The Effect Of A Different Treatment Time In Hypertension Patients With Ambulatory Blood Pressure And Target Organ

Background:Hypertension has become one of the most important risk factor ofcardiovascular disease in our country,and has the highest incidence in congestive heartfailure,ischemic or hemorrhagic stroke and coronary heart disease compared withsmoke,blood lipid abnormalities,diabetes and obesity[1].An investigation progressed bythe Chinese Center For Disease Control And Prevention about adult hypertensionepidemiology in our country in2010showed that the prevalence of hypertension was33.5%.The number were estimated to330million people[2].Therapies taking medicinein different time according to the rhythm of blood pressure,namely chronotherapy,hasbeen proposed nearly30years.A series of clinical trials have confirmed that patientswith hypertension have activated sympathetic nervous system and abnormal reninangiotensin aldosterone system (RAAS) activation at night,which increasethe night-time blood pressure level,and lead to abnormal24-hour blood pressure rhythm.Also,they can cause target organ damage,such as left ventricular hypertrophy,carotidartery intima-media thickness,microalbuminuria,eyeground arteriosclerosis,etc.Thus,itis a simple,high cost-effective and practicable therapies that take long-termantihypertensive drugs at bedtime to better control the average blood pressure atnight,increase nocturnal blood pressure drop,restore normal blood pressure rhythm, andeven control the average blood pressure in the early morning.Objective:By adopting ways of taking antihypertensive at different treatment timeto observe the change of ambulatory blood pressure and the related parameters of targetorgan damage in patients with mild-to-moderate hypertension,so as to analyza theprotective effect of a different treatment time with Ambulatory Blood PressureMonitoring(ABPM)and target organ damage.Methods:The67patients admitted to the Department of Cardiology of FirstAffiliated Hospital of Dalian Medical University from April2013to March2014wereenrolled in this study.All patients conform to the diagnostic criteria of 《China’sprevention and control of hypertension guidelines》revised in2010.The history,bloodroutine,biochemical test, ABPM,Electrocardiogram(ECG),Microalbuminuria/creatinine(Ma/Cre),Pulse WaveVelocity(PWV) and Ankle Brachial Index (ABI) were obtained in the hospital.Patientswere randomly distributed into two groups of taking telmisartan(Micardis,80mg/pill,produced by BoehringerIngelheim company)40/80mg sincemorning（6：:00-8:00）and at night(18:00-20:00),or combined with the calcium channelblocker(CCB) Amlodipine(Norvasc,5mg/pill,produced by Pfizer company)5mg/d atmorning.Followed up for8weeks,patients were called for reviewingABPM,ECG,Ma/Cre,PWV and ABI,and observing changes on both sides.In presentstudy,left ventricular voltage(RV5+SV1) obtained from ECG is used to evaluate leftventricular hypertrophy,Ma/Cre is used to evaluate early renal damage,PWV and ABI isused to evaluate peripheral vascular function.The mean systolic and diastolic blood pressure in the morning is defined as mean blood pressure acquired from ABPM at6:00-8:00.The SPSS version19.0and ECCEL2003are applicated for statisticalprocessing and analysis;the continuous variables are demonstrated in the form of“mean±standard deviation”;the two independent samples t test is applied to comparegeneral data and changes between groups;paired t test is applied to compare the resultsbefore and after follow-up;the classification variables is compared by chi-squaretest;two sides P<0.05is regard as statistical differences and P<0.01was regard assignificant differences.Results:1.The comparison of basic data between the two groups did not showstatistical significance(P>0.05)[sex,age,body massindex(BMI),smoking,dringking,familyhistory,FBG,ALT,AST,Cre,TC,TG,LDL-C,HDL-C,Na+,K+,amlodipine,telmisartan].2.Overall and between groups before and after the follow-up have a significant decreasein24h mean systolic pressure(24hMSBP),24h mean artery pressure(24hMAP),daytimemean systolic pressure(dMSBP),daytime mean artery pressure(dMAP),nocturnal meandiastolic pressure(nMDBP),nocturnal mean artery pressure(nMAP),morning meansystolic pressure(mSBP),and the difference is statistically significant.In addition,the24hmean diastolic pressure(24hMDBP),daytime mean diastolicpressure(dMDBP),nocturnal mean systolic pressure(nMSBP),morning mean diastolicpressure(mDBP) of the overall;24hMDBP and dMDBP of group taking telmisartan inthe morning;nMSBP,nocturnal systolic pressure drop percentage(SBP%),nocturnaldiastolic pressure drop percentage(DBP%),mDBP of group taking telmisartan at nightalso decreased respectively,and the difference is statistically significant.3.Comparedwith the morning group,the evening group acquires more significant decrease innMSBP(6±17vs17±12mmHg,P<0.01),nMAP(5±11vs11±10mmHg,P<0.05) andmSBP(10±14vs20±19mmHg,P<0.05),and more significant increase inSBP%(2.39±8.84vs-3.49±8.4%，P<0.05),DBP(1.97±10.52vs-4.76±9.68%,P<0.05).4.There are significant decrease in RV5+SV1of the overall,RV5+SV1of the morninggroup and ABI of the evening group.Compared with the morning group,the other had astatistical decrease in R-ABI（0.04±0.08vs-0.03±0.16,P<0.05）.5.At8weeks,there isno statistical differences in Ma/Cre（P总体=0.718，P早=0.438，P晚=0.195，PMa/Cre=0.138）and PWV（P总体=0.517，P早=0.326，P晚=0.088，PPWV=0.2）.Conclusion:1.Telmisartan can obviously reduce the blood pressure of patientswith mild-to-moderate hypertension;2.Compared to taking telmisartan in themorning,taking at night more effectively reduces the mean systolic blood pressure,andmakes more patients blood pressure rhythm to returned to normal dipper type;3.Takingmedicine at night can be more effective in reducing the mean systolic blood pressure inthe morning,so as to reduce the occurrence of hypertension in the earlymorning;4.Taking medicine at night may protect peripheral arterial through improve theABI,and this is not found in the morning group;5.Ma/Cre and PWV have no obviouschanges in eight-week drug intervention.