老年正常高值血压者动态血压及节律与中心动脉反射波增强指数的关系

目的探讨正常高值血压者动态血压及节律与中心动脉反射波增强指数的关系。方法选择正常血压者(正常组)138例,正常高值血压者(高值组)121例,高血压者(高血压组)100例,采用动态血压监测仪监测动态血压及节律;采用动脉脉搏波分析仪测量中心动脉压及增强指数(AIx)。结果与正常组比较,高值组24h平均收缩压、24h平均舒张压、昼间平均收缩压、昼间平均舒张压、夜间平均收缩压、夜间平均舒张压、中心动脉收缩压、中心动脉舒张压、中心动脉脉压、增强压、AIx均明显升高,夜间收缩压下降率明显降低(P<0.05)。正常高值血压经多元线性逐步回归分析显示,性别、年龄、吸烟、夜间收缩压下降率、非杓型血压发生率为AIx的主要影响因素。经协方差分析,血压水平与非杓型血压发生率对AIx均有影响,且有协同作用(F=12.37,P<0.05)。结论非杓型血压单独对AIx有影响,且与高水平血压有协同叠加效应。     

血压正常高值者动脉僵硬度与动态血压参数的关系

目的探讨血压正常高值者动脉僵硬度与动态血压参数的关系。方法选择理想血压者63例,血压正常高值者74例,高血压者67例。监测所有入选者24 h动态血压,应用脉搏波传导速度测定仪测定颈动脉-桡动脉脉搏波传导速度。结果血压正常高值组24 h收缩压、24 h舒张压、白昼收缩压、白昼舒张压、夜间收缩压、24 h脉压、白昼脉压及夜间脉压均高于理想血压组,低于高血压组(P<0.05或P<0.01);血压正常高值组夜间舒张压低于高血压组(P<0.05)。血压正常高值组颈动脉-桡动脉脉搏波传导速度(9.67±1.12 m/s)显著高于血压理想组(8.27±0.99 m/s),低于高血压组(10.55±1.71 m/s;P<0.05或P<0.01)。多元线性回归分析显示,24 h收缩压、24 h脉压、夜间收缩压是颈动脉-桡动脉脉搏波传导速度的影响因素(β值分别为0.385、0.351及0.247,P<0.05)。结论血压正常高值者动脉僵硬度增高,24 h收缩压、24 h脉压、夜间收缩压是影响动脉弹性的主要因素。     

血压正常高值者动态血压负荷及血压变异性与肿瘤坏死因子α的相关性

目的探讨血压正常高值者动态血压负荷及血压变异性与肿瘤坏死因子α(TNF-a)的关系。方法选择理想血压者100例,血压正常高值者105例,高血压患者110例,进行24 h动态血压监测,分别计算三组动态血压负荷及血压变异性,并测定TNF-a水平。结果血压正常高值组TNF-a水平、24 h、白昼及夜间动态血压负荷高于理想血压组,低于高血压组(P<0.01)。血压正常高值组24 h、白昼及夜间血压变异性高于理想血压组,24 h及白昼收缩压变异性、24 h及夜间舒张压变异性低于高血压组(P<0.05)。Pearson相关分析及多元逐步线性回归分析显示,血压正常高值组TNF-α与24 h收缩压负荷、24 h舒张压负荷、24 h收缩压变异性、白昼收缩压负荷、夜间舒张压负荷、夜间收缩压变异性呈正相关(P<0.05),24 h收缩压负荷及变异性、夜间收缩压负荷及变异性是TNF-α的影响因素(P<0.01)。结论血压正常高值者动态血压负荷及血压变异性与TNF-α相关,高血压早期炎症与血压升高有关。     

