Introduction: Chronic kidney disease (CKD) is a risk factor for cardiovascular diseases leading to rapid progression of arteriosclerosis. After renal transplantation some of the traditional and CKD-specific risk factors disappear, however, new risk factors emerge, such as metabolic effects of immunosuppression therapy and new onset diabetes mellitus (NODAT). Arterial properties can be evaluated by measuring pulse wave velocity (PWV) and augmentation index (AI). The aim of the study was to define the long-term impact of renal transplantation on arterial stiffness. Another goal of the study was to evaluate effects of diabetes mellitus on PWV and AI.
Materials and Methods: The study was conducted on renal graft recipients, who had successful kidney transplantation in the years between 2011 and 2013. PWV and AI were evaluated noninvasively by applanation tonometry using SphygmoCor™ (AtCor Medical Pty. Ltd., Sydney, Australia) immediately after transplantation and four to five years thereafter. Clinical and biochemical data were obtained from the hospital's database.
Results and Discussion:  44 graft recipients (17 women, 27 men, age 49.1±11.5 years) were included in the study. The average follow-up period between the first and the second measurement was 55.7±6.9 months. PWV did not change significantly during the follow-up period (9.1±1.8m/s vs. 8.7±1.8m/s; p=0.137). PWV in the group of non-diabetic patients decreased in the follow-up period by 0.62±1.23 m/s, while it increased for 0.43±2.1m/s in the group of diabetic patients. However, the difference between the two was not significant (p=0.057). At the second measurement the difference in PWV between diabetic and nondiabetic patients was significant (10.2±1.8 vs. 8.3±1.23m/s; p=0.02). Duration of smoking before transplantation correlated significantly with PWV (p=0.012). AI in the whole group increased significantly (from 18.3±10.3% to 25.9±9.4%; p<0.01), whereas a significant difference in AI between diabetic and nondiabetic patients was not found.
Conclusion: PWV of the whole group did not change significantly during the follow-up period, possibly due to stabilization of the process of arteriosclerosis after renal transplantation. In the subgroup of patients without diabetes we observed a trend of PWV reduction, whereas in the subgroup of patients with diabetes we observed the opposite. Diabetes mellitus and duration of smoking before  transplantation are important risk factors for arteriosclerosis progression after renal transplantation.