PATHOGENESIS OF ATHEROSCLEROSIS

Atherosclerosis is a disease which affects large and medium-sized arte ries. Typical features of atherosclerosis are accumulation of intra- a nd extracellular lipids, foam cell formation, proliferation of smooth muscle cells and accumulation of connective tissue. Plasma lipids and lipoproteins play an important role in the formation of atheroscleroti c lesions, Recent evidence suggests that oxidation of low-density lipo protein (LDL) may play an important role in the pathogenesis of athero sclerosis. Incidence of cardiovascular diseases increases significantl y after menopause. Part of the increase is due to atherogenic changes in plasma lipoproteins, i.e. increase in LDL and decrease in high dens ity lipoprotein (HDL). Clinical endpoints of cardiovascular diseases a re usually caused by atherosclerosis and thrombosis, both of which can be influenced after menopause by sex steroids. Hormone replacement th erapy has anti-atherogenic effects on plasma lipoprotein fractions. Re cent evidence also suggests that estrogens may have several protective effects on the vascular wall, including direct inhibition of LDL degr adation, oxidation and smooth muscle cell proliferation.