原发性高血压患者血压昼夜节律、血压变异性与动脉粥样硬化的相关性研究

目的:探讨原发性高血压患者的血压昼夜节律、血压变异性与动脉粥样硬化的关系。方法:入选原发性高血压患者120例,行24 h动态血压监测,根据血压昼夜节律分为杓型组(n=22)、非杓型组(n=36)和反杓型组(n=62)。分析比较3组的血压变异性、冠心病发生率及颈动脉斑块检出率。结果:反杓型组的24 h收缩压标准差(24hSSD)、24 h舒张压标准差(24hDSD)、白昼收缩压标准差(dSSD)、白昼舒张压标准差(dDSD)、24 h收缩压变异系数(24hSBP-CV)、夜间收缩压变异系数(nSBP-CV)均低于杓型组;反杓型组的24hDSD、dDSD、24hDBP-CV低于非勺型组;反杓型组冠心病发生率及颈动脉斑块检出率较杓型组明显升高(P均<0.05)。结论:原发性高血压患者血压昼夜节律异常对动脉粥样硬化进展可能有促进作用。     

老年高血压患者动态血压负荷和脉搏波传导速度的相关性研究

目的探讨老年高血压患者24 h动态血压负荷与颈桡动脉脉搏波传导速度(crPWV)的相关性。方法选取60～79岁的老年原发性高血压患者187例,对所有入选对象进行24 h动态血压监测,根据获取的24 h动态血压监测参数分为杓型组90例与非杓型组97例,选择同期体检人群82例为正常对照组。所有受试者行24 h动态血压监测,应用脉搏波速度测定仪测定crPWV,并进行分析。结果杓型组及非杓型组24 h、昼间及夜间收缩压、舒张压负荷均显著高于正常对照组(P<0.01)。非杓型组夜间血压负荷较杓型组升高(P<0.05)。杓型组及非杓型组crPWV均较正常对照组升高(P<0.05)。控制性别、年龄因素后,老年高血压患者24 h收缩压、夜间收缩压负荷、昼间舒张压负荷是crPWV影响的主要因素。结论老年高血压患者动态血压负荷升高,大动脉顺应性降低,其中24 h收缩压、夜间收缩压负荷、昼间舒张压负荷是影响大动脉顺应性的主要危险因素。     

正常血压者血压变异性与血压节律的相关性

目的探讨正常血压者血压变异性特点及其与血压昼夜节律、年龄和性别的关系。方法选择2002年1月至2011年12月在福建医科大学附属第一医院门诊(或体检中心)检查动态血压的正常血压者1024人。收集动态血压相关数据,分析24h血压标准差(24hBPSD)、白天血压标准差(dBPSD)、夜间血压标准差(nBPSD)、24h血压加权标准差(24hBPWSD)。采用血压标准差、变异系数来表示血压变异性,采用公式[(白天平均收缩压-夜间平均收缩压)/白天平均收缩压]计算夜间血压下降率,根据夜间血压下降率分为反杓型、非杓型、杓型和超杓型;按年龄分为40、40~50、50~60、≥60岁。结果正常血压人群反杓型、非杓型、杓型和超杓型的比例分别为6.0%、47.0%、43.6%、3.4%。正常血压人群24 h收缩压标准差为(12.8±3.4)mm Hg;24 h舒张压标准差为(9.1±2.2)mm Hg;24h收缩压变异系数为0.11±0.03;24h舒张压变异系数0.13±0.03。反杓型、非杓型、杓型、超杓型组24hBPSD、dBPSD、24hBPWSD逐渐增加,除反杓型与非杓型组外,其他组两两比较,差异有统计学意义(均P0.05),而4组nBPSD比较,差异无统计学意义(均P0.05)。24h、白天和夜间收缩压标准差随着年龄增加而升高(P0.05),而舒张压标准差差异无统计学意义(P0.05);男性较女性血压变异性高,但差异无统计学意义(P0.05)。结论正常血压人群杓型和超杓型血压变异性高于非杓型或反杓型。随着年龄增大,收缩压变异性逐渐增大,而与性别无明显相关。     

