Relationship of serum cystatin C with C-reactive protein and apolipoprotein A1 in patients on hemodialysis

Cystatin C is considered an indicator of acute renal failure and also a risk factor of cardiovascular disease. This study was undertaken to examine the relationship of serum cystatin C with C-reactive protein (CRP), lipids, and lipid-related compounds in patients on hemodialysis (HD). Cystatin C, CRP, total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, and apolipoprotein A1 and B were analyzed in serum of 30 patients on HD for 118 +/- 18 months with low-flux dialyzers, before and after HD. The results were compared with those obtained by 21 healthy individuals (NC). Multiple regression analysis was performed to evaluate the association of cystatin C concentration before HD with clinical and laboratory parameters. The results showed that cystatin C before HD was not associated with age, body mass index (BMI), or duration of HD. However, it was significantly correlated with creatinine (r = 0.435, p = 0.021) and albumin (r = 0.483, p = 0.009) concentrations. Moreover, a highly significant association was shown with logCRP (r = 0.692, p < 0.0001). Among the lipid and lipid-related compounds studied, a significant correlation was found between cystatin C and apolipoprotein A1 concentrations (r = 0.402, p = 0.034). None of those correlations were observed in the NC group. In conclusion, it seems that cystatin C levels before HD are related with CRP, an important inflammatory factor, and also with apolipoprotein A1, which has been proved to accelerate the atherosclerosis process. However more studies are needed to confirm these findings.