Association of body fat distribution with depression and social anxiety in children and adolescents: A cross-sectional study based on dual-energy X-ray detection / 北京大学学报(医学版)

OBJECTIVE@#To investigate the status of depression and social anxiety in children and adolescents, and to analyze the association between body fat distribution and depression, social anxiety in children and adolescents.@*METHODS@#A total of 1 412 children aged 7 to 18 years in Beijing were included by stratified cluster random sampling method. Body fat distribution, including total body fat percentage (total BF%), Android BF%, Gynoid BF% and Android-to-Gynoid fat ratio (AOI), were obtained by dual-energy X-ray absorption method. Depression and social anxiety were evaluated by Children Depression Inventory and Social Anxiety Scale for Children. Multivariate linear regression and restricted cubic spline analysis were used to estimate the linear and non-linear correlation between body fat distribution and depression and social anxiety.@*RESULTS@#13.1% and 31.1% of the children and adolescents had depressive symptoms and social anxiety symptoms respectively, and the detection rate of depression and social anxiety in the boys and young groups was significantly lower than those in the girls and old groups. There was no significant linear correlation between total BF%, Android BF%, Gynoid BF%, AOI and depression and social anxiety in the children and adolescents. However, total BF% and Gynoid BF% had significant nonlinear correlation with depression, showing an inverted U-shaped curve relationship with the tangent points of 26.8% and 30.9%, respectively. In terms of the nonlinear association of total BF%, Android BF%, Gynoid BF% and AOI with depression and social anxiety, the change trends of the boys and girls, low age group and high age group were consistent. The overall anxiety risk HR of body fat distribution in the boys was significantly higher than that in the girls, and the risk HR of depression and social anxiety were significantly higher in the high age group than those in the low age group.@*CONCLUSION@#There was no significant linear correlation between body fat distribution and depression and social anxiety in children and adolescents. Total BF% and depression showed an inverted U-shaped curve, mainly manifested in Gynoid BF%, and this trend was consistent in different genders and different age groups. Maintaining children and adolescents' body fat distribution at an appropriate level is the future direction of the prevention and control of depression and social anxiety in children and adolescents.

Association between different growth patterns and metabolic syndrome in children and adolescents aged 7 to 17 years / 北京大学学报(医学版)

OBJECTIVE@#To analyze the association between different growth patterns and metabolic syndrome in children and adolescents aged 7 to 17 years, and to provide suggestions for the prevention and control of metabolic syndrome in Chinese children and adolescents.@*METHODS@#Data were collected from the research project "Development and Application of Technology and Related Standards for Prevention and Control of Major Diseases among Students" of public health industry in 2012. This project is a cross-sectional study design. A total of 65 347 students from 93 primary and secondary schools in 7 provinces including Guangdong were selected by stratified cluster random sampling method. Given the budget, 25% of the students were randomly selected to collect blood samples. In this study, 10 176 primary and middle school students aged 7 to 17 years with complete physical measurements and blood biochemical indicators were selected as research objects. Chi-square test was used to compare the distribution differences of growth patterns under different demographic characteristics. Birth weight, waist circumference and blood biochemical indexes were expressed in the form of mean ± standard deviation, and the differences among different groups were compared by variance analysis. Binary Logistic regression model was used to analyze the relationship between different growth patterns and metabolic syndrome in children and adolescents aged 7 to 17 years.@*RESULTS@#The prevalence of metabolic syndrome in children and adolescents was 6.56%, 7.18% in boys and 5.97% in girls. The risk of metabolic syndrome was higher in the catch-down growth group than in the normal growth group (OR=1.417, 95%CI: 1.19-1.69), and lower in the catch-up growth group(OR=0.66, 95%CI: 0.53-0.82). After adjusting for gender, age and so on, the risk of developing metabolic syndrome in the catch-down growth group was higher than that in the normal growth group (OR=1.25, 95%CI: 1.02-1.52), but there was no significant difference between the catch-up growth group and the normal growth group (OR=0.79, 95%CI: 0.62-1.01). Stratified analysis showed that the association between different growth patterns and metabolic syndrome was statistically significant in the 7-12 years group, urban population, and Han Chinese student population.@*CONCLUSION@#There is a correlation between different growth patterns and metabolic syndrome in children and adolescents. The risk of developing metabolic syndrome in children and adolescents with catch-down growth is higher than that in the normal growth group, which suggests that attention should be paid to the growth and development of children and adolescents, timely correction of delayed growth and prevention of adverse health outcomes.

