Associations of school physical activity environment with comorbid obesity and myopia in children and adolescents: Findings from a Chinese national follow-up study.

BACKGROUND: Overweight and obesity (OWOB) and myopia have become two of the most important issues affecting the health of children and adolescents worldwide. Despite the recognition that the school physical activity (PA) environment is a critical factor for preventing and controlling overweight, obesity (OWOB), and myopia in children and adolescents, research on OWOB and myopia as a comorbidity remains unexplored, with evidence for effective strategies still being inconclusive. Hence, this study aimed to assess the prevalence and progression of comorbid OWOB/myopia and each condition alone, and to explore the association with school PA environment. METHODS: A total of 9814 children and adolescents aged 6-18 years were included from the Chinese National Survey on Students' Constitution and Health follow-up survey conducted from November 2019 to November 2020 in China. Anthropometric measurements, unaided distance vision acuity and non-cycloplegic refraction data were collected to assess OWOB and myopia, while eight indicators from questionnaires for children and adolescents aged 9-18 years were investigated to assess school PA environment. We calculated the one-year incidence and progression rates of comorbid OWOB/myopia, OWOB alone, and myopia alone. Mixed effect logistic regression was evaluated the association between school PA environment and incidence and progression of comorbid OWOB/myopia, OWOB, and myopia. RESULTS: The prevalence of comorbid OWOB/myopia increased from 11.1% in 2019 to 17.9% in 2020, and the incidence of comorbid OWOB/myopia was 10.9%. Children and adolescents experiencing an unfavorable school PA environment had a higher risk of the incidence of comorbid OWOB/myopia compared to a favorable school environment (OR = 1.85, 95% CI: 1.42-2.42). Similar findings were seen in the incidence of obesity (OR = 1.86, 95% CI: 1.26-2.75). Children and adolescents in an unfavorable school PA environment had a higher risk of myopia progression (OR = 1.29, 95% CI: 1.01-1.65). CONCLUSIONS: Obesity and myopia and their comorbidity have been serious among children and adolescents in China. A favorable school PA environment might mitigate the risk of comorbid OWOB/myopia, OWOB, and myopia progression.

[Status and pathways of factors influencing physical activity time among elementary and junior high school students in Beijing].

OBJECTIVE: To describe the current distribution of daily physical activity time among elementary and junior high school students in Beijing, and to analyze the influencing factors and pathways at the individual, family, school and community levels. METHODS: Data were drawn upon from a cross-sectional investigation in Beijing in 2023, and a total of 3 157 elementary and junior high school students were included in the final analysis. Questionnaire was used to collect data on basic characteristics, overall and in-school physical activity time per day, the number of sports mastered, perceived physical activity benefits and barriers scales, perceived family, school, and community physical activity supportive environment scales. Log-binomial regression model was used to analyze the associations between physical activity time and influencing factors, and structural equation modeling was used for the path analysis of the influencing factors. RESULTS: The reported rates of ≥2 hours of overall physical activity per day and ≥1 hour of physical activity in school per day among elementary and junior high school students in Beijing in 2023 were 33.1% and 64.8%, respectively. The associations between the number of sports mastered by students and the reported rate of ≥2 hours of overall physical activity per day showed a typical dose-response relationship (P-trend<0.001). The perceived physical activity benefits-to-barriers ratio (PR=1.24, 95%CI: 1.20-1.28), scores of perceived family, school, and community physical acti-vity supportive environment scales were all positively associated with the reported rate of ≥2 hours of overall physical activity per day (PR=1.51, 95%CI: 1.38-1.66; PR=1.50, 95%CI: 1.37-1.64; PR=1.21, 95%CI: 1.16-1.27). The structural equation modeling showed that the number of sports mastered by the students (ß=0.11, P<0.001), perceived physical activity benefits-to-barriers ratios (ß=0.15, P<0.001), and scores of supportive environment scales consisting of family, school, and community (ß=0.13, P<0.001) were associated with the reported rates of ≥2 hours of overall physical activity per day directly. In addition, the scores of supportive environment scales could indirectly influence the reported rates of ≥2 hours of overall physical activity per day by influencing the number of sports mastered by the students (ß=0.21, P<0.001) and the perceived physical activity benefits-to-barriers ratio (ß=0.56, P<0.001), while the number of sports mastered by the students could indirectly influence the reported rates of ≥2 hours of overall physical activity per day by influencing the perceived physical activity benefits-to-barriers ratios (ß=0.05, P=0.003). The influencing factors and pathways of the reported rates of ≥1 hour of physical activity in school per day were similar with those of the reported rates of ≥2 hours of overall physical activity per day described above. CONCLUSION: The daily physical activity time among elementary and junior high school students in Beijing in 2023 fell short of meeting the national requirement. There was a need to build a supportive environment consisting of family, school, and community for physical activity, to promote the students ' sports skills, to establish the idea of independent physical activity, and to ensure that primary and secondary school students were given one hour of physical activity time every day, both inside and outside the school.

