Association between latent class of health-risk behaviors and depressive symptoms among middle school students / 预防医学

Objective@#To analyze the association between latent class of health-risk behaviors and depressive symptoms among middle school students, so as to provide the evidence for the prevention and intervention of depressive symptoms among middle school students.@*Methods@#Students in two junior high schools, two senior high schools and one vocational high school in Yinzhou District, Ningbo City, Zhejiang Province, were selected using a stratified multi-stage cluster sampling method. Demography and health-risk behaviors were collected using questionnaire surveys, depressive symptoms were investigated using the Center for Epidemiological Studies Depression-10 Scale, and latent class analysis was conducted for health-risk behaviors. The association between different latent classes and depressive symptoms was analyzed using a multivariable logistic regression model.@*Results@#A total of 1 247 students were surveyed, including 641 boys (51.40%) and 606 girls (48.60%). There were 452 junior high school students (36.25%), 532 high school students (42.66%) and 263 vocational high school students (21.09%). Latent class analysis showed that health-risk behaviors in students were classified into three groups, namely healthy behavior group (52.93%), poor diet group (39.94%) and high-risk behavior group (7.14%), and the detection rates of depressive symptoms were 7.12%, 18.88% and 52.81%, respectively, with a statistically significant difference between groups (P<0.05). Multivariable logistic regression analysis showed that after adjusting for age, gender, native place, only child and living on campus, the poor diet group (OR=3.107, 95%CI: 2.086-4.627) and high-risk behavior group (OR=15.401, 95%CI: 9.031-26.262) had higher risks of depressive symptoms compared with the healthy behavior group.@*Conclusion@#Having high-risk behaviors and poor diet may increase the risk of developing depressive symptoms among middle school students.

Effect of lifestyle behaviors on myopia among primary and middle school students: a latent class analysis / 预防医学

Objective@#To examine the effect of lifestyle behaviors on myopia among primary and middle school students in Yinzhou District, Ningbo City using latent class analysis, so as to provide insights into prevention of myopia among primary and middle school students.@*Methods@#A total of 1 547 students were sampled from primary and middle schools in Yinzhou District using a stratified cluster sampling method. Myopia-associated lifestyle behaviors were collected using questionnaires, and visual acuity was tested. Myopia-associated lifestyle behaviors were subjected to latent class analysis among primary and middle school students, and the association between lifestyle behaviors and risk of myopia was examined using a logistic regression model.@*Results@#A total of 1 547 questionnaires were allocated, and 1 494 valid questionnaires were recovered, with an effective recovery rate of 96.57%. There were 247 primary school students (16.53%), 452 junior high school students (30.25%), 532 senior high school students (35.61%) and 263 vocational high school students (17.60%), and 773 men (51.74%) and 721 women (48.26%). Latent class analysis showed that students' lifestyle behaviors were classified into three groups, including the healthy behavior group (37.68%), reading and writing fatigue group (42.64%), and video fatigue and poor diet group (19.68%), with myopia prevalence of 79.22%, 88.38% and 86.73%, respectively. Moderate myopia was predominant in the reading and writing fatigue group and video fatigue and poor diet group, and low myopia was predominant in the healthy behavior group. A higher risk of myopia was found in the reading and writing fatigue group (OR=1.996, 95%CI: 1.454-2.739) and video fatigue and poor diet group (OR=1.715, 95%CI: 1.157-2.543) than in the healthy behavior group.@*Conclusions@#Long reading and writing duration, insufficient exercise and sleep, long video watching duration, and high intake frequency of sugary drinks and fried foods may increase the risk of myopia in primary and middle school students in Yinzhou District. Targeted myopia interventions are required tailored to different categories of lifestyle behaviors.

Skipping breakfast and physical fitness among school-aged adolescents

OBJECTIVES: This study explored the relationship between skipping breakfast and physical fitness in a group of school-aged adolescents in China. METHODS: This cross-sectional study from the Chinese National Surveillance on Students' Constitution and Health (CNSSCH) survey in Ningbo, China, used a standardized questionnaire to assess the frequency of breakfast consumption. Physical fitness was measured through standing long jump, 50-m sprint, 1,000 (or 800)-m run, and vital capacity tests. Multiple linear regression analysis was used to investigate the relationship between the frequency of breakfast consumption and physical fitness. RESULTS: Our study included a total of 1,849 school-aged adolescents (aged 15.53±1.80 years). Among boys, non-breakfast-skippers had good scores for 50-m sprints, 1,000-m run, and vital capacity tests when compared with breakfast skippers (all p<0.05). Among girls, non-breakfast-skippers had a good scores for the standing long jump test compared with breakfast skippers (p=0.003). The multiple linear regression model showed that not skipping breakfast was positively associated with vital capacity (β=-173.78, p=0.004) and inversely associated with 50-m sprint (β=-0.12, p=0.018) and 1,000-m run times (β=-8.08, p=0.001) in boys. CONCLUSION: The results of this cross-sectional study revealed that skipping breakfast might be associated with lower physical fitness in Chinese adolescents aged 13-18 years, especially boys. Breakfast consumption should be promoted among Chinese school-aged boys.