| Objective:To establish a risk prediction model of osteoporotic fracture(OF)in patients with type 2 diabetes mellitus(T2DM)and perform external validation in order to provide clinicians with some reference for identifying the population at high risk of OF in T2DM patients.Methods:201 patients with T2DM(model group)were enrolled in Northern Jiangsu People’s Hospital from January 2017 to January 2020,and 65 patients with T2DM(validation group)were enrolled in this hospital from February 2020 to January2021.Demographic data of each patient were collected in detail.Fasting venous blood was drawn from each patient to detect FPG,ALP,blood calcium,CTX,N-MID,TP1NP,and 25(OH)D.The bone mineral density(BMD)of lumbar spine,femoral neck and total hip was measured by DXA in all patients.We divided the patients of the model group into non-fracture group and fracture group according to whether OF occurred or not,using univariate analysis to compare the differences between the two groups.Indicators with P<0.05 were used as potential predictor variables.Multivariate logistic regression was used to analyze the potential predictor variables to determine the predictors and their coefficients of OF in patients with T2DM.The data in validation group were applied to externally validate the model,and its power to predict the risk of OF in T2DM patients was evaluated by receiver operating characteristic(ROC)curves.Results:1.266 T2DM patients who met the inclusion criteria were selected in this study,including 201 patients in model group and 65 patients in validation group.A total of 124patients had OF,accounting for 46.62%of the total subjects.The prevalence of thoracolumbar fracture was the highest,with 102 cases(73 in model group and 29 in validation group).There were 16 cases of femoral neck fracture(15 in model group and one in validation group),and all six cases of intertrochanteric fracture were in model group.2.A comparative analysis of variables between non-fracture group and fracture group showed that indicators with P<0.05 included age(61.23±9.41 vs 71.87±7.20,P<0.001),gender[male 61(57.0%)vs 12(12.8%),P<0.001],previous fracture history[5(4.67%)vs 21(22.34%),P<0.001],CTX[0.37(0.24～0.50)vs 0.47(0.30～0.75),P<0.001],N-MID[10.50(8.44～12.40)vs 13.33(9.63～18.62),P<0.001],TP1NP[33.59(27.31～41.30)vs 45.12(33.88～61.49),P<0.001],ALP[71(60～86)vs 91(75.75～112.25),P<0.001],25(OH)D(21.34±6.18 vs 13.65±6.11,P<0.001),L1～L4BMD(1.13±0.16)vs 0.91±0.15,P<0.001)and total hip BMD(0.94±0.13 vs 0.77±0.12,P<0.001).3.The results of multivariate analysis indicated that age(OR=1.121,95%CI:1.051～1.196),previous fracture history(OR=6.821,95%CI:1.258～36.974),TP1NP(OR=1.047,95%CI:1.008～1.088),ALP(OR=1.027,95%CI:1.004～1.050)were risk factors for OF in T2DM patients,and 25(OH)D(OR=0.803,95%CI:0.727～0.887),L1～L4 BMD(OR=0.001,95%CI:0.000～0.029)were protective factors for OF in T2DM patients.4.We constructed a risk prediction model for OF in patients with T2DM.The model formula was Logit P=-0.964+0.114×age+1.920×previous fracture history+0.046×TP1NP+0.026×ALP-0.220×25(OH)D-7.273×L1～L4 BMD.The results of Omnibus test showedχ~2=172.109,P<0.001.The results of Hosmer-Lemeshow test showedχ~2=2.468,P=0.963.It was able to correctly classify 89.6%of the study subjects,with an area under the ROC curve of 0.956(95%CI:0.931～0.982,P<0.001),a Youden index of 0.803,a sensitivity of 91.5%,and a specificity of 88.8%.5.We used the data of validation group to test the predictive power of this model.The plotted area under the ROC curve was 0.826(95%CI:0.726～0.926,P<0.001),with a Youden index of 0.505,a sensitivity of 73.3%,and a specificity of 77.1%.Conclusion:In this study,we found that age,previous fracture history,TP1NP,ALP were risk factors for OF in T2DM patients,and 25(OH)D,L1～L4 BMD were protective factors of OF in T2DM patients.These six factors were included to construct a risk prediction model for OF in T2DM patients.The model was validated to predict well and could help clinicians to screen people at high risk of OF in T2DM patients. |
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