ABSTRACT
The limitations of serum creatinine as a marker of impairment in GFR have led to continuing search for a better marker. Most studies have shown that serum cystatin C may be a more sensitive indicator of glomerular filtration rate (GFR) than serum creatinine in the clinical setting. This study was designed to evaluate serum cystatin C,creatinineand estimated GFR (eGFR)in Chronic Kidney Disease (CKD) patients. One hundred and fourteen (114) CKD Patients (comprising 59 males and 55 females) attending Nephrology Clinic at ABUTH and apparently healthy age and sex matched controls were recruited for the study. Serum creatinine and cystatin C were assayed by the Jaffe kinetic and immunoturbidimetric methods respectively. Estimated GFR was calculated usingthe Cockcroft-Gault (C-G) formula. Serum creatinine, cystatin C and Estimated GFR (eGFR) in patients and controls were comparedusing the t-test. Relationships between serum cystatin C, creatinine and estimated GFR were analysed using the Pearson's correlation. In this study,serumcystatin C and creatinine were significantly higher(p<0.0001)and estimated GFR significantly lower (p<0.0001) in patients than the control subjects.Cystatin C was better correlated with Estimated GFR (r =-0.708;p<0.0001) than creatinine (r =-0.694;p<0.0001). Mean cystatin C concentration showed step-by-step statistically significant increase as GFR decreases, allowing very early detection of reduction in renal function. The findings from this study showed that serum cystatin C is a better marker compared with serum creatininein evaluating GFR particularly for detecting very early reduction of renal function. Use of cystatin C to assess renal function will optimize early detection,treatment and monitoring strategies forpatients with CKD.