Prevalence of the white-coat effect at multiple visits before and during treatment

OBJECTIVE: To investigate the prevalence and persistence of the white-coat effect (WCE) and white-coat hypertension (WCH) on multiple blood pressure measurement occasions in hypertensive patients with and without treatment. DESIGN: Essential hypertensive patients in whom we took office blood pressure measurements (OBPM) at eight visits (three readings per visit) performed self blood pressure measurements (SBPM) for 1 week prior to each visit (42 readings per week) over a period of 1 year. All measurements were performed with the same automatic device (Omron 705CP). In addition, 24-h ambulatory blood pressure monitoring (ABPM) was performed at the start and at the end of the study. At the start, patients did not use any medication but on subsequent visits they were treated on the basis of their SBPM values. WCH was defined as an OBPM-value > or = 140 and/or 90 mmHg and a SBPM or daytime ABPM value < 135/85 mmHg. This definition was used irrespective of treatment. We also determined the prevalence of a substantial WCE (OBPM 20 mmHg systolic or 10 mmHg diastolic higher than SBPM or daytime ABPM). SETTING: Patients were recruited at hospital or general practice. PATIENTS: A total of 163 mild-to-moderate essential hypertensive patients with a mean age of 56 years (56% males). RESULTS: At eight blood pressure (BP) measurement occasions, 75% of all patients had a substantial WCE at least once, while 57% had WCH at least once. One-third of the patients consistently had a substantial WCE and 14% consistently had WCH on three or more occasions The magnitude of the WCE was significantly related to the height of blood pressure in treated but not in untreated patients. CONCLUSION: In some patients, WCH or a substantial WCE occurs consistently on multiple OBPM visits. Especially in untreated patients, the magnitude of the WCE varies widely among individuals. These results support the incorporation of SBPM and/or ABPM into optimal management of hypertension, not only to prevent misdiagnosis in untreated patients but also to determine the need for adjusting antihypertensive therapy in treated subjects.     

Isolated ambulatory hypertension is common in outpatients referred to a hypertension centre

The present investigation was aimed at determining the prevalence and the blood pressure (BP) profile of isolated ambulatory hypertension, defined as an elevated ambulatory BP with normal office blood pressure, in a series of 1488 consecutive outpatients referred for routine clinical evaluation of suspected or established arterial hypertension. All patients underwent both office BP (OBP) measurement by a physician and 24-h ambulatory blood pressure monitoring (ABPM). Using OBP values (cutoff for diagnosis of hypertension >/=140/90 mmHg) and daytime ABPM (cutoff for diagnosis of hypertension >/=135/85 mmHg), patients were classified into eight subgroups. In the whole series we found that, independent of treatment status, the prevalence of isolated ambulatory hypertension exceeded 10%. More importantly, 45.3% of individuals who presented with normal OBP values, showed elevated BP at ABPM. Night-time BP, 24-h pulse pressure, and BP variability were significantly higher in isolated ambulatory hypertensives than in normotensive or in white-coat hypertensive individuals. Therefore, isolated ambulatory hypertension is characterized by a blood pressure profile that is similar to that observed in sustained hypertension. These findings suggest that isolated ambulatory hypertension is very common and probably the indications for ABPM should be more extensive in outpatients referred to hypertensive centre.     

Performance of the automated BpTRU measurement device in the assessment of white-coat hypertension and white-coat effect

