more likely to be bullied than girls. Malicious teasing was the most common bullying behavior(43.2%), followed by sexual bullying behavior(27.0%). In addition to malicious teasing and sexual bullying, the prevalence of other types of bullying declined when the grade was increasing. Residential students were more likely to be maliciously teased, excluded or isolated and sexual bullied than non-residential students. Students from single-parent or recomposed-families were more likely to be bullied than other students. Male and ordinary school students, students living with single or step-parents were more likely to suffer multiple bullying behaviors at the same time. Conclusion The suggesting among students was associated with personal, familiar and social factors, mobilize more social forces and comprehensive actions to be taken to prevent bullying among students.

Parental anxiety and quality of life of epileptic children / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the prevalence of parental anxiety associated with epileptic children, and to explore whether and how this specific condition affects children's quality of life (QOL), and what are the significant determinants for parental anxiety.</p><p><b>METHODS</b>Three hundred and forty parents whose children were affected with known epilepsy were enrolled in the study. Questionnaires for quality of life in childhood epilepsy (QOLCE), and hospital anxiety and depression (HAD) of parents were used to collect demographic data of both children and their parents, as well as clinical manifestations of epilepsy and family status.</p><p><b>RESULTS</b>Parental anxiety (of any severity) was observed in 191 subjects at interview, giving a prevalence rate of 56.2%. Of the 191 subjects, 18.5% reported mild anxiety, 24.4% moderate anxiety, and 13.2% severe anxiety. Factors associated with parental anxiety included frequency of seizure in children, average monthly income per person and parents' knowledge about epilepsy (P < 0.05). Parental anxiety significantly (P = 0.000) correlated with quality of life of children with epilepsy.</p><p><b>CONCLUSION</b>Parents of children with epilepsy are at high risk of having anxiety. Factors associated with parental anxiety originate both from children and from parents. Parental anxiety is significantly related with children's QOL. It is important for experts concerned to recognize such a relationship to improve the QOL of children and their parents.</p>

Report on childhood obesity in China (7). Comparison of NCHS and WGOC / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To test the validity of Working Group on Obesity in China (WGOC) reference in screening childhood obesity using obesity-related metabolic syndrome (MS) and its components as disease risk evidence.</p><p><b>METHODS</b>A total of 2020 adolescents (1007 boys and 1013 girls) aged 14-16 years were sampled in Beijing, China. Anthropometric and biochemical measurements, as well as blood pressure parameters were available. Prevalence of overweight/obesity and related MS risk factors were analyzed across different body mass index (BMI) categories. The sensitivity and specificity of the WGOC cut-offs were compared with those of National Central Health Statistics (NCHS).</p><p><b>RESULTS</b>Significantly high prevalence of MS and its components were found both in the obesity and overweight groups, which were classified by the WGOC and NCHS references. Similar distribution pattern of MS risk factors existed among different BMI categories, but the frequency and clustering of these factors in the obesity group classified by the NCHS were much higher. Owing to its irrelevant high cut-offs for overweight/obesity (especially for girls since the mid- adolescence), the NCHS reference had a high specificity but a low sensitivity. By contrast, the WGOC reference with a high sensitivity (90.1% for boys and 89.2% for girls) and a relative high specificity (96.4% and 92.8% for obese boys and girls, 78.1% and 68.9% for overweight boys and girls respectively) was more suitable to support the need for early screening, intervention, and treatment of childhood obesity in China.</p><p><b>CONCLUSION</b>High sensitivity is more important than specificity in choosing appropriate screening tools for childhood obesity. Validity test demonstrates that it is rational to use the WGOC reference, established on the basis of the Chinese own reference population as a uniform screening tool for childhood obesity, which can effectively overcome the unnecessary treatment and psychosocial implications of stigmatization caused by misclassification.</p>

Correlation of 4-month infant feeding modes with their growth and iron status in Beijing / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Growth and development of infants has been an important topic in pediatrics for a long time. Infants must be provided with food containing all necessary nutrients. Breast milk is believed to be the most desirable natural and cheapest food for well-balanced nutrition. But with the progress in the development of substitute food in developed countries, it is thought that formula milk can meet the requirement for infant growth. During early infancy, growth, as the most sensitive index of health, is therefore a critical component in evaluating the adequacy of breast-feeding, mixed-feeding and formula feeding. Iron status is another important index of infant health. Iron deficiency anemia remains the most prevalent nutritional deficiency index in infants worldwide. This study is to compare infants in Beijing at 4 months who are on three different feeding modes (breast feeding, mixed feeding and formula feeding) in physical changes and iron status. The results may provide new mothers with support in feeding mode selection, which will also be helpful to the China Nutrition Association in feeding mode education.</p><p><b>METHODS</b>This is a cohort study. One thousand and one normal Beijing infants were followed regularly for 12 months. Body weight and horizontal length were measured. Hemoglobin, red blood cell counts, mean corpuscular volume, mean corpuscular hemoglobin and serum iron were analyzed at 4 months.</p><p><b>RESULTS</b>The breast feeding percentage in the first 4 months was 47.9%. The feeding mode was not significantly related to maternal delivery age, education, labor pathway nor infant sex (P>0.05). Infant boys and girls exclusively breast-fed from 0 to 4 months had the highest weight at 0-6 months. The anemia rate of breast-fed infant boys at 4 months was the highest.</p><p><b>CONCLUSIONS</b>Breast feeding should be given more emphasis. It is compulsory for new mothers to breast-feed their infants if possible. Social environment should also guarantee the requirement for breast feeding. Furthermore the normal values of hemoglobin, mean corpuscular volume and serum iron, which were originally used to judge children's iron deficiency anemia, might not be optimal for evaluating infants. There might be a need to develop sex-specific cutoff levels of hemoglobin, mean corpuscular volume and serum iron for infants.</p>