Objectives To investigate the effects of simvastatin therapy on vascular endothelial function in patients with coronary heart diseases (CAD).
Methods 90 patients with CAD were divided into three groups: group 1 (37patients, simvastatin 20mg daily for 8 weeks) and group 2 (35patients, simvastatin 10mg daily for 8 weeks), control group (18 patients, simvastatin 0 daily for 8 weeks). The flow-mediated dilatation (FMD) of brachial artery can be evaluated using high resolution ultrasound assessment of changes in the brachial artery diameter of subjects. The content of serum nitric oxide were detected by using the enzyme reduction of nitrate, respectively. Total cholestero,l triglyceride, low den-sity lipoprotein and high density lipoprotein for each group were measured by routine ways.
Results This study showed that the percentage of flow-mediated dilatation increased and the content of serum nitric oxide was enhanced more significantly in simvastatin therapy group than the control group (P<0.05). In simvastatin groups and control group, the values of FMD was (4.64 ± 0.08)% (9.01 ± 0.39)% (20mg), (4.55 ± 0.17)% (9.01 ± 0.47)% (10mg), (5.01 ± 0.49)% (6.01 ± 0.49)% respectively (P<0. 05)before and after treatment. In simvastatin groups and control group, the content of serum nitric oxide was (34.8 ± 7.03) umol/lvs (47.67 ± 10.89)umol/l (20mg), (36.9 ± 8.01) umol/l vs (45.61 ± 9.09)umol/l (10mg), (35.1 ± 6.93) umol/lvs (38.97 ± 8.89)umol/l (control group) respectively (P<0.05)before and after treatment in simvastatin therapy group than the control group. Compared with the simvastatin therapy and control group, total cholesterol, triglyceride and low density lipoprotein de-creased and high density lipoprotein increased in simvastatin therapy group (P<0.05). But there was no significant difference between the group 1 and group 2 in the FMD (P<0.05).
Conclusions Simvastatin can increase the content of serum nitric oxide, improve endothelial function of patients with CAD. The effects of simvastatin therapy on improving vascular endothelial function might mainly relate to the decrease in the concentration of blood lipids, but it has no obvious dose-dependent effect.