Sanusi Abubakr A, Arogundade Fatiu A, Famurewa O C, Akintomide Anthony O, Soyinka Folashade O, Ojo Olalekan E, Akinsola Adewale
Renal Unit, Department of Medicine, Obafemi Awolowo University/Teaching Hospitals Complex, Ile-Ife, Nigeria.
Nephrol Dial Transplant. 2009 May;24(5):1690-4. doi: 10.1093/ndt/gfp055. Epub 2009 Mar 4.
Kidney length has traditionally been used as a predictor of chronic kidney disease (CKD); however, kidney volume (KV) rather than length has been emphasized by researchers as a true predictor of kidney size in states of good health and disease. Since KV can be assumed to be a predictor of kidney mass or remaining surviving nephrons in CKD patients, we theorized that the KV should reflect the functional capacity of the kidneys, i.e. the glomerular filtration rate (GFR).
Forty CKD patients were recruited and investigated. Measured GFR was determined by calculating the average of endogenous creatinine clearance (mCrCl) and urea clearance (mUrCl) while predicted GFR was determined using Cockcroft and Gault, Hull and Modification of Diet in Renal Disease (MDRD) equations. KV was assessed ultrasonographically using the formulae of Dinkel et al. and Solvig et al. for ellipsoid organ. The relationship between the KV and GFR was assessed using Spearman's correlation coefficient while Bland and Altman tests were used to assess intraobserver variation and agreement between measured and predicted GFR.
The results showed a weak but positive correlation between KV and various indices of GFR, best with measured CrCl (correlation coefficient ranged between 0.408 and 0.503; P < 0.05), and which was not improved after normalization for body surface area (BSA). We also found a significant correlation between the measured CrCl and various values of estimated CrCl.
Ultrasonographically determined KV was found to correlate with GFR and hence can be used to predict it in established CKD, particularly in resource-poor settings.
传统上，肾脏长度一直被用作慢性肾脏病（CKD）的预测指标；然而，研究人员强调，肾脏体积（KV）而非长度才是健康状态和疾病状态下肾脏大小的真正预测指标。由于可以假定KV是CKD患者肾脏质量或剩余存活肾单位的预测指标，我们推测KV应反映肾脏的功能能力，即肾小球滤过率（GFR）。
招募并研究了40例CKD患者。通过计算内生肌酐清除率（mCrCl）和尿素清除率（mUrCl）的平均值来确定实测GFR，而使用Cockcroft和Gault、Hull以及肾脏病饮食改良（MDRD）方程来确定预测GFR。使用Dinkel等人和Solvig等人针对椭球体器官的公式通过超声评估KV。使用Spearman相关系数评估KV与GFR之间的关系，同时使用Bland和Altman检验评估观察者内变异以及实测GFR与预测GFR之间的一致性。
结果显示KV与GFR的各种指标之间存在微弱但呈正相关，与实测CrCl的相关性最佳（相关系数在0.408至0.503之间；P<0.05），并且在根据体表面积（BSA）进行标准化后并未得到改善。我们还发现实测CrCl与估计CrCl的各种值之间存在显著相关性。
发现超声测定的KV与GFR相关，因此可用于预测已确诊的CKD患者的GFR，尤其是在资源匮乏地区。
