白大衣性高血压的特征和临床意义

目的 :确定白大衣效应和白大衣性高血压的特征及其临床意义。方法 :应用心理行为方法探讨白大衣性高血压的机制。结果 :报道白大衣效应和白大衣性高血压的发生率及其与原发性高血压的联系。结论 :白大衣性高血压的发生与心理行为因素有关 ,宜进一步探讨其防治方法     

The placebo effect and white coat effect in isolated systolic hypertension and systo-diastolic hypertension

It is well recognised from many clinical trials that there is a blood pressure lowering effect when placebo is administered to patients with essential hypertension ("placebo effect"). The reduction in blood pressure, however, may also be partly due to loss of the alerting response ("white coat effect") as a result of familiarisation with the clinical environment. To investigate the hypothesis that there may be a more marked placebo effect and white coat effect in isolated systolic hypertension (ISH) compared with systo-diastolic hypertension (SDH), we studied 78 patients with hypertension: 34 had ISH and 44 patients had SDH. The 34 patients with ISH were older (68.7 vs 54.9 years), had a higher SBP (192.2 vs 169.6 mmHfg) and lower DBP (85.5 vs 102.0 mmHg) when compared to patients with SDH. Amongst the patients with ISH, there were no significant changes in mean blood pressures pre-placebo (paired t-test, p = NS). In the placebo period, there was a significant reduction in systolic blood pressures at all three points, and a significant reduction in diastolic blood pressures after 2 and 3 months placebo (paired t-test, p < 0.05). There was a mean reduction in mean systolic blood pressure at visit 1 by 5.2%, visit 2 by 5.1% and visit 3 by 4.6%, when compared to mean pre-placebo systolic blood pressures (p < 0.05). The mean reduction in diastolic blood pressure was 5.8% at visit 2 and 3.5% at visit 3, when compared to mean pre-placebo diastolic blood pressure (p < 0.05). At the 4-week visit after receiving placebo, the mean systolic blood pressure decreased by 9.4 mmHg (p = 0.003) and mean diastolic blood pressure by 2.7 mmHg (p = NS) in the patients with ISH. In patients with SDH, there were no statistically significant changes in recorded BP readings following the introduction of placebo. We suggest blood pressures in some patients with ISH may settle with careful follow up and initiation of treatment in these patients could potentially be delayed for at least 3 months, as therapy may not prove necessary.     

White coat effect and white coat hypertension in community pharmacy practice

OBJECTIVE: The aim of the present study was to investigate whether a white coat effect (WCE) can be observed and quantified in community pharmacy practice. METHODS: In five community pharmacies of Basel, Switzerland, clients asking for blood pressure (BP) measurement were recruited to participate in a free of charge study. Blood pressure was measured in four different settings: pharmacy (using mercury sphygmomanometers), outpatient clinic (measurement by a nurse using mercury sphygmomanometers), self-measurement at home (using automated wrist devices) and daytime ambulatory BP (ABP) monitoring (using SpaceLabs 90207 monitors). WCE was defined as the difference between pharmacy or outpatient and daytime ABP. RESULTS: A total of 50 subjects completed all measurements (42% male, mean age 53.7 years+/-14.0). Blood pressure values of the different settings: (means in mmHg+/-SD, systolic; diastolic): pharmacy BP 129+/-19; 82+/-10, outpatient clinic BP 127+/-15; 82+/-10, home BP 119+/-15; 73+/-9, daytime ABP 124+/-10; 79+/-8. Pharmacy BP was significantly higher (P=0.03 systolic; P=0.02 diastolic) compared with daytime ABP and differences among subjects with antihypertensive medication (n=22) were even more significant (P<0.01). Individual differences were found between pharmacy BP and daytime ABP: +4.6+/-14.8; +2.9+/-8.3. Outpatient BP was significantly higher compared with daytime ABP in diastolic (P=0.04) but not in systolic values. Individual differences between outpatient BP and daytime ABP were +2.5+/-13.1; +2.8+/-9.2. 'Clinically important WCE' (>or=20 mmHg systolic or >or=10 mmHg diastolic) was observed in 24% of all subjects in the pharmacy and in 20% in the outpatient clinic. CONCLUSIONS: Our findings show that WCE and white coat hypertension exist in community pharmacy practice and are similar to the effects in an outpatient clinic.     

