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 analyze the association and dose response relationship between physical activity and inflammatory markers in college students, so as to provide a reference for promoting cardiometabolic health in college students. Methods: A cluster random sampling method was used to select 747 college students from two universities in Hefei, Anhui Province and Shangrao, Jiangxi Province from April to May 2019. Physical activity was assessed by using the International Physical Activity Questionnaire-Short Form (IPAQ-SF), and peripheral blood was collected to detect plasma inflammatory factor levels [including hypersensitive C reactive protein (hsCRP), interleukin-10 (IL-10), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α)]. The differences between the groups were compared by using the χ 2 test and the Kruskal-Wallis rank sum test, and the association between physical activity and inflammatory markers was analyzed by using the Generalized Linear Model. The dose response relationship between physical activity and inflammatory markers was analyzed using the Restricted Cubic Spline Model. Results: The proportions of low physical activity, moderate physical activity, and high physical activity groups of college students were 15.9%, 53.7% and 30.4%, respectively. The levels of hsCRP, IL-10, IL-1β, IL-6 and TNF-α in the high physical activity group were 0.38(0.21, 1.10)mg/L, 70.74(47.90, 116.43)pg/mL, 1.75(1.21, 2.64)pg/mL, 4.33(2.93, 6.82) pg/mL , 5.27(3.89, 7.30)pg/mL,the levels in the low physical activity group were 0.80(0.31, 1.30)mg/L, 73.88 (47.90, 124.24)pg/mL, 1.88(1.42, 2.81) pg/mL, 4.82 (3.64, 6.67) pg/mL, 5.63 (4.34, 7.62)pg/mL, the levels in the moderate physical activity group were 0.63(0.25, 1.30)mg/L, 89.78(58.21, 127.65)pg/mL, 2.21(1.59, 3.27)pg/mL, 5.15( 3.72 , 7.72)pg/mL, 5.87( 4.63 , 8.00)g/mL, and the differences were statistically significant ( H=10.66, 11.38, 27.79, 14.13, 9.44, P <0.05). After adjusting for variables such as gender, body mass index, smoking, alcohol consumption and health status, the results of Generalized Linear Model showed that compared with the high physical activity group, the low physical activity group ( OR=2.20, 95%CI = 1.46- 3.31) and the moderate physical activity group ( OR=1.65, 95%CI =1.22-2.25) were more likely to have high levels of hsCRP, and the moderate physical activity group was more likely to have high levels of IL-1β ( OR=1.85, 95%CI =1.36-2.51), IL-6 ( OR=1.44, 95%CI =1.06-1.96), and TNF-α ( OR=1.43, 95%CI =1.05-1.94) ( P <0.05). The Restricted Cubic Spline Model showed that there was no linear dose response relationship between the time of moderate to vigorous physical activity weekly and IL-10, IL-6, II-1β, and TNF-α ( P <0.05). Conclusion There is an association between physical activity and inflammation in college students, and moderate to high intensity per week could reduce inflammation levels to promote cardiometabolic health in college students.

Abstract Dry eye is a multifactorial ocular surface disease characterized by tear film homeostasis imbalance, which usually causes eye discomfort and visual impairment. With the change of environment and lifestyle, the incidence of dry eye in children and adolescents has risen steadily. Epidemiological studies have confirmed that the incidence of dry eye is closely related to unhealthy lifestyle. Prevention should be given great priority to in avoiding lifestyle related dry eye. The review summarizes the definition, epidemiology, risk factors and preventive measures of lifestyle related dry eye, so as to provide a theoretical basis for improving the diagnosis, treatment and prevention of lifestyle related dry eye in children and adolescents.

Objective: To explore the longitudinal correlation between smartphone multitasking and depressive symptoms, so as to provide an evidence based basis for promoting the mental health of college students. Methods: A total of 967 college students were recruited from one university in Taiyuan, Chongqing, and Shenzhen cities, China, by using multi stage randomized cluster sampling from October to December 2021 at baseline, and a follow up survey was conducted in May 2022. Smartphone multitasking behaviors were assessed by means of the Assessment of Smartphone Multitasking for Adolescents (ASMA), and depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9) among college students. Chi square tests were performed to compare the differences in depressive symptoms between different groups of demographic characteristics, and binary Logistic regression models were employed to analyze the associations between smartphone multitasking and depressive symptoms among college students. Results: The rates of depressive symptoms among college students at baseline and follow up were 35.2% and 42.3%, respectively. Compared to the low level smartphone multitasking index group at baseline, the moderate and high level groups were more likely to experience depressive symptoms at baseline (moderate level group: OR=1.74, 95%CI =1.22-2.50, high level group: OR=2.77, 95%CI =1.94-3.95) and followup (moderate level group: OR=1.41, 95%CI =1.01-1.95, high level group: OR=1.64, 95%CI =1.17-2.29) ( P <0.05). In addition, compared to the persistently low smartphone multitasking index, increased risk of depressive symptoms was associated with maintaining a moderate to high ( OR=2.94, 95%CI =1.83-4.71), and a higher ( OR=2.07, 95%CI =1.31-3.27) or lower smartphone multitasking index ( OR=2.02, 95%CI =1.27-3.19) ( P <0.05). Moreover, higher smartphone multitasking index scores were positively associated with the risk of new-onset depressive symptoms at follow up ( OR=1.87, 95%CI=1.07-3.27, P <0.05). Conclusions Smartphone multitasking behaviors are find to be associated with an increased risk of depressive symptoms in college students. There is a need to reduce smartphone multitasking in order to decrease depressive symptoms and promote students mental health.

