目的 分析2型糖尿病肾病患者血清胱抑素C（cystatin C，CysC）的水平，为临床早期诊断提供依据。方法 对本院133例2型糖尿病患者进行回顾性分析，根据24h尿微量白蛋白排泄率（UAER），将其分成三组：一组为单纯糖尿病组（UAER﹤30mg/24h）(B组)，共58例，平均年龄56.6岁，其中男性28例，女性30例；二组为早期糖尿病肾病组（30 mg/24h﹤UAER﹤300mg/24h）（C组）,共41例，平均年龄58.5岁，其中男性20例，女性21例；三组为糖尿病肾病组（UAER﹥300mg/24h）（D组），共34例，平均年龄63.5岁，其中男性17例，女性17例。同时设立健康对照组（A组）50例，平均年龄61.8岁，其中男性24例，女性26例。四组分别测定CysC、血清肌酐（Scr）、血清尿素氮（BUN）及UAER，并对所得数据进行分析。结果 D组CysC、Scr、BUN及UAER均高于A组（P﹤0.01），C组CysC、UAER均高于A、B组（P﹤0.05），B组CysC、UAER均高于A组（P﹤0.05），C组Scr、BUN均高于A、B组（P﹤0.05），而Scr、BUN在A、B两组间差异无统计学意义（P﹥0.05）； CysC与UAER相关性良好（r=0.656，P＜0.01),与Scr、BUN无相关性。结论 相对于Scr和BUN，CysC在糖尿病肾病时升高较早而且明显，与UAER联合检测可以作为糖尿病肾病早期的预测指标。

Objective To explore the clinical significance of cystatin C in the early diagnosis of type 2 diabetic nephropathy. Methods The serum samples of 133 cases with type 2 diabetes were collected and analyzed. According to the 24-hour urinary albumin excretion rate (UAER), these cases were divided into three groups: Group one (B) was DM group (UAER <30mg/24h), with a total of 58 cases (28 males and 30 females) at an average age of 56.6; Group two (C) was early diabetic nephropathy group (30 mg/24h <300mg/24h) with a total of 41 cases (20 males and 21 females) at an average age of 58.5; Group three (D) was diabetic nephropathy group (UAER> 300mg/24h) with total of 34 cases (17 males and 17 females) at an average age of 63.5; a control group (A) was set up with 50 patients (24 males and 26 females) at average age of 61.8. Tests were done in terms of CysC, serum creatinine (Scr), blood urea nitrogen (BUN) and UAER among four groups, and results were analyzed. Results The levels of CysC, Scr, BUN and UAER in group D were higher than that of group A respectively (P <0.01). The levels of CysC and UAER in group C were higher than that of Group A and B respectively (P <0.05). The level of CysC and UAER in group B were higher than that group A respectively (P <0.05). The levels of Scr and BUN in group C were higher than that of group A and B respectively (P <0.05), whereas there was no significant difference between Group A and B in terms of Scr and BUN (P> 0.05). The level of CysC had good correlation with that of UAER（r=0.656，P＜0.01), but had no correlation with the levels of Scr and BUN. Conclusion As compared with Scr and BUN, the level of CysC rises significantly in the diabetic nephropathy. Therefore, the combination of CysC and UAER can be used as prediction indictors of early diabetic nephropathy.