Associations between combinations of 24-h movement behaviors and physical fitness among Chinese adolescents: Sex and age disparities.

OBJECTIVE: To analyze the relationship between 24-h movement behaviors and adolescents' physical fitness, with sex difference and age disparity explored specifically. METHODS: A total of 135 852 Chinese adolescents aged 13-22 years were included in this cross-sectional study. Self-reported 24-h movement behavioral times, including moderate to vigorous physical activity (MVPA), recreational screen, and sleep, were identified as meeting guidelines based on Canadian recommendations. Physical fitness indicator (PFI) was calculated through sex- and age-specific z scores of body mass index, forced vital capacity, 50 m dash, sit-and-reach, standing long jump, body muscle strength, and endurance running, and then classified as: low level (<20th), middle level (20th-80th), and high level (>80th). Mixed effect logistic regression was applied to analyze the association, and interaction terms were constructed to prove the sex and age disparities. RESULTS: Only 12.4% of adolescents aged 13-22 years met all three recommendations. The number of meeting guidelines exhibited a typical dose-response relationship with high level PFI (OR = 1.22 [95% CI: 1.19-1.25]), and in detail, meeting MVPA + recreational screen (OR = 2.29 [95% CI: 2.09-2.51]) or MVPA-only (OR = 2.16 [95% CI: 1.93-2.41]) guidelines were better associated with high-level PFI. Besides, meeting MVPA-only guideline was proved with stronger association with high-level PFI for boys (p-interaction = 0.005). The dose-response relationship in boys of the number of guidelines met with PFI was stronger in 19- to 22-year-olds (p-interaction <0.001) and 16- to 18-year-olds (p-interaction = 0.001) than that in 13- to 15-year-olds. CONCLUSION: The prevalence of meeting 24-h movement behaviors guidelines among Chinese adolescents aged 13-22 years was relatively low. It was associated with adolescents' physical fitness, with meeting MVPA + recreational screen or MVPA-only guidelines bringing greater benefits, and sex difference and age disparity existing.

A cluster randomized trial of a comprehensive intervention nesting family and clinic into school centered implementation to reduce myopia and obesity among children and adolescents in Beijing, China: study protocol.

BACKGROUND: Myopia and obesity in children and adolescents have become serious public health problems that endanger public health, especially in China. Unhealthy lifestyle behaviors are environmental drivers of both myopia and obesity. This protocol describes a study to evaluate the effectiveness of "22510SS", that is 2 h of daytime outdoor activities ('2'); Limit screen time to no more than 2 h per day ('2'); Consume at least 5 servings of fruits and vegetables daily ('5'); Attain 1 h of physical activity daily ('1'); Consume 0 sugar-sweetened beverages ('0'); Reasonable sleep duration ('S'); Regular supervision ('S'). A school-based, multifaceted intervention strategy for myopia and obesity prevention, and to assess and explore the implementation of "22510SS" with regards to acceptability, feasibility, adoption, usage and maintenance. METHODS AND ANALYSIS: This study aims to develop a comprehensive intervention strategy "22510SS" based on the socio-ecological model, and A two-arm cluster randomized trial with a parallel-group of a 1:1 allocation ratio in 36 primary and secondary schools to test its evidence-based intervention programs on the effects and implementation of myopia and obesity epidemics in children and adolescents in grades 4 and 7. The primary outcomes will include differences in visual acuity, body mass index, outdoor activity indicators, screen time, fruit and vegetable intake, high-quality protein intake, sugar-sweetened beverage intake, sleep duration, and level of monitoring among children and adolescents. Secondary outcomes will assess the acceptability, feasibility, uptake, use, and maintenance of the intervention. Effects on the primary and secondary outcomes will be analyzed using linear and logistic regression analyses, as well as difference-in-difference analysis, taking into account cluster effects and possible confounding factors. Process assessments will also be conducted through quantitative and qualitative analyses, including acceptability, feasibility, gender, adoption, implementation, and sustainability. DISCUSSION: This study will evaluate the effectiveness of "22510SS" and examine its implementation in the school-based network nesting family and clinic. Following this intervention study, the integrated intervention program focused on myopia and obesity among children and adolescents have great potential to be implemented in China to promote and support healthy lifestyle behavior change and reduce the risk of myopia and obesity in children and adolescents. TRIAL REGISTRATION: NCT05275959. Registered 23 Mach 2022.

