Cystatin C versus creatinine-based GFR formula in CKD patients

Introduction. Glomerular Filtration Rate (GFR) is the main tool to assess kidney function. Some experts suggest cystatin C as a more precise and accurate indicator than creatinine to calculate GFR. This study is designed to assess if cystatin C is more helpful in early diagnosis and better follow-up of Chronic Kidney Disease (CKD) patients who may benefit more from appropriate and timely management. Methods. We studied 312 patients in different stages of CKD and normal kidney function as control. GFR based on creatinine (Jaffe and enzymatic) and cystatin C were calculated and compared. Results. A total of 146(46.8%) patients were male with a mean age of 53±17.5 years. The patients were divided into 3 groups based on GFR (>60 cc/min/1.73m, 30< GFR<60cc/min/1.73m, 15<GFR<30cc/min/1.73m). No significant differences in GFR estimation based on creatinine and cystatin C were found. Conclusions. There were no significant differences between serum cystatin C-based formula and creatininebased formula for GFR calculation. Therefore, they can be used interchangeably.