ObjectiveTo explore the correlation between skeletal muscle mass and metabolic syndrome （MS） disease risk among middle-aged and elderly community residents in Urumqi， and to provide a theoretical basis for understanding the relationship between skeletal muscle mass and MS among middle-aged and elderly community residents in China. MethodsA total of 1 438 community residents ≥ 50 years old were selected as the research subjects from July 2018 to January 2019 in Urumqi. They were selected from a multi-ethnic natural population cohort in Xinjiang. Data were collected through questionnaires， physical examination， bioelectrical impedance analysis （BIA）， laboratory tests， etc. Skeletal muscle mass was evaluated using the limb skeletal muscle mass index （SMI） corrected for body weight； MS was defined as it at least includes three of the following： abdominal obesity， hypertension， hyperglycemia， high triglycerides and low high-density lipoprotein cholesterol. SMI was divided into four quantile arrays of Q₁‒Q₄. Trend χ² test was applied to explore whether there was a correlation between SMI changes and MS. A multivariate logistic regression model was used to analyze whether there is a difference in the risk of MS between the higher SMI group （Q₂， Q₃， Q₄） and the reference group Q₁. ResultA total of 560 MS patients were detected in this study， with a prevalence rate of 38.94%. Among them， the prevalence rate of MS was 39.16% in males and 38.80% in females. The increase in male SMI grading level is not correlated with the prevalence of MS （trend P>0.05）； After adjusting for confounding factors （model 4）， the increase in SMI was still not related to the prevalence of MS （P_trend=0.995）. There was no statistical difference in the risk of MS between the lowest quartile group Q₁ and the highest quartile group Q₄ （OR=1.01， 95%CI： 0.69‒1.78）. The prevalence of MS in women gradually decreased with the increase of SMI grading level （P_trend<0.001）； After adjusting for confounding factors （model 4）， there was still a correlation between the increase of SMI and the prevalence of MS （P_trend=0.005）. With the lowest quartile of SMI Q₁ as the reference group， the risk of MS in Q₂ （OR=0.63， 95%CI： 0.40‒1.00）， Q₃ （OR=0.56， 95%CI： 0.34‒0.94）， Q₄ （OR=0.42， 95%CI： 0.23‒0.76） decreased. ConclusionAn increase in skeletal muscle mass may be beneficial for preventing MS， especially among middle-aged and elderly female residents. Considering the intensification of aging in China and the close relationship between MS and related comorbidities， managing skeletal muscle mass may contribute to potential MS prevention.

Objective To observe the effect of in situ needle fenestration thoracic endovascular aortic repair(TEVAR)for treating aortic dissection(AD)involving aortic arch.Methods Data of 16 patients with AD involving aortic arch who underwent in situ needle fenestration TEVAR for reconstruction of aortic arch branches were retrospectively analyzed,and the number of fenestration,technical success rate and TEVAR related complications were recorded.Regular follow-up was conducted after TEVAR,the repair of dissection and the patency of fenestrated branch blood vessels were evaluated,the endoleak was assessed,and the survival of patients were recorded.Results The main aortic stent was successfully implanted in all 16 cases.Among them,4 received triple fenestration stent implantation in zones Z0,Z1 and Z2,6 received double fenestration stent implantation in zones Z1 and Z2,2 received double fenestration stent implantation in zones Z0 and Z1 and 4 received single fenestration stent implantation in zone Z2.The success rate of brachiocephalic trunk(BCT)fenestration was 83.33%(5/6).Left common carotid artery(LCCA)-right common carotid artery bypass was performed in 1 case without successful fenestration.The success rate of LCCA fenestration was 100%(12/12).The success rate of left subclavian artery(LSA)fenestration was 87.50%(14/16),2 cases with not successful fenestration were treated with axillar-axillary artery artificial vascular bypass.The technical success rate of intervention was 100%(16/16).Type Ⅰa endoleak occurred in 1 case during TEVAR process and improved after embolization with spring coil.One patient died of pericardial tamponade at the end of TEVAR.Fifteen patients were followed up for a median follow-up time of 20 months.During this period,transient ischemic attack and local small dissection at the proximal beginning of the main stent occurred each in 1 case,which improved after no special treatment.Type Ⅰ endoleak occurred in 1 case,type Ⅲ endoleak occurred in 2 cases,all improved after proximal fenestrated membrane stent implantation or spring coil embolization treatment.One case died of coronary heart disease.Conclusion In situ needle fenestration TEVAR was effective and safe for treating AD involving aortic arch.