Secular trend and urban-rural disparity for age at spermarche among Chinese Han boys from 1995 to 2019.

AIM: To examine the secular trend and the urban-rural disparity of spermarche among Chinese Han boys from 1995 to 2019. METHODS: A total of 392 775 boys of Han ethnicity aged 11-18 years were extracted from the 1995, 2000, 2005, 2010, 2014 and 2019 Chinese National Surveys on Students' Constitution and Health. The median age at spermarche was estimated using the status quo data and probit analysis. The chi-square, ANOVA and LSD tests were used to compare the differences between the year-subgroups. U-test was used to compare the difference between urban and rural areas at each year. RESULTS: The median age at spermarche in Chinese Han boys decreased from 14.6 years in 1995 to 13.9 years in 2019 (p < 0.001). The rural boys showed a faster decreasing pace with a 1-year advance of age at spermarche while the urban boys had only a 0.5-year decrement, and there was still a statistically significant difference between urban-rural areas in 2019 (p < 0.001). Similar to urban-rural disparity, the age gap at spermarche between areas with different urbanisation rates became smaller over time. CONCLUSIONS: In general, spermarche in Chinese Han boys showed a decreasing trend, but the pace was slowing down. The urban-rural disparity in puberty development still existed but was gradually narrowing.

[Application in SPSS of different methods for evaluating undernutrition in children and adolescents].

OBJECTIVE: To introduce the four widely used methods for evaluating undernutrition in children and adolescents in China and internationally, and to compile the corresponding SPSS program package according to the American CDC standard, the IOTF standard and the Chinese industry standard. METHODS: The SPSS program package for evaluating undernutrition in children and adolescents was compiled and explained. Based on the growth and development survey data of 62 517 children and adolescents aged 6-17 years in 93 primary and secondary schools in 7 provinces and cities in China in 2012, the nutritional deficiency status was judged and compared according to four evaluation methods, and the chi-square test was used to compare the differences between groups, the Bonferroni method was used for pairwise comparisons. RESULTS: The detection rates of the four evaluation methods were statistically different in the case population(P<0.01). When screening for stunning, the detection rate of the American CDC standard was the highest(3.5%), and the detection rate of the Chinese industry standard was the lowest(0.4%). When screening for wasting, the detection rate of the IOTF standard(11.8%) was significantly higher than those of the other standards. There was little difference between the result of the Chinese industry standard and the American CDC standard, and the detection rate of the WHO standard was the lowest(3.0%). CONCLUSION: Given the differences in the result of the four method, the SPSS package developed in this study facilitates the selection and application of appropriate evaluation method for pediatricians, school health staff, and researchers to choose appropriate evaluation method, so that they could identify undernutrition in children and adolescents rapidly and accurately.

Assessing the relationship between weight stigma, stress, depression, and sleep in Chinese adolescents.

INTRODUCTION: Weight stigma is defined as the social devaluation of people with overweight or obesity, and its negative effects on the health of adolescents from western countries are well documented, but little is known about the relationships with health behaviors and outcomes in Asian youth. The prevalence of obesity among Chinese adolescents continues to increase, potentially causing negative evaluations of youth with obesity, and potentially reduced quality of life. The health effects of these negative evaluations of Chinese youth with obesity have received little attention. PURPOSE: The purpose of this study was to examine relationships between weight stigma, stress, depression, and sleep in Chinese adolescents. METHODS: We utilized a cross-sectional study conducted in Wuhan, China. Sociodemographic, weight stigma, stress, depression, and sleep data were collected through a self-reported questionnaire. Descriptive statistics, t test, correlations, and mediation analyses were performed. A total of 1626 adolescents between 14 and 19 years of age were included in the analysis. RESULTS: The data showed that adolescents with weight stigma presented significantly higher level of stress and depression, lower global sleep quality, longer sleep latency, and shorter sleep duration than those without weight stigma (p < 0.05). Stress and depression mediated the relationship between weight stigma and global sleep quality (SE = 0.007, 95% CI = 0.053 to 0.081). CONCLUSION: These findings suggest that adolescents who experience weight stigma may have increased stress and depressive symptoms, which are associated with poorer global sleep quality and more daytime dysfunction.

[Identification and denitrification characteristics of an aerobic denitrifier in estuary phragmites wetland].

