Comparison of GFR estimation in patients with diabetes mellitus using the EKFC and CKD-EPI equations.

BACKGROUND

The estimation of glomerular filtration rate (eGFR) is essential in the early detection of diabetic nephropathy. We herein compare the performance of common eGFR formulas against a gold standard measurement of GFR in patients with diabetes mellitus.

METHODS

GFR was measured in 93 patients with diabetes mellitus using iohexol clearance as the reference standard. The performance of the creatinine- and cystatin C-based EKFC formulas (2021, 2023) and the CKD-EPI formulas (2009, 2012) was compared against measured GFR.

RESULTS

Sixty patients with type 2 diabetes mellitus and 33 patients with type 1 diabetes mellitus were included. The creatinine-based EKFC formula showed lower bias and higher accuracy than the CKD-EPI formula. No significant difference was observed between the cystatin C-based formulas. The combined creatinine- and cystatin C-based formulas had the highest accuracy and lowest bias. Body fat or diabetes type did not significantly influence the accuracy of the cystatin C-based formulas.

CONCLUSIONS

Our study demonstrated a slight advantage of the creatinine-based EKFC formula over the CKD-EPI formula in patients with diabetes. However, both for the CKD-EPI and the EKFC formula, the best performance was achieved by the combined creatinine- and cystatin C-based formulas.