Perceived exercise benefits and barriers and their association with physical activity time in Chinese Han children and adolescents aged 9 to 18 years / 中华流行病学杂志

Objective: To analyze the perceived exercise benefits and barriers and their association with physical activity time in Chinese Han children and adolescents aged 9-18 years. Methods: Data were extracted from the 2019 Chinese National Survey on Students' Constitution and Health and a total of 163 656 children and adolescents aged 9-18 years in Han ethnic group were included in the analysis. Mann-Whitney U test and Kruskal-Wallis test were used to compare the perceived exercise benefits score, perceived exercise barriers score and perceived exercise benefits to barriers ratio in the children and adolescents with different demographic characteristics and physical activity time. The differences in physical activity time in subgroups were compared with χ2 tests. log-binomial regression model was used to evaluate the association between physical activity time and perceived exercise benefits and barriers. Results: The M (Q1,Q3) of the perceived exercise benefits score, perceived exercise barriers score, and perceived exercise benefits to barriers ratio in the children and adolescents were 4.11 (3.78, 4.78), 2.70 (2.10, 3.20) and 1.55 (1.22, 2.07), respectively. Children and adolescents living in urban area, boys, those at younger age and those with physical activity time ≥1 hour had higher perceived exercise benefits score and perceived exercise benefits to barriers ratio, but lower perceived exercise barriers score (all P<0.001). The prevalence of physical activity time ≥1 hour was 41.4% in the children and adolescents. In the log-binomial model with two variables of perceived exercise benefits score and perceived exercise barriers score, for each 1-point increase in the perceived exercise benefits, the possibility of physical activity time ≥1 hour increased by 11% (OR=1.11, 95%CI: 1.10-1.12), and for each 1-point increase in the perceived exercise barriers, the possibility of physical activity time ≥1 hour decreased by 15% (OR=0.85, 95%CI: 0.84-0.85). In the log-binomial model with variable of perceived exercise benefits to barriers ratio, for each 1-point increase in the perceived exercise benefits to barriers ratio, the possibility of physical activity time ≥1 hour increased by 12% (OR=1.12, 95%CI: 1.11-1.12). Conclusion: The perceived exercise benefits and barriers are significantly associated with physical activity time in children and adolescents in China.

Trend of the detection rate of myopia among Chinese Han children and adolescents aged 7-18 years from 2010 to 2019 / 中华预防医学杂志

Objective: To analyze the trend of the detection rate of myopia among Chinese Han children and adolescents aged 7-18 years from 2010 to 2019. Methods: Data from the Chinese National Survey on Students' Constitution and Health in 2010, 2014 and 2019 were used, and about 213 833, 212 742 and 209 942 Han students aged 7-18 years were included in this study. The χ² test was used to compare the differences in the prevalence of myopia among the subgroups in the survey year, and logistic regression was used to compare the differences in the prevalence of myopia between different years. A curve-fitting method was used to obtain the growth rate of myopia among Han Chinese students from 2010 to 2019, and the differences in the change of myopia between different age groups were analyzed. Results: In 2019, the overall detection rate of myopia among Chinese Han children and adolescents aged 7-18 was 60.1%. The detection rate of urban students (62.7%) was higher than that of rural students (57.4%) and the detection rate of girls (63.5%) was higher than that of boys (56.7%). In 2019, the regional disparities were large in the detection rate of myopia in various provinces, with the lowest in Guizhou (49.6%) and the highest in Zhejiang (71.3%). The detection rate of myopia showed an upward trend from 2010 to 2019, from 55.5% in 2010 to 57.1% in 2014, and finally to 60.1% in 2019. The gap in the detection rate of myopia between urban and rural children and adolescents gradually shrank. The average annual growth rate of myopia detection rate from 2014 to 2019 was 0.6 percentage points per year, higher than that from 2010 to 2014 about 0.4 percentage points per year. The peak age of the growth rate of myopia detection rate decreased from 12 years in 2010 to 10 years in 2014, and finally to 7 years in 2019. Conclusions: The detection rate of myopia among Chinese Han children and adolescents is still at a high level, and the peak age of the growth rate of myopia detection rate continues to advance.

