PLANT STANOL ESTERS ON USUAL DIET VS NCEP STEP 1 DIET ON LIPIDS & LIP

植物甾醇是C5-C6键饱和的天然植物甾醇。因此，虽然谷甾醇在这个位置上有一个双键，但谷甾醇只有一个键。西他雄醇几乎完全不能被肠道吸收，而且还会减少胆固醇的吸收。谷甾醇的降胆固醇作用是通过将其转化为脂肪酸酯来增强的。在芬兰高胆固醇血症受试者中进行的研究表明，植物甾醇酯(PSE)的总胆固醇(TC)和低密度脂蛋白胆固醇(LDL-C)分别降低了6%至11%和9%至14%。芬兰研究对象的饮食中总脂肪、饱和脂肪和胆固醇的含量高于典型的美国饮食。重要的是要确定，如果饮食中总脂肪和饱和脂肪含量较低，第一步饮食和PSE结合在一起，是否会导致低密度脂蛋白胆固醇的降低超过任何一种单独治疗。这项为期6周的随机对照研究的目的是：1)确定四个治疗组(普通饮食、普通饮食+PSE、步骤I饮食、步骤I饮食+PSE)之间是否存在差异；2)量化极低密度脂蛋白(VLDL)、低密度脂蛋白(LDL-C)、高密度脂蛋白(HDL)以及将PSE纳入其日常饮食或步骤I饮食的受试者的适当亚组分的脂蛋白组成的变化；以及3)确定血脂和脂蛋白水平变化的时间依赖性。

Phytosterols are naturally occurring plant sterols in which the C5-C6 bond is saturated. Thus, while sitostanol bears a double bond at this position, sitostanol has a single bond. Sitostanol is almost completely unabsorbable by the intestine and also reduces the absorption of cholesterol. The cholesterol-lowering effect of sitostanol is increased by converting it to fatty acid esters. In studies conducted in Finnish hypercholesterolemic subjects, plant stanol esters (PSE) have shown decreases in total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) of 6 to 11% and 9 to 14%, respectively. The diet of Finnish research subjects was higher in total fat, saturated fat, and cholesterol than the typical American diet. It is important to determine if a diet lower in total and saturated fat, the Step I Diet, and PSE together will result in LDL-C lowering that exceeds either treatment alone. The purpose of this randomized controlled 6-week study is to: 1) determine if there are differences among four treatment groups (usual diet, usual diet + PSE, Step I Diet, Step I Diet + PSE), 2) to quantify changes that may occur in lipoprotein composition of very low density lipoprotein (VLDL), LDL-C, high density lipoprotein (HDL), and appropriate subfractions of subjects incorporating PSE into their usual diets or the Step I Diet, and 3) to determine the time dependence of changes in level of lipids and lipoproteins.