Changes in flow-mediated brachial artery vasoactivity with lowering of desirable cholesterol levels in healthy middle-aged men.
Current National Cholesterol Education Program guidelines consider desirable total and low-density lipoprotein cholesterol levels to be < 200 and < 160 mg/dl, respectively, for healthy individuals without multiple coronary risk factors. To determine the extent to which these levels affect vascular function, we assessed flow-mediated (endothelium-dependent) brachial artery vasoactivity noninvasively before, during, and after cholesterol lowering (simvastatin 10 mg/day) in 7 healthy middle-aged men with cholesterol levels meeting current recommendations. Flow-mediated brachial artery vasoactivity was measured using 7.5 MHz ultrasound and expressed as percent diameter change from baseline to hyperemic conditions (1 minute following 5 minutes of blood pressure cuff arterial occlusion). Flow-mediated vasoactivity rose from 5.0 +/- 3.6% at baseline to 10.5 +/- 5.6%, 13.3 +/- 4.3%, and 15.7 +/- 4.9% (all p < 0.05) as cholesterol fell from 200 +/- 12 to 161 +/- 18, 169 +/- 16, and 153 +/- 11 mg/dl after 2, 4, and 12 weeks, respectively, of cholesterol-lowering therapy. Vasoactivity and cholesterol returned to baseline levels 12 weeks after simvastatin discontinuation. Overall, vasoactivity was found to correlate inversely with cholesterol levels (r = -0.47, p = 0.004). These data suggest that flow-mediated brachial artery vasoactivity responds rapidly to changes in cholesterol levels and that endothelial function improves by lowering cholesterol levels below recommendations of current guidelines.
Vogel
R A
RA
Department of Medicine, University of Maryland School of Medicine, Baltimore, USA.
Corretti
M C
MC
Plotnick
G D
GD
D000328:Adult; D000704:Analysis of Variance; D000924:Anticholesteremic Agents / Q000494:pharmacology*; D001783:Blood Flow Velocity / Q000187:drug effects; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D008078:Cholesterol, LDL / Q000097:blood* / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008148:Lovastatin / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D019821:Simvastatin; D014463:Ultrasonography; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology
D000924:Anticholesteremic Agents; D008078:Cholesterol, LDL; D008148:Lovastatin; D019821:Simvastatin