Optimal assessment of the glomerular filtration rate in older chinese patients using the equations of the Berlin Initiative Study

Aim To evaluate the performances of the various estimated glomerular filtration rate (eGFR) equations of the Chronic Kidney Disease Epidemiology Collaboration, the Berlin Initiative Study (BIS), and the Full Age Spectrum (FAS) in older Chinese. Methods This study enrolled Chinese adults aged ≥ 65 years who underwent GFR measurements (via 99Tcm-DTPA renal dynamic imaging) in our hospital from 2011 to 2022. Using the measured glomerular filtration rate (mGFR) as the reference, we derived the bias, precision, accuracy, and consistency of each equation. Results We enrolled 519 participants, comprising 155 with mGFR ≥ 60 mL/min/1.73 m 2 and 364 with mGFR < 60 mL/min/1.73 m 2 . In the total patients, the BIS equation based on creatinine and cystatin C (BIScr-cys) exhibited the lowest bias [median (95% confidence interval): 1.61 (0.77–2.18)], highest precision [interquartile range 11.82 (10.32–13.70)], highest accuracy (P30: 81.12%), and best consistency (95% limit of agreement: 101.5 mL/min/1.73 m 2 ). In the mGFR ≥ 60 mL/min/1.73 m 2 subgroup, the BIScr-cys and FAS equation based on creatinine and cystatin C (FAScr-cys) performed better than the other equations; in the mGFR < 60 mL/min/1.73 m 2 subgroup, all equations exhibited relatively large deviations from the mGFR. Of all eight equations, the BIScr-cys performed the best. Conclusions Although no equation was fully accurate in the mGFR < 60 mL/min/1.73 m 2 subgroup, the BIScr-cys (of the eight equations) assessed the eGFRs of the entire population best. A new equation is urgently required for older Chinese and even East Asians, especially those with moderate-to-severe renal insufficiency.