Non-Doses Dependent Effect of Simvastatin on Endothelium Dependent Vasodilation in Patients with Hypertension Complicated with Hyperlipidemia

Objective To test the hypothesis if the effect of simvastatin on vascular endothelial flux modula- ted dilation(FMD)is associated with dose dependent effect on plasma LDL-C or total cholesterol in patients with hypertension complicated with hyperlipidemia.Methods Eighty patients with hypertension complicated with hy- perlipidemia were included and randomly assigned to receive placebo or various simvastatin(5,10,20 mg/d),(n =20,each group),with non-simvastatin treated patients(n=20)as control.The endothelial FMD of brachial artery was measured by ultrasound technique before and after 8 weeks treatmemt.The changes of lipids profiles were determined.Results After 8 weeks,decreases in serum total cholesterol(TC)(9%,18%,29%)and the serum low density lipoprotein cholesterol(LDL-C)(12%,24 %,35 %,respectively)shown in the 3 simvastatin groups(P0.05),with little changes in control subjects.All 3 doses of simvastatins increased FMD significant- ly(5 mg:before:3.4%±3.0% vs after:7.5%±5.1%;10 mg:before:3.8%±3.0% vs after:8.0%±4.9%,20 mg:before:3.6%±3.5% vs after:8.1%±6.1%;P0.01),with no statistic difference among them.The in- crease of FMD by 3 doses of simvastatin did not correspondingly relate to the changes of TC and LDL-C level. There was no significant change in vasodilatation response to nitroglycerin and brachial diameter in all groups after simvastatin therapy.Conclusion Simvastatin obviously improves the vascular endothelial function of patients with hypertension complicated with hyperlipidemia.However,on the contrary to statin dose-dependent effect on TC and LDL-C,no analogous dose-dependent effect relationship on simvastatin on vascular endothelial function was shown.