P Ravi Kumar
Aim
To study and compare the association between estimated GFR with cystatin-C and serum creatinine and the lipid profile in chronic kidney disease. Background Chronic kidney disease (CKD) is frequently complicated by the coexistence of cardiovascular (CV) events, making it essential to identify CV risk in CKD. Serum cystatin-C is an upcoming renal biomarker, which is used to measure estimated glomerular filtration rate (eGFR) by the CKD-EPI formula.
Methods This cross-sectional study, comprising of 120 CKD patients, attempted to determine, which of the two equations for estimating GFR, either by serum cystatin- C or by serum creatinine, is better related with lipid profile which is widely portrayed as a cardiovascular risk factor. The parameters evaluated included lipid profile, serum creatinine and serum cystatin-C among others. Staging was done by both the equations (MDRD equation by creatinine and CKD-EPI equation by cystatin-C) and compared, and both the eGFRs were correlated with the lipid profile. Results eGFR estimation by cystatin-C was found to relate inversely and significantly with lipid profile which included-TC, TG, LDL, VLDL (r = -0.19, -0.23, -0.18, -0.23; p < 0.05 respectively) and lipid ratios TC/HDL, LDL/HDL (r = -0.26, -0.24; p < 0.01 respectively). Lipid profile except HDL was found to correlate negatively and significantly with eGFR estimation by serum cystatin-C (p < 0.05). Lipid ratios- TC/HDL and LDL/ HDL were also found to correlate inversely and significantly (p < 0.01). However, eGFR using serum creatinine failed to offer a similar significant relation.
Conclusion Serum cystatin-C based eGFR was found to be better correlated with the lipid profile, when compared with eGFR estimation using serum creatinine. Hence, the correlation between cystatin-C based eGFR and lipids might indicate that this eGFR methodology may be a better marker of cardiovascular risk as lipids are a well-known traditional risk factor for cardiovascular disease.!
Keywords: Cystatin C, Renal insufficiency, Estimated glomerular filtration rate, MDRD equation, CKD-EPI equation, Cardio-renal disease, Cardiovascular risk, Lipid profile
