魏偉榮,雷夢(mèng)覺(jué),曹毅,涂燕平,龔愛(ài)斌,王凌玲,艾文偉,鄔甦
(江西省人民醫(yī)院二部心血管2科,南昌 330006)
·論著·
血清褪黑素水平及晝夜分泌節(jié)律的改變與老年高血壓患者血壓晨峰的關(guān)系
魏偉榮,雷夢(mèng)覺(jué),曹毅,涂燕平,龔愛(ài)斌,王凌玲,艾文偉,鄔甦
(江西省人民醫(yī)院二部心血管2科,南昌 330006)
目的 探討血清褪黑素水平及晝夜分泌節(jié)律的改變與老年高血壓患者血壓晨峰的關(guān)系。方法 將150例老年患者(大于65歲)按2010年高血壓診斷與治療指南標(biāo)準(zhǔn),分為老年高血壓(100例)及老年健康對(duì)照組(50例),100例高血壓病患者分為晨峰血壓增高組(56例)、非晨峰血壓增高組(44例),分別測(cè)量各研究對(duì)象血清褪黑素水平及晝夜節(jié)律變化、動(dòng)態(tài)血壓。結(jié)果 與對(duì)照組和非晨峰血增高組比較,晨峰血壓增高組患者夜間血清MT水平明顯下降,差異有統(tǒng)計(jì)學(xué)意義(P<0.01);晨峰血壓增高組夜間/早晨血清MT的比值低于對(duì)照組和非晨峰血壓增高組,差異有統(tǒng)計(jì)學(xué)意義(P<0.01),晨峰血壓增高組存在MT晝夜分泌節(jié)律異常。血壓晨峰值與夜間/早晨血清褪黑素的比值呈負(fù)相關(guān)(P<0.01)。結(jié)論 晨峰血壓增高組血清褪黑素水平為白晝分泌較少,夜間分泌也無(wú)明顯增多,晝夜分泌節(jié)律異常,導(dǎo)致具有升高血壓作用的神經(jīng)-內(nèi)分泌激素受抑制減少,引起晨峰血壓增高。
高血壓;褪黑激素;晝夜節(jié)律;老年人
血壓晨峰(MBPS)是指清晨短時(shí)間內(nèi)血壓的急劇上升現(xiàn)象,MBPS增高受交感神經(jīng)系統(tǒng)激活、腎素-血管緊張素-醛固酮系統(tǒng)激活、內(nèi)皮素-1及腎上腺皮質(zhì)激素水平升高、氧化應(yīng)激等神經(jīng)內(nèi)分泌的影響。而褪黑素(MT)可以通過(guò)抑制交感神經(jīng)和興奮迷走神經(jīng)、抑制下丘腦-垂體-腎上腺軸調(diào)節(jié)醛固酮和腎素等的分泌、降低血中兒茶酚胺的水平、抗氧化等作用而降壓。褪黑素分泌減少,可引起血壓升高,而褪黑素的血漿水平隨年齡增長(zhǎng)而發(fā)生相應(yīng)變化,到老年期明顯減少[1]。因此,通過(guò)測(cè)定老年高血壓患者血清褪黑素分泌水平和晝夜分泌節(jié)律改變與血壓晨峰的關(guān)系,可進(jìn)一步了解褪黑素在老年高血壓發(fā)病中的作用及對(duì)血壓晨峰的影響。
1.1 臨床資料 選取我院2014年1月至2016年8月就診的150例老年患者。按2010年高血壓診斷與治療指南標(biāo)準(zhǔn),分為老年高血壓病組(100例)及老年健康對(duì)照組(50例)。老年高血壓組100例,男56例,女44例;年齡65~91歲,平均(80.5±8.7)歲。老年健康對(duì)照組50例,男28例,女22例;年齡66~89歲,平均(79.3±10.2)歲。分別測(cè)量各組血清褪黑素水平及節(jié)律變化、動(dòng)態(tài)血壓監(jiān)測(cè)、臂踝脈搏波傳導(dǎo)速度測(cè)定、尿微量清蛋白檢查等。排除繼發(fā)性高血壓、急性心肌梗死、急性腦血管疾病,未控制的充血性心力衰竭及白大衣高血壓患者,無(wú)肝、腎功能損傷。記錄所有入選者的一般資料包括:姓名、性別、年齡、臨床表現(xiàn)、吸煙史、既往高血壓史,以及同時(shí)記錄肝腎功能、體質(zhì)量指數(shù)(BMI)、腰/臂圍比、超聲頸動(dòng)脈內(nèi)膜中層厚度的變化。各組間的性別、年齡、血糖、血脂及體質(zhì)量指數(shù)等比較,差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05),具有可比性。
1.2 分組 所有受試者(已服藥患者檢查前停服降壓藥3 d),采用瑞士Schiller BR 102型袖帶式示波測(cè)量動(dòng)態(tài)血壓記錄儀進(jìn)行24 h動(dòng)態(tài)血壓監(jiān)測(cè),過(guò)程中記錄患者白天平均收縮壓(dSBP)、白天平均舒張壓(dDBP)、夜間平均收縮壓(nSBP)、夜間平均舒張壓(nDBP),依據(jù)《中國(guó)高血壓防治指南(2010年版)》血壓晨峰:起床后2 h平均血壓-夜間睡眠時(shí)的最低血壓(包括最低值在內(nèi)1 h的平均值),≥35 mm Hg為晨峰血壓增高組;﹤35 mm Hg為非晨峰血壓增高組。
