Cardiovascular risk factors and endothelium-dependent vasodilation

Abstract: The vascular endothelium is a major modulator of vascular structur and function. This thesisincludes clinical studies investigating the associations between cardiovascular risk factors andendothelium-dependent vasodilation (EDV) in the human forearm vascular bed.A progressive decline in EDV with advancing age was found in men, while this decline wasevident only after the menopause in women. In men, but not in women, metabolic factors likefasting blood glucose and waist/hip ratio were independent predictors of EDV.Serum HDL-cholesterol, unsaturated fatty acids and vitamin E were all positively associatedwith EDV, while serum LDL-cholesterol and saturated fatty acids were negative predictors ofEDV.Cigarette smoking induced a dose-dependent attenuation in EDV in young healthy subjects,being maximal shortly after initiation of smoking and persisting up to 30-50 minutes. Alsonicotine chewing gum induced a similar impairment in EDV. Both serum nicotine levels andblood pressure were independent predictors of EDV.Mental stress induced by an arithmetic task selectively attenuated EDV in young healthysubjects, while two painful stress test, cold pressure and isometric handgrip test, induced amore general impairment in vasodilation.An ordinary mixed meal induced a transient decline in EDV in young healthy individuals,which was associated with postprandial levels of free fatty acids in serum.In conclusion, aging induced a progressive impairment in EDV in men, probably mediated bymetabolic factors. In women, the endothelium was protected against such impairment until theage of menopause. HDL-cholesterol, vitamin E and unsaturated fatty acids were positivepredictors and LDL-cholesterol and saturated fatty acids were negative predictors of EDV.Smoking, nicotine chewing gum and mental stress impaired EDV, while an ordinary mixedmeal only transiently impaired EDV.