Hongwei Si, Chunlei Han, Zhili Lei, Zhifang Wu, Sijin Li, Mingming Wang
Department of Nuclear Medicine, the First Affiliated Hospital of Shanxi Medical University , Taiyuan, Shanxi Province , China.
Scand J Clin Lab Invest. 2015 Sep;75(5):415-20. doi: 10.3109/00365513.2015.1033741. Epub 2015 Apr 15.
Using a best variable to scale glomerular filtration rate (GFR) is important for clinical practice. The variables, estimated by equations regressed from a healthy population, are usually used in scaling GFR of renal patients. However, because the predicted variables may deviate in renal patients, it is necessary to verify whether these variables can be used to reduce the variability of GFR of renal patients. This study was designed to use repeated measures analyses to identify the best variable for scaling GFR of renal patients.
Patients with non-obstructive renal diseases were enrolled in this study. The absolute GFRs of (99m)Tc-DTPA renography (gGFR) and plasma clearance (pGFR) were measured. The indices relating to between-subjects variability, such as Passing and Bablok regression, intraclass correlation coefficient (ICC) and concordance correlation coefficient (CCC) were used to identify the best variable from body surface area (BSA), extracellular fluid volume (ECV), lean body mass (LBM), total body water (TBW), body mass index (BMI), and metabolic rate (MR).
For the scaled indices related to between-subjects variability, ICC and CCC identified the same ranking sequence (BMI < LBMB(B; Boer) < LBMJ(J; James) < TBW < ECVB(B; Bird) < ECVS(S; Silva) < BSA < MR). In the Passing and Bablok regression, the ratio of residual standard deviation to pooled standard deviation (RSD/PSD) produced the same ranking sequence as that identified by ICC and CCC.
The estimated metabolic rate can explain most between-subjects variability of GFR, and seems to be the best variable for scaling GFR of renal patients.
使用最佳变量来标化肾小球滤过率（GFR）对临床实践很重要。通过对健康人群进行回归方程估算得到的变量通常用于标化肾病患者的GFR。然而，由于预测变量在肾病患者中可能会出现偏差，因此有必要验证这些变量是否可用于降低肾病患者GFR的变异性。本研究旨在使用重复测量分析来确定标化肾病患者GFR的最佳变量。
本研究纳入了非梗阻性肾病患者。测量了（99m）Tc-DTPA肾动态显像的绝对GFR（gGFR）和血浆清除率（pGFR）。使用与受试者间变异性相关的指标，如Passing和Bablok回归、组内相关系数（ICC）和一致性相关系数（CCC），从体表面积（BSA）、细胞外液量（ECV）、瘦体重（LBM）、总体水（TBW）、体重指数（BMI）和代谢率（MR）中确定最佳变量。
对于与受试者间变异性相关的标化指标，ICC和CCC确定了相同的排序顺序（BMI < LBMB（B；Boer）< LBMJ（J；James）< TBW < ECVB（B；Bird）< ECVS（S；Silva）< BSA < MR）。在Passing和Bablok回归中，残余标准差与合并标准差的比值（RSD/PSD）产生了与ICC和CCC确定的相同排序顺序。
估算的代谢率可以解释GFR在受试者间的大部分变异性，似乎是标化肾病患者GFR的最佳变量。
