Department of Medicine, University of Perugia, Perugia.
Unit of Internal Medicine, Terni University Hospital, Terni, Italy.
J Hypertens. 2018 Dec;36(12):2316-2323. doi: 10.1097/HJH.0000000000001869.
We aimed at evaluating the impact of genetic and environmental factors on longitudinal changes in aortic pulse wave velocity (aPWV) and aortic augmentation index (aAIx).
Three hundred and sixty-eight Italian and Hungarian adult twins (214 monozygotic, 154 dizygotic) underwent repeated evaluations of aPWV and aAIx (TensioMed Arteriograph). Within-individual/cross-wave, cross-twin/within-wave and cross-twin/cross-wave correlations were calculated; bivariate Cholesky models were fitted to calculate additive genetic (A), shared environmental (C) and unique environmental (E) components.
For both aPWV and aAIx, cross-twin correlations in monozygotic pairs (r between 0.35 and 0.56) were all significant and always higher than in dizygotic pairs, both at wave 1 and at wave 2. Heritability and unshared environmental proportion of variance at each wave were substantially time-invariant for aPWV (heritability 0.51, 95% CI 0.36-0.63 at wave 1; 0.49, 95% CI 0.34-0.62 at wave 2), whereas for aAIx, we observed a diminished genetic effect (heritability 0.57, 95% CI 0.45-0.67 at wave 1; 0.37, 95% CI 0.21-0.51 at wave 2). Overlapping genetic factors explained a high proportion (0.88, 95% CI 0.61-1.00) of longitudinal covariance for aPWV, and had a relatively lower impact on aAIx (0.55, 95% CI 0.35-0.70). Genetic correlations of aPWV (r = 0.64, 95% CI 0.42-0.85) and aAIx (r = 0.70, 95% CI 0.52-0.87) between waves were lower than 1, suggesting a potential contribution of novel genetic variance on arterial stiffening.
Changes in aPWV and aAIx over time are largely genetically determined. Our results might stimulate further studies on genetic and epigenetic factors influencing the process of vascular ageing.
本研究旨在评估遗传和环境因素对主动脉脉搏波速度（aPWV）和主动脉增强指数（aAIx）纵向变化的影响。
368 名意大利和匈牙利成年双胞胎（214 对同卵双胞胎，154 对异卵双胞胎）接受了重复的 aPWV 和 aAIx（TensioMed Arteriograph）评估。计算个体内/跨波、双胎内/同波和双胎间/跨波相关性；采用双变量 Cholesky 模型计算加性遗传（A）、共享环境（C）和独特环境（E）分量。
对于 aPWV 和 aAIx，同卵双胞胎间的双胎间相关性（r 在 0.35 到 0.56 之间）均为显著，且始终高于异卵双胞胎，无论是在第 1 波还是第 2 波。aPWV 的遗传率和未共享环境方差的比例在每个时间点都基本保持不变（第 1 波时的遗传率为 0.51，95%置信区间为 0.36-0.63；第 2 波时的遗传率为 0.49，95%置信区间为 0.34-0.62），而对于 aAIx，我们观察到遗传效应减弱（第 1 波时的遗传率为 0.57，95%置信区间为 0.45-0.67；第 2 波时的遗传率为 0.37，95%置信区间为 0.21-0.51）。重叠的遗传因素解释了 aPWV 纵向协方差的很大一部分（0.88，95%置信区间为 0.61-1.00），对 aAIx 的影响相对较低（0.55，95%置信区间为 0.35-0.70）。aPWV（r=0.64，95%置信区间为 0.42-0.85）和 aAIx（r=0.70，95%置信区间为 0.52-0.87）之间的波间遗传相关性低于 1，表明动脉僵硬度变化可能有新的遗传变异的贡献。
aPWV 和 aAIx 随时间的变化在很大程度上是由遗传决定的。我们的研究结果可能会激发更多关于影响血管老化过程的遗传和表观遗传因素的研究。