Objective: We isolated an aerobic denitrifier with affinity for nitrogen removing and low accumulation of nitrous oxide, and analyzed its denitrification activity to provide technical support for controlling eutrophic wetland lakes. Methods: An aerobic denitrifier named C3 was isolated from phragmites wetland soil in Liaohe estuary by BTB medium preliminary screening and denitrification activity analysis. We used morphological and physiological characteristics as well as sequence analysis of the 16S rRNA to identify the strain. Effects of culture conditions, such as temperature, carbon source, initial pH, C/N ratio were evaluated regarding removal of nitrite nitrogen and accumulation of nitrous oxide under aerobic condition. Results: The highly effective strain C3 was identified as Pseudomonas sp., for which the best carbon source was sodium citrate, optimal growth and denitrification occurred at 30℃, pH 7.0, and a C/N ratio of 10. Under these conditions, the concentration of nitrate was reduced from 179.55 mg/L to 5.08 mg/L by strain C3 in 36 hours, a reduction in NO3- of more than 97.17%. In the process of denitrification, nitrous oxide as an intermediate accumulated at a level of 0.22 mg/L. Conclusion: Strain C3, an aerobic denitrifying agent, was isolated from wetland soil and has obvious advantages in efficient removal of nutrients with low accumulation of nitrous oxide, representing a great potential to treat eutrophic wetland lakes.

Clustering of Multilevel Factors Among Children and Adolescents: Associations With Health-Related Physical Fitness.

BACKGROUND: To identify the clustering characteristics of individual-, family-, and school-level factors, and examine their associations with health-related physical fitness. METHODS: A total of 145,893 Chinese children and adolescents aged 9-18 years participated in this cross-sectional study. The 2-step cluster analysis was conducted to identify clusters among individual-, family-, and school-level factors. Physical fitness indicator was calculated through sex- and age-specific z scores of forced vital capacity, standing long jump, sit-and-reach flexibility, body muscle strength, endurance running, and body mass index. RESULTS: Three, 3, and 5 clusters were automatically identified at individual, family, and school levels, respectively. Students with low physical fitness indicator were more likely to be in the "longest sedentary time and skipping breakfast" cluster (odds ratio [OR] = 1.18; 95% confidence interval [CI], 1.12-1.24), and "physical inactivity and insufficient protein consumption" cluster (OR = 1.07; 95% CI, 1.02-1.12) at individual level, the "single children and high parental education level" cluster (OR = 1.15; 95% CI, 1.10-1.21), and "no physical activity support and preference" cluster (OR = 1.30; 95% CI, 1.25-1.36) at family level, and the "physical education occupied" cluster (OR = 1.06; 95% CI, 1.01-1.11), and "insufficient physical education frequency" cluster (OR = 1.16; 95% CI, 1.08-1.24) at school level. Girls were more vulnerable to individual- and school-level clusters, while boys were more susceptible to family clusters; the younger students were more sensitive to school clusters, and the older students were more susceptible to family clusters (P-interaction < .05). CONCLUSIONS: This study confirmed different clusters at multilevel factors and proved their associations with health-related physical fitness, thus providing new perspective for developing targeted interventions.

Secular trend and projection of overweight and obesity among Chinese children and adolescents aged 7-18 years from 1985 to 2019: Rural areas are becoming the focus of investment.

BACKGROUND: The urban-rural disparities in overweight and obesity among children and adolescents are narrowing, and there is a need for long-term and updated data to explain this inequality, understand the underlying mechanisms, and identify priority groups for interventions. METHODS: We analyzed data from seven rounds of the Chinese National Survey on Students Constitution and Health (CNSSCH) conducted from 1985 to 2019, focusing on school-age children and adolescents aged 7-18 years. Joinpoint regression was used to identify inflection points (indicating a change in the trend) in the prevalence of overweight and obesity during the study period, stratified by urban/rural areas and sex. Annual percent change (APC), average annual percent change (AAPC), and 95% confidence interval (CI) were used to describe changes in the prevalence of overweight and obesity. Polynomial regression models were used to predict the prevalence of overweight and obesity among children and adolescents in 2025 and 2030, considering urban/rural areas, sex, and age groups. RESULTS: The prevalence of overweight and obesity in urban boys and girls showed an inflection point of 2000, with AAPC values of 10.09% (95% CI: 7.33-12.92%, t = 7.414, P <0.001) and 8.67% (95% CI: 6.10-11.30%, t = 6.809, P <0.001), respectively. The APC for urban boys decreased from 18.31% (95% CI: 4.72-33.67%, t = 5.926, P = 0.027) to 4.01% (95% CI: 1.33-6.75%, t = 6.486, P = 0.023), while the APC for urban girls decreased from 13.88% (95% CI: 1.82-27.38%, t = 4.994, P = 0.038) to 4.72% (95% CI: 1.43-8.12%, t = 6.215, P = 0.025). However, no inflection points were observed in the best-fit models for rural boys and girls during the period 1985-2019. The prevalence of overweight and obesity for both urban and rural boys is expected to converge at 35.76% by approximately 2027. A similar pattern is observed for urban and rural girls, with a prevalence of overweight and obesity reaching 20.86% in 2025. CONCLUSIONS: The prevalence of overweight and obesity among Chinese children and adolescents has been steadily increasing from 1985 to 2019. A complete reversal in urban-rural prevalence is expected by 2027, with a higher prevalence of overweight and obesity in rural areas. Urgent action is needed to address health inequities and increase investments, particularly policies targeting rural children and adolescents.

