BACKGROUND:Some research has suggested that regulation of gut microbiota may influence the course of intervertebral disc degeneration.However,the causal relationship of gut microbiota on intervertebral disc degeneration is unknown.OBJECTIVE:To assess the potential causal relationship between gut microbiota and intervertebral disc degeneration using a Mendelian randomization method.METHODS:Genome-wide association analysis summary statistics for 473 gut microbiota and genome-wide association analysis summary data for intervertebral disc degeneration from the R11 of the FinnGen database(46 205 cases of intervertebral disc degeneration and 322 314 controls)from the most recent publicly available publication were applied.Inverse variance weighting,MR-Egger regression,weighted median,weighted modeling,and simple modeling were used to investigate the causal relationship between gut microbiota and intervertebral disc degeneration.Sensitivity analyses were used to test whether the results of Mendelian randomization analyses were reliable.Reverse Mendelian randomization was performed with all gut microbiota as the outcomes for effect analysis and sensitivity analysis.RESULTS AND CONCLUSION:(1)The results of the inverse variance weighting method of the forward Mendelian randomization method showed that the order Trichosporonaceae,the family UBA-6960,the family Anaerobes thermophilus,the family Salmonellaceae,the genus Pseudomonas tufts,the species Gordonella and the species Euclidia showed a positive correlation with intervertebral disc degeneration.The order Spirochaetes,the order Pseudomonas,the family Spirochaetaceae,the genus CAG-776,the genus Helicobacter,the species CAG-448 sp003150135,the species CAG-776 sp000438195,the species Brautella-A sp000285855 and the species Hanson's Brautella showed a negative correlation with intervertebral disc degeneration.(2)The results of reverse Mendelian randomization showed that intervertebral disc degeneration was positively correlated with the genus Bartonella rosea,the genus Geobacillus C,the species Escherichia fumigatus,the species Propionibacterium fumigatus,the species UBA-1777 sp900319835,the species Pseudomonas aeruginosa and the species Bacillus subtilis,while negatively correlated with the species Streptomyces mingoldii,the species Prevotella sp000434975,the species Brault's A sp000285855,the species CAG-194 sp002441865 and the species CAG-590 sp000431135.(3)No heterogeneity or horizontal pleiotropy was found in the two-way sensitivity analysis.(4)The results described above indicate that the causal relationship between gut microbiota and intervertebral disc degeneration based on the Finnish database contributes to the exploration on new biomarkers for the early prediction and treatment of intervertebral disc degeneration in clinical practice.In addition,the establishment of a large database and the integration of medical data from multiple centers can be drawn upon in biomedical research in China to provide a solid foundation for studying the relationship between gut microbiota and intervertebral disc degeneration.We will strengthen communication and cooperation with research teams in other countries to jointly promote the research on the relationship between gut microbiota and diseases and contribute to the development of global medicine.

