Causes of Hyper-α-lipoproteinemia and its relevance to atherosclerosis

高密度脂蛋白（HDL）是一种抗动脉粥样硬化的脂蛋白，它可以从外周组织中清除多余的胆固醇，并将其运送到肝脏排泄。流行病学研究清楚地表明，低高密度脂蛋白胆固醇水平与动脉粥样硬化性疾病如冠状动脉疾病（CAD）的高发有关。然而，非常高的hdl -胆固醇水平是否有利于预防CAD仍存在争议。在这项研究中，我们研究了高α-脂蛋白血症（HAL）的原因及其与动脉粥样硬化疾病的关系。我们得到了以下结果：(1)测定了2229名健康受试者的hdl -胆固醇【大于或等于】100mg/dL的频率。在1033名男性和1196名女性中，分别有7人（0.7%）和14人（1.2%）患有HAL。(2)我们测量了83例HAL和对照组的空腹血清CETP质量。在男性（n=26）中，HAL组的胆固醇酯转移蛋白（CETP）质量显著低于hdl -胆固醇正常组（1.6±0.6 vs 2.2±0.5gμ/mL, p<0.001）。另一方面，女性（n=57）的CETP水平在HAL和对照组之间相似（2.5±0.8 vs 2.4±0.5 μg/mL）。(3)非变性二维凝胶电泳结果显示，HAL组α -迁移率大、中型HDL （HDL2b和HDL2a）显著高于对照组。值得注意的是，细胞胆固醇的初始受体pre - hdl在HAL中也显著增加。(4)对83例无缺血性心脏病症状的HAL患者中42例（男12例，女30例，年龄21 ~ 73岁）进行跑步机运动心电图。虽然2例患者（4.8%）在运动中表现出明显的ST压抑，但均为假阳性。这些结果表明，在日本男性HAL中，低CETP活性比女性HAL更重要。HAL对CAD的促进作用有待于进一步的研究。少

High-density lipoprotein (HDL) is the anti-atherogenic lipoprotein that removes excess cholesterol from peripheral tissues an d transports it to the liver for the excretion. Epidemiological studies have clearly shown that low HDL-cholesterol level is as sociated with the high incidence of atherosclerotic disorders such as coronary artery disease (CAD). However, it is still controversial whether very high HDL-cholesterol level is favorable for the prevention of CAD. In this study, we examined the causes of hyper-α-lipoproteinemia (HAL) and its relation to atherosclerotic disorders. We obtained the following results ; (1) We determined the frequency of HAL (HDL-cholesterol【greater than or equal】100mg/dL) in 2,229 healthy subjects. HAL was found in 7 out of 1,033 men (0.7%), and 14 out of 1,196 women (1.2%), respectively. (2) We measured CETP mass in fasting serum from 83 HAL and control subjects. In men (n=26), the cholesteryl ester transfer protein (CETP) mass was significantly lower in … More HAL than in those with normal HDL-cholesterol level (1.6±0.6 vs. 2.2±0.5gμ/mL, p<0.001). In women (n=57), on the other hand, the CETP level was similar between HAL and control subjects (2.5±0.8 vs. 2.4±0.5 μg/mL). (3) Nondenaturing two-dimensional gel electrophoresis revealed that large- and medium-sized HDL with alpha-mobility (HDL2b, and HDL2a) were significantly higher in HAL subjects than in control subjects. It is noteworthy that prebetal-HDL, the initial acceptor of cellular cholesterol, also increased significantly in HAL. (4) Treadmill exercise electrocardiography was carried out in 42 (12 men and 30 women, aged 21-73 years) out of 83 HAL patients who were free from symptoms of ischemic heart disease. Although two patients (4.8%) showed significant ST depression during exercise, both of them were false positive. These results indicate that low CETP activity is more important in male HAL than in female HAL in Japan. Whether HAL promotes CAD remained to be determined in the future study. Less