Background Lung cancer, one of the most common malignant tumors worldwide, has long ranked first in cancer incidence and mortality, posing a severe challenge to public health systems. Objective To analyze the trends in incidence, mortality, and disability-adjusted life years (DALYs) of lung cancer among residents in Jing'an District, Shanghai, from 2002 to 2021, explore the impacts of population aging, population growth, and age-specific prevalence on disease burden, and provide a scientific basis for optimizing regional lung cancer prevention and control strategies. Methods Based on the cancer registration and cause-of-death surveillance data of registered residents in Jing'an District, Shanghai, from 2002 to 2021, Joinpoint regression models were used to analyze the annual change trends (APC) and average annual change trends (AAPC) of lung cancer incidence, mortality, DALY rate, and their age-standardized rates. Decomposition analysis was applied to quantify the contribution of population aging, population growth, and age-specific prevalence to changes in the number of new cases, deaths, and DALYs. Results From 2002 to 2021, the crude incidence rate of lung cancer in Jing'an District increased from 68.00 per 100000 to 144.36 per 100000 (AAPC=4.86%, P<0.001), and the age-standardized incidence rate rose from 43.09 per 100000 to 61.46 per 100000 (AAPC=2.89%, P<0.001). The growth rate of incidence was significantly higher in females (AAPC=6.73%) than in males (AAPC=3.62%). The crude mortality rate increased from 58.08 per 100000 to 66.11 per 100000 (AAPC=1.10%, P<0.001), while the age-standardized mortality rate decreased (AAPC=−1.54%, P<0.001). The crude DALY rate showed an upward trend (AAPC=0.94%, P=0.002), whereas the age-standardized DALY rate declined (AAPC=−1.63%, P<0.001). Significant differences were observed across genders and age groups: the mortality and DALY rates increased in males aged 60-64 years, while the fastest incidence growth occurred in females aged 45-64 years. The results of decomposition analysis indicated that the increase in new cases was primarily attributed to age-specific incidence (38.15%) and aging (37.31%); the growth in deaths and DALYs was driven by aging, while age-specific mortality and population growth showed offsetting effects. From 2002 to 2021, the probability of premature death from lung cancer among males (2.04%-2.52%) in Jing'an District showed no statistically significant trend (AAPC=−0.28%, P=0.440), while it presented a decreasing trend in the total population (1.37%-1.89%) and females (0.72%-1.26%) (AAPC=−0.80% and −2.23%, respectively; P=0.029 and <0.001, respectively). Conclusion From 2002 to 2021, the risk of lung cancer incidence in Jing’an District, Shanghai, continue to increase, with a disease burden exhibiting significant heterogeneity by gender and age: key features include a rapid increase in new cases and a trend toward younger onset among females, alongside rising mortality risk among males aged 60–64 years. Population aging and increasing age-specific incidence rates are primary drivers of the growing number of cases, while declining age-specific mortality rates mitigate the rise in mortality burden.

