DOI: 10.36347/sajb.2015.v03i04.002

Pages: 328-334

Chronic Kidney Disease (CKD) is a worldwide public health problem, both for the number of patients and cost of treatment involved. Creatinine is the most widely used biomarker of kidney function. It is inaccurate at detecting mild renal impairment. cystatin C, a non-glycosylated 13 kDa protein, has the potential to improve estimates of glomerular filtration rate (GFR) because it isless influenced by muscle mass or age unlike creatinine. 40 known patients of CKD attending nephrology unit of medicine at PGIMS, Rohtak were enrolled as cases for this hospital based cross-sectional study, 40 age and sex matched healthy subjects were taken as controls. Both the cases and controls were analyzed for serum creatinine, cystatin C and urine creatinine. Estimated glomerular filtration rate (eGFR) was calculated from MDRD equation along with creatinine clearance using standard formula. Serum Cystatin C increased with stage wise progression of CKD with mean level of 2.31 ± 0.97mg/L (stage III), 2.80 ± 0.55 mg/L (stage IV), 3.01 ± 0.81 mg/L (stage V) in comparison to controls (0.68±0.17 mg/L). Serum creatinine was also increased with stage wise progression in CKD with mean level of 1.7 ± 0.19 mg/dL (stage III), 2.72± 0.58 mg/dL (stage IV), 7.66 ± 2.33 mg/dL (stage V) in comparison to controls (0.84± 0.15 mg/dL).Serum Cystatin C (r= - 0.877; CI: 1.44 to 1.96; p=0.000) has shown more significant Pearson correlation with eGFR than serum creatinine (r= - 0.777; CI: 1.88 to 3.06; p=0.000). Cystatin C has small variability and is unaffected by preanalytic factors such as routine clinical storage conditions, freezing and thawing cycles, or interfering substances, such as bilirubin or triglycerides. Thus, it may be better to use cystatin C for staging of CKD than indirect measurement of eGFR with serum creatinine based equations.