Background: Pulse wave velocity (PWV) is a marker of arterial stiffness. Data from general population and end-stage renal disease patients suggest that PWV increases with age by about 0.1 m/s for each year of life and that PWV increase is steeper after the fifth decade. Recent follow-up studies showed decrease of arterial stiffness during the first year after kidney transplantation (KTx). This study aimed to investigate PWV change in kidney transplant recipients (KTR) during long-term follow-up.
Material/Methods: Carotid-femoral PWV was measured at baseline (PWV1) and then after at least 24 months (range 24–34, mean ±SD 28±3) of follow-up (PWV2) in 61 KTR aged 46±12 years. Baseline PWV measurements were performed at 36±27 months (range 4–121) after KTx. Clinical and laboratory data were also analyzed. GFR was calculated with MDRD formula (eGFR). ∆PWV was calculated as (PWV2-PWV1)/PWV1.
Results: Significant increase in PWV (9.1±1.7 vs. 9.8±2.0; p<0.002) and pulse pressure (PP) (50±11 vs. 53±14; p<0.05) was found during follow-up, but systolic, diastolic and mean arterial pressure did not change. eGFR did not change during follow-up (55±16 vs. 56±16 ml/min/1.73 m2). PWV increase was observed in patients aged ≥50 years (9.8±1.8 vs. 10.8±1.9; p<0.01), while not in younger patients (8.5±1.5 vs. 8.9±1.5; p=0.14). Significant positive correlation was found between ∆PWV and duration of the follow-up period.
Conclusions: The study revealed progressive arterial stiffening in kidney transplant recipients during long-term follow-up. Further studies are necessary to explain the pathophysiology of this phenomenon.

Keywords: pulse wave velocity, kidney transplant recipients, graft function, arterial stiffness