ObjectiveTo investigate the effects of Qizhujianwei granules （QZJW） on abnormal proliferation and malignant transformation of gastric mucosal cells in rats with gastric intraepithelial neoplasia （GIN） and to explore the related mechanisms. MethodsA total of 80 SPF male Wistar rats were used. A GIN rat model was established using a four-factor comprehensive method consisting of methylnitronitrosoguanidine （MNNG）， ranitidine， irregular feeding patterns， and sodium salicylate. Except for the normal group， after successful modeling， the rats were randomly divided according to body weight into a model group， a Moluodan group （0.55 g·kg^-1）， and a QZJW group （7.34 g·kg^-1）， with 12 rats in each group. All groups were treated for 8 weeks. The general characteristics of the rats and morphological changes of the gastric mucosa were observed. Histopathological changes of the gastric mucosa were examined by hematoxylin-eosin （HE） staining. Enzyme-linked immunosorbent assay （ELISA） was used to detect serum levels of pepsinogenⅠ （PGⅠ）， pepsinogenⅡ （PGⅡ）， and gastrin （G-17）， as well as the expression level of transforming growth factor-β₁ （TGF-β₁） in gastric mucosal tissue， and the PGⅠ/PGⅡ ratio was calculated. Immunohistochemistry （IHC） was used to detect the localization and expression levels of proliferating cell nuclear antigen （Ki-67） and Vimentin in gastric mucosal tissue. Western blot analysis was used to determine the protein expression levels of Wnt family member 3A （Wnt3a）， β-catenin， CyclinD₁， proto-oncogene Cmyc， transforming growth factor-β receptor Ⅰ （TGFβRⅠ）， intracellular signaling transducers Smad2/3， phosphorylated （p）-Smad2/3， twist family transcription factor （Twist1）， and Vimentin in gastric mucosal tissue. ResultsCompared with the normal group， the model group showed characteristic changes including dim eyes， pale ears and claws， dark-red tongue， and reduced luster of the tail. The gastric mucosa appeared pale， with surface congestion and erosion. The gastric mucosal glands were disordered， the nuclear-to-cytoplasmic ratio increased， and local tumor cells were observed. Serum PGⅠ and PGⅡ levels and the PGⅠ/PGⅡ ratio were significantly decreased （P<0.01）， while the level of G-17 was significantly increased （P<0.01）. The protein expression levels of Ki-67， Wnt3a， β-catenin， CyclinD₁， Cmyc， TGF-β₁， TGFβRⅠ， Smad2/3， Twist1， and Vimentin in gastric mucosal tissue were significantly increased （P<0.05， P<0.01）， whereas the ratio of p-Smad2/3 to Smad2/3 was significantly decreased （P<0.05）. Compared with the model group， the general characteristics and gastric mucosal conditions of rats in the Moluodan group and the QZJW group were improved. HE staining showed that QZJW could effectively block the malignant progression of GIN. Serum PGⅠ and PGⅡ levels and the PGⅠ/PGⅡ ratio were significantly increased （P<0.05， P<0.01）， while the level of G-17 was significantly decreased （P<0.01）. The protein expression levels of Ki-67， Wnt3a， β-catenin， CyclinD₁， Cmyc， TGF-β₁， TGFβRⅠ， Smad2/3， Twist1， and Vimentin in gastric mucosal tissue were significantly decreased （P<0.05， P<0.01）. ConclusionQZJW have a therapeutic effect on rats with GIN. The mechanism may involve inhibition of the Wnt/β-catenin signaling pathway to regulate the cell cycle and suppress abnormal cell proliferation. Meanwhile， it may inhibit epithelial-mesenchymal transition by suppressing the TGF-β₁/Smad/Twist1 signaling pathway， thereby blocking the malignant progression of GIN.

ObjectiveTo investigate the effects of Qizhujianwei granules （QZJW） on abnormal proliferation and malignant transformation of gastric mucosal cells in rats with gastric intraepithelial neoplasia （GIN） and to explore the related mechanisms. MethodsA total of 80 SPF male Wistar rats were used. A GIN rat model was established using a four-factor comprehensive method consisting of methylnitronitrosoguanidine （MNNG）， ranitidine， irregular feeding patterns， and sodium salicylate. Except for the normal group， after successful modeling， the rats were randomly divided according to body weight into a model group， a Moluodan group （0.55 g·kg^-1）， and a QZJW group （7.34 g·kg^-1）， with 12 rats in each group. All groups were treated for 8 weeks. The general characteristics of the rats and morphological changes of the gastric mucosa were observed. Histopathological changes of the gastric mucosa were examined by hematoxylin-eosin （HE） staining. Enzyme-linked immunosorbent assay （ELISA） was