OBJECTIVES: BpTRU (VSM MedTech Ltd, Vancouver, Canada) is an automated oscillometric device that provides serial blood pressure measurements in an office setting in the absence of a healthcare professional. We sought to determine whether the white-coat effect is reduced by a blood pressure measurement protocol using BpTRU compared with casual office measurements. Secondarily, we also sought to determine whether a blood pressure measurement protocol using BpTRU reduced white-coat hypertension compared with the casual office measurements, and reduced white-coat effect and white-coat hypertension compared with blood pressure obtained by a research nurse. METHODS: Blood pressure was measured in 107 adult hypertensive patients referred for ambulatory blood pressure monitoring using an ambulatory blood pressure monitor, a standardized protocol by a trained research nurse, and a protocol using BpTRU (five readings over 25 min, using the 5-min blood pressure measurement interval setting). Casual office blood pressure was also recorded in the family physicians' offices. Using the mean daytime ambulatory blood pressure as the reference standard, the proportion of patients with white-coat effect and white-coat hypertension were determined for measurements obtained by BpTRU, the research nurse, and the family physicians' offices. RESULTS: Casual office blood pressure measurements demonstrated a white-coat effect in 39 (36.4%) patients; seven (6.5%) patients demonstrated a white-coat effect using BpTRU (P<0.0001). White-coat hypertension was also less common using BpTRU than with the casual office readings (13 vs. 1 patient, P<0.0001). White-coat effect was also reduced with BpTRU compared with the research nurse measurements. Unfortunately, percentage agreement for the diagnosis of hypertension between the protocol using BpTRU and the reference standard was only 48%. This resulted in substantial misclassification of hypertension by the BpTRU measurement protocol. CONCLUSIONS: Although BpTRU reduces white-coat effect and white-coat hypertension, blood pressure is underestimated by the device, leading to misclassification of hypertension. BpTRU, when set at 5-min blood pressure measurement intervals, should not be used in clinical practice.     

'Reverse white-coat hypertension' in older hypertensives

OBJECTIVES: The role of ambulatory blood pressure monitoring (ABPM) in the elderly is unclear. This study has examined differences between clinic and ambulatory blood pressure (BP) in a large cohort of older hypertensives, with particular respect to the factors influencing the direction and magnitude of this difference. DESIGN: The Second Australian National Blood Pressure Study (ANBP2) is a general practice-based randomized-outcome trial in 6083 older hypertensives treated with an angiotensin-converting enzyme (ACE) inhibitor or diuretic-based regimen. Before starting treatment a subset of 713 patients (age range 65-83 years) had a 'successful' 26-hour ambulatory blood pressure recording with a SpaceLabs 90207 recorder. RESULTS: Average clinic BP (+/- SD) was 167 +/- 12/90 +/- 8 mmHg. Average daytime ambulatory BP was 157 +/- 15*/89 +/- 10* mmHg and night ambulatory BP was 137 +/- 16+/74 +/- 10+ mmHg (different from clinic BP: *P < 0.01;from daytime ambulatory BP: +P < 0.001). Twenty-one to 45% of all patients had higher daytime systolic or diastolic ambulatory BP than clinic readings, with smoking, previous treatment for hypertension and lower clinic BP being the main predictors of this 'reverse white-coat effect'. CONCLUSIONS: Although mean daytime ambulatory blood pressures were lower than clinic readings in this large cohort of untreated older hypertensives, a substantial proportion showed the reverse of the so-called 'white-coat effect'. These findings identify the important role for ABPM in the elderly, not only for avoiding overtreatment in those with typical 'white-coat hypertension' but also for ensuring adequate treatment is given to those with the reverse of this phenomenon.     

Anxiety and outcome expectations predict the white-coat effect

OBJECTIVE: To determine whether elevated clinic blood pressure compared with daytime ambulatory blood pressure, referred to as the white-coat effect, is associated with anxiety and increased blood pressure expectancy in the doctor's office. METHODS: The 24-h ambulatory blood pressure measurements and physicians' blood pressure measurements were obtained in 226 normotensive and hypertensive study participants. Anxiety levels were assessed multiple times during the clinic visit using a Visual Analog Scale. Participants' expectations regarding the clinic visit were assessed using a six-item scale (Expectations of Outcomes Scale). The white-coat effect was computed as the difference between the mean clinic blood pressure and the mean daytime ambulatory blood pressure. Multiple regression analysis was performed to examine the association between anxiety, outcome expectations and the white-coat effect, adjusting for age, sex, and ambulatory blood pressure level. RESULTS: As predicted, outcome expectations and anxiety during the clinic visit were significantly associated with the white-coat effect. Results of the regression analysis indicated that only expectancy had an independent effect on the systolic white-coat effect; however, both anxiety and expectancy had independent effects on the diastolic white-coat effect. CONCLUSION: Our results provide empirical support to the hypothesis that anxiety and blood pressure expectancy may elevate clinic blood pressure.     

