目的 探讨冠心病患者血清同型半胱氨酸（Hcy）与胱抑素C（CysC）水平的变化及其临床意义。方法 选取218例冠心病患者与129例健康对照者，分别检测其血清Hcy与CysC水平，并进行比较与分析。结果 冠心病组的血清Hcy与CysC水平显著高于对照组（P<0.01），且其阳性率显著高于对照组（P<0.01），而联合检测的阳性率显著高于单项检测（P<0.01）；血清Hcy与CysC对冠心病诊断有较高的特异度（分别为92.2%与97.7%）与阳性预测值（分别为89.2%与96.1%），而灵敏度（分别为38.1%与33.9%）与阴性预测值（分别为46.9%与46.7%）不高，联合并联检测可显著提高诊断灵敏度至51.8%；血清Hcy水平与CysC水平正相关（r=0.363，P<0.01）。结论 Hcy、CysC水平与冠心病关系密切，联合检测对于冠心病患者的诊断、治疗及预后具有重要临床意义。

Objective To investigate the changes of serum homocysteine (Hcy) and cystatin C (CysC) levels in patients with coronary artery disease (CHD) and its clinical significance. Methods The serum levels of Hcy and CysC in 218 cases of coronary heart disease patients and 129 healthy controls were detected and their relations were then analyzed. Results The serum levels of Hcy and CysC in CHD group were higher than that of control group (P<0.01), and the positive rate in CHD group was significantly higher than that in control group (P<0.01), while the positive rate of combined detection of Hcy and CysC was significantly higher than that of single detection(P<0.01). The serum Hcy and CysC to diagnose coronary heart disease had a high specificity (92.2% and 97.7% respectively) and positive predictive value (89.2% and 96.1% respectively), while the sensitivity (38.1% and 33.9% respectively) and negative predictive value (46.9% and 46.7% respectively) were not high. The combined detection could significantly improve the diagnostic sensitivity to 51.8%. The serum Hcy levels were positively correlated with CysC levels (r=0.363, P<0.01). Conclusion The serum Hcy and CysC levels closely associate with coronary heart disease. The combined detection of Hcy and CysC has important clinical significance in the diagnosis, treatment and prognosis of patients with coronary heart disease.