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.     

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.     

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。     

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.     

Arterial hypertension in the hemodialysis patient. A model of salt-sensitive hypertension in man]

In uremic patient treated by hemodialysis (HD), a low potassium intake and a salt load due to diet and or a high sodium concentration in dialysate are often associated to refractory hypertension. Numerous reports in general population, based on epidemiologic and demographic data, have pointed to the relationship between sodium intake and hypertension. The degree of blood pressure fall in patients who have evidence of salt-sensitivity varies directly with the severity of the hypertension, being most prominent in those with higher pressures. Recent studies have suggested that a reduction of dialysate sodium can control hypertension in maintenance haemodialysis patients. In this study, five hypertensive haemodialysis patients were assigned to a regime of lowering the dialysate sodium concentration from 142 to 135 mmol/L in combination with an attempt to lower salt intake by advising the patients to eat a NaCl-restricted diet of no more than 6-8 g/day. During the period under study, dialysis time was kept constant. A significant increase of ultrafiltrate sodium concentration was observed during the first week after lowering the dialysate sodium concentration. Post dialysis systolic and diastolic pressures showed a clear trend to fall (systolic pressure 174 +/- 18 vs 118 +/- 13 mmHg, diastolic pressure 96 +/- 7 vs 75 +/- 13 mmHg) without a change of dry weight. The reduction of the mean arterial pressure on 48 h was demonstrated with ambulatory blood pressure recording. The results of this study suggest that reducing the dialysate sodium concentration lead to a decrease in peripheral resistance. A link between sympathetic overactivity as it is found in haemodialysis patients and sodium load could be a stimulating hypothesis. It is concluded that increasing dialysate sodium in short dialysis is responsible for the high prevalence of arterial hypertension often insufficiently controlled by antihypertensive medication. In hemodialysis patients with refractory hypertension, the lowering of the dialysate sodium concentration is indicated.     

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).     

Arterial hypertension of the aged patient in general medicine. French national survey]

The aim of the study was to assess the management of elderly hypertensives in general practice. A sample of 2,727 general practitioners filled a specially designed questionnaire between February and March 1998 in France. Areas covered by the questionnaire included risk of hypertension, blood pressure measurement and treatment. Most respondents (97%) considered that hypertension remains a cardiovascular risk factor in elderly but 4% thought that hypertension is usefull by improving target organ perfusion. Fifty-five percent recorded both standing and supine measurement, 34% reported measuring blood pressure with patient supine only. All respondents reported that they would start antihypertensive treatment on the basis of blood pressure level. A minimum systolic level of 160 and 180 mmHg was given by 65% and 27% practitioners respectively while 2% required a minimum level ranging from 139 to 149 mmHg. Among the respondents who considered that isolated systolic hypertension is pathological (74%), 73% and 19% used 160 and 180 mmHg as cut-off, respectively. Among those who considered that isolated systolic hypertension is physiological (23%), 43% and 46% initiated treatment above 160 and 180 mmHg, respectively. A minimum diastolic level of 90 mmHg was reported by many respondents (61%) while 34% required a cut-off level of 100 mmHg. Comparison of systolic and diastolic levels showed that 49% practitioners started antihypertensive therapy above 160/90 mmHg and 16% above 180/100 mmHg. Less than 1% reported a threshold level of 140/90 mmHg. Most practitioners 5%) treated hypertensive patients regardless of their age. The others treated patients younger than 65 years old (3%), 70 (2%), 80 (5%) and 90 (4%). All respondents reported that they would treat their patients to prevent vascular complications, mainly cerebrovascular (96%), cardiac (89%) and kidney (75%) disease. In conclusion, for all general practitioners, hypertension remains a cardiovascular risk factor in elderly and hypertensive therapy is beneficial to prevent cardiovascular complications. This study reveals some inter-physician variability in blood pressure measurement and treatment. The risk of standing blood pressure fall is not taken into account by 66% of respondents. Variability in age threshold is in accordance with the lack of published data on benefice of hypertensive treatment in the very old. The risk of isolated systolic hypertension is under-estimated by 27% of physicians who reported a minimum systolic blood pressure level of 180 mmHg to initiate therapy.     

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.     

Relationships between ambulatory white coat effect and left ventricular mass in arterial hypertension

The aim of our study was to analyze, in a group of 296 essential hypertensives, the relationship between left ventricular mass (LVM) and ambulatory white coat effect (WCE); that is the difference between the elevation of the first measurements of ambulatory blood pressure monitoring and the mean daytime pressure. The study population was separated into two groups according to the median of the WCE. The LVM was greater in the groups with higher systolic and diastolic ambulatory WCE. The significant association between ambulatory WCE and LVM was confirmed by the results of multiple regression analysis, suggesting that ambulatory WCE may not be an innocent phenomenon.