Reduction of white coat effect by cilnidipine in essential hypertension.

Stress elevates blood pressure (BP) by increased sympathetic nerve activity. Cilnidipine, a novel dihydropyridine calcium antagonist that has inhibitory actions on N-type as well as L-type voltage-dependent calcium channels, has been reported to attenuate the cold stress-induced increase in plasma norepinephrine and BP in rats. Because white coat effect is associated with an enhanced pressor response to mental stress, we postulated that cilnidipine would attenuate white coat effect in patients with essential hypertension. Sixty-one consecutive outpatients (50 men, 11 women) with essential hypertension were studied prospectively. Twenty-nine patients were treated with either cilnidipine (n = 15) or nifedipine, a representative L-type voltage-dependent calcium antagonist (n = 14). Gender, age, body mass index, duration of hypertension, target organ damage of hypertension, and BP and heart rate (HR) were not significantly different between cilnidipine and nifedipine groups, and both systolic (SBP) and diastolic BP (DBP) were significantly decreased after treatment in both groups. White coat effects on systolic and DBP and HR were not significantly different between groups before antihypertensive treatment. Cilnidipine, but not nifedipine, significantly reduced white coat effects on SBP and HR. Furthermore, white coat effects on systolic BP and HR were significantly lower after treatment in the cilnidipine group compared with the nifedipine group. These data suggest that cilnidipine may reduce white coat effect in hypertensive patients by N-type calcium channel antagonism.     

Target organ damage in "white coat hypertension" and "masked hypertension"

BACKGROUND: In this study we investigated (i) the prevalence of white coat hypertension (WCH) and masked hypertension (MH) in patients who had never been treated earlier with antihypertensive medication, and (ii) the association of these conditions with target organ damage. METHODS: A total of 1,535 consecutive patients underwent office blood pressure (BP) measurements, 24-h ambulatory BP monitoring (ABPM), echocardiography, and ultrasonography of the carotid arteries. Subjects who showed normotension or hypertension on the basis of both office and ambulatory BP (ABP) measurement were characterized as having confirmed normotension or confirmed hypertension, respectively. WCH was defined as office hypertension with ambulatory normotension, and MH as office normotension with ambulatory hypertension. RESULTS: WCH was found in 17.9% and MH in 14.5% of the subjects. The prevalence of WCH was significantly higher in subjects with obesity, while the prevalence of MH was significantly higher in normal-weight subjects. The confirmed hypertensive subjects as well as the masked hypertensive subjects had significantly higher left ventricular mass (LVM) (corrected for body surface area) and carotid intima media thickness (cIMT) than the confirmed normotensive subjects did (108.9 +/- 30.6, 107.1 +/- 29.1 vs. 101.4 +/- 29.9 g/m(2) and 0.68 +/- 0.16, 0.68 +/- 0.21 vs. 0.63 +/- 0.15 mm, respectively, P < 0.005). White coat hypertensive subjects did not have a significantly higher LVM index than confirmed normotensive subjects (101.5 +/- 25.9 vs. 101.4 +/- 29.9 g/m(2)); they tended to have higher cIMT than the confirmed normotensive subjects, but the difference was not statistically significant (0.67 +/- 0.15 vs. 0.63 +/- 0.15 mm). CONCLUSIONS: WCH and MH are common conditions in patients who visit hypertension outpatient clinics. Confirmed hypertension and MH are accompanied by increased LVM index and cIMT, even after adjusting for other risk factors.     

