Clinical Chemistry. 2009;55:1932-1943

Background: Patients with chronic kidney disease (CKD) are at high risk for developing cardiovascular disease (CVD) and cardiovascular events. Cystatin C, a protease inhibitor synthesized in all nucleated cells, has been proposed as a replacement for serum creatinine for the assessment of renal function, particularly to detect small reductions in glomerular filtration rate.
Content: This report presents a review of the role of cystatin C as a predictor of cardiovascular risk.

Summary: Patients with higher circulating cystatin C concentrations appear to have an increased cardiovascular risk profile, i.e., they are older and have a higher prevalence of systemic hypertension, dyslipidemia, documented CVD, increased body mass index, and increased concentrations of C-reactive protein. Prospective studies have shown, in various clinical scenarios, that patients with increased cystatin C are at a higher risk of developing both CVD and CKD. Importantly, cystatin C appears to be a useful marker for identifying individuals at a higher risk for cardiovascular events among patients belonging to a relatively low-risk category as assessed by both creatinine and estimated glomerular filtration rate values. Of interest, elastolytic proteases and their inhibitors, in particular cystatin C, have been shown to be directly involved in the atherosclerotic process. Increased concentrations of cystatin C appear to be indicative of preclinical kidney disease associated with adverse outcomes. Clinical studies involving direct glomerular filtration rate measurements are required to ascertain both the true role of this promising marker in renal disease and whether atherogenic factors like inflammation can account for increases in cystatin C concentrations, thus explaining its predictive value in CVD.

Turk J Biochem, 2007; 32 (3) ; 95–103

Cystatin C, a low molecular weight inhibitor of cysteine proteases, is involved in various biological and pathological processes. Recently, serum cystatin C has been proposed to be a valuable alternative marker of glomerular filtration rate, particularly in situations in which creatinine fails to provide an accurate estimate of renal impairment. However, the use of cystatin C is interfered by nonrenal factors such as glucocorticoid therapy, malignancy or thyroid disorders, which influence serum cystatin C concentrations. The clinical utility of cystatin C as a renal marker is under evaluation. The standardisation of methods for cystatin C is necessary.