Assessment of indoor light-at-night exposure in children and adolescents during schooldays and weekends.

Light-At-Night (LAN) is increasingly recognized and may has adverse health effects on children and adolescents, yet few studies have reported objective indoor LAN exposure levels for children and adolescents. In this study, we measured the indoor LAN exposure levels and duration among 897 children and adolescents aged 6-14 in Beijing, China, using portable photometers during both school days and weekends. Results indicate that the median indoor LAN exposure from 9:00 p.m. to 7:00 a.m. was 5.1 lx, with 31.8% of the subjects experiencing an average exposure above 10 lx. Additionally, from the perspective of cumulative high exposure duration, children and adolescents were exposed to more than 10 lx for approximately 64 min from 9:00 p.m. to 7:00 a.m. During the entire nighttime (from self-reported bedtime to wake-up time), the median exposure was 2.1 lx, with 16.6% averaging exposures above 10 lx. Exposure levels were significantly higher on weekends than on schooldays. Both girls and upper-grade students had higher levels of exposure and longer durations of high exposure. Girls in grade 7 (OR:2.56, 95%CI: 1.68-3.88) experienced the highest LAN exposure in our subjects compared to boys in grade 1-4. Our findings underscore the importance of promoting healthy light exposure behaviors among children and adolescents and reducing their light exposure environments to mitigate the potential health impacts of LAN.

Establish a noninvasive model to screen metabolic dysfunction-associated steatotic liver disease in children aged 6-14 years in China and its applications in high-obesity-risk countries and regions.

Background: The prevalence of metabolic-associated steatotic liver disease (MASLD) is rising precipitously among children, particularly in regions or countries burdened with high prevalence of obesity. However, identifying those at high risk remains a significant challenge, as the majority do not exhibit distinct symptoms of MASLD. There is an urgent need for a widely accepted non-invasive predictor to facilitate early disease diagnosis and management of the disease. Our study aims to 1) evaluate and compare existing predictors of MASLD, and 2) develop a practical screening strategy for children, tailored to local prevalence of obesity. Methods: We utilized a school-based cross-sectional survey in Beijing as the training dataset to establish predictive models for screening MASLD in children. An independent school-based study in Ningbo was used to validate the models. We selected the optimal non-invasive MASLD predictor by comparing logistic regression model, random forest model, decision tree model, and support vector machine model using both the Beijing and Ningbo datasets. This was followed by serial testing using the best performance index we identified and indices from previous studies. Finally, we calculated the potential MASLD screening recommendation categories and corresponding profits based on national and subnational obesity prevalence, and applied those three categories to 200 countries according to their obesity prevalence from 1990 to 2022. Findings: A total of 1018 children were included (NBeijing = 596, NNingbo = 422). The logistic regression model demonstrated the best performance, identifying the waist-to-height ratio (WHtR, cutoff value ≥0.48) as the optimal noninvasive index for predicting MASLD, with strong performance in both training and validation set. Additionally, the combination of WHtR and lipid accumulation product (LAP) was selected as an optimal serial test to improve the positive predictive value, with a LAP cutoff value of ≥668.22 cm × mg/dL. Based on the obesity prevalence among 30 provinces, three MASLD screening recommendations were proposed: 1) "Population-screening-recommended": For regions with an obesity prevalence ≥12.0%, where MASLD prevalence ranged from 5.0% to 21.5%; 2) "Resources-permitted": For regions with an obesity prevalence between 8.4% and 12.0%, where MASLD prevalence ranged from 2.3% to 4.4%; 3) "Population-screening-not-recommended": For regions with an obesity prevalence <8.4%, where MASLD prevalence is difficult to detect using our tool. Using our proposed cutoff for screening MASLD, the number of countries classified into the "Population-screening-recommended" and "Resources-permitted" categories increased from one and 11 in 1990 to 95 and 28 in 2022, respectively. Interpretation: WHtR might serve as a practical and accessible index for predicting pediatric MASLD. A WHtR value ≥0.48 could facilitate early identification and management of MASLD in areas with obesity prevalence ≥12.0%. Furthermore, combining WHtR ≥0.48 with LAP ≥668.22 cm × mg/dL is recommended for individual MASLD screening. Moreover, linking these measures with population obesity prevalence not only helps estimate MASLD prevalence but also indicates potential screening profits in regions at varying levels of obesity risk. Funding: This study was supported by grants from Capital's Funds for Health Improvement and Research (Grant No. 2022-1G-4251), National Natural Science Foundation of China (Grant No. 82273654), Major Science and Technology Projects for Health of Zhejiang Province (Grant No. WKJ-ZJ-2216), Cyrus Tang Foundation for Young Scholar 2022 (2022-B126) and Sino-German Mobility Programme (M-0015).

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.