白大衣高血压对心脏功能的影响

目的 :了解白大衣高血压患者左心结构及左室收缩功能和舒张功能状况。方法 :通过汞柱血压计测量及 2 4h动态血压监测将患者分为白大衣高血压组 (35例 ) ,持续性高血压组 (30例 )及正常血压组 (30例 )。采用彩色多普勒超声心动图测量每组患者的左房及左室结构、左室重量指数 ;测定左室舒张功能并进行组间比较。结果 :各组的左室收缩功能参数无明显差别。白大衣高血压组左房室内径、室间隔及左室后壁、左室重量指数均高于正常血压组 (P <0 .0 5 ) ,左室舒张功能参数 (E/ A比值 )低于正常血压组 ,介于持续性高血压组和正常血压组之间。结论 :白大衣高血压患者已出现左室结构改变及舒张功能受损 ,应密切关注并予以防治。     

Urinary albumin excretion in elderly patients with white coat hypertension

The so-called white coat effect occurs in about 42% of elderly patients. This phenomenon leads to several problems in treatment and may also cause renal disease. One of the most frequently controlled parameters is microalbuminuria, an index of renal damage. The present case-control study intended to evaluate the urinary excretion of albumin in elderly patients suffering from white coat hypertension, and comparing their data to those of normotensive subjects. In addition, the study searched for correlations between albuminuria and various clinical and ambulatory blood pressure values. A total of 258 patients were enrolled, but after screening, only 129 were considered; 13 of the latter were further excluded because of problems encountered during ambulatory monitoring of arterial blood pressure. Therefore, 116 hypertensive subjects were included in the study. This pool of hypertensive patients was compared to a normotensive group of 33 subjects. The results have shown the occurrence of white coat effect in 25% of cases, and the microalbuminuria of these patients was statistically not significantly different from that of the normotensive group of patients. The microalbuminuria correlated only with ambulatory systolic blood pressure measured during the day.     

Diagnostic value of electrocardiography and echocardiography for white coat hypertension in the elderly

Although white coat hypertension is common in clinical practice,^1–3 its pathogenesis and clinical prognosis remain unknown. In elderly patients with office hypertension, white coat hypertension should be differentiated from true hypertension, since the excessive reduction in blood pressure (BP) caused by antihypertensive medication may induce an ischemic event in a vital organ. The present study assesses the sensitivity and specificity of electrocardiography in detection of white coat hypertension and quantitatively measures left ventricular hypertrophy in such patients using echocardiography. Results are compared with those in normotensive control subjects and in patients with true persistent hypertension.     

Prognostic significance of the white coat hypertension in patients with type 1 diabetes mellitus

Despite the high prevalence of white coat hypertension (WCH) in diabetes mellitus and the evidence that hypertension is a clear risk factor for the development of microalbuminuria (MA) in these patients, there is no information on the long-term prognostic significance of this condition in the diabetic population. We studied the evolution of 40 patients with type 1 diabetes mellitus (Type 1 DM). Twenty patients with WCH (office blood pressure> or =140/90mmHg associated with mean daytime blood pressure<135/85mmHg) classified as the WCH group and 20 patients with type 1 DM with a similar age and disease evolution, but who were normotensive, (office blood pressure<140/90mmHg associated with mean daytime blood pressure<135/85mmHg) classified as the normotensive control group. After 5 years of follow-up, MA appeared in four subjects and sustained hypertension in another, with a total of 31% of events in the WCH group, with none in the normotensive group. Kaplan-Meier analysis showed that the relative risk of developing these hypertensive events was 25% higher in the WCH group. At baseline, the night time systolic and diastolic blood pressure levels were significantly higher in patients who further developed MA and sustained hypertension. The findings in this study highlight the clinical importance of careful follow-up of type 1 diabetic patients with WCH.     