The prevention and control of chronic and non-communicable diseases is an important public health problem in China. The general environment in the northwestern China is unique, and the health and disease status of local population is distinctive. In order to meet the urgent need for in-depth research of the causes, mechanisms and prognosis of chronic and non-communicable diseases in this area, a general population cohort in Shaanxi Province, Gansu Province and Qinghai Province, Ningxia Hui Autonomous Region and Xinjiang Uygur Autonomous Region was established during 2017-2019. A total of 117 644 general individuals aged 35-74 years in the multi-ethnic groups (Han, Hui, Uygur, Kazak and Tibetan) were recruited according to the special ecological environment, population size and ethnic distribution. The baseline information about individual exposure, environment and society were collected. More than 900 000 biological samples, including whole blood, plasma, serum and buffy coat, were collected and stored at -80 ℃ in standardized biobank. The long-term observation has started in forms of routine monitoring and active follow-up. The average age of the cohort members was 52.43 years, and 70 391 cohort members were women (59.8%). There were some differences in socio-economic status and lifestyle among different ethnic groups. Although the cohort members in different ethnic groups had similar health status, different characteristics still existed. The cohort can serve as a platform for in-depth research of the relationship between major chronic and non-communicable diseases and environment, people's lifestyle and genetic factors, and the research results can be used as important epidemiological evidence for clarifying the causes of chronic and non-communicable diseases and long-term health hazards in different ethnic groups in this area and reference for the national chronic and non-communicable disease prevention and control. This paper briefly introduces the design and practice of general population cohort in northwestern China.

Background There is a lack of evidence on whether exposure to PM_2.5 and its constituents would affect the relationship between the dietary approaches to stop hypertension (DASH) and central obesity. Objective To investigate the effect of exposure to PM_2.5 and its constituents on the correlation between the DASH dietary pattern and the prevalence of central obesity. Methods The data were obtained from the baseline survey of the "Xinjiang Multi-Ethnic Natural Population Cohort Construction and Health Follow-Up Study" in Urumqi. A DASH score was calculated according to intake frequency of 8 food groups, and summed from intake frequency of recommended food groups scored from 1 to 5 from low to high, and intake frequency of restricted food groups scored from 1 to 5 from high to low. A higher DASH score indicates better compliance with the DASH dietary pattern. We estimated exposure using satellite-derived PM_2.5 and a chemical transport model (GEOS-Chem) for its constituents, including organic carbon (OC), black carbon (BC), sulfate (SO₄²⁻), nitrate (NO₃⁻), ammonium (NH₄⁺), and soil dust. Central obesity was defined by waist circumference: ≥90 cm for men or ≥85 cm for women according to Criteria of weight for adults (WS/T 428—2013). A logistic regression model was used to analyze the effects of the DASH dietary pattern as well as PM_2.5 and its constituents on central obesity, and a stratified analysis was used to explore the effects of PM_2.5 and its constituents on the association between the DASH dietary pattern and central obesity. Results The study included 9 565 urban residents, aged (62.30±9.42) years, with a central obesity prevalence rate of 60.75%. After adjusting for selected confounders, the DASH score Q5 group had a 17.5% lower risk of central obesity than the Q1 group (OR=0.825, 95%CI: 0.720-0.947). PM_2.5 and its constituents OC, BC, SO₄²⁻, NH₄⁺, and soil dust were positively associated with the prevalence of central obesity, but no association was observed between constituent NO₃⁻ exposure and central obesity. The stratified analysis revealed that the prevalence of central obesity was reduced in the DASH score Q5 group in participants exposed to low concentrations of PM_2.5 and its constituents NO₃⁻, NH₄⁺, and soil dust, while the protective effect of the DASH pattern on central obesity disappeared in subjects exposed to high concentrations of PM_2.5 and its constituents NO₃⁻, NH₄⁺, and soil dust. Conclusion Exposure to PM_2.5 and its constituents NO₃⁻, NH₄⁺, and soil dust could attenuate the protective effect of the DASH pattern on central obesity.