Combined Effect of Outdoor Time and Other Modifiable Factors on Myopia Incidence Among Children and Adolescents - 9 PLADs, China, 2020.

What is already known about this topic?: Myopia has been identified as a significant emerging challenge and policy priority among children and adolescents in China by the Ministry of Education and seven other departments. Limited research has been conducted to investigate the collective impact of outdoor time and other modifiable factors on the incidence of myopia. What is added by this report?: This study provides support for the protective effect of combining increased outdoor time with other prevention strategies in reducing the incidence of myopia. The results indicate the presence of a dose-response relationship. What are the implications for public health practice?: To effectively prevent myopia, it is important to implement comprehensive interventions that encompass various aspects such as outdoor time, eye-use habits, eye-use environments, and lifestyle modifications.

Association between early life exposure to the great famine and possible sarcopenia in older Chinese adults: a national cross-sectional study.

OBJECTIVES: We used data from the China Health and Retirement Longitudinal Study (CHARLS) to investigate how an early life famine exposure affected possible sarcopenia (PS) and to explore the extent to which a sex difference exists in the association among older Chinese adults, as well as whether risk factors modify the association. DESIGN: Cross-sectional study. SETTING: 28 provinces of China. PARTICIPANTS: Considering that the Great Chinese Famine lasted from the spring of 1959 to the fall of 1961, 3557 participants were selected and categorised into four subgroups based on their date of birth: unexposed group (1 October 1962 to 30 September 1964), fetal exposed group (1 October 1959 to 30 September 1961), infant exposed group (1 January 1958 to 31 December 1958) and preschool exposed group (1 January 1956 to 31 December 1957). OUTCOME MEASURE: PS was defined as having low muscle strength or low physical performance. METHODS: We used multivariable logistic models to analyse the association between early life famine exposure and the risk of PS in elderly life. RESULTS: The prevalences of PS among individuals in the unexposed, fetal, infant and preschool exposed groups were 15.1%, 14.4%, 23.6% and 21.9%, respectively. Compared with the unexposed group, the infant (OR: 1.55; 95% CI 1.17 to 2.05) and preschool exposed (OR: 1.46; 95% CI 1.17 to 1.82) groups exhibited significantly higher risks of PS. In men, the infant (OR: 2.15; 95% CI 1.40 to 3.31) and preschool exposed (OR: 1.78; 95% CI 1.23 to 2.57) groups were more likely to have PS, but no significant increase was seen in women. In both sexes, prevalence of PS was unrelated to early life famine exposure in the urban, underweight and normal weight subgroups. CONCLUSIONS: Early life exposure to the Great Chinese Famine was associated with a higher risk of PS in older adults. Keeping normal nutritional status in elderly life might help avoid the risk of PS, whatever the effect of early famine exposure.

Artificial Light-at-Night Exposure and Overweight and Obesity across GDP Levels among Chinese Children and Adolescents.

BACKGROUND: Evidence in adults suggests that exposure to artificial light-at-night (ALAN) leads to obesity. However, little is known about whether this effect exists in children and adolescents. We aimed to investigate whether ALAN exposure was associated with overweight and obesity in school-aged children and adolescents and whether this association varied with socioeconomic status. METHODS: Data on the height and weight of 129,500 children and adolescents aged 10-18 years from 72 cities were extracted from the 2014 Chinese National Survey on Students' Constitution and Health (CNSSCH). The ALAN area percentage and average ALAN intensity were calculated using the Visible/Infrared Imager/Radiometer Suite. The subjects were separated into three categories based on the cities' gross domestic product per capita (GDPPC). A mixed-effect logistic regression model and generalized additive model (GAM) were utilized to evaluate the association between ALAN exposure and overweight and obesity in children and adolescents stratified by municipal GDPPC. RESULTS: Both ALAN area (OR = 1.194, 95% CI: 1.175-1.212) and ALAN intensity (OR = 1.019, 95% CI: 1.017-1.020) were positively associated with overweight and obesity in children and adolescents, and the associations remained robust after adjusting for covariates. ORs for overweight and obesity and ALAN area decreased as GDPPC level increased (first tertile: OR = 1.457, 95% CI: 1.335-1.590; second tertile: OR = 1.350, 95% CI: 1.245-1.464; third tertile: OR = 1.100, 95% CI: 1.081-1.119). Similar results were observed for ALAN intensity. In the GAM models, thresholds existed in almost all these spline trends, indicating that ALAN might have a nonlinear association with overweight and obesity. CONCLUSIONS: ALAN contributed to the development of overweight and obesity in children and adolescents and this effect differed with GDPPC. Future longitudinal studies should confirm the causal relationship between ALAN and obesity. Moreover, reducing unnecessary exposure to artificial light at night may have beneficial implications for controlling childhood and adolescent obesity, particularly in low-income areas.

