INFLUENCE OF RENAL TRANSPLANTATION AND LIVING KIDNEY DONATION ON LARGE ARTERY STIFFNESS AND PERIPHERAL VASCULAR RESISTANCE

Abstract

Objective: Living kidney donation (LKD) is possibly associated with an increased cardiovascular risk while on the other hand vascular health following renal transplantation may improve. The objective of our study was to assess alterations in intermediate vascular risk factors among living donors as well as their renal transplant recipients. Design and method: In a prospective study we measured glomerular filtration rate (GFR, 51Chrome EDTA clearance), 24-hour ambulatory blood pressure (BP), pulse wave velocity (PWV, Spygmocor), central augmentation index (AIx) and in addition also forearm resting and minimal vascular resistance (Rrest and Rmin respectively) using classic venous occlusion plethysmography. The study population consisted of living kidney donors (n = 58, 45 ± 13 years, 46% males) and their corresponding renal transplant recipients who were willing to participate in the study (n = 51, 50 ± 12 years, 76% males). The investigations were performed before and one year after donation or transplantation. Results: After kidney donation GFR decreased by 33% to 65 ± 11 ml/min/1.73m2 while the transplant recipients obtained a GFR of 55 ± 9 ml/min/1.73m2. Twentyfour-hour mean BP (MAP) remained unchanged in donors but decreased by 5 mmHg in recipients (P < 0.05) despite reduction in antihypertensive medication. Carotid-femoral PWV increased significantly by 0.3 m/s in donors (P < 0.05) but remained unchanged in the recipients. AIx was unaltered after kidney donation but decreased by 3.5% following transplantation (P < 0.01). Rrest increased significantly after kidney donation (P < 0.05) but was unaffected by transplantation, while no changes were noticed in Rmin in either of the groups. Changes in PWV were directly related to changes in 24-hour MAP in both groups while this was only the case for AIx in recipients. Multiple linear regression analysis (adjusting for age, gender and the baseline value of the studied parameter) did not detect independent effects of the achieved graft function on 24-hour MAP, PWV, AIx or vascular resistance at one-year follow-up. However, in donors a low post-donation GFR was related to higher AIx and Rrest. Conclusions: Renal transplantation reduced AIx without affecting PWV although changes in both parameters were related to changes in 24-hour MAP. Despite an unchanged BP level, living kidney donation resulted in increased PVW and Rrest.