Vascular endothelial dysfunction in renal replacement therapy modalities

Introduction: Vascular endothelial dysfunction (VED) is an important cause of cardiovascular morbidity and mortality in end-stage renal disease (ESRD). Endothelin-1 (ET-1) and nitric oxide (NO) are vasoactive substances that are affected in ESRD. Objectives: The study aimed to compare serum ET-1 and NO levels in renal transplant recipients (RTx group) and patients receiving hemodialysis (HD group), online-hemodiafiltration (HDF group), and peritoneal dialysis (PD group). Material and Methods: Forty-one patients and 25 healthy children were enrolled in the study. Serum ET-1 and NO levels were measured by ELISA in all patients and controls. Intradialytic symptoms and ambulatory blood pressure monitoring were evaluated in HD and HDF groups. Results: When each patient group was compared with the control group separately NO and ET-1 levels were higher in patients groups (p=0.0001). Median ET-1 levels were significantly lower in the RTx group than in the HDF group (p=0.02) whereas they were not different than in the PD and HD groups (343.555ng/l, 593.717ng/l, 546.343ng/l, and 589.944ng/l; respectively). RTx group had the lowest level of serum ET-1 and NO comparing the PD and HD/HDF groups although the difference did not reach statistical significance. The median serum NO level was not different between the HD, HDF, PD, and RTx groups (590.237limol/l, 563.084limol/l, 582 .433limol/l, 438.268limol/l; respectively). ET-1 levels were negatively correlated to eGFR, hemoglobin, and serum calcium levels, and positively correlated to PTH levels. Conclusions: Our results suggest that VED continues in patients receiving different modalities of renal replacement therapy. We concluded that renal transplantation is superior to other treatment modalities since the RTx group had the lowest levels of ET-1 and NO.