Prevalence trend of malnutrition among Chinese Han children and adolescents aged 7-18 years from 2010 to 2019 / 中华预防医学杂志

Objective: To analyze the prevalence trend of malnutrition among Chinese Han children and adolescents aged 7-18 years from 2010 to 2019. Methods: Based on the data from the Chinese National Surveys on Students' Constitution and Health in 2010, 2014 and 2019, about 215 102, 214 268 and 212 713 Han students aged 7-18 years were included in this study. According to the National Screening Standard for Malnutrition of School-age Children and Adolescents, the detection rate of malnutrition among Chinese Han children and adolescents aged 7-18 was calculated, and the prevalence trend of malnutrition from 2010 to 2019 was analyzed. Results: In 2019, the detection rate of malnutrition among Chinese Han students aged 7-18 years was 8.64% (18 381/212 713), of which the rate of growth retardation, moderate-to-severe wasting and mild wasting was 0.50% (1 062/212 713), 3.25% (6 914/212 713) and 4.89% (10 405/212 713), respectively. In 2019, the detection rate of malnutrition in these boys was higher than that of girls (9.97% vs. 7.31%), and the detection rate in rural areas was higher than that in cities (9.30% vs. 7.98%). The detection rates were 9.74% (5 252/53 916), 8.17% (4 408/53 937), 7.29% (3 885/53 310), and 9.38% (4 836/51 550) in 7-9, 10-12, 13-15, and 16-18 years groups, and 8.14% (6 563/80 618), 7.61% (4 237/55 694) and 9.92% (7 581/76 401) in the eastern, central, and western regions. Malnutrition among students in China was mainly caused by mild wasting, and the detection rate of growth retardation accounted for only 5.78% (1 062/18 381). Malnutrition was mostly concentrated in the southwest region, and the rate was relatively low in eastern provinces. In three surveys from 2010 to 2019, the detection rate of malnutrition among Han students aged 7-18 in China decreased gradually, and the differences were statistically significant (P<0.05). Among them, the detection rates in western rural areas decreased significantly, as well as the gap between urban and rural areas. Compared with that in 2014, the detection rate of malnutrition in Shandong, Hunan, Qinghai and Hainan provinces in 2019 decreased significantly (P<0.05). Conclusion: In 2019, the malnutrition of Chinese children and adolescents aged 7-18 years is dominated by wasting malnutrition. The detection rate shows a downward trend from 2010 to 2019, with regional differences.

Epidemiology and prediction of overweight and obesity among children and adolescents aged 7-18 years in China from 1985 to 2019 / 中华预防医学杂志

