Cardiovascular Aging Research Laboratory, Department of Kinesiology and Health Education, The University of Texas at Austin, USA.
Department of Psychology, The University of Texas at Austin, USA.
Am J Hypertens. 2017 Dec 8;31(1):72-79. doi: 10.1093/ajh/hpx132.
Individuals with metabolic syndrome (MetS) exhibit reduced cerebral blood flow. The mechanisms of this reduction remain unknown but arterial stiffening has been implicated as a contributor. We determined if MetS was associated with reduced cerebral blood flow at midlife, and if so, whether arterial stiffness was responsible for mediating their relation.
Middle-aged (40-60 years) community dwelling adults (n = 83) were studied. MetS score was calculated for each subject. Middle cerebral artery hemodynamics was measured using transcranial Doppler ultrasound. Indices of aortic, systemic, and carotid artery stiffness were derived.
Subjects had subclinical MetS pathology (MetS score = 19.8 ± 10.4) that was inversely associated with cerebrovascular conductance (CVC: r = -0.261, P = 0.02). Carotid-femoral pulse wave velocity (cfPWV) (r = -0.188, P = 0.09), brachial-ankle pulse wave velocity (baPWV) (r = -0.161, P = 0.15), and carotid artery distensibility (r = -0.10, P = 0.37) abrogated the direct association of MetS score and CVC, demonstrating full mediation. Nonparametric bootstrapping further indicated significant indirect effects of cfPWV, baPWV, and carotid artery distensibility, fully mediating reductions of CVC exerted from sublcinical MetS. Carotid artery distensibility demonstrated the greatest effect on CVC (B = -0.0019, SE = 0.0012, -0.0050 to -0.0002 95% confidence interval).
Arterial stiffness, particularly the stiffness of the carotid artery, mediated reductions in CVC related to MetS.
患有代谢综合征（MetS）的个体表现出脑血流减少。这种减少的机制尚不清楚，但动脉僵硬已被认为是一个促成因素。我们确定代谢综合征是否与中年人脑血流减少有关，如果是这样，动脉僵硬是否负责介导它们之间的关系。
研究了中年（40-60 岁）社区居住的成年人（n=83）。为每个受试者计算代谢综合征评分。使用经颅多普勒超声测量大脑中动脉血液动力学。得出了主动脉、系统和颈动脉僵硬的指数。
受试者存在亚临床代谢综合征病理（代谢综合征评分=19.8±10.4），与脑血管导率（CVC：r=-0.261，P=0.02）呈负相关。颈动脉-股动脉脉搏波速度（cfPWV）（r=-0.188，P=0.09）、肱-踝脉搏波速度（baPWV）（r=-0.161，P=0.15）和颈动脉可扩张性（r=-0.10，P=0.37）消除了代谢综合征评分和 CVC 的直接关联，表明完全中介。非参数引导进一步表明 cfPWV、baPWV 和颈动脉可扩张性对 CVC 的显著间接影响，完全介导了亚临床代谢综合征对 CVC 的降低。颈动脉可扩张性对 CVC 的影响最大（B=-0.0019，SE=0.0012，-0.0050 至-0.0002 95%置信区间）。
动脉僵硬，特别是颈动脉的僵硬，介导了与代谢综合征相关的 CVC 减少。
