Abstract The physical and mental health issues of children and adolescents in China are becoming increasingly prominent. Integrating physical education deeply into the educational system and maximizing its role in fostering personal development, preventing common illnesses among students, and promoting mental health has emerged as the intersection of school health and sports. The article systematically arranges the development history and patterns of physical education in Chinese schools, summarizes the existing difficulties in the integration of physical education and educational system, and presents improvement suggestions to provide a basis for enhancing the integration system and promote the comprehensive development of children and adolescents.

Abstract The issue of multimorbidity in children and adolescents is becoming increasingly prominent, but there is no consensus on the definition of multimorbidity. As research deepens, issues related to the comparability and standardization of relevant findings are gradually emerging. As a solution, a systematic review of both domestic and international research on multimorbidity is conducted, and a classification system for defining the concept of multimorbidity is proposed, offering more convenient conditions for the advancement of future research and cross study exchange.

Objective: To explore the association between light at night (LAN) of different intensities and ocular biometric parameters among preschool children, so as to provide a reference for optimizing strategies for myopia prevention and control. Methods: From November 2024 to January 2025, a cross sectional study was conducted among 369 preschool children from one kindergarten in Quanzhou City, Fujian Province. Questionnaire survey and eye examination were performed, and portable light sensors were used to collect LAN exposure data. Spearman correlation analysis was used to examine the associations between the duration of LAN exposure at different intensities and ocular biometric parameters. Generalized linear model was employed to explore the relationships between LAN duration at various intensities and ocular biometric parameters, while restricted cubic spline was used to investigate potential nonlinear associations. Results: The spherical equivalent (SE), axial length (AL), and axial length/corneal radius of curvature (AL/CR) for preschool children were 0.38 (-0.13,0.63) diopters, 22.35 (21.86,22.88) mm, and 2.86 (2.82,2.90), respectively. The median daily duration (interquartile ranges) of LAN exposure at intensities of 0, >0-100, >100-300, and >300 lx were 6.09(5.31,6.74), 1.74(1.13,2.42), 0.06(0.00,0.26), 0.00(0.00,0.00)h/d, respectively. The generalized linear model showed that for every additional hour of LAN at >100-300 lx, the AL/CR increased by 0.26 (95% CI =0.01-0.52); for every additional hour of LAN at >300 lx, AL/CR increased by 0.32 (95% CI =0.05-0.59) (both P < 0.05). No statistically significant associations were observed between SE or AL and LAN exposure at any of the intensity levels (0, >0-100, >100-300, and >300 lx) (all P >0.05). The restricted cubic spline model revealed that, except for the nonlinear relationship between LAN duration and AL at >100-300 lx ( P =0.02), all other light intensity levels showed linear correlations between LAN duration and preschool children s SE, AL, and AL/CR (both P >0.05). Time of day subgroup analysis revealed that during school days, for every additional hour of LAN at >100-300 lx and over 300 lx，AL/CR increased by 0.18 (95% CI =0.01-0.35) and 0.22 (95% CI =0.03-0.41), respectively (both P <0.05). However, weekend exposure showed no statistically significant association (all P >0.05). Conclusion Higher intensity of LAN is associated with increased AL/CR, and reducing exposure to LAN may have a potential protective effect on the visual health of preschool children.