Flow-mediated vasoactivity and circulating adhesion molecules in hypertreglyceridemia: Association with small, dense LDL cholesterol particles

Background Endothelial dysfunction is considered one of the earliest events in the process of atherosclerosis, and on impaired vasodilatory response h as been reported in patients with dyslipidemias. However, the independent a ssociation between hypertriglyceridemia and endothelial dysfunction is cont roversial, and the relation between endothelium-dependent vasodilation and circulating cell adhesion molecules as markers of endothelial dysfunction h as not been fully determined. Methods Brachial artery flow mediated vasodilation (FMV) and the soluble fo rms of vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesi on molecule-1 (sVCAM-1) were determined after overnight fasting in 16 men w ith hypertriglyceridemia (age 33 +/- 6 years) and in 16 age-matched healthy men with normal triglycerides and cholesterol. Subjects who smoked and tho se with known cardiovascular disease, diabetes, hypertension, recent or act ive infections, or any other disease that could affect leukocyte activation were excluded from the study. Results Compared with normal subjects, subjects with hypertriglyceridemia s howed a higher level of sVCAM-1 and sICAM-1 (both P < .001), a reduced FMV (P < .01), and a smaller LDL particle size (P < .05). FMV had a significant inverse correlation with sVCAM-1 (r = -0.61, P < .001) and sICAM-1 (r = -0 .38, P < .03). LDL particle size had a strong, direct association with FMV (r = 0.75, P < .001) and an inverse association with adhesion molecules. By multiple regression analysis, triglycerides (P < .001) and small LDL parti cle size (P < .002) predicted a reduced FMV. Conclusions Serum level of cell adhesion molecules is increased end FMV is impaired in young healthy men with hypertriglyceridemia compared with age-m atched men with normal lipid levels. Small, dense LDL particles may play a role in determining endothelial dysfunction in these subjects.