1.3 褪黑素測(cè)定 所有研究對(duì)象分別于2∶00和8∶00抽取肘靜脈血,立即分離血清,分裝后存于-80 ℃冰箱保存,夜間抽取靜脈血時(shí),患者從睡眠中被喚醒后,帶不透光的眼罩,5 min內(nèi)完成抽血;8∶00抽血時(shí),患者空腹且保證清醒30 min以上。血清MT測(cè)定采用酶聯(lián)免疫吸附試驗(yàn)法。在兩個(gè)時(shí)間點(diǎn)的比值來(lái)表示其晝夜節(jié)律的變化。
1.4 統(tǒng)計(jì)學(xué)處理 應(yīng)用SPSS18.0統(tǒng)計(jì)軟件處理數(shù)據(jù),計(jì)量資料比較采用t檢驗(yàn),計(jì)數(shù)資料比較采用χ2檢驗(yàn),采用多元線性回歸分析血清MT水平與其他指標(biāo)的相關(guān)性。P<0.05為差異有統(tǒng)計(jì)學(xué)意義。
2.1 各組動(dòng)態(tài)血壓檢查結(jié)果比較 見(jiàn)表1。
2.2 各組血清褪黑素水平、夜間/早晨MT比值及血壓晨峰值比較 與對(duì)照組和非晨峰血增高組比較,晨峰血壓增高組患者夜間血清MT水平明顯下降,差異有統(tǒng)計(jì)學(xué)意義(P<0.01);晨峰血壓增高組夜間/早晨血清MT的比值低于對(duì)照組和非晨峰血壓增高組,差異有統(tǒng)計(jì)學(xué)意義(P<0.01),晨峰血壓增高組存在MT晝夜分泌節(jié)律異常。見(jiàn)表2。
2.3 三組間血壓晨峰值與夜間/早晨血清MT的比值相關(guān)性 經(jīng)相關(guān)分析發(fā)現(xiàn),晨峰血壓增高組、非晨峰血壓增高組和對(duì)照組的血壓晨峰值與夜間/早晨血清MT的比值呈負(fù)相關(guān)(r分別為-0.564、-0.452、-0.288,均P<0.01)。
表1 三組間動(dòng)態(tài)血壓監(jiān)測(cè)結(jié)果比較
注:與對(duì)照組比較,aP<0.01;與非晨峰血壓增高組比較,bP<0.01
表2 三組間晝夜血清MT水平、夜間/早晨MT比值及血壓晨峰值比較±s)
注:與早晨MT比較,aP<0.01;與非晨峰血壓增高組比較,bP<0.01;與對(duì)照組比較,cP<0.01
MBPS增高是心血管疾病的獨(dú)立危險(xiǎn)因素[2],特別對(duì)于老年高血壓患者,致殘率、致死率較高。血壓晨峰的發(fā)生機(jī)制較多,比較公認(rèn)的機(jī)制是交感神經(jīng)系統(tǒng)激活,清醒前后交感神經(jīng)系統(tǒng)活性迅速增強(qiáng),外周血管阻力增加及心率増快,心輸出量增加,使晨起血壓急劇升高[3];腎素-血管緊張素-醛固酮系統(tǒng)激活[4],血漿中腎素、血管緊張素Ⅱ和醛固酮清晨時(shí)段為分泌高峰,可通過(guò)擴(kuò)大血容量,促進(jìn)腎上腺髓質(zhì)和交感神經(jīng)末梢釋放兒茶酚胺等機(jī)制,顯著升高血壓。而MT主要由松果體腺分泌,呈晝夜節(jié)律性變化,白晝分泌較少,黑夜分泌較多[5],此變化與上述升高血壓的神經(jīng)-內(nèi)分泌激素的變化相反,提示它們之間可能存在著某種關(guān)聯(lián)[6]。本研究發(fā)現(xiàn)與對(duì)照組比較,無(wú)論是晨峰血壓增高組,還是非晨峰血壓增高組,高血壓病患者血清MT水平較低,提示MT與高血壓病密切相關(guān)。
已有研究發(fā)現(xiàn)MT通過(guò)自主神經(jīng)系統(tǒng)發(fā)揮降壓作用[7-8];可直接通過(guò)下丘腦-垂體-腎上腺軸調(diào)節(jié)醛固酮和腎素等的分泌,來(lái)降低血壓;通過(guò)對(duì)脈管系統(tǒng)的直接作用降壓,左室和脈管系統(tǒng)中存在MT2受體,使血管平滑肌磷酸肌醉生成抑制,降低血管對(duì)去甲腎上腺素的反應(yīng)性[9-10]。本研究發(fā)現(xiàn)晨峰血壓增高組,血清MT水平較低,且缺少晝夜節(jié)律,晨峰血壓值與夜間和清晨MT比值成負(fù)相關(guān),可能是具有降壓作用的MT分泌減少及晝夜節(jié)律消失,從而使具有升高血壓作用的神經(jīng)-內(nèi)分泌激素受抑制減少,導(dǎo)致清晨血壓急劇升高。也許對(duì)MT水平低下的晨峰血壓增高的老年高血壓患者,適當(dāng)補(bǔ)充MT,恢復(fù)期晝夜節(jié)律,有利于控制血壓,減少晨峰血壓增高,對(duì)防止其相關(guān)并發(fā)癥的發(fā)生具有重要意義。
