Abstract
Dietary and plasma fatty acid composition is strongly related to the development of coronary heart disease (CHD). Since low-density lipoprotein (LDL) is the main vehicle for the uptake of lipids into the artery wall, it is important to know whether the fatty acid composition of this lipoprotein fraction differs in patients with CHD and healthy control subjects. The study comprised 59 newly presenting male patients with myocardial infarction (MI) and 94 healthy male control subjects. The cholesteryl esters (CE) of LDL of the MI group contained less 14:0 (p<0.0000001) and 16:0 (p<0.0001) but more 18:0 (p<0.0001) than those of the control group. For LDL phospholipids (PL), 14:0 (p<0.02) and 16:0 (p<0.0001) were higher in the MI group while 18:0 was lower (p<0.003). In addition, polyunsaturated acids 18:3n-3, 20:2n-6 and 20:4n-6 were all significantly lower in PL in the patient group. Triglyceride fatty acids showed little differences between the two groups. The most striking feature was the difference in the distribution of saturated fatty acids between the LDL CE and PL in the two subject groups (the ratio of PL saturates to CE saturates was 3.41 +/- 1.21 for the control group and 5.39 +/- 3.08 for the MI group (p<0.0000001). This study therefore demonstrates for the first time that highly significant differences occur in the relative proportions of LDL fatty acids in MI patients and control subjects and suggests the importance of dietary lipid intake and of lipid exchange during lipoprotein metabolism in producing LDL particles of low atherogenicity.