Cheung Y F, Chan Godfrey C F, Ha S Y
Division of Paediatric Cardiology, Grantham Hospital, The University of Hong Kong, China.
Circulation. 2002 Nov 12;106(20):2561-6. doi: 10.1161/01.cir.0000037225.92759.a7.
Increased iron store has been linked to risk of cardiovascular disease. Structural alterations of arteries in beta-thalassemia major patients and in vitro functional disturbance of vascular endothelial cells by thalassemic serum have been described. We sought to determine whether arterial stiffness and endothelial function are altered in vivo.
Thirty thalassemia patients (16 male) aged 22.2+/-7.4 years were recruited. Left ventricular (LV) mass and function were assessed echocardiographically. Carotid and brachioradial artery stiffness was assessed by stiffness index and pulse-wave velocity (PWV), respectively. Brachial artery endothelial function was assessed by vascular response to reactive hyperemia (flow-mediated dilation [FMD]) and sublingual glyceryl trinitrate. These indexes were compared with those of 30 age- and sex-matched controls. None of the patients had LV systolic or diastolic dysfunction. When compared with controls, patients had greater absolute (113.8+/-38.0 versus 109.0+/- 32.6 g, P=0.04) and indexed (82.4+/-17.5 versus 66.7+/-12.7 g/m(2), P<0.001) LV mass, carotid artery stiffness index (8.1+/-3.5 versus 5.5+/-1.6, P<0.001), and brachioradial PWV (8.9+/-2.4 versus 7.9+/-1.7 m/s, P= 0.03). Their FMD was impaired (3.5+/-3.3% versus 8.8+/-3.9%, P<0.001), whereas glyceryl trinitrate- mediated dilation was preserved (17.9+/-7.6% versus 16.3+/-6.1%, P=0.40). Both stiffness index and PWV correlated inversely with magnitude of FMD (r=-0.40, P=0.03; r=-0.41, P=0.03) and positively with indexed LV mass (r=0.50, P=0.005; r=0.40, P=0.027). Nonetheless, no significant correlation existed between ferritin level and carotid stiffness, PWV, or FMD.
Increased arterial stiffness, endothelial dysfunction, and LV hypertrophy occur in patients with beta-thalassemia major, which may result in reduction of mechanical efficiency of the heart.
铁储存增加与心血管疾病风险相关。已有研究描述了重型β地中海贫血患者动脉结构改变以及地中海贫血血清对血管内皮细胞的体外功能干扰。我们试图确定体内动脉僵硬度和内皮功能是否发生改变。
招募了30例年龄为22.2±7.4岁的地中海贫血患者（16例男性）。通过超声心动图评估左心室（LV）质量和功能。分别通过僵硬度指数和脉搏波速度（PWV）评估颈动脉和肱桡动脉僵硬度。通过对反应性充血的血管反应（血流介导的扩张[FMD]）和舌下硝酸甘油评估肱动脉内皮功能。将这些指标与30例年龄和性别匹配的对照组进行比较。所有患者均无左心室收缩或舒张功能障碍。与对照组相比，患者的左心室绝对质量（113.8±38.0对109.0±32.6 g，P = 0.04）和指数化质量（82.4±17.5对66.7±12.7 g/m²，P < 0.001）更大，颈动脉僵硬度指数（8.1±3.5对5.5±1.6，P < 0.001）和肱桡动脉PWV（8.9±2.4对7.9±1.7 m/s，P = 0.03）更高。他们的FMD受损（3.5±3.3%对8.8±3.9%，P < 0.001），而硝酸甘油介导的扩张保留（17.9±7.6%对16.3±6.1%，P = 0.40）。僵硬度指数和PWV均与FMD幅度呈负相关（r = -0.40，P = 0.03；r = -0.41，P = 0.03），与指数化左心室质量呈正相关（r = 0.50，P = 0.005；r = 0.40，P = 0.027）。然而，铁蛋白水平与颈动脉僵硬度、PWV或FMD之间无显著相关性。
重型β地中海贫血患者存在动脉僵硬度增加、内皮功能障碍和左心室肥厚，这可能导致心脏机械效率降低。
