Objective: To analyze the correlation of physical activity and screen time with anxiety and depressive symptoms among college students, so as to provide a reference for formulating intervention measures for anxiety and depressive symptoms among college students. Methods: In May 2024, the method of combining convenient sampling with stratified sampling was adopted to select 3 076 college students from 5 colleges in Shaoxing of Zhejiang Province. Self compiled general situation questionnaires, Screen Time Questionnaire, Selfrating Anxiety Scale and Self rating Depression Scale were used to investigate the current status of college students physical activities, screen time, anxiety and depressive symptoms, etc. Inter group comparisons were conducted by using the χ 2 test, Fisher s exact probability test, t-test or analysis of variance. A multivariate Logistic regression model was established to explore the correlations between physical activity, screen time with anxiety and depressive symptoms among college students. Results: The constituent ratios of mild, moderate and severe anxiety symptoms were 59.97%, 28.99% and 11.04%, respectively. The constituent ratios of mild, moderate and severe depressive symptoms were 64.96%, 29.92% and 5.12%, respectively. There were statistically significant differences in the detection rates of anxiety symptom ( χ 2=15.99) and depressive symptom ( χ 2=16.54) among college students of different grades and screen time daily (both P <0.05). There were statistically significant differences in physical activity among college students of different genders and subject types ( t/F =11.67, 11.90, both P <0.01). Multivariate Logistic regression analysis showed that when physical activity was at least 1 hour per week <3 d, a screen time <2 h/d could reduce the risk of anxiety symptoms among college students ( OR =0.57), and screen time <2, 2-<3, 3-<4 h/d could reduce the risk of depressive symptoms among college students ( OR =0.65, 0.56, 0.64); when the number of days of physical activity exercise was at least 1 h per week ≥3 d, the occurrence risks of anxiety symptom( OR =0.49, 0.58) and depressive symptom ( OR =0.36, 0.43) were reduced for students with screen time <2 and 2-<3 h/d (all P <0.05). Conclusions There are correlations of physical activity and screen time with anxiety and depressive symptoms among college students. Low physical activity and longer screen time are more likely to increase the risk of anxiety and depressive symptom among college students.

Objective:To explore the impact of sleep duration, physical exercise, and their interactions on the risk of dyslipidemia in older adults aged ≥80 (the oldest old) in China.Methods:The study subjects were the oldest old from four rounds of Healthy Aging and Biomarkers Cohort Study (2008-2009, 2011-2012, 2014 and 2017-2018). The information about their demographic characteristics, lifestyles, physical examination results and others were collected, and fasting venous blood samples were collected from them for blood lipid testing. Competing risk model was used to analyze the causal associations of sleep duration and physical exercise with the risk for dyslipidemia. Restricted cubic spline (RCS) function was used to explore the dose-response relationship between sleep duration and the risk for dyslipidemia. Additive and multiplicative interaction model were used to explore the interaction of sleep duration and physical exercise on the risk for dyslipidemia.Results:The average age of 1 809 subjects was (93.1±7.7) years, 65.1% of them were women. The average sleep duration of the subjects was (8.0±2.5) hours/day, 28.1% of them had sleep duration for less than 7 hours/day, and 27.2% had sleep for duration more than 9 hours/day at baseline survey. During the 9-year cumulative follow-up of 6 150.6 person years (follow-up of average 3.4 years for one person), there were 304 new cases of dyslipidemia, with an incidence density of 4 942.6/100 000 person years. The results of competitive risk model analysis showed that compared with those who slept for 7-9 hours/day, the risk for dyslipidemia in oldest old with sleep duration >9 hours/day increased by 22% ( HR=1.22, 95% CI: 1.07-1.39). Compared with the oldest old having no physical exercise, the risk for dyslipidemia in the oldest old having physical exercise decreased by 33% ( HR=0.67, 95% CI: 0.57-0.78). The RCS function showed a linear positive dose-response relationship between sleep duration and the risk for hyperlipidemia. The interaction analysis showed that physical exercise and sleep duration had an antagonistic effect on the risk for hyperlipidemia. Conclusion:Physical exercise could reduce the adverse effects of prolonged sleep on blood lipids in the oldest old.