Arterial stiffness and blood pressure increase in pediatric kidney transplant recipients

Background Pulse wave velocity (PWV) is a measure of arterial stiffness. We investigated PWV and blood pressure (BP) to determine to what extent BP changes contribute to arterial stiffness, and secondly, to identify influencing factors on BP in children after kidney transplantation. Methods Seventy children >= 2.5 years post-transplantation with at least two PWV measurements were included. Changes of systolic (Delta SBP) and diastolic BP (Delta DBP) were classified into stable/decreasing, 1-10 mmHg increase, and > 10 mmHg increase. Linear mixed modeling for PWV z-score (PWVz) adjusted either for Delta SBP or Delta DBP was performed. An extended dataset with monthly entries of BP, immunosuppression, and creatinine was obtained in 35 participants over a median of 74 months to perform linear mixed modeling for SBP and DBP. Results PWVz increased with a rate of 0.11/year (95% CI 0.054 to 0.16). Compared to participants with stable BP, those with 1-10-mmHg SBP and DBP increase showed a higher PWVz of 0.59 (95% CI 0.046 to 1.13) and 0.86 (95% CI 0.43 to 1.30), respectively. A > 10-mmHg BP increase was associated with an even higher PWVz (SBP beta = 0.78, 95% CI 0.22 to 1.34; DBP beta = 1.37, 95% CI 0.80 to 1.94). Female sex and participants with lower eGFR showed higher PWVz. In the extended analysis, DBP was positively associated with cyclosporin A and everolimus trough levels. Conclusions A higher increase of PWV is seen in patients with greater BP increase, with higher cyclosporin A and everolimus trough levels associated with higher BP. This emphasizes the role of BP as a modifiable risk factor for the improvement of cardiovascular outcome after transplantation.

Automated summary

This study aimed to investigate the impact of blood pressure changes on arterial stiffness and the influencing factors on blood pressure in children after kidney transplantation. The results indicated that an increase in blood pressure was associated with an increase in pulse wave velocity (PWV), and female sex and lower estimated glomerular filtration rate (eGFR) were associated with higher PWV. Additionally, higher levels of cyclosporine A and everolimus in the blood were associated with increased blood pressure.