The Effect Of L-amlodipine And Amlodipine On Vascular Endothelial Function In Patients With Essential Hypertension

Objective: To observe the effect of L-amlodipine and amlodipine on endothelial function, blood pressure, and plasma lipid in patients with essential hypertension(EH) and compare the effects of the two dugs.Methods: Sixty -four subjects with EH were randomized to either L-amlodipine 5mg daily or amlodipine in a mono-blind fashion, two drugs were crossed during the observation. Twenty healthy subjects were observed as controlled group. The endothelium-dependent vasodilation were observed by using high differentiate ultrasounds imagines measuring brachial artery diameter by celemajer method. The plasma cholesterol levels and blood pressure levels were measured simultaneously. The condition of the endothelial function before and after treatment were analysed and the effect of L-amlodipine and amlodipine were compared too. The relationship of endothelial function and plasma cholesterol levels was analysed .The relationship of endothelial function and the danger risk rank of the patients were analysed too.Results: l.The flow-mediated vasodilation of two EH patients groups were greatly impaired compared to healthy group (3.7+4.2, 2.7+4.3 v.s. 17.2+4.1, PO.01) .After using L-amlodipine or amlodipine for 6 weeks, the FMD were all improved compared with baseline (7.4+4.3 6.5 + 3.3, P<0.01). There was no significant difference between the two groups (P>0.05), whereas the difference to the controlled subjects was still existed (P<0.01). After 6 weeks two drugs were crossed and the FMD were improved continuously. (P<0.01) There was no significant difference between two groups (P>0.05), whereas the difference with controlled group was still existed (P<0.01). The vasodilation to glyceryl trinitrate before and after intervention had no significant difference with controlled group (P>0.05). 2. The BP was reduced markedly after treatment and there was no difference (P>0.05) between the two groups.3. After 6 weeks treatment the plasma cholesterol levels did not change. (P>0.05) After 12 weeks treatment the plasma cholesterol levels decreased slightly (P<0.01). The two groups had no difference (P>0.05). The changes of cholesterol levels were negative correlative with the changes of FMD(r=-0.46,P<0.01). 4.The FMD before treatment and its changes after treatment were negative correlative with the risk rank of the hypertension patients (rs/=-0.45,P<0.02 =-0.50 P<0.01).Conclusions: Endothelium-dependent vasodilation was impaired in EH patients .The FMD in all patients were impairedand can be improved by using L-amlodipine and amlodipine. And the effect of L-amlodipine had no difference with double-dose amlodipine. The longer time the drugs were used, the more significant effects were observed. The higher the risk rank of EH patients were, the more damage the FMD had. It suggests that the drugs that can improve the FMD such as L-amlodipne may have a better effect on FMD and may contribute to prevent the subsequent cardiac events. The plasma level of cholesterol has a negative correlation with FMD and L-amlodipine had a weak effect in decreasing the plasma levels of cholesterol.