Objective To investigate the effect of perindopril combined with amlodipine and perindopril combined with hydrochlorothiazide on blood pressure variability in elderly patients with hypertension.Methods A total of80 elderly patients with hypertension who were admitted to a hospital in Beijing from January 2018 to January2019 were selected as the research subjects.The patients were divided into a control group and a study group using a random number table

with 40 patients in each group.Patients in the control group were treated with perindopril combnined with hydrochlorothiazide

and patients in the study group were treated with perindopril combined with amlodipine.Both groups were treated for 8 weeks.The daytime systolic blood pressure（dSBP）

nighttime systolic blood pressure（nSBP）

24 hsystolic blood pressure（24 hSBP）

coefficient of variation of24 hsystolic blood pressure（24 hSCV）

coefficient of variation of daytime systolic blood pressure（dSCV）

coefficient of variation of nighttime systolic blood pressure（nSCV）

daytime diastolic blood pressure（dDBP）

nighttime diastolic blood pressure（nDBP）

24 hdiastolic blood pressure（24 hDBP）

coefficient of variation of24 hdiastolic blood pressure（24 hDCV）

coefficient of variation of daytime diastolic blood pressure（dDCV）

coeffitient of variation of nighttime diastolic blood pressure（nDCV）

and changes in relevant endothelial function indices including endothelin（ET）

nitric oxide（NO）

endothelial nitric oxide synthase（eNOS）

carotid intimamedia thickness（IMT）and flow-mediated diamete（FMD）before and after treatment were compared.The adverse reactions and complications of the two groups were compared.Results Before treatment

there was no significant difference in 24 hSBP

dSBP

nSBP

24 hSCV

dSCV

and nSCV between the two groups（P>0.05）.After treatment

the 24 hSBP

dSBP

nSBP

24 hSCV

dSCV

and nSCV of the two groups were lower than before treatment

and those of the study group were significantly lower than those of the the control group（P<0.05）.Before treatment

there was no significant difference in 24 hDBP

dDBP

nDBP

24 hDCV

dDCV

and nDCV between the two groups（P>0.05）.After treatment

the 24 hDBP

dDBP

nDBP

24 hDCV

dDCV

and nDCV of the two groups were lower than before treatment

and the 24 hDCV

dDCV

and nDCV of the study group were significantly lower than those of the control group（P<0.05）.Before treatment

there was no significant difference in the levels of ET

NO

eNOS

IMT

and FMD between the two groups（P>0.05）.After treatment

the levels of ET and IMT of the two groups were lower than before treatment

and those of the study group were significantly lower than those of the control group（P<0.05）;the levels of NO

eNOS

and FMD of the two groups were higher than before treatment

and those of the study group were significantly higher than those of the control group（P<0.05）.No adverse drug reactions or serious complications was observed during treatment.Conclusion Perindopril combined with amlodipine and perindopril combined with hydrochlorothiazide can effectively treat hypertension in the elderly.Both therapies can safely and effectively control the blood pressure level of patients and reduce blood pressure variability

while perindopril combined with amlodipine is more effective.According to the actual condition of the patient

appropriate drug treatment options can be selected to improve the effectiveness and safety of clinical treatment of hypertension in the elderly.