Pucci Laura, Triscornia Stefano, Lucchesi Daniela, Fotino Carmen, Pellegrini Giovanni, Pardini Ennia, Miccoli Roberto, Del Prato Stefano, Penno Giuseppe
Dipartimento di Endocrinologia e Metabolismo, Azienda Ospedaliero Universitaria di Pisa, Pisa, Italy.
Clin Chem. 2007 Mar;53(3):480-8. doi: 10.1373/clinchem.2006.076042. Epub 2007 Jan 26.
Early identification of impairment in renal function is crucial in diabetic patients. Serum cystatin C may be the most sensitive indicator of glomerular filtration rate (GFR) in the clinical setting.
We compared cystatin C with creatinine, the Cockcroft-Gault (C-G) formula, and the Modification of Diet in Renal Disease (MDRD) study equation for the assessment of early decreased renal function in 288 diabetic patients (125 type 1, 163 type 2) with renal impairment [GFR: 4-222 mL x min(-1) x (1.73 m(2))(-1)]. Relationships of cystatin C, creatinine, and iohexol clearance were linearized by plotting their reciprocals in a simple regression model. Diagnostic efficiency was calculated from ROC curves.
In this study population, cystatin C (P = 0.0013) was better correlated with GFR (r = 0.857) than were creatinine (r = 0.772), C-G (r = 0.750), and MDRD (r = 0.806), a result replicated in patients with normal renal function (P = 0.023, type 1; P = 0.011, type 2), but not in those with decreased GFR. Mean cystatin C concentrations showed step-by-step statistically significant increases as GFR decreased, allowing very early detection of reduction in renal function. At 90 mL x min(-1) x (1.73 m(2))(-1) and 75 mL x min(-1) x (1.73 m(2))(-1) cut-points, diagnostic efficiencies of cystatin C (89% and 92%) were better than those of the other variables (79%-82% and 85%-86%, respectively; P = 0.01).
All data supported the value of serum cystatin C compared with conventional estimates based on serum creatinine measurement for detecting very early reduction of renal function. Use of cystatin C to measure renal function will optimize early detection, prevention, and treatment strategies for diabetic nephropathy.
早期识别肾功能损害对糖尿病患者至关重要。血清胱抑素C可能是临床环境中肾小球滤过率（GFR）最敏感的指标。
我们比较了胱抑素C与肌酐、Cockcroft-Gault（C-G）公式以及肾脏病饮食改良（MDRD）研究方程，以评估288例肾功能损害的糖尿病患者（125例1型，163例2型）[GFR：4 - 222 mL×min⁻¹×(1.73 m²)⁻¹]早期肾功能下降情况。通过在简单回归模型中绘制胱抑素C、肌酐和碘海醇清除率的倒数，使其关系线性化。从ROC曲线计算诊断效率。
在该研究人群中，胱抑素C（P = 0.0013）与GFR的相关性（r = 0.857）优于肌酐（r = 0.772）、C-G（r = 0.750）和MDRD（r = 0.806），在肾功能正常的患者中也得到了类似结果（1型糖尿病患者P = 0.023；2型糖尿病患者P = 0.011），但在GFR降低的患者中未得到类似结果。随着GFR降低，平均胱抑素C浓度呈现逐步的统计学显著升高，从而能够非常早期地检测到肾功能下降。在90 mL×min⁻¹×(1.73 m²)⁻¹和75 mL×min⁻¹×(1.73 m²)⁻¹的切点处，胱抑素C的诊断效率（分别为89%和92%）优于其他变量（分别为79% - 82%和85% - 86%；P = 0.01）。
所有数据均支持血清胱抑素C相较于基于血清肌酐测量的传统评估方法在检测肾功能极早期下降方面的价值。使用胱抑素C来测量肾功能将优化糖尿病肾病的早期检测、预防和治疗策略。