Objective:To investigate the incidence rate, surgical rate and spontaneous cure of indirect inguinal hernia in children of Xinjiang region.Methods:Children, aged from 4?14 years, coming from 24 kindergartens, 18 primary schools and 9 junior middle schools of 3 countries and 5 cities in Xinjiang Uygur Autonomous Region were recruited to participate as respondents. The survey time for baseline data collection was from May 2013 to June 2014 and the retrospective cross-sectional survey was conducted. Parents of children were investigated by questionnaire, and children were examined on site. Observation indicators: (1) results of questionnaire survey; (2) illness and treatment of children involved in the study; (3) follow-up. Follow-up was conducted using telephone interview. Children who had been diagnosed and not been treated surgically at the time of questionnaire survey were followed up to detect disease progression and treatment in the past 5 years. If the symptoms of a child had disappeared during follow-up, parents of the child should accompany the child to hospital for physical examination and B-ultrasound examination to confirm the diagnosis, and then follow-up was conducted by telephone interview. The follow-up was up to January 2020. Count data were described as absolute numbers and percentages, and compari-son between groups was conducted using the chi-square test. Odds ratio and 95% confidence interval were calculated. Results:(1) Results of questionnaire survey. A total of 19 132 question-naires were distributed, and 19 132 complete questionnaires were recovered. Of the 19 132 children who completed the questionnaire survey, there were 9 670 males and 9 462 females. (2) Illness and treatment of children involved in the study. ① Incidence of indirect inguinal hernia in children with different sexes. Of the 19 132 children, 498 cases were diagnosed as indirect inguinal hernia, including 368 boys and 130 girls, with the prevalence as 3.806%(368/9 670) and 1.374%(130/9 462), respectively. There was a significant difference in the prevalence of indirect inguinal hernia between boys and girls ( χ2=111.54, P<0.05). The proportion of boys and girls in children with indirect inguinal hernia was 73.896%(368/498) and 26.104%(130/498), respectively, with the ratio of 2.8:1. The prevalence of boys was higher than girls ( odds ratio=2.84, 95% confidence interval as 2.32?3.48).② Age of children at first onset. Of the 498 children with indirect inguinal hernia, 59 cases were aged 1?4 years at first onset including 54 boys and 5 girls, 264 cases were aged 5?8 years including 196 boys and 68 girls, 148 cases were aged 9?12 years including 104 boys and 44 girls, 27 cases were aged 13?14 years including 14 boys and 13 girls. There was a significant difference in the age of children at first onset between boys and girls ( χ2=17.33, P<0.05). ③ Pathogenic factors in children with indirect inguinal hernia. Of the 498 children with indirect inguinal hernia, 457 cases had complete family history and crying history, and 41 cases were missing. Family history: of the 457 children with indirect inguinal hernia who had complete family history, there were 175 cases with the family history of indirect inguinal hernia and 282 cases without the family history. Of the 478 healthy children surveyed in the same period, there were 25 cases with the family history and 453 cases without the family history. There was a significant difference in the family history between the 457 children with indirect inguinal hernia and the 478 healthy children ( χ2=515.89, P<0.05). Crying history: of the 457 children with indirect inguinal hernia who had complete crying history, there were 194 cases with obvious crying history and 263 cases without obvious crying history. Of the 496 healthy children surveyed in the same period, there were 99 cases with obvious crying history and 397 cases without obvious crying history. There was a significant difference in the crying history between the 457 children with indirect inguinal hernia and the 496 healthy children ( χ2=56.51, P<0.05). ④ Surgical treatment. Of the 498 children with indirect inguinal hernia, 233 cases underwent surgical treatment including 217 boys and 16 girls, 265 cases were followed up without surgical treatment including 151 boys and 114 girls. The surgical rate for indirect inguinal hernia in boys and girls was 58.967%(217/368) and 12.308%(16/130), respectively, showing a significant difference between them ( χ2=84.01, P<0.05). The operation ratio of boys and girls was 13.6:1, and the surgical rate of boys was higher than girls ( odds ratio=10.24, 95% confidence interval as 5.83?17.98). (3) Follow-up. All the 265 children without surgical treatment for indirect inguinal hernia were followed up for 5 years. During the follow-up, there were 142 of 151 boys with surgical treatment and 9 boys without surgical treatments, showing negative in spontaneous cure. There were 27 of 114 girls with surgical treatment and 87 girls without surgical treatment, showing 55 cases positive in spontaneous cure and 32 cases still with indirect inguinal hernia. There was a significant difference in spontaneous cure between the 151 boys and the 114 girls ( χ2=143.79, P<0.05). Conclusion:In Xinjiang region, the incidence rate and surgical rate of indirect inguinal hernia are lower in girls compared with boys, and the spontaneous cure rate is higher in girls compared with boys.

