血浆β_2-MG及HCY在下肢动脉粥样硬化的风险分级和预后评估中的价值

Values of plasma β_2-microglobulin and homocysteine for risk rating and prognosis estimation in patients with lower extremity atherosclerotic disease

目的:探讨血浆β2微球蛋白(β2-MG)及同型半胱氨酸(HCY)对下肢动脉粥样硬化病(LEAD)患者病变的风险分级和预后评估的价值。方法:收集136例明确诊断的LEAD患者,按Fontaine分期标准分为:I期组(n=27),II期组(n=39),Ⅲ期组(n=38),IV期组(n=32),或以ABI值分为:低风险组(0.7≤ABI<0.9,n=36),中风险组(0.4≤ABI<0.7,n=60)和高风险组(ABI<0.4,n=40),均以同期35例健康检查者作为对照。比较各组血浆β2-MG和HCY浓度,并进行相关性分析和生存分析。患者每3个月随访1次,随访期为2年。因截肢或心脑血管疾病死亡作为终点事件,并以此进行预后判断。结果:血浆β2-MG和HCY水平均随着Fontaine分期的进展或风险分级的增加而升高(均P<0.05),且ABI值与β2-MG和HCY水平均呈负相关(r=-0.867,r=-0.846);HCY水平用于判断LEAD患者预后的ROC曲线下面积为0.831,以36.085μmol/L作为截断点,其预测终点事件发生的灵敏度为86.0%,特异度为68.6%,Youden指数为0.546;COX回归分析提示ABI值及HCY水平可作为预测LEAD终点事件发生的独立因素(P=0.018,P=0.001)。结论:LEAD随病情的进展,血浆β2-MG,HCY浓度逐渐升高;HCY水平是预测LEAD发生和预后的良好指标;HCY和ABI风险分级相结合方法有助于更好地判断LEAD患者的预后。

Objective：To assess the values of plasma levels of β2-microglobulin（β2-MG） and homocysteine（HCY） for risk rating and prognosis estimation in patients with lower extremity atherosclerotic disease（LEAD）. Methods：One hundred and thirty-six patients with confirmed LEAD were enrolled and grouped according to the Fontaine staging as stage I（n=27）,stage Ⅱ（n=39）,stage ⅡI（n=38） and IV（n=32） group,or according to the values of ankle-brachial index（ABI） as low-risk（0.7≤ABI〈0.9,n=36）,mid-risk（0.4≤ABI〈0.7,n=60） and high-risk（ABI〈0.4,n=40） group.In addition,35 subjects undergoing health maintenance examination during the same period were enrolled as control population for the two hierarchic methods.The plasma levels of β2-MG and HCY were measured and compared among the groups,and the correlation between variables and survival rates were also analyzed.The patients were interviewed every 3 months over a 2-year period.Amputation and death from cardiovascular or cerebrovascular diseases were considered as end-point events,which were also used to determine the prognosis of the patients. Results：The plasma levels of both β2-MG and HCY increased with the progression of the Fontaine stage and with the increase of risk rating as well（both P〈0.01）.Furthermore,the ABI value was negatively correlated with the plasma levels of β2-MG and HCY（r=–0.867,–0.846）.The area under ROC curve of HCY that was used to predict the prognosis of the LEAD patients was 0.831.With a cut-off value at 36.085（μmol/L）,the prediction sensitivity was 86.0%,specificity was 68.6% and Youden index（YI） was 0.546,respectively.COX regression analysis showed the HCY level and ABI value could be used as the independent risk factors to predict the end-point events of LEAD（P=0.018,P=0.001）. Conclusion：The plasma levels of β2-MG and HCY increase with the progression of LEAD.HCY is a good index for predicting the occurrence and prognosis of LEAD,but the combined analysis of HCY level and ABI value（risk rating） yields a better judgment of prognosis of LEAD patients.