Sakaguchi Satsuki, Tanaka Atsuo, Kawanishi Tomoko, Tanaka Anzu, Koshikawa Masao, Kuwahara Takashi
Derpartment of Nephrology, Saiseikai Nakatsu Hospital, Osaka, Japan.
Nihon Jinzo Gakkai Shi. 2008;50(8):1011-6.
Glomerular filtration rate(GFR) can be estimated from serum (s-) creatinine using the modification of diet in renal disease (MDRD). However, its calculation is sometimes cumbersome in clinical use. Cystatin C is less influenced by age, gender and muscle mass than serum creatinine, and it has been proposed as an alternative marker for estimating GFR (eGFR). The comparison of s-cystatin C with MDRD-eGFR from 245 Japanese outpatients with chronic kidney disease (CKD)resulted in the equation of eGFR = 82.8/s-cystatin C - 10.7 (r = 0.85, n = 245). Based on this equation, there were 22 patients above + SD, which was the high-group in which s-cystatin C levels were higher than the corresponding eGFR, and there were 21 patients below -SD, which was the low-group in which s-cystatin C levels were lower than the corresponding eGER. Between the two groups there was no significant difference in age, gender, weight, and body mass index. The high-group included 1 case of hyperthyroidism and 7 cases of steroid user. The low-group included 4 cases of hypothyroidism and 1 case of steroid user. In healthy individuals, MDRD-eGFR is unsuitable for estimating GFR. Thyroid dysfunction or glucocorticoid excess are known to influence s-cystatin C levels. An improved eGFR equation was provided from 144 cases excluding 88 with normal renal function (eGFR > 90 mL/min/1.73 m2), 5 with thyroid dysfunction and 8 steroid users. eGFR = 86.1/s-cystatin C - 13.6 (r = 0.94, n = 144). Each GFR estimation provided from males or from females yielded nearly the same results as this equation. The prediction of eGFR using s-cystatin C may be convenient and useful in clinical practice, and the comparison of s-cystatin C with creatinine-based eGFR may reveal some factors that affect s-cystatin C or s-creatinine levels independent of GFR.
肾小球滤过率（GFR）可通过肾病饮食改良法（MDRD）根据血清（s-）肌酐进行估算。然而，其计算在临床应用中有时较为繁琐。与血清肌酐相比，胱抑素C受年龄、性别和肌肉量的影响较小，有人提出将其作为估算GFR（eGFR）的替代标志物。对245例日本慢性肾脏病（CKD）门诊患者的s-胱抑素C与MDRD-eGFR进行比较，得出eGFR = 82.8/s-胱抑素C - 10.7的方程（r = 0.85，n = 245）。基于该方程，有22例患者高于+标准差，为高分组，即s-胱抑素C水平高于相应eGFR的组；有21例患者低于-标准差，为低分组，即s-胱抑素C水平低于相应eGER的组。两组在年龄、性别、体重和体重指数方面无显著差异。高分组包括1例甲状腺功能亢进症患者和7例使用类固醇的患者。低分组包括4例甲状腺功能减退症患者和1例使用类固醇的患者。在健康个体中，MDRD-eGFR不适用于估算GFR。已知甲状腺功能障碍或糖皮质激素过量会影响s-胱抑素C水平。从144例患者（排除88例肾功能正常者（eGFR > 90 mL/min/1.73 m2）、5例甲状腺功能障碍患者和8例使用类固醇的患者）中得出了一个改进的eGFR方程。eGFR = 86.1/s-胱抑素C - 13.6（r = 0.94，n = 144）。由男性或女性得出的每个GFR估算值与该方程得出的结果几乎相同。在临床实践中，使用s-胱抑素C预测eGFR可能方便且有用，并且将s-胱抑素C与基于肌酐的eGFR进行比较可能会揭示一些独立于GFR影响s-胱抑素C或s-肌酐水平的因素。