Objective: To analyze and predict the epidemic trend of overweight and obesity among children and adolescents aged 7-18 years in China from 1985 to 2019. Methods: Data were collected from the Chinese National Survey on Students Constitution and Health in 1985, 1995, 2000, 2005, 2010, 2014, and 2019 with the sample size of 409 945, 204 931, 209 209, 234 420, 215 317, 214 353, and 212 711, respectively. Overweight and obesity were evaluated according to the "classification standard of the weight index value of overweight and obesity screening for Chinese school-age children and adolescents" of the Working Group on Obesity in China (WGOC). The detection rate and average annual growth rate of overweight and obesity, and single obesity among children and adolescents aged 7-18 years were calculated, and ArcGis10.6 software was used to analyze the difference in the prevalence of overweight and obesity among children and adolescents in different regions in 2019. Polynomial regression function was used to fit the prevalence and average annual growth rate of overweight and obesity, and single obesity among children and adolescents from 1985 to 2019, and to predict the prevalence of overweight and obesity and single obesity among children and adolescents in China. Results: In 2019, the total prevalence of overweight and obesity among children and adolescents aged 7-18 years in China was 23.4%, and the prevalence of single obesity was 9.6%. The prevalence of overweight and obesity among urban children and adolescents was higher than that in rural areas (25.4% vs. 21.5%), and the prevalence in boys was higher than that in girls (28.4% vs. 18.4%) (both P values<0.001). In 2019, there was a large regional disparity in the prevalence of overweight and obesity in different provinces, with the lowest in Guangdong (12.2%) and the highest in Shandong (38.9%), and the high epidemic areas were mainly concentrated in North China and Northeast China. From 1985 to 2019, the prevalence of overweight and obesity among children and adolescents aged 7-18 years in China increased from 1.2% to 23.4%, with an increase of 18.1 times, while the prevalence of obesity alone increased from 0.1% to 9.6%, with an increase of 75.6 times. The prevalence of overweight and obesity in urban boys, urban girls, rural boys and rural girls increased from 1.3%, 1.5%, 0.5%, and 1.6% in 1985 to 31.2%, 19.4%, 25.6%, and 17.4% in 2019, with an increase of 22.3, 11.7, 54.2, and 10.1 times, respectively. According to the prediction model, the prevalence of overweight and obesity among children and adolescents aged 7-18 years in China will increase from 23.4% in 2019 to 32.7% in 2030, and the prevalence of obesity alone will increase from 9.6% in 2019 to 15.1% in 2030. The growth of rural children and adolescents is obvious. By 2025, the prevalence of overweight and obesity among rural children and adolescents in China will comprehensively exceed that of urban, and there will be an "urban-rural reversal" phenomenon. At the same time, the prevalence of children's obesity in China's low, medium and high epidemic areas will also continue to increase. By 2035, the prevalence of overweight and obesity among children and adolescents in medium epidemic areas will exceed that in high epidemic areas, and there will be a "provincial reversal" phenomenon. Conclusion: From 1985 to 2019, the overweight and obesity of children and adolescents in China will continue to grow rapidly with large regional differences.

Long-term trend of the age of spermarche and its association with nutritional status among Chinese Han boys aged 11-18 from 2010 to 2019 / 中华预防医学杂志

Objective: To analyze the long-term trend of the age of spermarche among Chinese Han boys aged 11 to 18 from 2010 to 2019 and its association with nutritional status. Methods: The data from Chinese National Surveys on Students' Constitution and Health in 2010, 2014 and 2019 were used. The age, residence and spermarche of the participants were collected by questionnaire, and their height and weight were measured. A total of 184 633 Han boys aged 11‒18 years with complete data on spermarche, height, and weight were included in this study. The probability regression method was used to calculate the median age (95%CI) at spermarche in different areas, and the trend of age at spermarche in different groups was compared. The multivariate logistic regression model was used to analyze the association between nutritional status and spermarche of Chinese Han boys aged 11‒18 years. Results: The median age of spermarche (95%CI) was 13.85 (13.45-14.22) years old among Chinese Han boys aged 11‒18 years in 2019, with 0.18 years earlier than that in 2010. The median age at spermarche in urban and rural boys was 13.89 and 13.81 years, respectively. Compared with that in 2010, the age at spermarche in urban and rural boys was 0.08 and 0.27 years earlier, respectively. After adjusting for age, province and urban/rural areas, compared with normal weight, spermarche was negatively associated with wasting and positively associated with overweight and obesity, with OR (95%CI) about 0.73 (0.67-0.80), 1.09 (1.02-1.17) and 1.09 (1.01-1.18), respectively. Conclusion: The age of spermarche generally shows an advanced trend among Chinese Han boys and is associated with nutritional status.

Prevalence trend of high normal blood pressure and elevated blood pressure in Chinese Han children and adolescents aged 7-17 years from 2010 to 2019 / 中华预防医学杂志