血压正常高值者动态血压变化与动脉顺应性的相关性研究

目的探讨血压正常高值者24 h动态血压变化与颈桡动脉脉搏波传导速度(crPWV)、颈动脉内膜中层厚度(IMT)的相关性。方法入选受试对象286例,其中理想血压组(血压<120/80 mm Hg,1 mm Hg=0.1 33 kPa)90例,血压正常高值组196例,对所有入选对象进行24 h动态血压监测,根据监测参数将血压正常高值组又分为杓型组103例,非杓型组93例,同时进行crPWV及颈动脉IMT检测。结果非杓型组24h收缩压均值较杓型组升高[(122.00)±9.74)mm Hg vs(11 6.74±8.66)mm Hg,P<0.05]。非杓型组夜间血压各指标均较杓型组明显升高(P<0.01),非杓型组crPWV较杓型组升高[(9.53±1.14)m/s vs(8.38±0.88)m/s.P<0.05],非杓型组IMT较杓型组升高[(0.93±0.11)mm vs(0.81±0.1 2)mm,P<0.05],多元回归分析显示,夜间收缩压均值、夜间收缩压下降率、夜间舒张压均值等是crPWV的影响因素,夜间舒张压下降率、24 h收缩压均值、甘油三酯是IMT的影响因素。结论血压昼夜节律异常与crPWV及IMT密切相关,血压正常高值者已出现血管结构与弹性功能异常。     

高龄老年高血压患者动态血压特点

目的探讨高龄老年高血压患者动态血压特点。方法选择我院心血管内科及老年医学科住院的高血压患者265例,按年龄分为高龄老年组(年龄≥80岁)94例、老年组(60～79岁)90例和60岁组81例,行动态血压监测,分析其血压节律、3个时段(24h、昼间及夜间)血压均值及血压变异性的特点。结果高龄老年组和老年组杓型血压发生率、24h舒张压、昼间舒张压、昼间平均压、夜间舒张压明显低于60岁组,反杓型血压发生率、24h脉压、昼间脉压、夜间收缩压、夜间脉压明显高于60岁组(P0.05,P0.01);高龄老年组杓型血压发生率及24h、昼间、夜间舒张压明显低于老年组[13.83%vs 26.66%,(66.17±7.39)mm Hg(1mm Hg=0.133kPa)vs (70.39±10.96)mm Hg,(66.90±7.55)mm Hg vs (70.88±11.68)mm Hg,(64.10±8.14)mm Hg vs (68.27±11.86)mm Hg,P0.05,P0.01],24h、夜间脉压明显高于老年组(P0.05,P0.01),昼间收缩压变异明显高于老年组和60岁组,24h收缩压变异高于60岁组,差异有统计学意义(P0.01);老年组24h平均压明显低于60岁组(P0.05)。结论高龄老年高血压患者动态血压表现出血压节律异常、脉压增大、血压变异性升高等特点。     

原发性高血压患者血压变异性与早期肾损害

目的探讨血压变异性(BPV)和原发性高血压患者早期肾损害的关系。方法根据尿白蛋白与尿肌酐比值(UACR)把181例原发性高血压患者分为两组,UACR≤30mg/g为单纯高血压组(A组,120例),UACR>30mg/g为合并早期肾损害组(B组,61例),行24h动态血压监测,BPV以血压标准差和变异系数表示,用Pearson相关分析和多元线性回归分析比较两组患者BPV和早期肾损害之间的关系。结果两组患者各个时段的血压均值差异无统计学意义(P>0.05);除白昼收缩压变异性外,A组和B组24h收缩压变异性[标准差(13.6±3.0)比(15.3±4.1)mmHg;变异系数(0.11±0.02)比(0.12±0.03)]、24h舒张压变异性[标准差(9.6±2.6)比(11.8±4.2)mmHg;变异系数(0.13±0.04)比(0.15±0.05)]、白昼舒张压变异性[标准差(9.5±3.0)比(11.3±4.6)mmHg;变异系数(0.12±0.04)比(0.14±0.06)]、夜间收缩压变异性[标准差(10.0±3.9)比(13.2±4.7)mmHg;变异系数(0.08±0.03)比(0.11±0.04)]和夜间舒张压变异性[标准差(7.7±3.7)比(10.0±3.8)mmHg;变异系数(0.11±0.05)比(0.14±0.05)]差异均有统计学意义(均P<0.05)。Pearson相关分析显示UACR与24h收缩压变异性、24h舒张压变异性、白昼舒张压变异性、夜间收缩压变异性及夜间舒张压变异性呈正相关(均P<0.01)。多元线性回归分析显示UACR与夜间收缩压变异性、24h舒张压变异性、夜间舒张压水平和三酰甘油呈正相关(均P<0.05)。结论原发性高血压患者夜间收缩压变异性、24h舒张压变异性、夜间舒张压水平和三酰甘油与早期肾损害相关。     