Objective To study the impact of brief intervention on HPV cognition of medical students in Xinjiang, and to provide a reference for the development of HPV related education in medical students. Methods Sudents from 20 classes of a medical university in Xinjiang were randomly selected. The first 10 classes were enrolled into group 1, which was a self-controlled study group evaluating the effect before and after intervention. The other 10 classes were included in group 2, in which students in each class were randomly divided into control group (filling in questionnaires before the intervention) and intervention group (filling in questionnaires after the intervention). Medical students were given a 10 minutes presentation on the intervention of HPV by trained personnel. Results (1) For HPV related knowledge, the difference in the awareness rates between the two groups before and after intervention was statistically significant (P < 0.001), and the awareness rate after intervention was higher than that before intervention. Before the intervention, the awareness rates of medical students in group 1 and group 2 were 18.67% and 17.71%, respectively, which increased to 66.75% and 52.85% after the intervention (P<0.01). (2) Regarding HPV-related attitudes and behavioral content, the differences in the response results of the two groups of students before and after the intervention were statistically significant (P<0.05), showing a more positive state after the intervention. Before the intervention, there were 86.19% and 88.02% of the students in group 1 and group 2 willing to publicize HPV-related knowledge to their relatives and friends, and the numbers increased to 94.12% and 94.82%, respectively, after the intervention (P < 0.05). Conclusion Both self-controlled and parallel-controlled studies demonstrated that brief interventions improved medical students' awareness of HPV.

Matching is a standard method for selecting research objects regarding the observational research, which controls confounding factors and improves statistical efficiency. However, its role in controlling confounding is not consistent in different observational studies. Matching can eliminate the confounding bias of matching variables in cohort studies, but checking on itself cannot eliminate confounding bias in case-control studies. In matched case-control studies, researchers may not accurately judge whether the variable is a confounder. Sometimes the variables that are not confounders are mistakenly matched. In that case, it will result in overmatching, which will lead to the decline of statistical efficiency or the introduction of unavoidable bias or increase of workload. If the real confounding factors are omitted, it will cause confounding bias. Therefore, researchers should consider what kind of matching variable selection criteria should be formulated. A directed acyclic graph is a visual graphic language that can show the complicated causality among different epidemiological research designs. This article analyzes the role of Matching in different observational research designs from the perspective of the directed acyclic graph, formulates the selection criteria for matching variables in matched case-control studies, and provides some reference suggestions for future epidemiological research design.

