Plasma Lipoproteins and Platelet Aggregation During Alimentary Lipemia

Abstract

Ten healthy women in their tenth decade of life were compared with ten healthy women in their fourth decade of life regarding the response of plasma lipoproteins and platelet aggregation to one meal rich in saturated fats. In the elderly group, plasma cholesterol decreased in the postprandial state three hours after the meal in comparison to no significant changes in the younger group. This resulted from reduction in plasma lipoprotein cholesterol levels, except for the high-density lipoprotein (HDL) cholesterol, which was enhanced. A similar pattern was found for plasma lipoprotein levels. The increase in plasma triglyceride concentration in the elderly women was less than in the younger women, as fewer changes in their plasma triglyceride-rich lipoproteins (chylomicrons and very-low-density lipoprotein) were observed. Platelet aggregation in response to collagen was reduced in the elderly women, whereas in the younger group, increased platelet aggregation in the postprandial state was found. Our study thus demonstrates a clear advantage of the elderly women in comparison to the younger ones in reducing atherosclerosis and thrombotic risks. The elderly group responded to the saturated fat-rich meal by minimal plasma triglyceride elevation, an increase in HDL cholesterol concentration, and reduced platelet aggregation.

EPA, but not DHA, decreases mean platelet volume in normal subjects

“…Platelet aggregation induced by ADP (24) and by collagen (25) was significantly increased in normolipemic subjects after fatty meals. Fuhrman et al (24) showed that platelets maintained their hypersensitivity to aggregation 5 h after meals, at a time when plasma TG levels had returned to normal.…”

“…The eight conditions were: unstimulated or stimulated with collagen, heat or cold, all in the fasting and the fed states. The effect of eating was examined because platelet activation was expected to be greater in the fed than the fasting state (24,25). Three different ex vivo stimuli were included in anticipation that, if EPA or DHA did not activate platelets in the basal state, they might affect platelet response to stimulation.…”