The effects of renal replacement therapy on plasma, asymmetric dimethylarginine, nitric oxide and C-reactive protein levels

Asymmetric dimethylarginine (ADMA), nitric oxide (NOx), and C-reactive protein (CRP) are important risk factors for endothelial dysfunction and mortality in the end stage renal diseases population. The aim of the study was to investigate the relationship between renal replacement therapy and endothelial dysfunction. Plasma NOx, ADMA and CRP levels were examined in randomized selected 30 patients with chronic kidney diseases (CKD), 28 patients receiving continuous ambulatory peritoneal dialysis (PD) and 30 patients receiving regular hemodialysis (HD) and age-matched 20 healthy controls. The duration of dialysis was from 4, 5 to 11, and 6 years, respectively. CKD patients had higher plasma ADMA (1.26+/-0.53 micromol/L) and CRP levels (1.02+/-025 mg/L) and lower NOx levels (28.6+/-5.4 micromol/L) than controls (0.45+/-0.20; 0.65+/- 0.45; 32.5+/-37 respectively, P < 0.001). Plasma NOx and CRP levels were higher in HD patients (32.9+/-5.5 micromol/L, P < 0.05 and 4.59+/-3.18 mg/L, P < 0.001) and plasma ADMA and CRP levels were higher in PD patients (1.82+/-0.98 micromol/L, P < 0.001 and 2.40+/-1.53 mg/L, P < 0.001) than in CKD patients. PD patients had higher plasma ADMA levels (P < 0.05) and lower plasma NOx and CRP levels than HD patients (P < 0.001 and P < 0.001). Plasma ADMA levels were negatively correlated with NOx levels in all patient groups (P < 0.001). Plasma CRP levels in CKD and HD patients were positively correlated with plasma urea levels (r:0,437, P < 0,001) and duration of dialysis (r:0,370, P < 0.01), respectively. CRP and ADMA may be emerging as important risk factors for atherosclerosis in dialysis patients. Reduced NO elaboration secondary to accumulation of ADMA and elevated inflammation may be important pathogenic factors for endothelial dysfunction in both dialysis treatment strategies.