To compare the effect of a high-fat meal and a high-carbohydrate meal (pizza), with
and without antioxidant vitamins, on endothelial activation in healthy subjects and
in patients with type 2 diabetes mellitus.
The postprandial state is becoming increasingly acknowledged to affect some early
events of atherogenesis.
In a randomized, observer-blinded, crossover study, 20 newly diagnosed type 2 diabetic
patients and 20 age- and gender-matched healthy subjects received two meals at one-week
intervals: a high-fat meal (760 calories) and an isoenergetic high-carbohydrate meal
(non-cheese pizza). In all subjects, the same meals were repeated immediately following
ingestion of vitamin E, 800 IU, and ascorbic acid, 1,000 mg.
In normal subjects, the high-fat meal increased the plasma levels of tumor necrosis
factor-alpha (TNF-alpha), interleukin-6 (IL-6), intercellular adhesion molecule-1
(ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), which were prevented by vitamins.
No change in these parameters occurred after pizza ingestion or pizza ingestion with
vitamins. In diabetic patients, basal concentrations of glucose, cytokines and adhesion
molecules were significantly higher than in nondiabetic controls. Both meals significantly
increased cytokine and adhesion molecule levels, but the increase was more sustained
following the high-fat meal. There was no significant change from baseline when vitamin
supplementation accompanied each meal. There was a relationship between changes in
serum triglycerides and changes in TNF-alpha (r = 0.39, p < 0.01), IL-6 (r = 0.28,
p < 0.05) and VCAM-1 (r = 0.25, p < 0.05), and between changes in plasma glucose and
changes in IL-6 (r = 0.36, p < 0.01) and ICAM-1 (r = 0.31, p < 0.02).
An oxidative mechanism mediates endothelial activation induced by post-meal hyperlipidemia
and hyperglycemia.