Objective: To investigate the prevalence trend of high normal blood pressure and elevated blood pressure in children and adolescents aged 7 to 17 years in China from 2010 to 2019. Methods: Students aged 7-17 years were selected from the Chinese National Survey on Students' Constitution and Health from 2010 to 2019. High normal blood pressure and elevated blood pressure were determined according to the "Reference of screening for elevated blood pressure among children and adolescents aged 7-18 years" (WS/T 610-2018). The Chi-square test was performed to determine whether there was a difference in the prevalence of high normal blood pressure and elevated blood pressure by gender, residence and age group. Results: In 2019, the prevalence of high normal blood pressure in children and adolescents aged 7-17 years was 15.3% (29 855/195 625), which was higher in boys (20.2%, 19 779/97 847) and rural areas (15.4%, 15 066/97 567) than that in girls (10.3%, 10 076/97 778) and urban areas (15.1%, 14 789/98 058), respectively (all P<0.05). The prevalence of elevated blood pressure was 13.0% (25 377/195 625), which was higher in girls (13.2%, 12 925/97 778) and rural areas (14.1%, 13 753/97 567) than that in boys (12.7%, 12 452/97 847) and urban areas (11.9%, 11 624/98 058) (all P<0.05). From 2010 to 2019, the prevalence of high normal blood pressure showed an increasing trend, with an annual average growth rate from 1.14% to 3.18%. The overall prevalence of elevated blood pressure also showed an increasing trend from 2010 to 2019 but decreased in 2014. The annual average growth rate of elevated blood pressure was-1.07% from 2010 to 2014 and 9.33% from 2014 to 2019. About 17 provinces had an increasing trend in the prevalence of elevated blood pressure from 2010 to 2014, and 22 provinces with an increasing trend from 2014 to 2019. There were obvious regional differences in the annual average growth rate of the prevalence of high normal blood pressure and elevated blood pressure. The regions with the highest annual average growth rate of the prevalence of high normal blood pressure were the Northeast (5.47%) from 2010 to 2014 and the Western region (5.21%) from 2014 to 2019. For elevated blood pressure, the Northeast had the highest annual average growth rate from 2010 to 2014 (12.35%), while the Central (15.79%) and Western (12.87%) had the highest growth rate from 2014 to 2019. Conclusion: From 2010 to 2019, the prevalence of high normal blood pressure and elevated blood pressure in Chinese Han children and adolescents aged 7 to 17 shows an increasing trend, with regional disparities.

Trends of age of menarche among Chinese Han girls aged 9 to 18 years from 2010 to 2019 / 中华预防医学杂志

Objective: To analyze the trends of the age of menarche among Chinese Han girls aged 9 to 18 years from 2010 to 2019. Methods: Data were extracted from the Chinese National Surveys on Students' Constitution and Health in 2010, 2014 and 2019. A total of 253 037 Han girls aged 9 to 18 years with complete data on menarche were selected in this study. They were asked one-on-one about their menstrual status, age and residence information. The median age of menarche was estimated by probability regression. U tests were used to compare the difference in median age at menarche in different years. Results: The median age at menarche (95%CI) among Chinese Han girls was 12.47 (12.09-12.83) years in 2010, 12.17 (11.95-12.38) years in 2014 and 12.05 (10.82-13.08) years in 2019, respectively. Compared with that in 2010, the median age at menarche in 2019 decreased by 0.42 years (U=-77.27, P<0.001). The annual average changes were-0.076 years from 2010 to 2014 (U=-57.19, P<0.001) and-0.023 years from 2014 to 2019 (U=-21.41, P<0.001), respectively. The average annual changes in urban areas in the periods of 2010 to 2014 and 2014 to 2019 were-0.071 years and 0.006 years, respectively, while those in rural areas were-0.082 years and-0.053 years, respectively. The average annual changes in the regions of north, northeast, east, south central, southwest and northwest were-0.064, -0.099, -0.091, -0.080, -0.096 and-0.041 years in the period of 2010 to 2014 and 0.001, -0.040, -0.002, -0.005, -0.043 and-0.081 years in the period of 2014 to 2019. Conclusion: The age of menarche among Chinese Han girls aged 9 to 18 years shows an advanced trend from 2010 to 2019, and the trends in urban and rural areas and different regions have different characteristics.

