Ginsberg H N, Karmally W, Siddiqui M, Holleran S, Tall A R, Rumsey S C, Deckelbaum R J, Blaner W S, Ramakrishnan R
Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032.
Arterioscler Thromb. 1994 Apr;14(4):576-86. doi: 10.1161/01.atv.14.4.576.
Despite many previous studies, controversy remains concerning the effects of dietary cholesterol on plasma cholesterol concentrations. In addition, the focus of previous studies has been fasting lipid and lipoprotein concentrations; there are no published studies with postprandial measurements. We studied the effects of four levels of dietary cholesterol intake on fasting lipid, lipoprotein, and apoprotein levels, as well as postprandial lipid levels, in a group of young, healthy men who were otherwise eating a low-fat, American Heart Association step 1 diet. Twenty young, healthy men completed a randomized, four-way crossover design study to test the effects of an American Heart Association step 1 diet containing 0, 1, 2, or 4 eggs per day. Dietary cholesterol ranged from 128 to 858 mg cholesterol per day. Each diet was eaten for 8 weeks, with a break between diets. Three fasting blood samples were obtained at the end of each diet period. In addition, blood samples were obtained just before and 2, 4, and 6 hours after ingestion of a standard lunch containing the various amounts of egg cholesterol. We also obtained blood 4 and 8 hours after the subjects ingested a standard, high-fat formula. Fasting plasma total cholesterol concentrations increased by 1.47 mg/dL (0.038 mmol/L) for every 100 mg dietary cholesterol added to the diet (P < .001). Low-density lipoprotein (LDL) cholesterol increased in parallel. Responsiveness varied but appeared to be normally distributed. Fasting plasma apoprotein B concentrations increased approximately 10% between the 0- and 4-egg diets and were correlated with changes in total and LDL cholesterol concentrations. Although there was a trend toward a greater response in men with an apoprotein E4 allele, this was not statistically significant. Fasting plasma cholesteryl ester transfer protein levels were higher only on the 4-egg diet, and changes in cholesteryl ester transfer protein levels between the 0- and 4-egg diets correlated with changes in total and LDL cholesterol. There were no differences in the postlunch or post-fat-formula responses of plasma lipids across the diets. Incubation of the 4-hour postlunch serum with J774 macrophages did not affect cell cholesteryl ester content at any level of dietary cholesterol. Cellular free cholesterol levels were slightly higher on each of the egg-containing diets versus the 0-egg diet. In summary, increases in dietary cholesterol resulted in linear increases in fasting total and LDL cholesterol in young, healthy men.(ABSTRACT TRUNCATED AT 400 WORDS)
尽管此前已有许多研究，但饮食中的胆固醇对血浆胆固醇浓度的影响仍存在争议。此外，以往研究的重点一直是空腹血脂和脂蛋白浓度；尚无关于餐后测量的已发表研究。我们研究了在一组年轻健康男性中，四种饮食胆固醇摄入量水平对空腹血脂、脂蛋白和载脂蛋白水平以及餐后血脂水平的影响，这些男性原本遵循低脂的美国心脏协会第一步饮食方案。20名年轻健康男性完成了一项随机、四因素交叉设计研究，以测试每天摄入0、1、2或4个鸡蛋的美国心脏协会第一步饮食方案的效果。饮食中的胆固醇含量为每天128至858毫克。每种饮食方案持续8周，不同饮食方案之间有间隔。在每个饮食阶段结束时采集三份空腹血样。此外，在摄入含有不同量鸡蛋胆固醇的标准午餐前以及午餐后2、4和6小时采集血样。我们还在受试者摄入标准高脂配方食品后4小时和8小时采集血样。饮食中每增加100毫克胆固醇，空腹血浆总胆固醇浓度就会升高1.47毫克/分升（0.038毫摩尔/升）（P <.001）。低密度脂蛋白（LDL）胆固醇也随之平行升高。反应性有所不同，但似乎呈正态分布。在0个鸡蛋饮食和4个鸡蛋饮食之间，空腹血浆载脂蛋白B浓度增加了约10%，且与总胆固醇和LDL胆固醇浓度的变化相关。尽管携带载脂蛋白E4等位基因的男性有更大反应的趋势，但这在统计学上并不显著。仅在4个鸡蛋饮食时，空腹血浆胆固醇酯转移蛋白水平较高，0个鸡蛋饮食和4个鸡蛋饮食之间胆固醇酯转移蛋白水平的变化与总胆固醇和LDL胆固醇的变化相关。不同饮食方案之间午餐后或高脂配方食品餐后血浆脂质的反应没有差异。在任何饮食胆固醇水平下，将午餐后4小时的血清与J774巨噬细胞孵育均不会影响细胞胆固醇酯含量。与0个鸡蛋饮食相比，每种含鸡蛋饮食的细胞游离胆固醇水平略高。总之，饮食中胆固醇的增加导致年轻健康男性空腹总胆固醇和LDL胆固醇呈线性增加。（摘要截选至400字）
