Delaney Michael P, Stevens Paul E, Al Hasani Mohammed, Stowe Helen J, Judge Caroline, Lamb Edmund J
Department of Renal Medicine, East Kent Hospitals NHS Trust, Kent and Canterbury Hospital, Canterbury, Kent, UK.
Am J Kidney Dis. 2008 Feb;51(2):278-84. doi: 10.1053/j.ajkd.2007.08.018.
Clinical management of peritoneal dialysis patients includes assessments of peritoneal and renal clearances of the low-molecular-weight endogenous solutes creatinine and urea. Cystatin C is a low-molecular-weight protein used as a glomerular filtration rate marker. We investigated whether serum cystatin C concentration is related to peritoneal and renal clearances of creatinine and urea.
Cross-sectional study.
SETTING & PARTICIPANTS: 119 patients undergoing peritoneal dialysis in a single dialysis unit.
Peritoneal, renal, and total clearance of urea as Kt/V(urea) and creatinine as weekly creatinine clearance (C(Cr)). Residual renal function (RRF) as the average of renal clearances of urea and creatinine.
OUTCOMES & MEASUREMENTS: Serum concentrations of cystatin C measured by using a particle-enhanced nephelometric immunoassay.
Serum cystatin C concentration was related inversely to RRF (Spearman rank correlation coefficient [r(s)] = -0.65; P < 0.001), total weekly C(Cr) (r(s) = -0.52; P < 0.001), and total Kt/V(urea) (r(s) = -0.23; P = 0.01). In a multiple regression model, weight, normalized protein catabolic rate, and RRF had independent effects on serum cystatin C concentrations. Additional multiple regression models showed that only the renal components of Kt/V(urea) and weekly C(Cr) contributed to serum cystatin C concentrations.
Absence of reference GFR method.
Serum cystatin C concentrations reflect predominantly renal, not peritoneal, clearance. Serum cystatin C measurement may be a simple and practical alternative to measurement of RRF.
腹膜透析患者的临床管理包括评估低分子量内源性溶质肌酐和尿素的腹膜清除率和肾脏清除率。胱抑素C是一种用作肾小球滤过率标志物的低分子量蛋白质。我们研究了血清胱抑素C浓度是否与肌酐和尿素的腹膜清除率及肾脏清除率相关。
横断面研究。
单个透析单元中119例接受腹膜透析的患者。
以尿素清除率（Kt/V(urea)）表示的尿素腹膜清除率、肾脏清除率及总清除率，以每周肌酐清除率（C(Cr)）表示的肌酐清除率。残余肾功能（RRF）为尿素和肌酐肾脏清除率的平均值。
采用颗粒增强散射比浊免疫分析法测量血清胱抑素C浓度。
血清胱抑素C浓度与RRF呈负相关（斯皮尔曼等级相关系数[r(s)] = -0.65；P < 0.001）、与每周总C(Cr)呈负相关（r(s) = -0.52；P < 0.001）、与总Kt/V(urea)呈负相关（r(s) = -0.23；P = 0.01）。在多元回归模型中，体重、标准化蛋白分解代谢率和RRF对血清胱抑素C浓度有独立影响。其他多元回归模型显示，只有Kt/V(urea)和每周C(Cr)的肾脏部分对血清胱抑素C浓度有影响。
缺乏参考肾小球滤过率方法。
血清胱抑素C浓度主要反映肾脏清除率，而非腹膜清除率。测量血清胱抑素C可能是一种简单实用的替代测量RRF的方法。