used to detect serum levels of pepsinogenⅠ （PGⅠ）， pepsinogenⅡ （PGⅡ）， and gastrin （G-17）， as well as the expression level of transforming growth factor-β₁ （TGF-β₁） in gastric mucosal tissue， and the PGⅠ/PGⅡ ratio was calculated. Immunohistochemistry （IHC） was used to detect the localization and expression levels of proliferating cell nuclear antigen （Ki-67） and Vimentin in gastric mucosal tissue. Western blot analysis was used to determine the protein expression levels of Wnt family member 3A （Wnt3a）， β-catenin， CyclinD₁， proto-oncogene Cmyc， transforming growth factor-β receptor Ⅰ （TGFβRⅠ）， intracellular signaling transducers Smad2/3， phosphorylated （p）-Smad2/3， twist family transcription factor （Twist1）， and Vimentin in gastric mucosal tissue. ResultsCompared with the normal group， the model group showed characteristic changes including dim eyes， pale ears and claws， dark-red tongue， and reduced luster of the tail. The gastric mucosa appeared pale， with surface congestion and erosion. The gastric mucosal glands were disordered， the nuclear-to-cytoplasmic ratio increased， and local tumor cells were observed. Serum PGⅠ and PGⅡ levels and the PGⅠ/PGⅡ ratio were significantly decreased （P<0.01）， while the level of G-17 was significantly increased （P<0.01）. The protein expression levels of Ki-67， Wnt3a， β-catenin， CyclinD₁， Cmyc， TGF-β₁， TGFβRⅠ， Smad2/3， Twist1， and Vimentin in gastric mucosal tissue were significantly increased （P<0.05， P<0.01）， whereas the ratio of p-Smad2/3 to Smad2/3 was significantly decreased （P<0.05）. Compared with the model group， the general characteristics and gastric mucosal conditions of rats in the Moluodan group and the QZJW group were improved. HE staining showed that QZJW could effectively block the malignant progression of GIN. Serum PGⅠ and PGⅡ levels and the PGⅠ/PGⅡ ratio were significantly increased （P<0.05， P<0.01）， while the level of G-17 was significantly decreased （P<0.01）. The protein expression levels of Ki-67， Wnt3a， β-catenin， CyclinD₁， Cmyc， TGF-β₁， TGFβRⅠ， Smad2/3， Twist1， and Vimentin in gastric mucosal tissue were significantly decreased （P<0.05， P<0.01）. ConclusionQZJW have a therapeutic effect on rats with GIN. The mechanism may involve inhibition of the Wnt/β-catenin signaling pathway to regulate the cell cycle and suppress abnormal cell proliferation. Meanwhile， it may inhibit epithelial-mesenchymal transition by suppressing the TGF-β₁/Smad/Twist1 signaling pathway， thereby blocking the malignant progression of GIN.

Objective To preliminary explore the imaging manifestations of digital breast tomosynthesis (DBT) and contrast-enhanced mammography (CEM) in triple-negative breast cancer (TNBC) patients with different levels of human epidermal growth factor receptor 2 (HER2) expression. Methods A retrospective analysis was conducted on TNBC patients who underwent preoperative DBT or CEM examinations at Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2018 to December 2019 and Shanghai Second People’s Hospital from January 2022 to May 2025. Clinical data, pathological and immunohistochemical results, and imaging data were collected. Results A total of 69 TNBC patients pathologically confirmed as invasive ductal carcinoma were included, among which 34 underwent DBT and 35 underwent CEM. Among these patients, 34 (49.28%) had HER2-low expression and 35 (50.72%) had HER2-zero expression. DBT results showed that the proportion of spiculation signs in HER2-low group (n＝14) was significantly higher than that in HER2-zero group (n＝20; P＝0.009, P_adj＝0.045). However, there were no significant differences in breast density type, mass shape, or calcification between the two groups. CEM results showed that on low-energy images, the proportion of spiculation signs in the HER2-low group (n＝20) was higher than that in the HER2-zero group (n＝15; P＝0.011, P_adj＝0.077). Results of CEM showed that on reconstructed images, differences in background parenchymal enhancement and mass enhancement patterns between the two groups were not statistically significant; in both groups, heterogeneous enhancement was the most common, followed by homogeneous enhancement, with ring enhancement being the least common. Conclusions TNBC with low HER2 expression and TNBC with zero HER2 expression may have potential differences in the presentation of spiculation signs on DBT. However, the correlation between CEM manifestations and TNBC with different HER2 expression levels requires further research.

