Correlation of eGFR values estimated by different equations based on creatinine and cystatin-C in patients on hemodialysis treatment at Teaching Hospital Karapitiya, Galle, Sri Lanka

The present study was to compare eGFR values estimated from different equations based on creatinine and cystatin-C in patients on hemodialysis treatment. eGFR values were calculated using Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology equations based on Creatinine (CKD-EPI_Cr) and cystatin-C values alone (CKDEPI _{Cys C}) and by their combination (CKD-EPI_{Cr-Cys C}), using 40 pre-dialysis samples. No significant differences in renal function parameters and eGFR were observed, either between male (55%) and female (45%) patients or within different age groups (p>0.05). Certain levels of agreement (p>0.05) were observed between the equations, except for the values derived from CKD-EPI_{Cys C} and CKD-EPI_{Cr-Cys C} (p = 0.022). Significant positive correlations were observed between all selected equations. The highest correlation was observed between CKD-EPICr and MDRD (r = 0.998, p = 0.000), whereas the lowest correlation was found between MDRD and CKD-EPI_{Cys C} (r = 0.552, p = 0.000). The present findings revealed that MDRD and CKD-EPI_Cr equations are suitable for the calculation of eGFR in routine local clinical settings for the assessment of progression of kidney impairment in patients with CKD on hemodialysis treatment. However, the use of CKD-EPI_{Cr-Cys C} rather than the CKD-EPI_{Cys C} is recommended as a confirmatory tool where necessary.