CHU de Québec Research Center, Hotel-Dieu de Québec Hospital, Division of Nephrology, Université Laval, Québec, Québec City, Canada.
Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia.
J Hypertens. 2019 Jul;37(7):1521-1528. doi: 10.1097/HJH.0000000000002058.
In chronic kidney disease, the enhanced aortic stiffness increases risk of cardiovascular events. Kidney transplantation (KTx) may improve aortic stiffness; however, it is unclear whether the improvement of aortic stiffness is merely the outcome of the reduction of blood pressure (BP) post-KTx. Furthermore, the long-term trajectory of aortic stiffness remains uncertain, as activation of the immune system may have a negative long-term impact on arterial wall property.
Using aortic stiffness β0 as a BP-independent stiffness parameter, and a statistical adjustment for BP, we aimed to examine the early vs. late changes in aortic stiffness, and to define the characteristics of patients with favourable and unfavourable long-term trajectories of aortic stiffness. In this longitudinal study, aortic stiffness was assessed before, 3, 6 and 24 months after KTx in 79 individuals. Aortic stiffness was determined by carotid-femoral pulse wave velocity (cf-PWV), and aortic stiffness index β0 was obtained by applying the stiffness parameter β0 theory to cf-PWV based on Bramwell-Hill's equation using a reference pressure.
There was an early reduction of β0 3 months after KTx (29.0 ± 2.0 to 25.8 ± 1.2, P = 0.033) followed by a gradual increase at 6 (28.0 ± 1.4, P = 0.005 vs. 3 months) and 24 months (28.3 ± 1.3, P = 0.003 vs. 3 months). A late increase in β0 was associated with higher levels of the interleukin-6 (P = 0.029) even after adjustment for potential cofounders. Using statistical adjustments for BP showed similar results.
Reduction of aortic stiffness index β0 3 months after KTx suggests that KTx leads to an early de-stiffening of the intrinsic mechanical properties of aorta. However, this improvement is followed by a later stiffening, which is associated with increased interleukin-6, suggesting that activation of the immune system may be involved in arterial wall remodelling in kidney recipients.
在慢性肾脏病中，主动脉僵硬度增加会增加心血管事件的风险。肾移植（KTx）可能改善主动脉僵硬度；然而，尚不清楚主动脉僵硬度的改善是否仅仅是 KTx 后血压（BP）降低的结果。此外，主动脉僵硬度的长期轨迹尚不确定，因为免疫系统的激活可能对动脉壁特性产生负面影响。
使用主动脉僵硬度β0作为与血压无关的僵硬度参数，并对血压进行统计调整，我们旨在检查主动脉僵硬度的早期和晚期变化，并定义主动脉僵硬度具有良好和不良长期轨迹的患者的特征。在这项纵向研究中，79 名个体在 KTx 前、3、6 和 24 个月时评估了主动脉僵硬度。通过颈股脉搏波速度（cf-PWV）确定主动脉僵硬度，并通过应用 Bramwell-Hill 方程基于 cf-PWV 应用刚度参数β0 理论，使用参考压力获得β0 指数。
KTx 后 3 个月β0 早期降低（29.0±2.0 至 25.8±1.2，P=0.033），随后在 6（28.0±1.4，P=0.005 与 3 个月相比）和 24 个月（28.3±1.3，P=0.003 与 3 个月相比）逐渐增加。β0 晚期增加与白细胞介素-6（P=0.029）水平升高有关，即使在调整潜在混杂因素后也是如此。使用 BP 的统计调整显示出相似的结果。
KTx 后 3 个月β0 指数降低表明 KTx 导致主动脉固有机械特性的早期去僵硬度。然而，这种改善随后是后期的僵硬，这与白细胞介素-6 的增加有关，这表明肾脏受者的动脉壁重塑可能涉及免疫系统的激活。