Objective To investigate the toxic effects of combined yttrium and lead exposure on liver and kidney functions in male Sprague-Dawley (SD) rats. Methods Adult male specific pathogen-free SD rats were randomly divided into four groups. Rats in the low-, medium-, and high-dose groups were co-administered with yttrium acetate (10.0, 50.0, and 100.0 mg/kg body weight, respectively) and lead acetate (4.0, 20.0, and 40.0 mg/kg body weight, respectively) by intragastric gavage, once per day for 28 consecutive days. Rats in the control group received an equal volume of deionized water. Yttrium and lead levels in whole blood, liver, and kidney tissues of the rats were measured using inductively coupled plasma mass spectrometry. Serum index of liver and kidney function were measured by a double reagent method, and histopathological changes in the liver and kidney were observed. Results The body weights of rats in all the three exposure groups were lower than those in the control group from day 14 of exposure until the end of exposure (all P<0.05). Body weight gain of rats was observed only in the low-dose group at day 28, whereas no body weight gain was observed throughout the exposure period in the medium- and high-dose groups. Histopathological examination showed dose-dependent liver and kidney injuries in rats of the three exposure groups compared with the control group. Specifically, the liver exhibited widening of intercellular spaces and increased inflammatory cell infiltration, while the kidney showed increased tissue hemorrhage and increased damage to glomeruli and renal tubules. Lead levels in whole blood, liver, and kidney tissues of the rats were higher than yttrium levels in all the three exposure groups (all P<0.05). Blood yttrium levels in rats of the high-dose group were higher than those in the other three groups (all P<0.05), and yttrium levels in the liver and kidney tissues of the three exposure groups were higher than those in the control group (all P<0.05). Lead levels in whole blood, liver, and kidney tissues of the rats increased with increasing exposure dose (all P<0.05). At the end of exposure, the kidney organ coefficient of rats in the high-dose group was higher than those in the other three groups (all P<0.05). The serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST) ratio of rats in the high‑dose group was lower than that in the control group (P<0.05). The serum urea and uric acid levels in the medium‑ and high‑dose groups were lower than those in the control group (both P<0.05). The serum cystatin C level in the high‑dose group was higher than that in the control group (P<0.05). Blood yttrium and blood lead levels were each negatively correlated with serum ALT/AST ratio, serum urea nitrogen, and uric acid levels (both P<0.05). Both yttrium and lead levels in liver tissue were each negatively correlated with serum ALT/AST ratio (all P<0.05). Both yttrium and lead levels in kidney tissue were each negatively correlated with both serum urea nitrogen and uric acid levels (all P<0.05), and each positively correlated with serum cystatin C levels (both P<0.05). Conclusion Co-exposure to yttrium and lead induces dose‑dependent hepatotoxicity and nephrotoxicity in male SD rats. Lead exhibits a more pronounced accumulation effect and contributes more substantially to the observed toxicity.

