The effects of lipid-lowering and antioxidant vitamin therapies on flow-mediated vasodilation of the brachial artery in older adults with hypercholesterolemia

Objectives The goal of this study was to determine the long-term effects of statins and antioxidant vitamins on flow-mediated vasodilation of the brac hial artery in older adults with hypercholesterolemia. Background Lipid-lowering therapy and antioxidant vitamins improve endothel ium-dependent vasodilation in young and middle-aged adults with hypercholes terolemia, but their effects in older adults are not known. Methods Two double-blind, placebo-controlled studies were performed in indi viduals greater than or equal to 70 years old with low-density lipoprotein cholesterol (LDL-C) greater than or equal to 140 mg/dl. In the first study, 37 subjects were randomized to receive (group 1) pravastatin for six month s then pravastatin and vitamin E for six additional months or (group 2) vit amin E for six months, then pravastatin and vitamin E for six additional mo nths. In the second study, additional 17 subjects sequentially received sim vastatin for six months, then simvastatin an vitamins C and E for six addit ional months. Flow-mediated vasodilation of the brachial artery was measure d by high-resolution ultrasound. Results At baseline, subjects in both studies were similar in age (mean +/- SD, 75.8 +/-4.2 years), gender, Systolic blood pressure, total cholesterol (261.6 +/- 37.4 mg/dl), LDL-C (180.3 +/- 28.1 mg dl), high-density lipopro tein cholesterol and triglycerides levels. Flow-mediated vasodilation was s everely impaired (2.2 +/-3.9%). Both statins reduced total and LDL-C levels (p<0.001); however, neither statin, antioxidant vitamin regimen nor the co mbination of statins and antioxidant vitamins improved flow-mediated vasodi lation of the brachial artery. At baseline, nitroglycerin-mediated vasodila tion also was impaired (10.7<plus/minus>5.6%) and did not change in either study. Conclusions Older adults with hypercholesterolemia have impaired Row-mediat ed vasodilation of the brachial artery that does not improve after one year of therapy with statins and antioxidant vitamins, despite significant lipi d-lowering. (J Am Coll Cardiol 2001;38:1806-13) (C) 2001 bv the American Co llege of Cardiology.