Rigalleau V, Beauvieux M-C, Le Moigne F, Lasseur C, Chauveau P, Raffaitin C, Perlemoine C, Barthe N, Combe C, Gin H
Nutrition-diabétologie, hôpital Haut-Lévêque, avenue de Magellan, 33600 Pessac, France; Université de Bordeaux-II Victor-Segalen, 33000 Bordeaux, France.
Diabetes Metab. 2008 Nov;34(5):482-9. doi: 10.1016/j.diabet.2008.03.004. Epub 2008 Aug 13.
Estimation of glomerular filtration rate (GFR) is recommended to diagnose and stratify chronic kidney disease (CKD). Can cystatin-C (cysC) assay improve the results in diabetic patients?
In 124 diabetic patients with a wide range of GFR, as determined by 51Cr-EDTA clearance (i-GFR), we estimated 'e-GFR' by: the recommended Cockcroft-Gault (CG) formula and Modification of Diet in Renal Disease (MDRD) study equation; the new Mayo Clinic quadratic (MCQ) equation; the recently proposed composite estimation including both serum creatinine and cysC; and a simplified approach dividing the MDRD by cysC if less than 1.10mg/L.
The highest diagnostic accuracy (receiver operating characteristic [ROC] curves) and the highest proportions of well-stratified patients were obtained by cysC and the MDRD which, however, underestimated i-GFR for patients without CKD (-17%, P<0.001). The CG overestimated GFR in KDOQI stages 1 and 2, ignored stage 5 and was the least accurate. The MCQ equation overrepresented stage 2, overestimating GFR at this stage (+23%, P<0.005). The composite estimation (54.7+/-27.0mL per minute 1.73m(2)) correlated best with i-GFR (56.1+/-35.3; r=0.90, P<0.001), and did not significantly differ from it across the entire population and within each Kidney Disease Outcome Quality Initiative (KDOQI) stage but was also biased (Bland-Altman procedure). Simply dividing the MDRD by cysC ifless than1.10mg/L produced a comparable performance and eliminated the bias.
The recommended creatinine-based estimations of GFR need to be improved. CysC assay helps in the diagnosis and stratification of CKD and leads to better estimates of GFR in diabetic patients without any substantial increase in complexity.
推荐估算肾小球滤过率（GFR）以诊断慢性肾脏病（CKD）并对其进行分层。胱抑素C（cysC）检测能否改善糖尿病患者的检测结果？
在124例GFR范围广泛的糖尿病患者中，通过51Cr-EDTA清除率（i-GFR）测定GFR，我们通过以下方法估算“e-GFR”：推荐的Cockcroft-Gault（CG）公式和肾脏病饮食改良（MDRD）研究方程；新的梅奥诊所二次方程（MCQ）；最近提出的包括血清肌酐和cysC的综合估算方法；以及一种简化方法，即当cysC小于1.10mg/L时，用MDRD除以cysC。
cysC和MDRD获得了最高的诊断准确性（受试者工作特征[ROC]曲线）和最高比例的分层良好的患者，然而，对于无CKD的患者，它们低估了i-GFR（-17%，P<0.001）。CG在KDOQI 1期和2期高估了GFR，忽略了5期，且准确性最低。MCQ方程在2期表现过度，在该阶段高估了GFR（+23%，P<0.005）。综合估算（每分钟54.7±27.0mL/1.73m²）与i-GFR相关性最佳（56.1±35.3；r=0.90，P<0.001），在整个人群以及每个肾脏病预后质量倡议（KDOQI）阶段内与i-GFR无显著差异，但也存在偏差（Bland-Altman法）。当cysC小于1.10mg/L时，简单地用MDRD除以cysC产生了可比的性能并消除了偏差。
推荐的基于肌酐的GFR估算方法需要改进。CysC检测有助于CKD的诊断和分层，并能在不显著增加复杂性的情况下更好地估算糖尿病患者的GFR。