Objective:To analyze the differences in screening neonatal glucose-6-phosphate dehydrogenase (G6PD) deficiency in different birth seasons, establish screening thresholds for G6PD concentration in each season using indirect methods, and verify the reliability of the results.Methods:This was a cross-sectional study.A total of 140 823 newborns were collected from the Neonatal Screening Center of Shanghai Children′s Hospital from January 2020 to December 2023, including 41 029 cases, 35 796 cases, 33 969 cases and 30 029 cases in spring, summer, autumn and winter groups, respectively.The concentration of G6PD on the dried blood filter paper was determined using an automatic fluorescence analyzer.The distribution and statistical index of concentration values in four seasons were analyzed.The Kolmogorov-Smirnov test was used for normal distribution.The skewed distribution data was converted into approximately normal distribution using Box-Cox.Outliers were eliminated using the interquartile range (Turkey) method.The cumulative frequency distribution map was drawn through R language programming.The linear regression equation Y=B X+ A was fitted.The 0.5th percentile ( P0.5) was used as the screening threshold, which was compared with the reference value given by the manufacturer or laboratory and with the reference change value (RCV). Results:In the spring group, the positive rate was 4.02‰, 91 cases were confirmed, and the incidence was 1∶451.In the summer group, the positive rate was 7.18‰, 90 cases were confirmed, and the incidence was 1∶398.In the autumn group, the positive rate was 3.21‰, 86 cases were confirmed, and the incidence was 1∶395.In the winter group, the positive rate was 2.26‰, 61 cases were confirmed, and the incidence was 1∶492.The incidence rate did not change significantly in the four seasons ( P>0.05).The G6PD concentrations in the four seasons were compared in pairs, and the result was winter>autumn>spring>summer.The thresholds for G6PD screening were established indirectly: 25.08 U/dL, 22.83 U/dL, 26.63 U/dL and 38.01 U/dL in spring, summer, autumn and winter groups, respectively.The relative deviation in the threshold between the summer group and the laboratory was lower than RCV, while that between the other groups was higher than RCV.According to the screening threshold, the negative and positive conformity rates of 12 batches of 120 samples in the inter-laboratory evaluation program of Chinese Taiwan Preventive Medicine Foundation of China reached 100%. Conclusions:There is no difference in the incidence of G6PD deficiency between birth seasons.It is feasible to establish the screening threshold in each season using indirect methods, which is conducive to improving the efficiency of screening.

Objective To explore the relationship between corrected QT interval(QTc)and short-term mortality rate in patients with cirrhotic ascites and the predictive value of QTc combined with Child-Pugh class for short-term death.Methods Patients hospitalized with cirrhotic ascites from October 2022 to March 2024 were selected as study subjects(training set,n=245),and similar patients from April to October 2024 were included for external validation(validation set,n=88).Patients'demographic data,basic clinical data,and first electrocardiography related indicators on admission were collected.Patients were divided into a death group and a survival group according to the 30-day follow-up result.The influencing factors for prognosis were explored by Lasso regression and univariate and multivariate binary logistic regression.A death risk nomogram model was constructed and evaluated by receiver operating characteristic curve(ROC curve),calibration curve,and decision curve.Data were analyzed for normality using Shapiro-Wilk test.Pairwise comparison for continuous data that were normally distributed was conducted by the independent-samples t test.Pairwise comparison for continuous data that were not normally distributed was conducted by the Mann-Whitney U test.Pairwise comparison for categorical data was performed using the chi-square test.Results The mortality rates were 35.1%(86/245)in the training set and 30.7%(27/88)in the validation set.Lasso regression showed that combined tumor,QTc,hematocrit,total bilirubin(TBil),direct bilirubin,alkaline phosphatase,albumin,cholinesterase,high-density lipoprotein cholesterol,carcinoembryonic antigen,international normalized ratio,model for end-stage liver disease(MELD),and Child-Pugh class were potential influencing factors for 30-day death in patients with cirrhotic ascites.Univariate and multivariate logistic regression showed that QTc(odds ratio[OR]=1.010,95%confidence interval[CI]:1.001-1.020,P=0.039),presence of tumor(OR=6.904,95%CI:2.997-12.391,P<0.001),TBil(OR=1.009,95%CI:1.004-1.014,P=0.001),and Child-Pugh class(OR=2.532,95%CI:1.256-5.105,P=0.009)were independent risk factors for 30-day death in patients with cirrhotic ascites.For the nomogram model constructed based on the results of the multivariate logistic analysis,the area under the ROC curve in the training set was 0.824;the sensitivity and specificity were 81.1%and 74.4%,respectively;the Hosmer-Lemeshow goodness-of-fit test showed P=0.673;the mean absolute error of the calibration curve was 0.020.The area under the ROC curve in the validation set was 0.886;the sensitivity and specificity were 91.8%and 70.4%,respectively;the Hosmer-Lemeshow goodness-of-fit test showed P=0.965;the mean absolute error of the calibration curve was 0.032.With the threshold probability of 0.15 to 0.85,the decision curve suggested a good benefit.The area under the ROC curve of the predictive model(0.824)was greater than conventional MELD score(0.700),MELD-Na score(0.698),and Child-Pugh score(0.674)(all P<0.05).Conclusion QTc is an independent predictor of short-term death in patients with cirrhotic ascites,and the prognostic model including QTc and Child-Pugh class has a good predictive value for short-term mortality rate.

