Analysis And Modeling Of Risk Factors For Osteoporosis In Middle-aged And Elderly Patients With End-stage Knee Osteoarthritis

Objective: To investigate the independent risk factors for osteoporosis in middle-aged and elderly patients with end-stage osteoarthritis of the knee,and to construct a nomogram prediction model to predict the risk of osteoporosis in middle-aged and elderly patients with end-stage osteoarthritis of the knee.This will help clinicians to identify patients with end-stage osteoarthritis of the knee who are at high risk of osteoporosis,and to improve the examination and consider the treatment of patients at high risk of osteoporosis in order to reduce the risk of fracture in the future.Methods: Middle-aged and elderly patients with end-stage knee osteoarthritis who are scheduled for knee arthroplasty in our osteoarthroplasty department from January 2021 to November 2022 were collected according to the inclusion and exclusion criteria.Information collected included gender,age,weight,height,history of smoking and drinking,presence of hypertension,presence of diabetes,Venous blood haemoglobin,serum uric acid(SUA),serum albumin,serum calcium ion concentration,triglycerides,total cholesterol,LDL cholesterol,HDL cholesterol,type I collagen carboxy-terminal peptide,N-terminal middle osteocalcin,type I collagen amino-terminal peptide,total vitamin D and bone mineral density(BMD)and BMD T values,including L1 T,L2T,L3 T,L4T,mean BMD and its T value for L1-L4,BMD and its T value for the left femoral neck and mean BMD and its T value for the left hip.The geriatric nutritional risk index(GNRI)was calculated according to the method of Bouillanne,O.SPSS 26.0 for data analysis and statistics.Correlation analysis was performed using Pearson analysis,and factors that were significantly correlated(p < 0.05)with mean BMD values of L1-L4,BMD values at the left femoral neck and mean BMD values at the left hip were included in the multiple linear regression analysis,to investigate the independent influence of the mean BMD values of L1-L4,the BMD values of the left femoral neck and the mean BMD values of the left hip.The data were divided into two groups according to the presence or absence of osteoporosis,a univariate analysis was performed and a multibi abn Logistic regression analysis was performed with the factors that were statistically significant(P < 0.05)when comparing the two groups as independent variables to analyse independent risk factors for the presence of osteoporosis in middleaged and elderly patients with end-stage knee osteoarthritis.Construction of a nomogram prediction model to predict the risk of osteoporosis in middle-aged and elderly patients with end-stage knee osteoarthritis using the R Studio software car,rms,p Roc,Hmisc package.Subject work characteristic curves were used to analyse the predictive ability of the model and calibration curves were plotted to verify the accuracy of the model.Results: Multiple linear regression of the total patient data collected showed that female,reduced BMI levels were independent risk factors for reduced BMD values in the lumbar spine,left hip and left femoral neck in middle-aged and elderly patients with knee endstage osteoarthritis.Ageing was an independent risk factor for lower BMD values in their left hip and left femoral neck.lower GNRI was an independent risk factor for lower BMD values in their left hip.Multiple linear regression results,grouped by gender,showed that lower BMI,lower SUA and increasing age were independent risk factors for lower lumbar spine BMD values in middle-aged and older women with end-stage knee osteoarthritis.Lower BMI and increasing age were independent risk factors for lower BMD values in their left hip and left femoral neck.Pearson analysis showed a significant positive correlation between BMI and lumbar spine,left hip and left femoral neck BMD values in middle-aged and elderly men with end-stage osteoarthritis of the knee.There were statistically significant differences between the two groups with and without osteoporosis in terms of gender,age,BMI,GNRI,serum uric acid,venous haemoglobin,HDL cholesterol,type I collagen carboxy-terminal peptide,N-terminal mid-segment osteocalcin,type I collagen amino-terminal peptide and total vitamin D.Multivariate logistic regression analysis showed that gender,age,BMI and total vitamin D were independent influences on the presence of osteoporosis at the end stage of knee osteoarthritis in the middle-aged and elderly.The area under the curve for each independent factor was 0.646 for gender,0.584 for age,0.601 for total serum vitamin D,0.660 for BMI and 0.816 for the combined model of each independent risk factor,all with P < 0.05.Conclusion: Female,advanced age,low BMI and low total vitamin D levels are independent risk factors for osteoporosis in middle-aged and elderly patients with endstage knee osteoarthritis.Based on these we developed a Nomogram model to predict the risk of osteoporosis in middle-aged and elderly patients with end-stage knee osteoarthritis.In addition GNRI growth was an independent protective factor for reduced hip BMD values in middle-aged and elderly patients with end-stage knee osteoarthritis.The bone density of the lumbar spine in female patients may be affected by serum uric acid,and maintaining a high level of serum uric acid is beneficial in preventing osteoporosis of the lumbar spine in female patients.