Postprandial Lipemia is Associated With Platelet and Monocyte Activation and Increased Monocyte Cytokine Expression in Normolipemic Men

Abstract

The activation of platelets and monocytes has been implicated in the development of cardiovascular diseases. We asked the question if postprandial lipemia following a fatcontaining meal is associated with platelet and monocyte activation and increased platelet-monocyte interaction. Thirteen healthy, normal weight, normolipemic males, 20 to 49 years, consumed a 40% fat meal of whole foods. Blood samples were obtained at fasting and 3½ and 6 hours after ingestion. Triglyceride levels increased to 48% over baseline at 3½ hours postconsumption and returned to fasting levels by 6 hours. Multiparameter flow cytometry using monoclonal antibodies showed that the percentage of platelets expressing surface P-selectin and the activated conformation the GPIIb-IIIa receptor was significantly higher at 3½ hours compared to fasting. The percentage of platelet-monocyte aggregates increased by 36% at 3½ hours and 43% at 6 hours postconsumption. The percentage of monocytes expressing intracellular tumor necrosis factor-tx (TNF-ax) increased seven and eightfold at 3½ and 6 hours, respectively. The expression of interleukin-l,B (IL-1p increased in a similar manner. These data suggest activation of platelets and monocytes after a moderate fat meal. Repetitive activation of platelets and monocytes could be an early event in the initiation and development of atherosclerosis.