This study analyzed the epidemiological characteristics and trends of respiratory syncytial virus (RSV) infections among inpatients with acute respiratory infections (ARI) in a children′s hospital in Shenzhen City inpatients from 2020 to 2023. From January 2020 to December 2023, multiple reverse transcription polymerase chain reaction (RT-PCR) combined with capillary electrophoresis fragment analysis technology was used to detect the nucleic acids of 12 respiratory pathogens, including RSV, in hospitalized children diagnosed with ARI. The patients were divided into six age groups: 0 to <6 months, 6 months to <1 year, 1 to <2 years, 2 to <5 years, 5 to <10 years, and 10 to <18 years. A total of 53 033 children were tested, including 6 830 RSV positive cases, with an overall positivity rate of 12.88%. The annual RSV positivity rates from 2020 to 2023 were 20.04%, 16.18%, 4.89%, and 13.33%, respectively, with statistically significant differences between the years ( χ2=1 185.994, P<0.001). The positive rate of RSV detection decreased with increasing age across all years (all P trend<0.05). From 2020 to 2023, the proportion of RSV-positive cases aged 2 to 5 years and older showed an increasing trend ( P trend<0.001 for all years). Compared to 2023, the median age of RSV-infected children was lower in 2020 ( Z=7.826, P<0.001) and 2021 ( Z=6.106, P<0.001). The proportion of severe infections requiring ICU admission did not change significantly across all years ( χ2=0.179, P=0.981). The RSV epidemic season in 2020 mainly occurred during 28-43 weeks, and in 2021, it spanned from 22-43 weeks. However, in 2022, the season was delayed until the 49th week and lasted for three weeks. In 2023, the seasonal epidemic appeared earlier, starting in the 14th week and lasting for 28 weeks. From 2020 to 2023, the rate of RSV co-infections with other pathogens (mycoplasma pneumoniae, human parainfluenza virus, human bocavirus, human coronavirus, human metapneumovirus, and influenza A) significantly increased (all P trend<0.01). In conclusion, the epidemiological characteristics of RSV infections in Shenzhen Children′s Hospital changed from 2020 to 2023. In 2022, there were only delayed, low-intensity and short-lived seasonal epidemics. However, in 2023, there was an earlier and prolonged epidemic, with increased infections in children aged 2 to 5 years and older and a rise in co-infections, while the proportion of severe infections requiring ICU admission remained unchanged.

