Objective: To explore the association between mental health and muscle strength among Chinese adolescents aged 13- 18, providing a theoretical foundation and intervention strategies for mental health promotion. Methods: Data were obtained from the 2019 Chinese National Survey on Students Constitution and Health, including 98 631 Chinese adolescents aged 13- 18. Psychological distress was assessed by using the Kessler Psychological Distress Scale (K10), and mental well being was measured with the Warwick-Edinburgh Mental Well being Scale (WEMWBS). Based on the gender and age specific Z scores of various test items [grip strength, standing long jump, pull ups (for males), and sit ups (for females)], muscle strength index (MSI) was constructed to evaluate the comprehensive level of muscle strength in adolescents. According to the Dual factor Model (DFM) of mental health, participants were categorized into four groups:troubled, symptomatic but content, vulnerable, and complete mental health. Gender differences were analyzed by using Chi-square tests, trends were tested with Cochran-Armitage tests, and multinomial Logistic regression models were applied to assess associations between muscle strength and mental health among adolescents. Results: In 2019, 37.4% of Chinese adolescents aged 13-18 were reported of high mental distress, and 59.9% were reported of low mental well being. Boys had significantly lower rates of high mental distress (35.3%) and low mental well being (55.6%) compared to girls (39.4%, 64.3%), and the differences were of statistical significance ( χ 2=176.13, 780.42, both P <0.05). In 2019, the rate of complete mental health among adolescents showed a downward trend with increasing age ( χ 2 trend = 258.47) and a gradual upward trend with increasing muscle strength levels ( χ 2 trend =123.14)，and both boys and girls exhibited similar trends ( χ 2 trend =103.83, 168.46; 57.00 , 67.34) (all P <0.05). The results of the unordered multiclass Logistic regression model showed that after controlling for confounding factors such as age and gender, when the completely pathological group as a reference, for every 1 unit increase in MSI in adolescents, the likelihood of being in a completely mental health state increased by 29% ( OR = 1.29); for every unit increase in the Z-score for pull ups, the likelihood of being in a completely mental health state increased by 6% ( OR =1.06) among boys; for every 1 unit increase in sit up Z score, the likelihood of being in a completely mental health state increased by 19% ( OR =1.19) among girls (all P <0.05). Conclusions The mental health status of Chinese adolescents is not good enough. Muscle strength is positively associated with mental health.

Objective To observe the value of anatomical characteristics of femoral intercondylar notch of knee joint for predicting non-contact anterior cruciate ligament tear(NC-ACLT).Methods MRI data of knee joint of 55 patients with NC-ACLT(NC-ACLT group)and 55 controls(control group)were retrospectively analyzed.The parameters of intercondylar notch,including depth,width,depth/width ratio,opening width,opening width index,area and width of the femoral condyle's outer edge at the same level were measured between groups,and the types of intercondylar notch(type A,U and W)were recorded.Univariate and multivariate logistic regression analysis were used to screen the independent impact factors of NC-ACLT.Receiver operating characteristic curves were drawn,and the area under the curves(AUC)were calculated to evaluate the efficacy of each intercondylar notch parameter for predicting NC-ACLT.Results The depth and depth/width ratio of intercondylar notch in NC-ACLT group were both higher,while the opening width and opening width index of intercondylar notch in NC-ACLT group were both lower than those in control group(all P＜0.05).Multivariate logistic regression analysis revealed that the depth of intercondylar notch was an independent impact factors of NC-ACLT(P＜0.05).Taken 29.55 mm in depth of intercondylar notch,1.45 in depth/width ratio of intercondylar notch,21.15 mm in opening width of intercondylar notch and 0.29 in opening width index as the optimal cut-off value,respectively,the sensitivity of the above parameters for predicting NC-ACLT was 74.55％,58.18％,67.27％and 67.27％,the specificity was 69.09％,80.00％,61.82％and 78.18％,and the AUC was 0.720,0.713,0.652 and 0.710,respectively.Conclusion The anatomical characteristics of femoral intercondylar notch of knee joint could be used to predict NC-ACLT.The depth,depth/width ratio,opening width and opening width index of intercondylar notch could be used as predictive indicators.

