同型半胱氨酸对老年糖尿病足截肢的预测价值

The predictive value of homocysteine for diabetic foot amputation in the elderly

目的:通过对134例老年糖尿病足患者的病例特点分析,了解老年糖尿病足截肢的危险因素及同型半胱氨酸(homocysteine,Hcy)对老年糖尿病足截肢的预测价值。方法:回顾性搜集2012年12月至2018年2月于锦州市中心医院内分泌科住院的符合纳入标准的老年糖尿病足患者共134例,根据截肢与否分组,应用t检验、非参数Mann-Whitney检验、卡方检验比较2组间资料,多因素回归分析老年糖尿病足患者截肢的危险因素;应用受试者工作曲线(ROC曲线)判断同型半胱氨酸对老年糖尿病足截肢的预测价值。结果:134例老年糖尿病足患者非截肢组90例,截肢组44例,截肢率为32.83%。截肢组平均住院天数高于非截肢组(P<0.01)。截肢组血清白蛋白(serum albumin,ALB)、踝肱比值(ankle brachial index,ABI)低于非截肢组(P<0.01);截肢组Hcy、白细胞计数(white blood cell,WBC)均高于非截肢组(P<0.01)。多因素logistic回归分析显示,Hcy(OR=1.168,95%CI=1.096~1.244)、WBC(OR=1.186,95%CI=1.039~1.354)为老年糖尿病足截肢的独立危险因素。在Hcy对老年糖尿病足截肢预测能力的ROC曲线中,其曲线下面积为0.812(95%CI=0.731~0.893,P<0.01)。当Hcy取最佳临界值22.5μmol/L时,其预测截肢的敏感性为63.60%,特异性为90.00%,准确性为81.34%,阳性预测价值为75.67%,阴性预测价值为83.50%。Hcy大于界值的患者截肢率75.67%,为总体截肢率的2.30倍。结论:高Hcy血症为老年糖尿病足截肢的独立危险因素;Hcy大于22.5μmol/L时,其预测老年糖尿病足截肢具有较高的特异性、阳性预测价值及阴性预测价值,总的符合率较高。

Objective:To investigate the risk factors for diabetic foot amputation in the elderly,as well as the predictive value of homocysteine(Hcy)for amputation.Methods:The retrospective study included 134 eligible elderly patients with diabetic foot,who were hospitalized in the Department of Endocrinology,Jinzhou Central Hospital,from December 2012 to February 2018.According to the limb status,the patients were divided into amputation group(AMP group)and non-amputation group(NAMP group).The intergroup data were analyzed with t test,Mann-Whitney test,and chi-square test;the risk factors for amputation in elderly patients with diabetic foot were analyzed with multivariate regression.The receiver operating characteristic(ROC)curve was used to determine the predictive value of Hcy for amputation in the elderly patients with diabetic foot.Results:In the 134 elderly patients with diabetic foot,90 were non-amputated,and 44 were amputated;the amputation rate was 32.83%.The mean length of hospital stay in the AMP group was significantly longer than that in the NAMP group(P<0.01).The serum albumin level and ankle-brachial index in the AMP group were significantly lower than those in the NAMP group(P<0.01).The Hcy level and white blood cell(WBC)count in the AMP group were significantly higher than those in the NAMP group(P<0.01).Multivariate logistic regression analysis showed that Hcy(OR=1.168,95%CI=1.096-1.244)and WBC(OR=1.186,95%CI=1.039-1.354)were independent risk factors for amputation in elderly patients with diabetic foot.The area under the ROC curve representing the predictive value of Hcy for diabetic foot amputation in the elderly was 0.812(95%CI=0.731-0.893,P<0.01).At the optimal cut-off value of 22.5μmol/L,Hcy had a sensitivity of 63.60%,a specificity of 90.00%,an accuracy of 81.34%,a positive predictive value of 75.67%,and a negative predictive value of 83.50%in predicting amputation.The amputation rate of patients with Hcy levels higher than the cut-off value was 75.67%,which was 2.30 times the overall amputation rate.Conclusion:High Hcy is an independent risk factor for diabetic foot amputation in the elderly.When Hcy level is higher than 22.5μmol/L,it has high specificity,positive predictive value,and negative predictive value in predicting diabetic foot amputation in the elderly,with a high overall coincidence rate.