Shidfar Farzad, Keshavarz Ali, Jallali Mahamood, Miri Reza, Eshraghian Mohammadreza
Laboratory of Biochemistry, Department of Nutrition and Biochemistry, School of Health, Tehran University of Medical Sciences.
Int J Vitam Nutr Res. 2003 May;73(3):163-70. doi: 10.1024/0300-9831.73.3.163.
Control of hyperlipidemia is vital in patients with cardiovascular disease (CVD). Omega-3 fatty acids (n-3FAs) have desirable effects on serum triglyceride (TG) levels, thrombosis, and arrhythmia, but lead to increases in serum low-density lipoprotein (LDL) and apo-B as well.
To determine and compare the effects of administration of n-3FAs, vitamin C (VitC) and n-3FAs + VitC on the serum levels of LDL, apoB, other serum lipids, and malondialdehyde (MDA). The present study was performed in Tehran University of Medical Sciences from 2000 to 2001.
In a double-blind, placebo trial of parallel design, 68 hyperlipidemic patients [total cholesterol (TC) and TG greater than 200 mg/dL] were randomly assigned to receive daily 500 mg VitC, 1 g n-3FAs, 500 mg VitC + 1 g n-3FAs, or placebo (control) for 10 weeks. Fasting blood samples were collected at the beginning and at the end of the period. TG, TC, LDL-cholesterol-C (LDL-C), and high-density lipoprotein-cholesterol (HDL-C) were measured enzymatically, VitC and MDA colorimetrically, and apo-B and apo-A-I immunoturbidometrically. The pattern of food consumption, socio-economic, and anthropometric indices were determined; there was no significant change in these indices during the study.
There was a significant difference in the blood VitC level at the end of the study in comparison to the initial value in the VitC (p = 0.001) and VitC + n-3FAs (p = 0.027) groups. Similarly, the serum TG level at the end of study was significantly different from the initial value in the n-3FAs group (p = 0.002) and also from the final value in the control group (p = 0.013). In the VitC group, there was a significant decrease in TC (p = 0.004), apo-B (p = 0.005), and MDA (p = 0.015) at the end of study as compared to the respective initial values. There was also a significant increase in blood VitC compared to the control value (p = 0.018) and a significant decrease in MDA compared to the n-3FAs group (p = 0.034). At the end of study, in the n-3FAs group, there was a significant (p = 0.04) and a marginally significant decrease (p = 0.05), respectively, in TG/HDL and apo-B levels as compared to the initial values, and the TG/HDL ratio showed a significant decrease as compared to the control group (p = 0.047).
Simultaneous administration of n-3FAs and VitC had no beneficial effects on the lipid profile of hyperlipidemic patients, but 1 g purified n-3FAs daily for 10 weeks is a beneficial supplement for decreasing TG without any increase in LDL-C, apo-B or MDA. Administration of 500 mg VitC for more than 10 weeks might decrease significantly TC and apo-B in hyperlipidemic patients.
高脂血症的控制对心血管疾病（CVD）患者至关重要。ω-3脂肪酸（n-3FAs）对血清甘油三酯（TG）水平、血栓形成和心律失常有有益作用，但也会导致血清低密度脂蛋白（LDL）和载脂蛋白B（apo-B）升高。
确定并比较给予n-3FAs、维生素C（VitC）以及n-3FAs + VitC对血清LDL、apoB、其他血脂和丙二醛（MDA）水平的影响。本研究于2000年至2001年在德黑兰医科大学进行。
在一项双盲、平行设计的安慰剂试验中，68例高脂血症患者[总胆固醇（TC）和TG大于200 mg/dL]被随机分配，每天接受500 mg VitC、1 g n-3FAs、500 mg VitC + 1 g n-3FAs或安慰剂（对照组），持续10周。在研究开始和结束时采集空腹血样。采用酶法测定TG、TC、低密度脂蛋白胆固醇（LDL-C）和高密度脂蛋白胆固醇（HDL-C），比色法测定VitC和MDA，免疫比浊法测定apo-B和载脂蛋白A-I（apo-A-I）。确定食物消费模式、社会经济和人体测量指标；在研究期间这些指标无显著变化。
与初始值相比，研究结束时VitC组（p = 0.001）和VitC + n-3FAs组（p = 0.027）的血液VitC水平有显著差异。同样，研究结束时n-3FAs组的血清TG水平与初始值有显著差异（p = 0.002），与对照组的最终值也有显著差异（p = 0.013）。在VitC组，与各自的初始值相比，研究结束时TC（p = 0.004）、apo-B（p = 0.005）和MDA（p = 0.015）有显著降低。与对照组相比，血液VitC也有显著升高（p = 0.018），与n-3FAs组相比，MDA有显著降低（p = 0.034）。研究结束时，在n-3FAs组，与初始值相比，TG/HDL和apo-B水平分别有显著降低（p = 0.04）和边缘显著降低（p = 0.05），且与对照组相比，TG/HDL比值有显著降低（p = 0.047）。
同时给予n-3FAs和VitC对高脂血症患者的血脂谱无有益影响，但每天1 g纯化的n-3FAs持续10周是降低TG的有益补充，且不会使LDL-C、apo-B或MDA升高。给予500 mg VitC超过10周可能会显著降低高脂血症患者的TC和apo-B。