BACKGROUND:Some research has suggested that regulation of gut microbiota may influence the course of intervertebral disc degeneration.However,the causal relationship of gut microbiota on intervertebral disc degeneration is unknown.OBJECTIVE:To assess the potential causal relationship between gut microbiota and intervertebral disc degeneration using a Mendelian randomization method.METHODS:Genome-wide association analysis summary statistics for 473 gut microbiota and genome-wide association analysis summary data for intervertebral disc degeneration from the R11 of the FinnGen database(46 205 cases of intervertebral disc degeneration and 322 314 controls)from the most recent publicly available publication were applied.Inverse variance weighting,MR-Egger regression,weighted median,weighted modeling,and simple modeling were used to investigate the causal relationship between gut microbiota and intervertebral disc degeneration.Sensitivity analyses were used to test whether the results of Mendelian randomization analyses were reliable.Reverse Mendelian randomization was performed with all gut microbiota as the outcomes for effect analysis and sensitivity analysis.RESULTS AND CONCLUSION:(1)The results of the inverse variance weighting method of the forward Mendelian randomization method showed that the order Trichosporonaceae,the family UBA-6960,the family Anaerobes thermophilus,the family Salmonellaceae,the genus Pseudomonas tufts,the species Gordonella and the species Euclidia showed a positive correlation with intervertebral disc degeneration.The order Spirochaetes,the order Pseudomonas,the family Spirochaetaceae,the genus CAG-776,the genus Helicobacter,the species CAG-448 sp003150135,the species CAG-776 sp000438195,the species Brautella-A sp000285855 and the species Hanson's Brautella showed a negative correlation with intervertebral disc degeneration.(2)The results of reverse Mendelian randomization showed that intervertebral disc degeneration was positively correlated with the genus Bartonella rosea,the genus Geobacillus C,the species Escherichia fumigatus,the species Propionibacterium fumigatus,the species UBA-1777 sp900319835,the species Pseudomonas aeruginosa and the species Bacillus subtilis,while negatively correlated with the species Streptomyces mingoldii,the species Prevotella sp000434975,the species Brault's A sp000285855,the species CAG-194 sp002441865 and the species CAG-590 sp000431135.(3)No heterogeneity or horizontal pleiotropy was found in the two-way sensitivity analysis.(4)The results described above indicate that the causal relationship between gut microbiota and intervertebral disc degeneration based on the Finnish database contributes to the exploration on new biomarkers for the early prediction and treatment of intervertebral disc degeneration in clinical practice.In addition,the establishment of a large database and the integration of medical data from multiple centers can be drawn upon in biomedical research in China to provide a solid foundation for studying the relationship between gut microbiota and intervertebral disc degeneration.We will strengthen communication and cooperation with research teams in other countries to jointly promote the research on the relationship between gut microbiota and diseases and contribute to the development of global medicine.

Objective:To study the association between preoperative hemoglobin amount and incidence of lower limb deep vein thrombosis (DVT) in patients with lower limb fracture.Methods:A retrospective study was performed of the 2, 482 patients with lower limb fracture who had been treated at Department of Orthopaedics Trauma, Honghui Hospital Affiliated to Xi'an Jiaotong University from July 2014 to August 2019. They were 1, 174 males and 1, 308 females with an age of (60.6±19.3) years. Recorded were the patients' age, gender, injury time, hemoglobin amount, D-dimer measurement, combined medical conditions, time and results of ultrasound vein examination on both lower extremities. According to the ultrasound results, the patients were divided into a thrombosis group and a thrombosis-free group. The 2 groups were compared in hemoglobin amount. Logistic regression was used to analyze the relationship between preoperative hemoglobin amount and incidence of lower limb DVT. The patients were divided into 5 groups according to the quintile of hemoglobin amount; the incidences of thrombosis were compared between the 5 groups.Results:The total incidence of DVT in this cohort was 29.53%(733/2, 482). The hemoglobin amount in the thrombosis group was (116.57±19.24) g/L, significantly lower than that in the thrombosis-free group (124.76±19.79) g/L ( P<0.05). The preoperative hemoglobin amount was a risk factor for incidence of DVT after a lower limb fracture ( OR=0.985, 95% CI: 0.980 to 0.990, P<0.001). As the quintile level of hemoglobin increased, the incidence of DVT showed a downward trend. In comparison of the group with the highest DVT incidence (40.58%) and the group with the lowest DVT incidence (17.27%), the risk increased by 2.386 times (95% CI: 1.718 to 3.315). Conclusions:The preoperative hemoglobin amount can affect the DVT incidence after a lower limb fracture, and a low hemoglobin amount may more likely lead to lower limb DVT.