Objective:To investigate, for multi-sensitized allergic rhinitis (AR) patients allergic to dust mites combined with other allergens (pollen, mold, animal dander, etc.), whether the single dust mite subcutaneous immunotherapy (SCIT) can improve the specific symptoms caused by other allergens in the patients, and to analyze the relationship between the effectiveness of symptom improvement in these patients and the type, quantity and severity of the allergens.Methods:A multicenter retrospective study was conducted to collect mul-sensitized AR patients from allergy or respiratory departments of 5 hospitals who received house dust mite allergen preparation SCIT for 12 to 36 months and met other inclusion and exclusion criteria from February to July 2024. General clinical data were collected and the perennial or seasonal symptoms before and after treatment were evaluated with visual analogue scale (VAS) to assess whether there was an perennial or allergen-specific symptom improvement (VAS score decrease ≥30%), by which the patients were divided into effective group and ineffective. R software was used to analyze the differences between groups by using Fisher′s exact test and Mann-Whitney U test. Results:A total of 62 patients were enrolled, and the treatment were effective in 39 of them, with an effective rate of 62.9%. For allergen-specific symptoms, the median age of the effective group was higher than that of the ineffective group (12 years old vs. 8 years old, P=0.039), and the effective rate in dust mite specific immunoglobin E (sIgE) grade ≤5 group was higher than that in sIgE grade >5 group (81.6% vs. 45.5%, P=0.008), and the effective rate of mold sIgE grade ≤2 group was higher than that of sIgE grade >2 group (83.3% vs. 28.6%, P=0.045), and there was no statistically significant correlation between the other allergen grades and the effective rate ( P>0.05). For perennial symptoms, the effective rate in the mold grade ≤2 group was higher than that in the sIgE grade >2 group (91.3% vs. 28.6%, P=0.010), and there was no statistically significant correlation between the other allergen grades and the effective rate ( P>0.05). There was no significant correlation between the treatment effectiveness of perennial or allergen-specific symptoms and the number of combined allergens, the grade of skin test, and the difference between the grade of combined allergens and that of dust mites ( P>0.05). Conclusion:Among the patients with multi-sensitized AR allergic to dust mites included in this study, single dust mite SCIT is effective in some of them, and for allergen-specific symptoms, the effective group was elder, and dust mite sIgE grade 6 and mold sIgE grade ≥2 was related to the low effective rate of SCIT. The present results are insufficient for selecting single or multiple AIT in any type of multi-sensitized patients.

Objective:To explore the structural equation model to explore the levels of work-related musculoskeletal disorders (WMSDs) and various risk factors in the feet and ankle of China's occupational population, providing scientific basis for for preventing WMSDs in feet and ankles.Methods:Data of 73497 national occupational epidemiological cases were selected from June 2018 to December 2023 used the Chinese version of the Electronic Questionnaire on Musculoskeletal Disorders. The adverse ergonomic factors and their source classification standard and confirmatory factor analysis were used to investigate foot and ankle WMSDs and their related risk factors (including individual factors, work organization, work posture, work type, fatigue, etc.) in key occupational groups in China, and structural equation model hypothesis, fitting, verification, and path and intermediary effect analysis were carried out. The model fit evaluation indexes included Chi-square specific degrees of freedom ( χ2/ df), gauge fit index (NFI), Tucker Lewis index (TLI), goodness of Fit index (GFI), adjusted Goodness of Fit index (AGFI) and approximate root mean square error (RMSEA) . Results:A total of 73497 occupational workers were surveyed, with local muscle fatigue and WMSDs incidence rates in the feet and ankles being 17.17% and 12.06%, respectively. The fitting index of the adjusted structural equation model basically meets the standard (GFI=1, AGFI=1, RMESA=0.042, NFI=0.716, TLI=0.663). The top three factors affecting feet and ankle WMSDs are feet and ankle muscle fatigue, work type, and work organization, with standardized path coefficients of 0.221, 0.105, and 0.095, respectively. The top two factors affecting feet and ankle muscle fatigue are work organization and work type, with standardized path coefficients of 0.548 and 0.383, respectively. Feet and ankle muscle fatigue, work type, work organization, and work posture have a direct effect on feet and ankle WMSDs, with effect values of 0.221, 0.105, 0.095, and 0.077, respectively. The organization and type of work can also have indirect effects through feet and ankle muscle fatigue, with effect values of 0.121 and 0.084, respectively.Conclusion:Feet and ankle muscle fatigue has a direct impact on WMSDs, and plays a mediating role between ankle and ankle WMSDs caused by work organization and work type. Feet and ankle muscle fatigue is an important pathway leading to feet and ankle WMSDs. It is recommended that employers and managers detect job fatigue early and take corresponding prevention and intervention measures, which can play a key role in preventing feet and ankle WMSDs.