Knopp R H, Walden C E, Retzlaff B M, McCann B S, Dowdy A A, Albers J J, Gey G O, Cooper M N
Northwest Lipid Research Clinic, Department of Medicine, University of Washington, Seattle 98104, USA.
JAMA. 1997 Nov 12;278(18):1509-15.
The long-term effect of aggressively vs moderately fat-restricted diets has not been studied extensively in free-living subjects with different types of hyperlipidemia.
To compare the cholesterol-lowering effects of 4 levels of dietary fat intake restriction after 1 year.
Randomized, parallel, comparison trial.
Male employees of a large industry.
A total of 444 men had low-density lipoprotein cholesterol (LDL-C) levels above the 75th age-specific percentile. Subjects with triglyceride (TG) levels less than the 75th age-specific percentile were defined as hypercholesterolemic (HC) and those with TG levels at or above the 75th age-specific percentile were defined as combined hyperlipidemic (CHL).
Hypercholesterolemic subjects were randomized to diets 1, 2, 3, and 4 taught to contain 30%, 26%, 22%, and 18% fat, and the CHL subjects were randomized to diets 1, 2, and 3. All 4 diets were taught to subjects and spouses or partners in 8 weekly 2-hour classes.
Plasma lipoprotein levels after 1 year.
Fat intake after 1 year declined from a mean of 34% to 36% of energy to 27%, 26%, 25%, and 22% in the 4 HC diet groups and 28%, 26%, and 25% in the 3 CHL diet groups. Mean+/-SD percent LDL-C reductions were 5.3%+/-16.2%, 13.4%+/-12.6%, 8.4%+/-11.2%, and 13.0%+/-15.7% in the HC diet groups and 7.0%+/-16.2%, 2.8%+/-15.8%, and 4.6%+/-13.5% in the CHL diet groups (P<.01 in all but 1 instance). Apoprotein B levels decreased 8.6%, 10.7%, 4.3%, and 5.3% in the HC groups and 14.6%, 11.4%, and 9.9% in the CHL groups (P<.05-.01 in each instance). Triglyceride levels increased significantly in subjects following HC diets 3 and 4, 21.7% and 38.7% (P<.05 and .01), but not in any CHL subjects. High-density lipoprotein cholesterol decreased 2.8% and 3.2% in subjects on HC diets 3 and 4, respectively (P<.05 in both cases).
After 1 year, moderate restriction of dietary fat intake attains meaningful and sustained LDL-C reductions in HC subjects and apoprotein B reductions in both HC and CHL subjects. More extreme restriction of fat intake offers little further advantage in HC or CHL subjects and potentially undesirable effects in HC subjects.
在患有不同类型高脂血症的自由生活人群中，积极限制脂肪饮食与适度限制脂肪饮食的长期效果尚未得到广泛研究。
比较1年后4种饮食脂肪摄入限制水平的降胆固醇效果。
随机、平行对照试验。
某大型企业的男性员工。
共有444名男性，其低密度脂蛋白胆固醇（LDL-C）水平高于特定年龄组第75百分位数。甘油三酯（TG）水平低于特定年龄组第75百分位数的受试者被定义为高胆固醇血症（HC）患者，TG水平处于或高于特定年龄组第75百分位数的受试者被定义为混合型高脂血症（CHL）患者。
高胆固醇血症受试者被随机分配到饮食1、2、3和4组，据教导这些饮食分别含30%、26%、22%和18%的脂肪，混合型高脂血症受试者被随机分配到饮食1、2和3组。通过8次每周2小时的课程向受试者及其配偶或伴侣传授所有4种饮食。
1年后的血浆脂蛋白水平。
1年后，4个高胆固醇血症饮食组的脂肪摄入量从平均占能量的34%至36%降至27%、26%、25%和22%，3个混合型高脂血症饮食组的脂肪摄入量降至28%、26%和25%。高胆固醇血症饮食组LDL-C平均降低百分比±标准差分别为5.3%±16.2%、13.4%±12.6%、8.4%±11.2%和13.0%±15.7%，混合型高脂血症饮食组为7.0%±16.2%、2.8%±15.8%和4.6%±13.5%（除1例情况外，所有情况P<0.01）。载脂蛋白B水平在高胆固醇血症组分别降低8.6%、10.7%、4.3%和5.3%，在混合型高脂血症组分别降低14.6%、11.4%和9.9%（每种情况P<0.05 - 0.01）。遵循高胆固醇血症饮食3组和4组的受试者甘油三酯水平显著升高，分别升高21.7%和38.7%（P<0.05和0.01），但混合型高脂血症受试者中无此情况。高胆固醇血症饮食3组和4组的受试者高密度脂蛋白胆固醇分别降低2.8%和3.2%（两种情况P<0.05）。
1年后，适度限制饮食脂肪摄入可使高胆固醇血症受试者的LDL-C有显著且持续的降低，使高胆固醇血症和混合型高脂血症受试者的载脂蛋白B降低。对脂肪摄入进行更严格的限制在高胆固醇血症或混合型高脂血症受试者中几乎没有进一步的益处，且可能对高胆固醇血症受试者产生不良影响。