Prevalence of unhealthy lifestyle among children and adolescents of Han nationality in China / 中华心血管病杂志

Objective: To explore the epidemiological characteristics and geographical distribution of unhealthy lifestyle among children and adolescents of Han nationality in China and obtain evidence for proposing the related strategies to improve the well-being of this population. Methods: Students aged 6-22 years old were selected from the Chinese National Survey on Students Constitution and Health in 2019. The prevalence of unhealthy lifestyles (physical inactivity, lack of outdoor activity, sedentary behavior, excessive screen time, sleep insufficiency, unhealthy eating behavior) between sex, residence, and age groups was calculated and compared. Multilevel logistic regression was used to explore the influencing factors of unhealthy lifestyle. Results: The prevalence of moderate-to-vigorous physical activity less than 1 h/d or 30 min/d were 82.06% and 54.69%, respectively. The prevalence of less than 2 h/d or 3 h/d of outdoor activities were 95.20% and 83.26%, respectively. The prevalence of more than 2 h/d or 3 h/d of sitting time were 50.64% and 31.92%, respectively. The prevalence of more than 2 h/d or 3 h/d of screen time were 42.02% and 27.79%, respectively. The prevalence of sleep insufficiency, excessive sugary beverages consumption (≥ 1 time/d), and insufficient consumption of eggs, milk, and breakfast (<7 d/week) were 66.49%, 20.97%, 83.36%, 70.71%, and 34.34%, respectively. The prevalence of severe sleep insufficiency, excessive sugary beverages consumption (≥ 3 times/d), and insufficient consumption of eggs, milk, and breakfast (≤2 d/week) were 27.77%, 8.21%, 47.21%, 32.36% and 9.73%, respectively. Conclusion: In 2019, unhealthy lifestyle is common among Han students aged 6-22 years in China. It is of importance to propose policies to strengthen the health education and initiatives to support healthy behaviors in Han children and adolescents. Jointly promotion on the creation of a healthy environment for Han children and adolescents, and formulation of targeted improvement measures in accordance with the epidemic characteristics in various regions are essential to improve the healthy lifestyle of this population.

Analysis on the law of height growth spurt in adolescence of children and adolescents in Zhongshan City / 北京大学学报(医学版)

OBJECTIVE@#To analyze the characteristics of the age at peak height velocity and peak height velocity of primary and middle school students in Zhongshan City, Guangdong Province, and to explore the law of the sudden increase in adolescent height in this area, and to understand the law of height growth spurt in adolescence by longitudinal tracking of the height of children and adolescents in Zhong-shan City.@*METHODS@#Based on the physical examination database of primary and middle school students in Zhongshan City, Guangdong Province from 2005 to 2016, individuals who had been continuously tracked for more than 6 times were selected as research samples. SITAR model was used to fit the height data of the sample population, and the age at peak height velocity and peak height velocity were calcula-ted.@*RESULTS@#A total of 49 579 subjects were included in this study, including 26 524 boys and 26 008 urban students. The median follow-up ages of boys and girls were 7.74 and 7.72 years, respectively. The boy's height spurt peak age was (12.72±0.89) years, and later than the girls at the age of (10.98±0.95) years (t=207.639, P < 0.001), the boy's height spurt peak velocity of (10.12±1.49) cm/year, higher than the girls of (8.35±1.12) cm/year (t=150.826, P < 0.001). The gender differences of height spurt peak age and height spurt peak speed in urban and rural students were consistent with the whole sample. The height surge peak age of urban male students was earlier than that of rural male students, and the height surge peak speed of urban female students was lower than that of rural female students.@*CONCLUSION@#The peak age of the surge of girls was earlier than that of boys, but the peak rate of the surge of girls was lower than that of boys, the peak age of urban students was earlier than that of rural students, but the peak rate of urban boys was lower than that of rural boys in Guangdong Province.

Epidemiological characteristics of infectious diseases of group A, B and C among Chinese students' population / 北京大学学报(医学版)

