Endothelial function is more impaired in hemodialysis patients than renal transplant recipients

Endothelial dysfunction (ED) is a common precursor and denominator of cardiovascular events including development of atherosclerosis. In this cross-sectional, controlled study, we aimed to investigate ED measured by ischemia-induced forearm vasodilatation in chronic hemodialysis (HD) patients and renal transplant recipients (rTX).

Thirty-nine HD patients, 39 rTX and 38 normotensive healthy controls were included. There was no difference in age and gender distribution among the study groups. The mean time spent on dialysis and transplantation were 74 +/- 46 and 68 +/- 39 months. Serum high sensitive C-reactive protein (hs-CRP) and plasma fibrinogen levels were measured. Endothelium dependent post-ischemic vasodilatation of brachial artery was used to evaluate ED.

The hs-CRP and plasma fibrinogen levels were significantly increased in HD patients when compared with rTX. On high resolution ultrasonographic examination, post-ischemic vasodilatation values in HD patients (9.55 +/- 6.47%) were significantly lower than rTX (14.39 +/- 8.06%, p = 0.007) and controls (20.42 +/- 6.10%, p < 0.001). Renal transplant recipients also had significantly lower post-ischemic vasodilatation values than controls (p = 0.001). The hs-CRP levels were negatively correlated with endothelium-dependent dilatations in TX (r = -0.59, p = 0.001), however, this correlation was not detected in HDp.

Patients with end-stage renal disease have ED. Endothelial function is more impaired in HD patients than rTX. Different mechanisms might be responsible for ED in HD patients and rTX.