Dyslipidemia evaluated by brachial artery vasoactivity: a case study of eight patients.

Current National Cholesterol Education Program (NCEP) guidelines consider a desirable low-density lipoprotein cholesterol level to be < 100 mg/dl for an individual with coronary artery disease (CAD). To assess the affect of these cholesterol levels on endothelial cell functioning, flow-mediated brachial artery vasoactivity was measured non-invasively (7.5 MHz ultrasound) before and during Simvastatin (Zocor) therapy. Vasoactivity was expressed as a percent diameter change from baseline to hyperemic conditions and increased from 2.4 +/- 3.0% at baseline to 13.1 +/- 3.4% (p < .05) and 15.1 +/- 2.7% (p < .01) as cholesterol decreased from 243 +/- 24.7 to 221 +/- 27.3 and 213 +/- 22 mg/dl after three and six months, respectively, during therapy. LDL cholesterol subsequently decreased from 155 +/- 22.1 at baseline to 143 +/- 20.2 and 130 +/- 10.6 after three and six months of treatment, respectively. In conclusion, vasoactivity was found to correlate inversely with cholesterol levels (r = 0.44). This suggests that vasoactivity responds to changes in cholesterol levels and that endothelial function improves by lowering cholesterol levels.