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

BACKGROUND: Menarche is a substantial milestone of female puberty. Timing of age at menarche is considered the key to understanding the potential linkages with women's health outcomes later in life. This study aimed to explore the secular trends and urban‒rural disparities in the median age at menarche among Chinese Han girls from 1985 to 2019. METHODS: Data were extracted from the 1985, 1995, 2005, 2014, and 2019 Chinese National Surveys on Students' Constitution and Health, which were nationally representative cross-sectional studies, and a total of 173,535 Han girls aged 9-18 years were examined. Girls were asked whether menarche had occurred. The median age at menarche was estimated by probit analysis. Z tests were used to compare the differences between survey years and between urban and rural areas. RESULTS: The median age at menarche among Chinese Han girls decreased from 13.37 years in 1985 to 12.00 years in 2019, and the overall decrease was more significant in rural areas (1.77 years) than in urban areas (0.99 years). The average five-year change in the decrease in the median age at menarche showed an accelerating and then slowing pace; and it was observed similarly in both urban and rural areas. The urban‒rural disparities shrank from 0.64 years in 1985 to 0.44 years in 1995, then to 0.27 years in 2005, 0.24 years in 2014, and finally to - 0.14 years in 2019. CONCLUSIONS: The median age at menarche among Chinese Han girls continued to decline from 1985 to 2019 but at a slowing pace in the last five years. Urban‒rural disparities gradually narrowed. Sexual and reproductive health education and interventions to prevent the decline in the age of menarche are needed, especially in rural areas.

Associations between Breastfeeding Duration and Obesity Phenotypes and the Offsetting Effect of a Healthy Lifestyle.

Background: Additional metabolic indicators ought to be combined as outcome variables when exploring the impact of breastfeeding on obesity risk. Given the role of a healthy lifestyle in reducing obesity, we aimed to assess the effect of breastfeeding duration on different obesity phenotypes according to metabolic status in children and adolescents, and to explore the offsetting effect of healthy lifestyle factors on the associations between breastfeeding duration and obesity phenotypes. Methods: A total of 8208 eligible children and adolescents aged 7-18 years were recruited from a Chinese national cross-sectional study conducted in 2013. Anthropometric indicators were measured in the survey sites, metabolic indicators were tested from fasting blood samples, and breastfeeding duration and sociodemographic factors were collected by questionnaires. According to anthropometric and metabolic indicators, obesity phenotypes were divided into metabolic healthy normal weight (MHNW), metabolic unhealthy normal weight (MUNW), metabolic healthy obesity (MHO), and metabolic unhealthy obesity (MUO). Four common obesity risk factors (dietary consumption, physical activity, screen time, and sleep duration) were used to construct a healthy lifestyle score. Scores on the lifestyle index ranged from 0 to 4 and were further divided into unfavorable lifestyles (zero or one healthy lifestyle factor), intermediate lifestyles (two healthy lifestyle factors), and favorable lifestyle (three or four healthy lifestyle factors). Multinomial logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (95% CI) for the associations between breastfeeding duration and obesity phenotypes. Furthermore, the interaction terms of breastfeeding duration and each healthy lifestyle category were tested to explore the offsetting effect of lifestyle factors. Results: The prevalence of obesity among Chinese children and adolescents aged 7-18 years was 11.0%. Among the children and adolescents with obesity, the prevalence of MHO and MUO was 41.0% and 59.0%, respectively. Compared to the children and adolescents who were breastfed for 6-11 months, prolonged breastfeeding (≥12 months) increased the risks of MUNW (OR = 1.35, 95% CI: 1.19-1.52), MHO (OR = 1.61, 95% CI: 1.27-2.05), and MUO (OR = 1.46, 95% CI: 1.20-1.76). When stratified by healthy lifestyle category, there was a typical dose-response relationship between duration of breastfeeding over 12 months and MUNW, MHO, and MUO, with an increased risk of a favorable lifestyle moved to an unfavorable lifestyle. Conclusions: Prolonged breastfeeding (≥12 months) may be associated with increased risks of MUNW, MHO, and MUO, and the benefits of breastfeeding among children and adolescents may begin to wane around the age of 12 months. The increased risks may be largely offset by a favorable lifestyle.