老年单纯收缩期高血压患者动态血压参数对脑白质病变的影响

目的探讨老年单纯收缩期高血压(ISH)患者24h动态血压参数对脑白质病变(WML)的影响。方法选择老年ISH患者96例,根据WML评分标准分为无-轻度WML组49例和中-重度WML组47例,比较2组患者一般情况及动态血压参数。结果中-重度WML组24h收缩压、昼间收缩压、夜间收缩压、昼间收缩压变异系数、夜间收缩压变异系数、非杓型、反杓型比例明显升高,而24h舒张压、昼间舒张压、夜间舒张压及杓型比例明显降低(P<0.05)。多因素logistic回归分析显示,24h收缩压(OR=2.89,95%CI:1.14~5.89,P=0.016)、昼间收缩压变异系数(OR=1.75,95%CI:1.30~3.42,P=0.005)、夜间收缩压变异系数(OR=1.46,95%CI:0.99~1.55,P=0.001)及年龄(OR=1.13,95%CI:0.82~1.57,P=0.021)是WML的独立危险因素。结论老年ISH患者24h收缩压、昼间收缩压变异系数、夜间收缩压变异系数是WML的独立危险因素,高收缩压、低舒张压、高收缩压变异系数及异常的血压节律对WML的发生、发展有不良影响。     

降压治疗对老老年高血压患者动态血压节律影响研究

目的:研究降压治疗对老老年高血压患者动态血压节律的影响。方法:167例老老年高血压患者被随机分为降压治疗组(吲哒帕胺,或培托普利治疗)和安慰剂对照组,对比治疗1年。所有病例在安慰剂洗脱2个月后和治疗1年结束时,分别2次接受24 h动态血压监测(ABPM),并进行统计分析。结果:对照组和治疗组治疗前动态血压各指标比较均无显著性差异,节律为非杓型。治疗组治疗后SBP、SBP-L和PP显著降低(P<0.01),且较对照组显著降低(P<0.01);收缩压夜间下降率(SBPF)和舒张压夜间下降率(DBPF)分别为(5.8±1.98)%、(6.4±2.11)%,较对照组显著下降(P<0.05),动态血压节律呈浅杓型。结论:降压治疗对于减轻老老年高血压患者的靶器官损害可能有重要意义。     

Assessment of mean platelet volume and soluble CD40 ligand levels in patients with non-dipper hypertension,dippers and normotensives

Abstract

Objective: Patients with a lack of nocturnal decline in blood pressure (BP) are at an increased risk for cardiovascular events. Mean platelet volume (MPV) and soluble CD40 ligand (sCD40L) are accepted biomarkers of platelet activation and considered as a risk factor for cardiovascular disease. The aim of this study was to determine whether MPV and sCD40L levels are higher in non-dipper hypertensive (NDHT) patients than in dipper hypertensive (DHT) patients and healthy controls.

Methods: 124 consecutive patients were included to this study. Patients were divided into three groups: NDHT patient group [n?=?43; mean age 51.8?±?6.6; 31?males (72.1%)]; DHT patient group [n?=?41; mean age 50.2?±?7.3; 22?males (53.7%)]; and normotensive group [n?=?40; mean age 49.9?±?6.7; 22?males (55%)]. Physical examination, laboratory work-up and 24-h ABPM were performed for all participants.

