Font_2009_Nefrologia_29_228

Cystatin C is a marker of renal function and a major cardiovascular risk factor. In the general population, cystatin C appears to be influenced by factors other than renal function alone. However, information for serum cystatin C levels in chronic kidney disease (CKD) is lacking. Methods: We studied 52 nondiabetic patients (38 men, mean age 49 years) with CKD stage 3 (22), 4 (25) or 5 (5) who had measurements of serum cystatin C levels, estimated glomerular filtration rate (MDRD), inflammatory (C-reactive protein, interleukin-6 and fibrinogen), and oxidative markers (anti-oxidized LDL antibodies, serum paraoxonase-1 activity and concentration), left ventricular mass index by echocardiography and other cardiovascular risk factors. Results: Mean cystatin C levels were 2.35 +/- 0.9 mg/l. Cystatin C was positively correlated with creatinine serum levels, estimated glomerular filtration rate, PTH levels and negatively with anti-oxidized LDL antibodies. On the other hand, cystatin C was not related to inflammatory markers, serum paraoxonase-1 activity and concentration, proteinuria, HDL or LDL cholesterol, serum triglycerides, left ventricular mass index or demographic factors such as age, body mass index and blood pressure. After adjustment for PTH levels and anti- oxidized LDL antibodies, only estimated glomerular filtration rate was independently related serum cystatin C levels (beta = -0.500, p = 0.001). Conclusion: In nondiabetic patients with CKD, cystatin C is closely related to the degree of renal dysfunction. In contrast, inflammatory state, oxidative stress, left ventricular mass index and other cardiovascular risk factors are not related to cystatin C levels in this population.