Frequent nurse visits decrease white coat effect in stage III hypertension

Arterial hypertension is a public health problem and patient adherence to treatment is challenging. This study tested whether frequent nurse visits provide additional benefits to antihypertensive treatment. Every 30 days, a pharmacist visited these patients to deliver antihypertensive drugs and perform a pill count. Nurses visited group A (48 patients) every 15 days and group B (52 patients) every 90 days. Ambulatory blood pressure (BP) monitoring was performed 15 and 180 days after randomization. At randomization, groups A and B had the same clinical systolic (191 +/- 5 v 186 +/- 3 mm Hg) and diastolic BP levels (122 +/- 3 v 117 +/- 4 mm Hg), respectively. After 90 days, BP declined more in group A than in group B (35 +/- 5/19 +/- 3 v 27 +/- 5/9 +/- 3 mm Hg). At 180 days, the difference increased because the reduction persisted in group A but decreased in group B (36 +/- 6/21 +/- 4 v 17 +/- 4/10 +/- 2 mm Hg). The mean ambulatory BP monitoring values were similar in both groups at 15 and 180 days. However, the attenuation of the clinic-daytime BP difference was larger in group A than in group B (systolic, -13 +/- 4 v -3 +/- 4 mm Hg; diastolic -11 +/- 3 v -4 +/- 3 mm Hg). The patients with clinic-daytime differences decreased more in group A (systolic, 16 to 10; diastolic, 20 to 14) than in group B (systolic, 19 and 20; diastolic, 22 and 22). These data indicate that frequent nurse visits significantly attenuate the white coat effect (clinic daytime BP difference).     

老年隐匿性高血压及白大衣性高血压对血管弹性及内皮功能的影响

目的探讨隐匿性高血压及白大衣性高血压对血管弹性及内皮功能的影响。方法选择健康体检老人487例,根据诊室血压和24h动态血压水平分为正常血压组128例,白大衣性高血压组115例,隐匿性高血压组112例和高血压组132例。检测所有受试者肱动脉血流介导的血管舒张功能(FMD)、NO、内皮素1及颈股动脉脉搏波传导速度(cfPWV)。结果与正常血压组比较,白大衣性高血压组、隐匿性高血压组及高血压组FMD、NO显著降低,内皮素1、cfPWV显著升高(P0.05)。白大衣性高血压组和隐匿性高血压组FMD、NO较高血压组显著升高(P0.05)。内皮素1、cfPWV较高血压组显著降低[(45.63±6.76)ng/L、(45.20±7.00)ng/L vs(49.04±6.93)ng/L,(10.91±1.08)cm/s、(10.87±0.96)cm/s vs(11.75±1.35)cm/s,P0.05]。回归分析显示,以正常血压为参照,校正混杂因素后,白大衣性高血压、隐匿性高血压及高血压是FMD、NO、内皮素1及cfPWV的独立影响因素(P0.01)。结论白大衣性高血压及隐匿性高血压是血管弹性下降及内皮紊乱的危险因素。     

Genome-wide association study for white coat effect in Japanese middle-aged to elderly people: The HOMED-BP study

Background: White coat effect (WCE), the blood pressure (BP) difference between clinical and non-clinical settings, can lead to clinical problems such as misdiagnosis of hypertension. Etiology of WCE has been still unclear, especially from genetic aspects. The present article investigated association between genome-wide single nucleotide polymorphisms (SNPs) and WCE in patients with essential hypertension.

Methods: The present cross-sectional analyses were based on 295 Japanese essential hypertensive outpatients aged ≧40 years enrolled in randomized control study, Hypertension Objective Treatment Based on Measurement by Electrical Devices of Blood Pressure (HOMED-BP) study, who were not taking antihypertensive medications before the randomization. Home and clinic BP were measured. WCE was defined by subtracting home BP from clinic BP. Genotyping was conducted with 500K DNA microarray chips. Association between genome-wide SNPs and WCE were analyzed. For replication (p < 10^–4), we analyzed participants from Ohasama study who took no antihypertension medications and whose SNPs were collected.

Results: Genome-wide SNPs were not significantly associated with WCE of systolic and diastolic BP after corrections of multiple comparisons (p < 2 × 10^–7). We found suggestive SNPs associated with WCE of systolic and diastolic BP (p < 10^–4). However, the consistent results were not obtained in the replication study.