Objective:To analyze the association between the occurrence of spermarche and menarche and psychological distress among Chinese Han children and adolescents aged 9 to 18 years.Methods:Data were drawn from the 2019 Chinese National Survey on Students' Constitution and Health, and a total of 54 438 boys aged 11 to 18 years and 76 376 girls aged 9 to 18 years with psychological distress, spermarche/menarche records were included in the final analysis. The occurrence of spermarche/menarche was recorded by physicians, and psychological distress was classified according to the Kessler Psychological Distress Scale scores. The chi-square test was used to compare the difference between groups in the occurrence of spermarche/menarche, and the multinomial logistic regression model and stratification analysis was established to analyze the association between psychological distress and spermarche/menarche.Results:The incidence of spermarche/menarche in 2019 ranged from 6.3% to 96.5% for eight age groups of Chinese boys and 2.8% to 99.0% for ten age groups of girls. The rates of high psychological distress among boys and girls were 32.5% and 32.7%. Among boys aged 11 to 18 years, the rate of high psychological distress increased with age, with a trend test P<0.001, and the difference in the rate of high psychological distress between those who had and had not had their spermarche was not statistically significant in all age groups. Among girls aged 9 to 18 years, the rate of high psychological distress increased with age, with a trend P<0.001; the rate of high psychological distress was higher in the group with menarche at age 10 and 12 than in the group without menarche (all P<0.05). High psychological distress was positively correlated with spermarche among boys aged 13-15 years living in urban areas and hight level economic development areas ( OR=1.11, 95% CI: 1.02-1.21; OR=1.18, 95% CI: 1.06-1.32). Overall, high psychological distress was positively correlated with menarche in girls aged 9-12 and 13-15 years ( OR=1.33, 95% CI: 1.25-1.42; OR=1.22, 95% CI: 1.07-1.39). High psychological distress was positively correlated with menarche among girls aged 9-12 years living in different regions except for the Northeast region, in areas with different levels of economic development, and in urban and rural areas, in girls aged 13-15 years living in urban, central, and western regions, and in girls aged 16-18 years residing in the central region. Conclusions:This study found an association between the occurrence of spermarche/menarche and psychological distress among Chinese Han children and adolescents aged 9 to 18 years in 2019, which was particularly significant among girls aged 9 to 12 years and boys aged 13 to 15 years living in areas with higher levels of socioeconomic development.

Objective:To describe the status of physical fitness of children and adolescents aged 13-18 years in China in 2019 and analyze its association with psychological distress.Methods:Data were drawn from the 2019 Chinese National Survey on Students' Constitution and Health, and 90 633 Han children and adolescents aged 13-18 years were included. Physical fitness was evaluated by "National Students Constitutional Health Standards" (2014 revised edition). Psychological distress was classified according to the scores of the Kessler Psychological Distress Scale: ≤19, 20-24, 25-29, and ≥30 scores indicated no, mild, moderate, and severe psychological distress, respectively, with moderate and severe psychological distress collectively referred to as high psychological distress. The χ2 test was used to compare the distribution differences between boys and girls, the Cochran-Armitage test was used to analyze the trend, and the multinomial logistic regression in the mixed effect model was established to analyze the association between physical fitness and psychological distress. Results:In 2019, the unqualified rate of physical fitness among children and adolescents aged 13-18 years in China was 17.2%, and the prevalence of excellent and good physical fitness was 18.2%, which was lower among boys (15.9%) than girls (20.5%) with a statistically significant difference ( P<0.05). The excellent and good physical fitness rate showed a significantly decreasing trend with age (trend test P<0.05). The rate of high psychological distress among children and adolescents aged 13-18 years in China in 2019 was 39.3%, with boys (37.0%) having a lower prevalence than girls (41.6%), supported by a statistically significant difference ( P<0.05), and a decreasing trend with the degree of physical fitness was observed both in boys and girls (trend test P<0.05). The multinomial logistic regression model showed that the prevalence of moderate ( OR=0.83, 95% CI: 0.79-0.88, P<0.001) and severe ( OR=0.81, 95% CI: 0.77-0.86, P<0.001) psychological distress were both lower in children and adolescents with excellent and good physical fitness. Conclusion:The status of physical fitness and psychological distress of Chinese children and adolescents aged 13-18 in 2019 was not optimistic, with physical fitness showing a significantly negative association with psychological distress.

