胱抑素C在评价2型糖尿病患者颈动脉粥样硬化中的作用

The Correlation of Serum Cystatin C Level with the Severity of Carotid Atherosclerosis in Patients with Type 2 Diabetes Mellitus

目的研究胱抑素C(Cys C)在评价2型糖尿病(DM)患者颈动脉粥样硬化中的作用。方法 633例符合纳入/排除标准的2型DM患者,收集血标本,检测Cys C、血常规、生化等指标,超声探测颈动脉内中膜厚度(IMT)及颈动脉粥样硬化(AS)斑块部位及大小。简化肾脏病膳食改良试验(MDRD)公式估算肾小球滤过率(eGFR),结合肾脏病生存质量指导(K/DOQI)指南将eGFR<60mL/(min.1.73m2)的患者定义为糖尿病合并慢性肾脏病(CKD)组(DM-CKD,237例),eGFR≥60mL/(min.1.73m2)为糖尿病非CKD组(DM-NCKD,396例)。进一步分成两个亚组:IMT正常组和IMT增厚组,以及AS斑块组和无AS斑块组。通过相关分析、多元线性回归分析探索Cys C与颈AS的关系。结果 396例DM-NCKD中,IMT增厚组Cys C浓度高于IMT正常组〔(1.00±0.20)mg/L vs.(0.90±0.30)mg/L,P<0.05〕,但调整混杂因素后,差异无统计学意义。而AS斑块组Cys C浓度高于无AS斑块组〔(1.05±0.27)mg/L vs.(0.89±0.22)mg/L,P<0.05〕,调整混杂因素(年龄、糖尿病病程)后,差异有统计学意义(P<0.05)。相关分析显示Cys C与动脉粥样硬化呈正相关(r=0.338,P<0.001);调整糖尿病病程、肌酐、年龄后,相关减弱(r=0.14,P=0.005)。多元线性回归分析示Cys C与动脉粥样斑块严重程度正相关(B=0.071,P=0.001)。而在DM-CKD组(236例)中,并未显示Cys C与颈动脉粥样硬化严重程度相关。方差分析示随着Cys C浓度增加,颈动脉粥样硬化斑块病变加重。结论 DM-NCKD中,Cys C与AS斑块严重程度呈正相关,可作为AS严重程度的候选生物学标志。

Objective To investigate whether serum cystatin C （Cys C） concentration correlates with the severity of carotid atherosclerosis （CAS） in patients with type 2 diabetes mellitus （DM）. Methods This study enrolled 633 type 2 DM patients met the inclusion/exclusion criteria. All the patients were subjected to the measurement of serum Cys C, concentration, complete blood count, and blood biochemical test. The severity of CAS was evaluated by Doppler ultrasound to define intimal medial thickness （IMT） of carotid artery, the location and size of atherosclerotic plaque. Based on the estimated glomerular filtation rate （eGFR）, the patients were divided into DM with chronic kidney diease （CKD） group （DM-CKD） and DM without CKD group （DM-NCKD）, then were further divided into two subgroups by IMT and AS plaque. The relationship of serum Cys C with the severity of CAS was evaluated by the comparison between the two groups, correlation analysis and multiple linear regression analysis. Results In 396 DM-NCKD patients with the eGFR ≥60 mL/（min · 1. 73 m2）, Cys C concentration of IMT thickening group was higher than that of normal IMT group （（1.00±0.20） mg/L vs. （0.90±0.30） mg/L, P〈0. 053, but the difference was not statistically significant after the adjustment for confounding factors. The patients with obvious CAS plaques formation had higher Cys C concentration than those without AS plaques formation [（1. 05±0. 27） mg/L vs. （0. 89±0.22） mg/L, P〈0. 053. Moreover, the concentration of Cys C was correlated with the severity of CAS （r=0. 338, P〈0. 001）, even after the adjustment for confounding factors （r= 0.14, P= 0. 005）. Multiple linear regression analysis also showed a close correlation of Cys C with the severity of CAS （B= 0. 071,P= 0. 001）. Analysis of variance showed that the severity of CAS was increased accordingly with the increasing level of Cys C. However, the concentration of Cys C was not correlated with the severity of CAS in 237 DM-CKD patients. Conclusion The concentration of Cys C was positively correlated with the severity of CAS, it may be a candidate marker of CAS severity in type 2 DM patients without CKD.