Objective:To investigate the differences in incidence of deep vein thrombosis (DVT) after closed fracture of lower extremity between patients with different blood types ABO.Methods:A retrospective study was conducted in the 1, 951 patients who had been admitted to Department of Orthopaedics Trauma, Honghui Hospital Affiliated to Xi'an Jiaotong University for lower extremity fractures from August 2014 to June 2018. They were 924 males and 1,027 females with a mean age of 63 (46, 78) years (range, from 16 to 102 years). Of them, 572 were type O, 564 type A, 609 type B and 206 type AB. Venous ultrasonography was performed on both lower extremities within 12 hours after admission. The incidences of DVT after fracture were compared between different blood types in all the patients, patients with proximal fracture of the knee, peri-knee fracture and distal fracture of the knee, and patients<60 years old and ≥60 years old.Results:The incidences of DVT were, respectively, 26.75% (153/572), 28.72% (162/564), 34.32% (209/609) and 29.61% (61/206) for patients with blood type O, type A, type B and type AB. The DVT incidence for type B was significantly higher than that for type O ( P< 0.008). The incidences of DVT were, respectively, 28.74% (98/341), 28.99% (100/345), 39.45% (144/365) and 30.97% (35/113) for blood type O, type A, type B and type AB in the patients with proximal fracture of the knee. The DVT incidence for blood type B was significantly higher than those for blood type O and blood type A ( P< 0.008). There were no significant differences in the DVT incidence between different blood types ABO in the patients with peri-knee fracture, distal fracture of the knee,<60 years old or ≥60 years old( P>0.05). The incidences of DVT were, respectively, 30.99% (97/313), 33.33% (108/324), 45.22% (156/345), 34.74% (33/95) for blood type O, type A, type B and type AB in the patients ≥60 years old. The DVT incidence for blood type B was significantly higher than those for blood type O and blood type A ( P< 0.008). Conclusions:The incidence of DVT varied with different blood types ABO after lower extremity fracture. The highest DVT incidence was found in patients with blood type B. The impact of blood type on the DVT incidence after lower extremity fracture was mainly observed in the patients with proximal fracture of the knee or an age of ≥ 60 years old.

Objective:To investigate the risk factors of deep venous thrombosis in patients before hip arthroplasty, and to explore the possible causes of postoperative thrombosis.Methods:The clinical data of 361 patients with hip arthroplasty treated in the Department of Orthopaedic Trauma of Xi′an Honghui Hospital from September 2015 to December 2019 were studied retrospectively, including 102 males and 259 females, aged 65 to 94 years, and the average age was 72.25 years old. All fracture patients were given subcutaneous injection of low molecular weight heparin calcium to prevent lower extremity thrombosis. The deep veins of both lower extremities were examined before and after operation. The general data of the two groups of patients were collected and recorded, including age, sex, whether complicated with medical diseases (essential hypertension, type 2 diabetes, coronary heart disease), serological indexes, time from injury to admission, and time from admission to operation. The software of SPSS 19.0 was used for statistical analysis.Results:The incidence of lower limb DVT, before operation was 29.92%, including 26 males (24.07%) and 82 females (75.93%). The results of multivariate logistic regression analysis showed that diabetes mellitus ( OR=2.127, 95% CI: 1.134-3.989, P=0.019), coronary heart disease ( OR=1.692, 95% CI: 1.056-2.713, P=0.029) and the time from injury to admission ( OR=1.677, 95% CI: 1.037-2.712, P=0.035) were independent risk factors for DVT in elderly patients undergoing hip arthroplasty. The incidence of lower limb DVT, after operation was 46.54%. After operation, proximal thrombus were occurred in 2 cases (1.19%), distal thrombus in 143 cases (85.12%), and mixed thrombus in 23 cases (13.69%). Postoperative thrombus was ipsilateral to the fracture limb in 84 cases (50.00%), thrombus was located in the healthy side of the fracture in 19 cases (11.31%), and DVT occurred in 65 cases (38.69%) in both lower limbs. Conclusions:Delayed admission longed than 48 hours, coronary heart disease and diabetes mellitus are the risk factors for the formation of DVT. The thrombus that existed before operation and did not disappear after operation accounted for 48.81% of the total incidence of postoperative thrombosis, and the new thrombus accounted for 51.19% of the total incidence of postoperative thrombosis. For the elderly patients with femoral neck fracture undergoing hip arthroplasty, ultrasonic examination of both lower limbs should be performed before and after operation to find the changes of thrombus in time and do a good job of prevention and treatment.