Results: The sCD40L and MPV levels were significantly higher in the NDHT group than in the DHT and normotensive groups (p?<?0.05). In correlation analysis, MPV, 24-h systolic blood pressure (SBP), 24-h diastolic blood pressure (DBP), night-time SBP and night-time DBP were positively correlated with sCD40L.

Conclusion: Our study demonstrated that MPV and sCD40L levels were significantly higher in NDHT patients compared to DHT and normotensive patients. sCD40L levels were positively correlated with MPV, 24-h SBP, 24-h DBP, night-time SBP and night-time DBP.     

Ambulatory blood pressure monitoring in patients with hyperthyroidism before and after control of thyroid function

BACKGROUND AND OBJECTIVE: Thyroid hormones have pronounced effects on the cardiovascular system. Thyrotoxicosis affects blood pressure (BP), modifying both diastolic (DBP) and systolic (SBP) pressures. There are no studies examining BP with ambulatory blood pressure monitoring (ABPM) in hyperthyroidism before and after control of thyroid function. Our aims were (1) to analyse ABPM in a group of normotensive hyperthyroid patients before and after normalizing circulating thyroid hormones and (2) to compare these results with those obtained in a group of euthyroid subjects. PATIENTS AND MEASUREMENTS: We studied 20 normotensive hyperthyroid subjects [18 women; age (mean +/- SEM) 49.0 +/- 3.0 years] and 15 healthy subjects. Patients were evaluated by ABPM over 24 h, at diagnosis and after therapy (n = 18). RESULTS: The average 24-h, daytime and night-time SBP was significantly greater in hyperthyroid patients than in controls with no significant differences in DBP. Circadian BP rhythm, estimated by the difference between mean values of SBP, DBP and mean BP during daytime and night-time, was unchanged. The average 24-h and daytime SBP significantly decreased after normalizing thyroid function in the 18 hyperthyroid evaluated patients. Daytime SBP and DBP were higher than night-time values both before and after control of thyroid function. However, no differences in circadian BP rhythm were observed. CONCLUSIONS: Normotensive hyperthyroid patients exhibit higher ambulatory SBP throughout 24 h than normotensive euthyroid subjects. Control of hyperthyroidism decreases ambulatory SBP values. Mean nocturnal fall in BP is comparable in normotensive hyperthyroid patients and control subjects.     

大医院重症监护科室女护士心率血压及其节律的变化

目的：分析大医院重症监护科室女性护士群体血压夜间值及昼夜节律表现。方法：选择在辽宁省肿瘤医院重症监护室的47例女护士为观察对象（ICU组）,白班对照组为同一医院门诊科室白班女护士51例。两组入选对象均接受了24h动态血压（ABPM）监测。结果：24hABPM数据分析显示：白班对照组比较,ICU组的平均夜间收缩压[nSBP,（103．29±11．94）mmHg比（115．86±12．29）mmHg]、夜间舒张压[nDBP,（72．11±8．96）mmHg比（74．37±8．45）mmHg]和夜间心率[nHR,（67．05±7．16）次／min比（72．69±9．30）次／min]均显著升高（P均〈0．05）,夜间收缩压下降率FSBPF,（7．90±1．72）％比（5．75±1．21）％]、夜间舒张压下降率[nDBPF,（7．15±1.43）％比（5．39±0．84）％]和夜间心率下降率[nHRF,（6．04±1．15）％比（4．88±0．70）％]均显著降低（P均〈0．01）,SBP、DBP和HR非杓型比例显著升高（P〈0．05或〈0．01）。结论：大医院重症监护科室女护士存在明确的心率、夜间血压及昼夜节律的异常表现。     

