Overestimation of Glomerular Filtration Rate Calculated from Creatinine As Compared with Cystatin C in Patients with Type 2 Diabetes Receiving Sodium-glucose Cotransportor 2 Inhibitors

Aim: The aim of this cross-sectional study is to compare creatinine-based estimated glomerular filtration rate (eGFRcr) and cystatin C-based estimated glomerular filtration rate (eGFRcys) between patients with type 2 diabetes receiving and not receiving sodium-glucose cotransporter 2 (SGLT2) inhibitors.

Methods: The plasma specimens from 90 patients with type 2 diabetes who had been receiving SGLT2 inhibitors for at least 24 weeks (SGLT2 inhibitors group) were selected. Meanwhile, the plasma specimens from age-, sex- and BMI-matched patients with type 2 diabetes not receiving SGLT2 inhibitors (non-SGLT2 inhibitors group) in 1:1 matching were also selected for comparison. eGFRcr and eGFRcys were calculated using the Chronic Kidney Disease Epidemiology Collaboration equation.

Results: When compared with the non-SGLT2 inhibitors group, eGFRcr was significantly higher in the SGLT2 inhibitors group (70.54 ± 24.87 vs. 79.95 ± 19.57 mL/min/1.73 m , p = 0.014) while eGFRcys was not different (66.32 ± 24.98 vs 69.17 ± 20.10 ml/min/1.73 m , p = 0.401). Based on eGFRcr, the chronic kidney disease (CKD) stage in the SGLT2 inhibitors group was lower than that in the non-SGLT2 inhibitors group, but it was not different when CKD stage was classified by eGFRcys. The difference between eGFRcr and eGFRcys (eGFRcr-cys) was significantly higher in the SGLT2 inhibitors group (4.22 ± 11.20 vs. 10.78 ± 10.42 ml/min/1.73 m , p < 0.001). In male patients, there was significant correlation between the eGFRcr-cys and duration of receiving SGLT-2 inhibitors (r = 0.398, p = 0.004). This correlation was not found in female patients.

Conclusions: There was a discrepancy between eGFRcr and eGFRcys in patients with type 2 diabetes receiving SGLT2 inhibitors when compared with those not receiving SGLT2 inhibitors.