Objective:To understand the infection status and elimination of anal human papillomavirus (HPV) among men who have sex with men (MSM) in Urumqi, Xinjiang.Methods:The sample size formula in cohort study, a dynamic cohort study method, was used, with the sample size estimated to be 712 according to the new infection rate of HPV16. With the help from non-government organzitions in Urumqi, we recruited 810 MSMs by the snowballing method, and a follow-up program was carried every six months. Anal exfoliated cells were collected to analyze HPV type 16 and 18 infection rates. For statistical analyses, Poisson regression was used to estimate the density of new infections and persistent infections. Cox proportional hazard model was used to explore the influencing factors on both new and persistent infections and the diseases' natural clearing.Results:A total of 810 MSM were recruited, and 482 MSMs with the number of follow-ups more than 2 times were included in the analysis, with the total follow-up numbers as 994.7 person-years. The median number of follow-up and follow-up times was 4 ( P 25, P 75:3,5) times , and 2.2 ( P 25, P 75:1.8, 2.6) years. The baseline infection rates of HPV16 and HPV18 were 8.5% (41/482) and 3.3% (16/482), respectively. And the baseline mixed infection rate of the two types was 0.6% (3/482). The first new infection densities of HPV16 and HPV18 were 10.06 (95% CI:8.12-12.45)/100 person-years and 5.24 (95% CI:3.95-6.96)/100 person-years. The rate of natural infection clearance of HPV16 and HPV18 were 71.2% (89/125) and 71.8% (46/64), respectively. The natural clearance rate of HPV18 after 1.5 years follow-up was higher than HPV16 (97.7% vs. 94.1%). The persistent infection rate of HPV16 and HPV18 were 4.5% (20/441) and 1.7% (8/466), respectively. The risk of persistent HPV16 infection among unmarried subjects was lower than that of married subjects (a HR=0.29,95% CI:0.12-0.71). The natural clearance rate of HPV18 without condom use in anal intercourse in the last six months was 2.63 times higher than that of condom use (95% CI:1.08-6.42). Conclusions:HPV16 and 18 new infections are more common among MSM in Urumqi, and the natural clearance rate is higher. Compared with HPV18, HPV16 has a higher density of new and persistent infections, a low natural clearance rate, and a greater risk of the diseases.

Epidemiological analysis describes and compares the characteristics of a certain number of people to make causal inferences. The formation of the study population is always the first step. In this paper, we first define the concepts of cross-sections at both individual level and population level and introduce the three assumptions needed in the measurements in observational studies, i. e. the true values of the attributes are stable with time, the attribute variables are independent and the individuals are independent during the measuring process. We also determine that the causal inference research should be unified based on the time of the occurrence or beginning of a postulated cause, or exposure, should be in. Then, based on the dual roles of the population cross-section with causal thinking, we propose that research designs can be classified into two types with different characteristics: history reconstruction research and future exploration research. Finally, we briefly analyze the research design framework and the relationship between estimated effects and different designs. The discussion of the formation of a study population from the perspective of causal thinking can make a foundation for the classification of causal inference research design with appropriate effect parameters, which needs to be further studied.

Objective: The purpose of the present study was to evaluate of continuous metabolic syndrome score (cMetS) in screening metabolic syndrome (MetS) and to determine the cut-off values in a representative sample of Xinjiang population aged 15 to 18 years old. Methods: A stratified cluster sampling was used to select participants aged 15-18 years from 13 cities in Xinjiang. cMetS was calculated by summing up the Zscores of standardized waist circumference, mean arterial pressure, high-density lipoprotein, triglyceride, and fasting blood glucose by age and gender. Results: Totally 16.3% of subjects were overweight, and 5.2% were obese. The proportion of overweight and obesity in males was significantly higher than that in females (18.1% vs 13.8%)(6.0% vs. 4.1%)(χ2=15.36，7.89，P<0.05). The prevalence of total MetS was 6.1%, with 6.6% and 5.4% for men and women, respectively. There was a correlation between cMetS and MetS components, and the average cMetS value increased with increasing MetS component(P<0.05). The total cut-off value of cMetS was 0.99 (sensitivity 68.0%, specificity 80.7%), and the area under the ROC curve was 84.9%. The cMetS scores for boys and girls were 0.80 and 1.48, respectively. Conclusion Compared with MetS, cMetS shows more accuracy in screening MetS among youth aged 15-18 years in both gender.