Fliser D, Ritz E
Division of Nephrology, Department of Internal Medicine, Ruperto-Carola University Heidelberg, Germany.
Am J Kidney Dis. 2001 Jan;37(1):79-83. doi: 10.1053/ajkd.2001.20628.
Serum cystatin C is a novel marker of renal function claimed to be superior to plasma creatinine. We assessed both parameters in young normotensive subjects (n = 12; 6 men; mean age, 25 +/- 2 years) and elderly normotensive and hypertensive subjects (n = 41; 19 men; mean age, 67 +/- 6 years). Glomerular filtration rate (GFR) was measured in all individuals using the inulin clearance (C(in)) technique. Compared with young subjects, mean GFR was modestly but significantly (P: < 0.001) less in elderly subjects (young, 119 +/- 11 mL/min/1.73 m(2) versus elderly, 104 +/- 12 mL/min/1.73 m(2)). Mean plasma creatinine concentration was identical in both groups (young, 0.93 +/- 0.11 mg/dL versus elderly, 0.93 +/- 0.10 mg/dL; P: < 0.90). Mean serum cystatin C concentration was significantly (P: < 0.001) greater in elderly subjects (0.84 +/- 0.10 mg/L) compared with young subjects (0.69 +/- 0.08 mg/L). In all but one elderly subject, plasma creatinine concentration was within the 95% confidence interval of plasma creatinine concentration in young subjects. Eleven of 41 elderly subjects (27%) had GFRs less than the lower 95% confidence interval, respectively, and 12 of 41 elderly subjects (29%) had a serum cystatin C concentration greater than the upper 95% confidence interval in young subjects. The correlation between serum cystatin C concentration and C(in) (r = -0.65; P: < 0.001) was considerably better than between plasma creatinine concentration and C(in) (r = -0.30; P: < 0.02). Serum cystatin C concentration is a better marker of renal dysfunction (ie, reduced GFR) than plasma creatinine concentration, at least in elderly subjects with plasma creatinine concentrations within the normal range.
血清胱抑素C是一种新的肾功能标志物，据称优于血肌酐。我们评估了年轻血压正常受试者（n = 12；6名男性；平均年龄，25±2岁）以及老年血压正常和高血压受试者（n = 41；19名男性；平均年龄，67±6岁）的这两个参数。使用菊粉清除率（C(in)）技术测量了所有个体的肾小球滤过率（GFR）。与年轻受试者相比，老年受试者的平均GFR略有降低但差异显著（P：<0.001）（年轻受试者为119±11 mL/min/1.73 m²，老年受试者为104±12 mL/min/1.73 m²）。两组的平均血肌酐浓度相同（年轻受试者为0.93±0.11 mg/dL，老年受试者为0.93±0.10 mg/dL；P：<0.90）。与年轻受试者（0.69±0.08 mg/L）相比，老年受试者的平均血清胱抑素C浓度显著更高（P：<0.001）（0.84±0.10 mg/L）。除一名老年受试者外，其他所有老年受试者的血肌酐浓度均在年轻受试者血肌酐浓度的95%置信区间内。41名老年受试者中有11名（27%）的GFR低于年轻受试者的95%置信区间下限，41名老年受试者中有12名（29%）的血清胱抑素C浓度高于年轻受试者的95%置信区间上限。血清胱抑素C浓度与C(in)之间的相关性（r = -0.65；P：<0.001）明显优于血肌酐浓度与C(in)之间的相关性（r = -0.30；P：<0.02）。至少在血肌酐浓度处于正常范围内的老年受试者中，血清胱抑素C浓度比血肌酐浓度更能准确反映肾功能不全（即GFR降低）。