Objective: To explore the association among neck-shoulder pain (NSP), low back pain (LBP) and co occurring symptoms with mental sub health in adolescents, so as to provide evidence for improving physical and mental health of adolescents. Methods: Stratified cluster random sampling method was used to select 7 986 students from 12 middle and high schools in Shenzhen, Nanchang, and Shenyang cities from October to December 2019. The Assessment of Spinal Health of Youth (ASHY) and the Brief Instrument on Psychological Health of Youth (BIOPHY) were used to assess NSP, LBP and mental sub health. Binary Logistic regression model was used to analyze the association between NSP, LBP and co occurring symptoms with mental sub health in adolescents. Results: The detection rates of adolescents with NSP, LBP and co occurring symptoms and mental sub health were 9.1% , 9.8%, 9.5%, and 10.0%, respectively. The co occurring rate of neck shoulder pain, low back pain and mental sub health was 3.2%. After adjusting for confounding variables such as gender, age, being an only child, family residence, and parental education level, NSP ( OR=6.01, 95%CI =5.02-7.19), LBP ( OR=5.08, 95%CI =4.25-6.07), and co occurring symptoms ( OR= 5.96 , 95%CI =4.98-7.12) in adolescents were positively correlated with mental sub health risk ( P <0.01). Stratifying the gender, boys with NSP, LBP and co occurring symptoms ( OR =6.84, 5.80, 6.74)had a higher risk of mental sub health compared to girls ( OR =5.52, 4.65, 5.49) ( P <0.01). Conclusions NSP, LBP and co occurring symptoms in adolescents are associated with mental sub health. The mental health status of boys is more affected by NSP, LBP and their co occurring symptoms. Measures should be taken to improve spinal health in adolescents to reduce the incidence of mental sub health.

Objective To investigate the influencing factors of peripheral infections of knee joint tumor prosthesis as well as the value of serum D-D and TLR2 in predicting the infection risks so as to provide a reference for early diagnosis of tumorous periprosthetic infection(PJI)of knee joint.Methods The patients who were treated and followed up in our department from January 2008 to June 2020 were selected.According to the inclusion and exclusion criteria,136 of the patients were selected.The data including age,gender,BMI,history of diabetes,smoking history,tumor location,stage of malignant tumor,operation time,osteotomy length,intraoperative bleed-ing,and the percentage of neutrophils,leukocytes,serum D-dimer,and serum TLR value 3 days after operation were collected.The risk factors of PJI and the diagnostic value of serum D-dimer and serum TLR were analyzed.Results The incidence of PJI was 11.76%.Postoperative chemotherapy and operation time≥180 min were the risk factors of PJI(P<0.05).The area under curve(AUC)of the combination of two indicators,serum D-dimer and serum TLR2 were 0.917,0.894 and 0.778,respectively.The AUC of TLR2 was lower than that of the combina-tion of two indicators(P<0.05);The sensitivity was 0.975,0.908 and 0.708,respectively,and the specificity was 0.75,0.75,and 0.812,respectively.Conclusion Postoperative chemotherapy and operation time≥180 min are the risk factors of PJI.The combination of D-dimer and TLR2 has good diagnostic value.

Objective: To describe the association of different sleep characteristics and cardiometabolic risk among college students, so as to provide reference for health promotion of college students. Methods: By random cluster sampling method, a questionnaire survey and physical examination including blood pressure, waist circumference and blood lipid indicators, which were conducted in April and May of 2019 among a total of 1 179 college students from the first grade in two universities in Hefei City of Anhui Province and Shangrao City of Jiangxi Province. A total of 729 college students with valid questionnaires were included into analysis. The Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI) were used to investigate sleep behavior, and the Morning And Evening Questionnaire-5 (MEQ-5) was used to investigate sleep characteristics. The cardiometabolic risk score was derived using the sum of the standardized sex specific Z scores of waist circumference, mean arterial pressure, HDL cholesterol (multiplied by -1), triglycerides, and insulin resistance index. The rank sum tests were used to compare differences in cardiometabolic risk scores across demographic characteristics. Generalized linear models were used to compare the association of different sleep characteristics with cardiometabolic risk scores among college students. Results: The average cardiovascular metabolic risk score of college students was -0.32(-2.03, 1.58). There were statistically significant differences in cardiovascular metabolic risk scores among college students in variables such as smoking, health status, and physical activity levels ( t/F=-3.41, 12.88, 51.07, P <0.01). The results of the generalized linear model showed that nighttime preference ( B=1.89, 95%CI =1.02-3.49), insomnia symptoms ( B=3.25, 95%CI =1.79-5.90), and short or long sleep duration ( B=1.92, 95%CI =1.21-3.05) were positively correlated with the cardiovascular metabolic risk score of college students ( P <0.05). Conclusions Poor sleep patterns among college students are positively correlated with the risk of cardiovascular metabolism. The sleep behavior of college students should be actively changed to reduce the risk of cardiovascular disease.