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Relation between the serum level of melatonin,the circadian rhythm of melatonin secretion and morning blood pressure peak in elderly hypertensive patient
WeiWeirong,LeiMengjue,CaoYi,TuYanping,GongAibin,WangLingling,AiWenwei,WuSu
(TheSecondCadreWardofCardiology,JiangxiProvincialPeople′sHospital,Nanchang330006,China)
Objective To explore the circadian rhythm of melatonin and morning blood pressure peak in elderly hypertensive patient.Methods According to the 2010 Guidelines for the diagnosis and treatment of hypertension,150 cases of elderly patients (over 65 years) were divided into elderly hypertension group (100 cases) and healthy elderly control group (50 cases).100 cases of hypertension patients were divided into the morning blood pressure peak group (MBPS,56 cases) and the non morning blood pressure peak group (44 cases).The serum level of melatonin,the circadian rhythm of melatonin secretion and ambulatory blood pressure were measured.Results Compared with the control group,the serum level of melatonin were significantly decreased in the morning blood pressure peak group and the non morning blood pressure peak group(P<0.01);The ratio of melatonin level at nighttime/daytime was lower in the morning blood pressure peak group than that in the control group and the non morning blood pressure peak group(P<0.01),There were negative relation in the control group,the non morning blood pressure peak group and the morning blood pressure peak group between the ratio of melatonin level at nighttime/daytime and the level of morning blood pressure peak(P<0.01).Conclusion The secretion of melatonin in the morning blood pressure peak group is lower in the daytime, not increased significantly in the nighttime,abnormal circadian secretion. with the inhibition of neuroendocrine hormones which causing elevated blood pressure is decreased, the level of morning blood pressure peak increases.
Hypertension;Melatonin;Circadian rhythm;Aged
江西省衛(wèi)生廳立項(xiàng)課題(20143028)
魏偉榮,主治醫(yī)師,Email:wwr5636@126.com
R544.1
A
10.3969/J.issn.1672-6790.2017.04.018
2016-11-10)