A lower level of reduced albumin induces serious cardiovascular incidence among peritoneal dialysis patients

Human serum albumin is composed of human mercaptoalbumin (HMA) with cysteine residues having reducing powers and of oxidized human non-mercaptoalbumin. Previously, we reported that a lower HMA level is closely related to serious cardiovascular disease (CVD) incidence and mortality among hemodialysis patients. However, the relationship between HMA level and CVD incidence among peritoneal dialysis (PD) patients is unclear. We measured the redox state of human serum albumin using high-performance liquid chromatography in 30 continuous ambulatory PD patients. The association between HMA and incidental CVD events was evaluated. Eight patients experienced symptomatic CVD events (5 patients died) at the 5-year follow-up. The concentration and fraction of HMA (cHMA and f(HMA), respectively) showed significantly lower values in patients with CVD than those without CVD (cHMA 1.58 +/- A 0.39 and 2.16 +/- A 0.43 g/dL, f(HMA) 48.9 +/- A 5.4 and 56.4 +/- A 8.6%, respectively). Multiple forward stepwise regression analysis using cHMA and f(HMA) as the criterion variables was performed, and C-reactive protein and hemoglobin were adopted as significant explanatory variables in the former equation, whereas urea nitrogen was adopted in the latter equation. Multiple logistic regression analysis revealed that cHMA is a statistically, and f(HMA) is a marginally significant explanatory variable of CVD incidence (p = 0.0369, R = -0.260 and p = 0.0580, R = -0.214, respectively). Lower HMA level, which might be caused by chronic inflammation, anemia and accumulation of dialyzable uremic toxin(s), is closely related to serious CVD incidence among PD patients.