Application of glomerular filtration rate estimation equations in elderly patients with chronic kidney disease over 60 years old / 中华肾脏病杂志

ABSTRACT

Objective:To compare the advantages and disadvantages of several formulas for estimated glomerular filtration rate (eGFR) based on serum creatinine in elderly patients with chronic kidney disease (CKD) over 60 years old.Methods:CKD patients aged≥60 years old in Beijing Hospital from January 2012 to October 2017 were selected as subjects. Measured glomerular filtration rate (mGFR) was detected by 99mTc-DTPA renal dynamic imaging and used as a reference standard. According to the mGFR value, the patients were divided into 4 groups: mGFR<30 ml·min -1·(1.73 m 2) -1 group, 30≤mGFR<45 ml·min -1·(1.73 m 2) -1 group, 45≤mGFR<60 ml·min -1·(1.73 m 2) -1 group and mGFR≥60 ml·min -1·(1.73 m 2) -1 group. The deviation of each formula was compared by Bland-Altman scatter chart, and the accuracy of each formula was evaluated by the proportion of eGFR within mGFR (1±30%) ( P30) and root mean square error ( RMSE). Wilcoxon paired rank sum test was used to compare the deviation of each formula, and McNemar test was used to compare the difference of P30 among these formulas. Results:A total of 628 patients with CKD were enrolled in this study. The median age was 76.0(71.0, 81.0) years old. The median serum creatinine and mGFR were 110.0(86.0, 152.0) μmol/L and 42.90(29.88, 55.68) ml·min -1·(1.73 m 2) -1, respectively. Each eGFR formula based on serum creatinine overestimated glomerular filtration rate in varying degrees. Among them, the accuracy of Berlin Initiative Study (BIS) formula and full age spectrum (FAS) formula was the best ( P30 were 68.3% and 68.0% respectively), followed by the Chinese race coefficient of Chronic Kidney Disease Epidemiology Collaboration (C-CKD-EPI) formula ( P30 was 65.4%). The accuracy of the other formulas was poor. In terms of deviation, C-CKD-EPI formula was the best (0.27). In the group of mGFR<30 ml·min -1·(1.73 m 2) -1, the accuracy of all formulas was poor, and the accuracy of FAS formula was slightly better than that of other formulas ( P30 was 51.0%). In the group of 30≤mGFR<45 ml·min -1·(1.73 m 2) -1, the deviation of C-CKD-EPI formula was the smallest (3.11). In terms of accuracy, BIS and FAS formulas were better than others, and the P30 were 64.6% and 63.0% respectively. In the group of 45≤mGFR<60 ml·min -1·(1.73 m 2) -1, the deviation of C-CKD-EPI formula was also the smallest (0.72), and the accuracy of BIS formula was the best ( P30 was 82.5%), followed by FAS formula ( P30 was 79.7%). In the group of mGFR≥60 ml·min -1·(1.73 m 2) -1, the deviation and accuracy of Xiangya formula were the best (the deviation and P30 were -0.53 and 96.5% respectively), and the P30 of BIS and C-CKD-EPI formulas were 87.6% and 87.6%, respectively. Conclusions:In the elderly patients with CKD over 60 years old, the accuracy of eGFR based on serum creatinine increases with the increase of mGFR. BIS and FAS formulas are recommended first. The accuracy of each formula is poor in patients with severe renal insufficiency.