老老年人群动态血压参数与动脉僵硬度的相关性

目的探讨老老年人群动态血压参数与动脉僵硬度的相关性。方法筛选年龄≥80岁的老老年人238例,以血压≥160/95 mm Hg(1 mm Hg=0.133 kPa)为标准,分为高血压组(134例)和对照组(104例),并进行臂-踝脉搏传导速度(baPWV)和24 h动态血压监测。用Pearson分析动态血压各参数与动脉僵硬度的相关性。结果高血压组baPWV高于对照组(P<0.05)。高血压组偶测收缩压,24 h、昼间和夜间收缩压、舒张压、脉压,收缩压负荷及舒张压负荷均高于对照组.夜间收缩压下降率、舒张压下降率低于对照组,差异有统计学意义(P<0.05,P<0.01)。baPWV与偶测血压;24 h收缩压、舒张压、脉压;昼间收缩压、舒张压、脉压、心率;夜间收缩压、舒张压、脉压;收缩压负荷、舒张压负荷呈正相关(P<0.05,P<0.01),而与夜间收缩压下降率呈负相关(P<0.01)。结论高血压是老老年人群动脉僵硬度增加的一个重要因素,动脉僵硬度与动态血压、脉压、心率及血压负荷相关。     

Clinic blood pressure, ambulatory blood pressure and cardiac structural alterations in nonagenarians and in centenarians

scant information is available on the alterations in cardiac structure and function characterizing very elderly people as well as on their relationships to clinic and ambulatory blood pressure (BP) values. In 106 subjects aged 95.3 ± 3.7 years (mean ± standard deviation, 89 nonagenarians and 17 centenarians) in good clinical conditions and living in the municipal house in Milan, we measured, along with standard clinical and laboratory variables, clinic BP, 24-h ambulatory BP and echocardiographic parameters. Forty-five of the recruited subjects were normotensive individuals, whereas 61 were treated hypertensive patients. Subjects with an age greater than 90 years showed clinic systolic (SBP) and diastolic BP (DBP) both within the normal range, with values that for clinic SBP were slightly lower than the corresponding 24-h SBP (120.8 ± 15.9 vs 128.0 ± 16.3 mmHg) and for DBP slightly higher (69.7 ± 8.8 vs 64.9 ± 8.0 mmHg). Daytime average mean BP was slightly lower than night-time average mean BP, indicating the attenuation of the BP reduction during night-time. Left ventricular mass index (LVMI) was increased and significantly related to both 24-h and clinic BP values (r = 0.24, p < 0.04 and r = 0.20, p < 0.05). Thus in nonagenarians and centenarians, abnormalities in left ventricular pattern are of frequent detection and may be related both to the ageing process and to BP load.     

Clinical prediction of normotension in borderline hypertensive men--a 10 year study

OBJECTIVE: To investigate 24-h ambulatory blood pressure measurements (ABPM) as a tool for long-term prediction of future blood pressure (BP) status in high normal and low stage 1 hypertensives. DESIGN, SETTING AND PARTICIPANTS: A total of 165 men from a population screening program with diastolic BP (DBP) 85-94 mmHg and a systolic BP (SBP) < 150 mmHg performed a 24-h ABPM. Ten years later, 120 participants (73%) returned for renewed measurements. MAIN OUTCOME MEASURES: Blood pressure status at 10 years. RESULTS: At the 10-year follow-up, 53% of the participants were classified as hypertensive (HT) (BP > or = 140/90 or taking anti-hypertensive medication) and 47% were classified as normotensive (NT) (BP < 140/90 mmHg). There was no significant baseline differences in office SBP levels between those who were normotensive or hypertensive at follow-up (136/91 versus 138/92 mmHg), whereas both SBP and DBP night-time levels were significantly lower in the future normotensives as compared to the future hypertensives (107/69 versus 112/74 mmHg, P < 0.01). Using recommended normalcy night-time ABP levels of < 120/75 mmHg in addition to office BP (140/90) at baseline, over 85% of the subjects were correctly classified provided they met both clinic and ambulatory night-time criteria for HT and NT classification at baseline. CONCLUSION: The use of ABPM in addition to office BP's in patients with borderline hypertension greatly increases the possibility of identifying those individuals who are at a very small risk of developing future hypertension. This could potentially lead to considerable savings in both patient anxiety, physician time and resource consumption.     

Clinical trial of arotinolol in the treatment of hypertension: dippers vs. non-dippers.