Conclusion: The present article showed no significant association between genome-wide SNPs and WCE. Since there were several suggestive SNPs associated with WCE, the present study warrants a further study with bigger sample size for investigating the genetic influence on WCE.     

原发性高血压患者中的白大衣效应及其与血压变异性的相关性

目的 探讨原发性高血压患者中的白大衣效应的发生率及其与血压变异性的相关性.方法 1级、2级原发性高血压患者410例自愿参加本研究.受试者自测1周家庭血压,根据诊室血压与家庭血压情况进行分类:未治疗患者分为白大衣性高血压(n=38)和持续性高血压(n=66);已治疗患者分为已控制高血压(n=131)、白大衣未控制高血压(...     

Syndrome of white coat hypertension in pregnant women

Among 127 pregnant women with hypertension 17 (13.4%) were found to have white coat hypertension because they had elevated blood pressure (BP) according to office measurements and normal BP during 24-hour BP monitoring. Investigation of b-adrenoreception of erythrocyte membranes and analysis of calculated parameters of 24-hour BP monitoring demonstrated normal physiological level of functioning of sympathico-adrenal system. However the study of psychological status evidenced for the presence of intrapersonality conflicts and anxiety in the majority of patients. This can be a factor, provoking BP elevation.     

Arterial hypertension and mortality in the elderly

BACKGROUND: The aim of this study was to evaluate at a population level whether hypertension is a risk factor for cardiovascular mortality and to verify whether or not this is true for both genders at any age. METHODS: This population-based, long-lasting, prospective study includes a 14-year mortality (institutional epidemiology in primary care). Unselected, unbiased subjects (5185) aged 22 to 95 years were recruited from the Italian general population, and divided into normotensive (<140 mm Hg systolic blood pressure [BP] and <90 mm Hg diastolic BP and untreated) and hypertensive groups. The main aim was to identify the significant predictors of mortality due to stroke, coronary artery disease, heart failure, and pulmonary embolism, and to quantify the age-adjusted relative risk of hypertension in men and women, at different age classes (<70, 70 to 79, >or =80 years) for each mortality cause. The analysis was repeated among 1091 normotensive and 1091 hypertensive age-matched subjects to clean statistics from the effects of age. RESULTS: There were 846 cardiovascular deaths, 178 due to stroke, 273 to coronary disease, 351 to heart failure, and 44 to pulmonary embolism. Hypertension predicted stroke mortality, but not that due to other causes. This prediction was only significant in women, not in men. No prediction was possible after the age of 80 years. Age-matching increased the significance level of stroke mortality prediction in women aged <80 years; in these women, systolic BP predicted stroke mortality directly and diastolic inversely. CONCLUSIONS; In this population, hypertension predicted only stroke mortality in women aged <80 years. High systolic and low diastolic BP were predictive of stroke mortality, confirming a prognostic role for high pulse pressure.     

No evidence that panic attacks are associated with the white coat effect in hypertension

The authors aimed to determine whether hypertensive patients with panic attacks or panic disorder have a larger white coat effect (difference between clinic blood pressure measured under standard conditions and mean daytime ambulatory blood pressure) than hypertensive patients without panic attacks. White coat effect was compared in a hospital hypertension clinic between 24 patients with panic attacks in the previous 6 months (12 with panic disorder) and 23 hypertensive controls. There were no significant differences between cases and controls in clinic blood pressure, mean daytime ambulatory blood pressure, or white coat effect (18/3 vs. 19/6 mm Hg; difference for systolic, −1.9 mm Hg; 95% confidence interval, −15.8 to +12.0; difference for diastolic, −3.0 mm Hg; 95% confidence interval, −10.2 to +4.3). Comparing only patients with panic disorder with controls, there were again no significant differences in clinic blood pressure, mean daytime ambulatory blood pressure, or white coat effect. This study provides no evidence for an exaggerated white coat effect in hypertensive patients who have experienced panic attacks or panic disorder. However, only larger studies could exclude differences in white coat effect <12/4 mm Hg, or an exaggerated white coat effect in a minority of patients with panic attacks.