The independent and combined effects of single-child status and ideal lifestyle on clustered cardio-metabolic risk factors among Chinese children and adolescents.

Background: Cardio-metabolic risk factors (CMRFs) represent the accumulation of metabolic abnormalities, significantly increasing the likelihood of cardiovascular diseases. Although studies assessed the independent association of single-child status and lifestyle risk factors with components of CMRFs or clustered CMRFs, little has been known about the combined effect of single-child status and lifestyles on clustered CMRFs as well as sex differences. Materials and methods: Data was collected from a cross-sectional survey conducted in September 2013 in China. A total of 13,859 children and adolescents aged 7-18 years with blood samples were included. Anthropometric measurements and serum biochemical indexes were collected to assess clustered CMRFs, while questionnaires were used to obtain single-child status, lifestyle information, and characteristics of children and their parents. Mixed effect logistic regression was applied to analyze the independent and the combined effects of single-child status and ideal lifestyle category on clustered CMRFs. Results: The prevalence of clustered CMRFs was 3.4%, with a higher prevalence in boys (4.0%) than girls (2.7%). Children and adolescents with clustered CMRFs had a higher proportion of single children (76.6 vs. 69.7%) and unfavorable lifestyles (62.1 vs. 29.2%) compared with their peers with non-clustered CMRFs. Both single children (OR = 1.67, 95% CI: 1.32-2.11) and unfavorable lifestyles (OR = 9.03, 95% CI: 6.26-13.02) were associated with an increased risk of clustered CMRFs. The risk of clustered CMRFs increased significantly (OR = 12.79, 95% CI: 6.67-24.52) when single children and an unfavorable lifestyle were combined, which was almost neutralized (OR = 1.33, 95% CI: 0.63-2.82) when single children adhered to a favorable lifestyle. However, no sex differences were observed in this study. Conclusion: Single children with unfavorable lifestyles were associated with an obvious risk of clustered CMRFs, which might be partially offset by expanding family size (the number of siblings) or establishing a favorable lifestyle. A birth-friendly social environment as well as a family environment with a favorable lifestyle are encouraged in China.

Global trends and regional differences in non-transport unintentional injuries mortality among children and adolescents, 1990 to 2019: results from the Global Burden of Disease 2019 study.

BACKGROUND: Non-transport unintentional injuries (NTUIs) are major public concerns, especially among children and adolescents in low- and middle-income countries. With environmental and cognitive changes, a recent systematic description of global trends and regional differences concerning NTUIs is urgently needed for the global agenda of relevant policy-making and intervention target findings. METHODS: We used mortality, population, and socio-demographic-index (SDI) data from Global Burden of Disease 2019 to analyze the trends of NTUIs mortality. We applied the slope index of inequality (SII) and relative index of inequality (RII) to measure the absolute and relative inequality between countries and territories. The concentration curve and concentration index (CI) were also used to measure the inequality. We conducted a sensitivity analysis to make our findings credible. RESULTS: In 2019, there were 205,000 deaths due to NTUIs among children and adolescents aged 5 to 24 years, which decreased from 375,000 in 1990. In 2019, the age-standardized mortality rate (ASMR) was 8.13 per 100,000, ranging from the lowest in the Netherlands (0.90 per 100,000) to the highest in the Solomon Islands (29.34 per 100,000). The low-middle SDI group had the highest ASMR of NTUIs, while the low SDI group had the slowest decrease. After excluding the death caused by "exposure to forces of nature" and "other unintentional injuries", drowning accounted for the most deaths in almost every SDI group, gender, and age group, but the major causes of death varied in different subgroups. For example, animal contact was a major cause in low and low-middle SDI groups but less in high SDI groups, while high and high-middle SDI groups had a higher proportion of deaths for foreign body and poisonings. The SII showed a declining trend, but the RII and CI did not, which might indicate that inequality was persistent. Similar results were found in the sensitivity analysis. CONCLUSIONS: Despite the declining trend of the mortality rate and the narrowing gap between countries, there were still a large number of children and adolescents dying from NTUIs, and those experiencing social-economic disadvantages remained at high mortality. Embedding the prevention of NTUIs into sustainable development goals might contribute to the progress of reducing death and inequalities, which ensures that no one is left behind.

The Combined Effect of Birth Weight and Lifestyle on Clustered Cardio-Metabolic Risk Factors in Children and Adolescents: A National School-Based Cross-Sectional Survey.