OBJECTIVE@#To analyze the secular trend, ranking change, age- and regional- characteristics of leading infectious diseases among Chinese students population aged 6 to 22 years from 2008 to 2017.@*METHODS@#Data were drawn from the national surveillance from 2008 to 2017, and the participants were students aged from 6 to 22 years who were diagnosed with notifiable infectious diseases. A total of 40 infectious diseases were classified into three groups based on national notifiable infectious diseases classification of A, B and C. The morbidity and mortality rates from infectious diseases were calculated using the numbers of students published by the ministry of education as the denominator. The age- and province-specific infectious diseases with the highest incidence were selected as the leading infectious diseases for analysis.@*RESULTS@#From 2008 to 2017, the incidence rate, the number of cases and the number of deaths of infectious diseases among the boys aged 6-22 years in China were higher than that of the girls, and the overall trend was downward during the study period. The incidence rates in the boys and girls decreased from 2008 to 2015 with decrease of 43.4% and 40.1%, respectively. However, by 2017, the increase rate rebounded with the increases of 47.1% and 53.8%. The rebound trend was mainly caused by the increase of group C of infectious diseases. During the past decade, the top leading three diseases of groups A and B of infectious diseases were viral hepatitis, tuberculosis and dysentery in 2018, respectively, which changed to tuberculosis, scarlet fever and viral hepatitis in 2017. The top leading three infectious diseases in terms of mortality were rabies, tuberculosis, and human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) in 2008, which were transformed into HIV/AIDS, rabies, and tuberculosis in 2017. There was no significantly obvious change in the incidence and mortality order of group C of infectious diseases during the decade. In the analysis of age groups and regions, the leading infectious diseases in groups A and B transferred from viral hepatitis to scarlet fever and tuberculosis, while in group C, mumps and infectious diarrhoea almost always dominated the leading infectious diseases. But in recent years, influenza and hand-foot-and-mouth disease increased significantly in the eastern region.@*CONCLUSION@#During the past decade, China has got remarkable achievements in the prevention and control of children infectious disease. However, the change patterns and characteristics of notifiable infectious diseases among children and adolescents show the urgent need for prevention and control of respiratory tract infectious diseases, HIV/AIDS and other sexually transmitted diseases as well as new emerging infectious diseases in China in the future. This study provides important basis for policy making of Chinese national school-based infectious disease prevention and control mechanism.

Association between speed and endurance performance with sleep duration in children and adolescents / 北京大学学报(医学版)

OBJECTIVE@#To analyze the association between sleep duration and athletic performance, and provide scientific basis to improve the 50 m and endurance performance in children and adolescents.@*METHODS@#All the 119 462 subjects aged 9-15 years in both genders were sampled from 2014 National Physical Fitness and Health Surveillance by using stratified random cluster sampling method, to measure the height, weight, 50 meters and endurance performance and investigate sleep duration with questionnaire. Their body mass indexes (BMI) were calculated and the students' 50 m, endurance run scores and sleep durations were assessed. Binary Logistic regression was used to analyze the difference between the different sleep groups, and multifactor Logistic regression was used to analyze the relationship between the sleep condition and athletic performance.@*RESULTS@#The prevalence of insufficient sleep was 94.67% in the total subjects, the prevalence was higher among the girls (95.26%)than the boys (94.09%, χ2=80.99, P<0.001), and higher among the urban (95.41%) than the rural students(93.93%, χ2=128.48, P<0.001).The children with sufficient sleep had better performance in 50 m and endurance run scores( χ250 m=10.10, P50 m＜0.01; χ2endurance run=21.76, P<0.001). Logistic regression analysis after controlling the gender, area, grade and BMI showed that children with adequate sleep showed better results(OR50 m=1.14, 95%CI50 m=1.05-1.23, P50 m<0.01; ORendurance run=1.21, 95%CIendurance run=1.11-1.31, Pendurance run<0.001). As for gender, the excellent rates of 50 m and endurance run scores in the boys with adequate sleep were higher (P<0.001), but there were no significant difference in 50 m and endurance run excellent rates in the girls of different sleep conditions. The excellent rates of 50 m and endurance run in the urban children and the endurance rate in the rural children and adolescents with adequate sleep were higher than those with insufficient sleep (P<0.01) while there were no significant difference in the 50 m excellent rates between the different sleep groups in rural areas. The 50 m and endurance run excellent rates of the children and adolescents with adequate sleep in each grade were higher than those of the children in the same grade with insufficient sleep (Pprimary students' endurance performance<0.001, and the rest P<0.05). Children and adolescents with normal BMI and overweight who slept well had better performance in 50 m (P<0.05). The endurance run excellent rate of children and adolescents with adequate sleep in each BMI group was higher than that in children and adolescents with insufficient sleep in the same BMI group (Pmalnutrition<0.01, Pnormal<0.01, Poverweight<0.05, Pobesity<0.05). The children and adolescents were divided into different groups according to the sleep duration,the one who slept less than 7 hours had lower 50 m excellent rate than the other groups with longer sleeping duration (P<0.01) and the rate in the ones who slept more than 9 hours was the highest (P<0.001).The endurance excellent rate in the children and adolescents who slept more than 9 hours was significantly higher than that in the other groups (P<0.001).There was no significant dose-response relationship in excellent rates and sleep durations.@*CONCLUSION@#The prevalence of insufficient sleep has increased, and the sleep condition in children and adolescents is severe. Children and adolescents with sufficient sleep have better athletic performance, so we should strengthen the prevention and control of the lack of sleep in children and adolescents.