Objective: To describe the prevalence and the association of sleep quality trajectory, social jetlag and comorbid symptoms of anxiety and depression among college students, in order to provide a theoretical basis for improving the comorbid symptoms of anxiety and depression in college students. Methods: A questionnaire survey was conducted among 1 135 college students from two universities in Shangrao, Jiangxi Province and Hefei, Anhui Province from April to May 2019, and were followed up once every one year for a total of three times, with a valid sample size of 1 034 individuals after matching with the baseline survey. A selfassessment questionnaire was used to investigate the social jetlag of college students, the Generalized Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire 9 (PHQ-9) were used to evaluate anxiety and depression symptoms, respectively, while the Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. College students with GAD-7 score ≥5 and PHQ-9 score ≥5 were defined as having comorbid anxiety and depression symptoms. Latent class growth model (LCGM) was employed to analyze the sleep quality trajectory of college students, and binary Logistic regression was used to analyze the relationship between social jetlag, sleep quality trajectory and comorbid symptoms of anxiety and depression. Results: The detection rate of comorbid symptoms of anxiety and depression among college students was 16.9%, and the detection rate of social jetlag ≥2 h was 13.8%. The sleep quality showed an overall improvement trend, and the two trajectories were good sleep quality (81.6%) and poor sleep quality (18.4%). Binary Logistic regression model showed that poor sleep quality and social jetlag ≥2 h were positively correlated with comorbid symptoms of anxiety and depression (OR=5.94, 1.84, P<0.05). Conclusions Poor sleep quality and social jetlag ≥2 h in college students increase the risk of comorbid symptoms of anxiety and depression. Early screening and intervention of sleep quality and reduction of social jetlag are crucial for enhancing the mental health of college students.

Objective: The aim of the present study was to develop the beverage addiction scale for college students,so as to provide an effective tool for assessing college students beverage addiction. Methods: In November 2022, a cluster sample of 8 792 college students from three colleges in Yunnan and Jiangxi were surveyed by Beverage Addication Scale for College Students. After a through literature review, 12 items were proposed, including withdrawal symptoms, health effects and addiction symptoms, with 4 items each. The ttest and correlation analysis were used to filter the items, and exploratory factor analysis and confirmatory factor analysis were used to evaluate the structural validity of the questionnaire. In May 2023, 5 279 college students from the above three universities were surveyed again to evaluate the reliability and validity of the scale and the positive demarcation value of symptoms. Results: The scale fitted into a tool for measuring symptoms of beverage dependence in a college student population. The scale was composed of 11 items in accordance with withdrawal symptoms, health effects and addiction symptoms, with a cumulative contribution rate of variance was 74.51%. Cronbach α coefficients for the overall scale and three dimensions were 0.94, 0.88, 0.90 and 0.92, respectively. The correlation coefficient between each item and the total score ranged from 0.56 to 0.79, and the correlation coefficient with the dimension ranged from 0.71 to 0.92. The confirmatory factor analysis model was well fitted, and the RMSEA, CFI, TLI and SRMR value were 0.06, 0.95, 0.93 and 0.04, respectively. The application of the scale showed that scores on the scale and each dimension ≥P85 were positive for symptoms. Conclusion The reliability and validity of Beverage Addiction Scale for College Students is good, which can be used to evaluate the beverage addiction symptom of college students.

Abstract Common diseases among students such as myopia, overweight and obesity, scoliosis, and mental health problems are prevalent, which usually exist concurrently under similar public health influencing factors. Therefore, there is a need to carry out the joint prevention of multimorbidity. The National Disease Control and Prevention Administration of China have organize the development of the Technical Guidelines for the Joint Prevention of Common Disease Multimorbidity among Students (hereafter referred to as the Guidelines). For the first time, the Guidelines clarifies the concept of multimorbidity joint prevention, specifies that the departments of centers for disease control and prevention should strengthen environmental and behavioral surveillance, proposes integrated public health interventions for multimorbidity joint prevention based on a three tiered prevention strategy, and recommends the appropriate technology of a healthy lifestyle featuring six key principles. It also advocates exploring the establishment of a six in one model (government-professional institution-community-school-family-students collaboration) for multimorbidity joint prevention, which has achieved a leap in theory and practice in the prevention and control of common diseases among students. The article focuses on the background, theoretical basis and core content of the Guidelines, in order to improve the understanding of the Guidelines by professionals in public health institutions and people concerned about students health, and to promote the application and dissemination of the Guidelines.