Objective:To analyze the relationship between red cell distribution width (RDW) and disease severity in patients with non-ST-elevation myocardial infarction.Methods:Seventy patients with non-ST-elevation myocardial infarction who received treatment in Chaozhou People's Hospital from June 2019 to June 2020 were included in the observation group. An additional 70 patients with ST-elevation myocardial infarction who concurrently received treatment in the same hospital were included in the control group. All patients underwent electrocardiography and blood biochemical index examination. RDW was compared between the observation and control groups. The relationship between RDW and the severity of non-ST-elevation myocardial infarction was analyzed.Results:RDW in the observation group was significantly higher than that in the control group [(14.60 ± 1.00) % vs. (13.06 ± 1.70) %, t = 5.884, P = 0.012). The detection rate of coronary artery thrombosis in the observation group was significantly higher than that in the control group [70.00% (49/70) vs. 50.00% (35/70), χ2 = 7.563, P = 0.002]. In the observation group, the area under the receiver operating characteristic (ROC) curve plotted taking RDW as the variable was 0.649 (95% CI 0.546-0.753, P = 0.006). When the critical value of RDW was 14%, the sensitivity and specificity of RDW in the prediction of non-ST-elevation myocardial infarction were 73% and 59% respectively. RDW was positively correlated with cardiac troponin I level ( r = 0.19, P = 0.006). Conclusion:In patients with non-ST-elevation myocardial infarction, the increase in RDW is related to myocardial injury and the increase in cardiac troponin I level. RDW can be used as an effective index to predict the severity of non-ST-elevation myocardial infarction.

Objective: To investigate the snoring status and related family factors of children from 3 to 14 years old in Beijing. Methods: From May to July, 2015, data of children from 3 to 14 years old were obtained from a status survey from 7 districts(Xicheng, Chaoyang, Changping, Shunyi, Fangshan, Huairou and Mentougou) in Beijing. A total of 11 420 children from 25 primary and middle schools were randomly selected. Pediatric Sleep Questionnaire (PSQ) and a self-administered questionnaire were carried out for the adopted children. Self-administered questionnaire included the snoring related family factors. Logistic regression was used to estimate the odd ratio(OR) with 95% confidence intervals for variables. Results: A total of 9 198 children meet the inclusion criteria and are analyzed in the study, of whom 901 (9.80%) were found with snoring behavior. The incidence of boys is higher than girls. Obese children take higher risk of snoring. Compared with younger children (≤6 years old), older children (≥12 years old) have a significantly lower risk of snoring (OR=0.464, 95%CI 0.368-0.585). There is no statistical association between full-term infants, infant feeding pattern, parental cigarette smoking and child snoring.The children with family history of snoring have a significantly higher risk of snoring occurrence. The educational background of mother is statistically related to children snoring (OR=1.241, 95%CI 1.058-1.457). Conclusions The incidence of children snoring in Beijing is 9.80%, male gender, obesity, and young age are all risk factors for children snoring. There is a significantly statistical relationship between snoring and related family factors, such as family snoring history and education experience.

Objective: To investigate the sleep quality of children in Beijing and to analyze the related factors. Methods: The data were collected from the survey of 3-14 years old children in 7 urban districts of Beijing in 2015. By using multi-stage stratified cluster random sampling method, 26 kindergartens and primary and secondary schools in 7 districts and counties, including Xicheng, Chaoyang, Changping, Shunyi, Fangshan, Huairou and Mentougou, were randomly selected, with a total of 11 420 children. Children′s sleep status was investigated with Children′s Sleep Questionnaire (PSQ), and the proportion of children with sleep quality problems when the PSQ score was greater than 7. Various sleep related factors were investigated with self-made questionnaire. A multilevel model was used to analyze the relationship between PSQ score and related factors. Results: The average PSQ score of the children was 3.60±2.69. The proportion of children with sleep quality problems was 8.87%(816/9 198). Multilevel model analysis showed that the younger the children, the higher the PSQ score (<6 years old vs. 6~12 years old vs. >12 years old: 3.94±2.58 vs. 3.58±2.66 vs. 3.30±2.84, F=33.015, P<0.001); male PSQ score higher than female (3.89±2.75 vs. 3.30±2.60, t=10.560, P<0.001); and snoring, obesity, father/mother snoring, playing games before bed, surfing the internet, eating and other factors were statistically related to PSQ. Conclusions Sleep quality of children in Beijing should not be neglected, especially preschool children with high PSQ scores. Parents should pay attention to children′s snoring problems and try to reduce some pre-sleep behaviors that may affect sleep quality.