To compare the effects of an alpha, beta blocker, arotinolol, in the treatment of essential hypertension between patients with a dipper and those with a non-dipper profile by means of 24-h ambulatory blood pressure monitoring (ABPM), a multicenter single blind parallel trial was carried out in five clinical centers. After a one-week single blind placebo run-in period, the patients underwent ABPM if their clinic diastolic blood pressure (DBP) ranged from 90-109 mmHg and their clinic systolic blood pressure (SBP) was <180 mmHg. They were divided into two groups according to the absence (non-dipper group, 24 cases) or presence (dipper group, 23 cases) of nocturnal BP reduction > or =10% of daytime BP. ABPM was measured again at the end of the active treatment phase. All patients were given Arotinolol 10-20 mg twice daily for 4 weeks. Twenty four-hour systolic and diastolic average BPs (MSBP, MDBP), 24-h systolic and diastolic blood pressure load (LS BP, LDBP), daytime systolic and diastolic average BPs (dMSBP, dMDBP), daytime systolic and diastolic blood pressure load (dLSBP, dLDBP), nighttime systolic and diastolic average BPs (nMSBP, nMDBP) and nighttime systolic and diastolic blood pressure load (nLSBP, nLDBP) were calculated. Arotinolol was effective in 78.2% of dippers and 54.2% of non-dippers, but the difference in effectiveness between these groups was not statistically significant. After treatment, SBP and DBP-including 24-h, daytime and nighttime systolic and diastolic BPs- were significantly reduced in both groups. During the daytime period, the systolic and diastolic blood pressures were significantly reduced in both dippers and non-dippers, while nighttime systolic and diastolic blood pressures were significantly reduced only in the non-dipper group. No significant changes were found in the dipper group over this period. In conclusion, Arotinolol, which can be dosed twice daily, is an effective antihypertensive agent which effectively lowers blood pressure during the day while reducing nighttime blood pressure more in non-dippers than in dippers, without excessive lowering blood pressure in the latter.     

Cardiovascular characteristics in American youth with prehypertension

BACKGROUND: Cardiovascular structure and function in youth with prehypertension have been incompletely investigated. METHODS: Casual and ambulatory blood pressure (BP) measurement, arterial stiffness, noninvasive hemodynamic profiles, and cardiac structure were studied in a twin cohort of American black and white youth (n = 942; mean age, 17.6 +/- 3.3 years SD). A family history of essential hypertension was used as a proxy to study genetic susceptibility to prehypertension. RESULTS: The occurrence of prehypertension was approximately 12% in the entire sample. Body mass index and waist circumference were significantly greater in prehypertensive subjects than in normotensive subjects. The 24-h ambulatory systolic BP (SBP), 24-h ambulatory diastolic BP (DBP), nighttime ambulatory SBP, and nighttime ambulatory DBP were significantly elevated in prehypertensive subjects compared with normotensive subjects. In whites, prehypertensive subjects compared with normotensive subjects showed increased radial (6.8 +/- 0.1 v 6.2 +/- 0.1 m/sec, P < .001) and foot pulse-wave velocity (PWV) (7.4 +/- 0.1 v 7.0 +/- 0.1 m/sec, P = .001). In whites, the total peripheral resistance index was greater in prehypertensive subjects than in normotensive subjects (P = .005). White prehypertensive subjects had a significantly greater heart rate than white normotensive subjects (69.0 +/- 1.4 v 64.0 +/- 0.6 bpm). In contrast, in blacks, the cardiac index was higher in prehypertensive subjects than in normotensive subjects (3.3 +/- 0.1 v 3.0 +/- 0.1 L/min/m2, P = .004). In blacks and whites, there were no statistical differences in the parameters of left-ventricular structure between normotensive subjects and prehypertensive subjects. Finally, prehypertensive subjects were more likely to have a positive family history of essential hypertension, especially in blacks. CONCLUSIONS: Prehypertension compared with normotension exhibited unfavorable cardiovascular phenotypes. Cardiovascular characteristics of prehypertension appear to be race-dependent.