疾病营养治疗指导方案：代谢性疾病营养治疗血脂异常和脂蛋白异常血症

代谢性疾病营养治疗血脂异常和脂蛋白异常血症

The hyperlipidemias may occur from increased levels of cholesterol and/or triglycerides in a variety of lipoproteins. These disorders may be inherited or of dietary origin. Elevated cholesterol levels in plasma usually involve LDL and result from the increased production and/or delayed or defective removal of LDL cholesterol. Hypercholesterolemia can occur from without or combined with mild hypertriglyceridemia. Elevated triglyceride levels in association with hypercholesterolemia result from genetic defects or diet or both. Primary hypertriglyceridemia may result from overproduction of VLDL alone, or with chylomicrons, or from defective removal via lipoprotein lipase. Thus, the primary hyperlipoproteinemias are metabolic disorders characterized by an excess of one or more lipoproteins in the circulation. Responses to diet modifications vary with the disorder and among individuals. Dietary saturated long-chain fatty acids raise plasma cholesterol levels and decrease LDL receptor activity. Eicosapentaenoic acid and other w-3 fatty acids found in fish and fish oils may have a hypocholesterolemic effect in normal subjects or raise LDL and HDL cholesterol in hyperlipidemic subjects and have significant hypotriglyceridemic effects in normal and hyperlipidemic subjects. Monounsaturated liquid vegetable oils have a cholesterol-lowering effect, perhaps

by replacing saturated liquid fat. Polyunsaturated fats of the ε-6 series in liquid vegetable oils result in decreased levels of LDL cholesterol and at high intake may decrease HDL cholesterol. Intake of refined carbohydrates may exacerbate hypertriglyceridemia.

一、概述

血浆中的脂类包括胆固醇、胆固醇酯、甘油三酯、磷脂和游离脂肪酸等。高脂血症（hyperlipidemia）是指机体血浆中胆固醇或/和甘油三酯水平升高。可表现为高胆固醇血症（hypercholesterolemia）、高甘油三酯血症（hypertriglyceridemia），或两者兼有（混合型高脂血症）。由于脂质难溶于水，必须与血浆中的蛋白质结合形成大分子的脂蛋白后，才能在血液中被运输，进入组织进行代谢。胆固醇和甘油三酯在血浆中都是以脂蛋白的形式存在，严格地说，高脂血症应称为高脂蛋白血症（hyperlipoproteinemia）。另外，血浆中高密度脂蛋白水平降低也是一种血脂代谢紊乱，并多与胆固醇和甘油三酯水平升高同时存在，故称为血脂异常（dyslipidermia）能更准确、全面反映血脂代谢紊乱状态。

血脂异常是一类较常见的疾病，其发病原因除了人类自身遗传基因缺陷外，主要与饮食因素有关，肥胖、年龄、性别等也是重要因素。

主要临床表现：高脂血症病人，由于血浆中脂蛋白水平升高，血液黏稠度增加，血流速度缓慢，血氧饱合度降低。表现为倦怠、易困，肢体末端麻木、感觉障碍，记忆力减退，反应迟钝等。出现动脉硬化或原有动脉硬化加重，细小动脉阻塞时，出现相应靶器官功能障碍。

诊断标准：根据《中国成人血脂异常防治指南（2007年）》，中国人血清总胆固醇的合适范围为＜5.18mmol/L（200mg/dl），5.18～6.19mmol/L （200～239mg/dl）为边缘升高，≥6.22mmol/L（240mg/dl）为升高；血清LDL-胆固醇的合适范围为＜3.37mmol/L（130mg/dl），3.37～4.12mmol/L （130～159mg/dl）为边缘升高，≥4.14mmol/L（160mg/dl）为升高；血清HDL-胆固醇的合适范围为≥1.04mmol/L（40mg/dl），≥1.55mmol/L

（60mg/dl）为升高，＜1.04mmol/L（40mg/dl）为减低；甘油三酯的合适范围为＜1.70mmol/L（150mg/dl），1.70～2.25mmol/L（150～199mg/dl）为边缘升高，≥2.26mmol/L（200mg/dl）为升高。

二、营养代谢特点

（一）脂类

1. 饱和脂肪酸高脂肪膳食易导致血浆胆固醇水平升高。脂肪不仅能促进胆汁分泌，其水解产物还有利于形成混合微胶粒，并能促进胆固醇在黏膜细胞中进一步参与形成乳糜微粒、转运入血，从而使血浆胆固醇水平