Objective: To investigate the snoring status of school-aged children in Beijing and explore the association of snoring and academic performance. Methods: A total of 7 925 children aged from 6 to 14 were selected from 15 primary and middle schools at 7 districts (Xicheng, Chaoyang, Changping, Shunyi, Fangshan, Huairou and Mentougou) in Beijing in 2015, using multi-stage stratified cluster random sampling method. The recruited children were asked to complete the Pediatric Sleep Questionnaire (PSQ) and a questionnaire related to sleep behavior. The multiplelogistic regression was used to analyze the association of snoring and academic performance. Results: A total of 794 (12.44%) children showed a decline in academic performance among 6 383 eligible respondentsfor data analysis. 580 (9.08%) children with snoring was identified, of which 333 and 247 were in frequency of 1-2 times per week and frequency of ≥3 times per week, respectively; 357, 170 and 53 were in snoring grade Ⅰ, grade Ⅱ and grade Ⅲ, respectively. Compared with the children without snoring, the OR (95%CI) for children with 1-2 times per week and ≥3 times per week was 1.363 (1.000-1.857) and 1.605 (1.135-2.269), respectively; and the OR (95%CI) for children with grade Ⅰ, grade Ⅱ and grade Ⅲ of snoring was 1.226 (0.893-1.683), 1.595 (1.062-2.397) and 2.31 (1.17-4.565), respectively. Conclusion There is a statistical relationship between snoring and the decline of academic performance. The decline of academic performance positively associated with increased frequency and grade of snoring.

Objective To study the effect of intensive atorvastatin therapy on blood glucose in ACS patients.Methods Two hundred ACS patients were divided into control group (n=100) and intensive atorvastatin therapy group (n=100).The patients in both groups underwent secondary preventive treatment of CHD.The patients in control group were treated with 20 mg oral atorvastatin before going to bed and those in intensive atorvastatin therapy group were treated with 40mg oral atorvastatin.The patients were followed up for 6 months,during which their serum levels of FPG,HbA1c,TC,TG,LDL-C and HDL-C were measured before and after treatment.Results The serum levels of HDL-C were significantly higher while those of TC,TG and LDL-C were significantly lower in control group after treatment than before treatment (P＜0.01).The serum levels of HDL-C,FPG and HbA1c were significantly higher while those of TC,TG and LDL-C were significantly lower in intensive atorvastatin therapy group after treatment than before treatment(P＜0.05,P＜0.01).The serum levels of HDL-C,FPG and HbA1c were significantly higher while those of TC and LDL-C were significantly lower in intensive atorvastatin therapy group after treatment than before treatment (1.48±0.39 mmol/L vs 1.36±0.20 mmol/L,P＜0.05;5.71±0.67 mmol/L vs 5.21±0.53 mmol/L,P＜0.01;5.44％±0.75％ vs 5.19％±0.31％,P＜0.01).Conclusion Intensive statin therapy can effectively reduce the serum lipid level,elevate the serum FPG level,and increase the risk of diabetes in ACS patients.

BACKGROUND:As a novel noninvasive method, high frequency ultrasound has been used for the detection of skeletal muscle widely. OBJECTIVE:To detect the thickness of the dorsalLisfrancligament between the first (medial) cuneiform (C1) and second metatarsal (M2) using high frequency ultrasound to evaluate the feasibility and clinical application value of high frequency ultrasound for the detection of theLisfrancjoint. METHODS:Both feet of 100 healthy volunteers were included and the thickness of dorsalLisfranc ligament and the distance between C1 and M2wereexamined using high frequency ultrasound. RESULTS AND CONCLUSION:The display rate of high frequency ultrasound for the dorsalLisfranc ligament in the 100 healthy volunteers was 100%. There was no significant difference in the thickness of the dorsalLisfrancligament between both feet or sexes in adults(P> 0.05); as did the distance between C1 and M2 (P> 0.05). These findings suggest that visual dorsalLisfrancligament is detected by high frequency ultrasound. The measurement of the distance between C1 and M2by high frequency ultrasound may be a feasible, noninvasive, low-cost, and early diagnostic method forLisfrancinjuries.