Increase in arterial stiffness in living kidney donors after renal donation

Objective: Low glomerular filtration rate (GFR) is associated with high cardiovascular mortality and morbidity. Living kidney donor’s vascular characteristics have been poorly investigated till now. In this analysis, living kidney donors were followed up with respect to vascular parameters for one year after renal donation. Design and method: Blood pressure (BP) and different arterial stiffness parameters were assessed before, 6 months and 1 year after renal donation using a 24-hour blood pressure device (Mobil-o-graph®). Cortical, medullary and total renal perfusion of the donors were assessed using Arterial Spin Labeling MRI before and 6 months after donation. Preimplantation biopsy of the donor kidney was obtained. Biopsies were scored for glomerulosclerosis, interstitial fibrosis, tubular atrophy, and arteriosclerosis, which was combined to a total renal chronicity score. Living donors with and without chronic renal histological changes were compared. Results: Twenty five living kidney donors with mean age of 54±9.4 were followed up for one year. The estimated GFR and urinary albumin creatinine ratio (UACR) were 87.7±15.9ml/min/1.73m2 and 19.5±18.4mg/g creatinine respectively at baseline. 12months after renal donation the eGFR was 55.6±10.9 ml/min/1.73 m2 and the UACR was 19.5±12.2mg/g creatinine. Pulse wave velocity (7.5±1.4 vs. 7.8±1.4;p=0.001), peripheral resistance (1.1±0.19 vs. 1.23±0.19;p=0.003), and augmentation index (heart rate corrected) (24.4±5.5 vs. 26.7±6.1;p=0.025) over 24 hours increased significantly 12months after donation, while no change has been noticed in systolic and diastolic BP. A relationship has been found between eGFR at baseline and mean 24-hour pulse wave velocity at 12months (r=-594, p=0.002). An increase in cortex perfusion was found 6 months after donation (351±53.4 vs. 88±40.7;p=0.013). The 24-hour systolic BP (116.6±6.8 vs. 129.1±10.7;p=0.011), -diastolic BP (73.2±4.4 vs. 81.3±5.6;p=0.006) and -central BP (118.6± 8.9 vs. 128.9±7.7;p=0.013) at 12 months post donation was significantly higher in donors with renal histological changes compared to donors without renal histological changes, while no difference in BP was noticed at baseline between thesegroups. Conclusions: Our data indicates that arterial stiffness increases after living kidney donation. This can be interpreted as an early change before increase in BP. Living donors with chronic renal histological changes tend to develop high BP after donation.