BACKGROUND: Due to the adverse effects of cardio-metabolic risk factors (CMRFs) in children and adolescents on their current and later life health, and the growing evidence that birth weight and lifestyle have on CMRFs, we aimed to estimate the combined effect of birth weight and lifestyle on clustered CMRFs in children and adolescents. METHODS: We enrolled 11,509 participants aged 7-18 years old in a national school-based cross-sectional study in seven provinces in China in 2013. Information on CMRFs was collected through anthropometric measurements and blood sample testing. Information on birth weight, lifestyle and other basic information were investigated through children and adolescents' as well as parents' questionnaires. The generalized linear mixed model was applied to estimate the odd ratio (OR) and 95% confidence interval (95% CI) for the associations between CMRFs, clustered CMRFs and birth weight, lifestyle, and the combinations of birth weight and lifestyle. RESULTS: Overall, the prevalence of clustered CMRFs was 3.6% in children and adolescents aged 7-18 years, higher in boys (4.4%) than girls (2.9%). The combination of LBW/ideal lifestyle (OR = 2.00, 95% CI: 1.07-3.72) was associated with higher risk of clustered CMRFs, as well as in adolescents aged 13-18 years and in boys. The combination of HBW/poor lifestyle (OR = 1.74, 95% CI: 1.13-2.68) was related to elevated risk of clustered CMRFs, especially in children aged 7-12 years. CONCLUSIONS: CMRFs in Chinese children and adolescents is concerning, ideal lifestyle could weaken the association of birth weight with clustered CMRFs, especially in younger age, indicating that programs to prevent abnormal birth weight or poor lifestyle or both among children and adolescents may reduce CMRFs in China.

Corrigendum: Sex differences in metabolically healthy and metabolically unhealthy obesity among Chinese children and adolescents.

[This corrects the article DOI: 10.3389/fendo.2022.980332.].

Sex differences in metabolically healthy and metabolically unhealthy obesity among Chinese children and adolescents.

Objectives: To analyze sex differences in the prevalence of obesity phenotypes and their risk factors among children and adolescents aged 7-18 years in China. Methods: We enrolled 15,114 children and adolescents aged 7-18 years into the final analysis. Obesity phenotypes were classified by body mass index (BMI) and metabolic status as metabolically healthy or unhealthy obesity. In addition, we collected four possible influencing factors on obesity phenotypes through questionnaires, including demographic, parental, early life, and lifestyle indicators. Multinomial logistic regression analysis in a generalized linear mixed model (GLMM) was selected to estimate the odds ratio (OR) and 95% confidence interval (95% CI) for identifying risk factors and control the cluster effects of schools. More importantly, the interaction terms of sex and each indicator were established to demonstrate the sex differences. Results: The prevalence of metabolically healthy obesity (MHO), metabolically unhealthy obesity (MUO), metabolically healthy overweight and obesity (MHOO), and metabolically unhealthy overweight and obesity (MUOO) were 3.5%, 5.6%, 11.1%, and 13.0% respectively, with higher prevalence in boys (5.3% vs. 1.6%, 7.9% vs. 3.1%, 14.3% vs. 7.7%, 15.6% vs. 10.1%). In addition, younger ages, single children, parental smoking, parental history of diseases (overweight, hypertension, diabetes), caesarean, premature, and delayed delivery time, high birth weight, insufficient sleep time, and excessive screen time were considered as important risk factors of MHO and MUO among children and adolescents (p < 0.05). More notably, boys were at higher risks of MUO when they were single children (boys: OR = 1.56, 95% CI: 1.24-1.96; girls: OR = 1.12, 95% CI: 0.82-1.54), while girls were more sensitive to MUO with parental smoking (girls: OR = 1.34, 95% CI: 1.02-1.76; boys: OR = 1.16, 95% CI: 0.97-1.39), premature delivery (girls: OR = 3.11, 95% CI: 1.59-6.07; boys: OR = 1.22, 95% CI: 0.67-2.22), high birth weight (girls: OR = 2.45, 95% CI: 1.63-3.69; boys: OR = 1.28, 95% CI: 0.96-1.70), and excessive screen time (girls: OR = 1.47, 95% CI: 1.06-2.04; boys: OR = 0.97, 95% CI: 0.79-1.20), with significant interaction term for sex difference (pinteraction < 0.05). Conclusions: MHO and MUO are becoming prevalent among Chinese children and adolescents. Significant sex differences in the prevalence of obesity phenotypes as well as their environmental and genetic risk factors suggest it might be necessary to manage obesity phenotypes problems from a sex perspective.