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.
Department of Medicine, University of Maryland School of Medicine, Baltimore, USA.
R A
RA
Vogel
M C
MC
Corretti
G D
GD
Plotnick
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