Association between the blood pressure status and nutritional status among Chinese students aged 7-18 years in 2014: based on the national blood pressure reference for Chinese children and adolescents / 北京大学学报(医学版)

OBJECTIVE@#To analyze the epidemic situation of blood pressure (BP) status and its association with nutritional status among Chinese children and adolescents aged 7-18 years old in 2014, and to provide important scientific basis for the control of students' hypertension.@*METHODS@#All the subjects aged 7 to 18 years in both genders were sampled from 2014 Chinese national surveys on students' constitution and health. BP status was evaluated according to Chinese national gender-, age- and height-specific references, including hypertension (HTN), elevated hypertension (elevated HTN), isolated systolic HTN (SHTN), isolated diastolic HTN (DHTN) and mix HTN. Their nutritional status was evaluated using the international obesity task force (IOTF) definition, including thinness (severe thinness and moderate thinness), normal, overweight and obesity (severe obesity and moderate obesity). The Logistics method was used to analyze the association between BP status and nutritional status. The population attributable risk (PAR%) of overweight and obesity for BP status was calculated.@*RESULTS@#The prevalence of HTN and elevated HTN among the Chinese children and adolescents aged 7-18 years in 2014 was 14.9% and 9.2%, respectively. And the prevalence of isolated SHTN, isolated DHTN and mix HTN was 3.1%, 8.8% and 3.0%, respectively. The prevalence estimates for HTN differed the greatest for the boys, those in rural, those with high age, those in the East, and those with high BMI. The highest prevalence of HTN was detected in those with severe obesity with 44.2% and 38.8% in the boys and girls respectively, which was 2.8-fold and 3.7-fold than those with normal groups. The negative association was detected between HTN and thinness, but the positive association with overweight and obesity. The PAR% of HTN due to overweight and obesity was 16.2%, and the expected prevalence of HTN was 12.5% if controlling for overweight and obesity. Higher PAR% of isolated SHTN and mix HTN due to overweight and obesity was detected in the Chinese children and adolescents with proportions of 28.7% and 35.1%.@*CONCLUSION@#The prevalence of HTN among the Chinese children and adolescents aged 7-18 years was still high, whose components mainly focused on isolated DHTN. Overweight and obesity can increase the risk of HTN in children and adolescents significantly, especially for isolated SHTN and mix HTN. Controlling for overweight and obesity can decrease the risk of HTN among Chinese national children and adolescents largely, which can play an important role in preventing the occurrence of chronic disease in adults.

Comparative Analysis of the Multi-Frequency Bio-impedance and Dual-energy X-ray Absorptiometry on Body Composition in Obese Subjects / 生物医学与环境科学（英文）

To examine accuracy of body composition predicted by the Multi-Frequency Bioelectric Impedance Analysis (MF-BIA) compared with the Dual-energy X-ray Absorptiometry (DXA) in adults with obese. We measured body composition of 749 adults with obese both by the MF-BIA and DXA. The Lin's concordance correlation and the Bland-Altman plots were used to examine the consistency. The concordance correlation coefficient of %BF between the MF-BIA and DXA in men and women was 0.560, and 0.669, respectively. Compared with the DXA, the MF-BIA significantly underestimated %BF by 4.33% in men (P < 0.001), however overestimated %BF by 0.50% in women (P < 0.001). After corrected by the correction equations established in this study, the differences were significantly decreased. Therefore, the MF-BIA (TANITA MC-180) may need to be corrected in estimating body composition for adults with obese.