Ambulatory blood pressure monitoring and clinical characteristics of the true and white-coat resistant hypertension

The resistant hypertension has been differentiated in true resistant hypertension and white-coat resistant hypertension by using ambulatory blood pressure monitoring. White-coat resistant hypertension was defined as high clinic blood pressure, despite triple treatment for at least 3 months, but day-time blood pressure values < 135/85 mmHg. The aim of this study was to evaluate the presence of different clinical characteristics between two types of resistant hypertension. The study group consisted of 49 patients with essential hypertension, resistant to an adequate and appropriate triple-drug therapy, that included a diuretic, with all 3 drugs prescribed in near maximal doses and that had persistently elevated clinic blood pressure (> 140/90 mm Hg), for at least 3 months. They represented the 2% of 2500 hypertensive outpatients that referred at our Hypertension Unit. Patients with white-coat resistant hypertension (n=19) were older (p<0.05) than those with true resistant hypertension (n=30). The sodium intake (p<0.05) and alcohol intake (p<0.05) were significantly higher in patients with true resistant hypertension than in those with white-coat resistant hypertension. The renin plasma activity and plasma aldosterone were higher (p<0.05) in patients with true resistant hypertension than in those with white-coat resistant hypertension with normal plasma electrolyte balance. There were no significant differences in mean values of office systolic and diastolic blood pressures between white coat resistant hypertensives and true resistant hypertensives (165+17 vs 172+28 and 98+12 vs 102+14 mmHg). Day-time and night-time ambulatory 24-h-systolic and diastolic blood pressures were significantly higher in the true resistant hypertensive patients when compared with white-coat resistant hypertensives (153+15 vs 124+10 mmHg and 97+9 vs 76+6 mmHg all p<0.001). Day-time and night-time ambulatory 24-h-heart rate were significantly higher in the true resistant hypertensive patients when compared with white-coat resistant hypertensives (79+11 vs 71+9 beats/min; p<0.01; 68+9 vs 60+6 beats/min, p<0.001). The ABP readings were analysed by a Fourier series with 4 harmonics. According to the runs test both two groups of patients showed a circadian rhythm for both systolic and diastolic blood pressure. The nocturnal fall in SBP, DBP and HR was not different in both groups of patients. In conclusion, our findings showed that true resistant hypertensive patients were characterized both by higher heart rate and higher plasma renin activity values as an expression of a possible increased sympathetic activity. Thus, the combination of ABPM with the assessment of the clinical characteristics allow to differentiate better the true drug-resistant hypertension from the white coat resistant hypertension.     

Determinants of white-coat hypertension

BACKGROUND: The prevalence of white-coat hypertension (WCH) is considerable in patients referred with elevated office blood pressure. Failure to recognise this phenomenon can lead to the inappropriate use of antihypertensive medications. We undertook this study to determine the profile of patients with WCH. METHODS: Baseline clinic and daytime ambulatory blood pressures were available from 5716 patients referred over a 22-year period. Individuals were considered to have WCH if they had an elevated clinic blood pressure measurement greater than 140/90 mmHg and normal daytime mean ambulatory blood pressure. Mean age was 53.6 years and 53.2% were female. RESULTS: The overall prevalence of white-coat hypertension was 15.4%. A higher prevalence was seen amongst older adults, females, and non-smokers. CONCLUSION: Multivariate logistic regression analysis confirmed these characteristics as independent predictors of WCH.     

Office hypertension: abnormal blood pressure regulation and increased sympathetic activity compared with normotension

BACKGROUND: The percentage of patients with office or white-coat hypertension has been reported in international studies to be 20-30% of the hypertensive population. These patients can be identified and distinguished from patients with established hypertension by ambulatory blood pressure monitoring (ABPM) or self-measurement. There is still no satisfactory explanation for the phenomenon of 'office hypertension' and there are no data available to show how the blood pressure behaviour of office hypertensives differs from that of normotensive subjects away from the physician's office or clinic environment. OBJECTIVE: To investigate the blood pressure behaviour of patients with office hypertension away from the clinical setting over a 24 h period and to compare it with that of normotensive subjects. DESIGN AND METHODS: The blood pressure and heart rate of 36 patients with office hyhpertension and 33 normotensive subjects matched for age and sex were measured in a hypertension outpatient clinic and over 24 h using ABPM. The ambulatory data were subjected both to conventional and to modern rhythm analysis. Urinary catecholamine excretion was measured as a marker of sympathetic activity. RESULTS: In the clinic, the patients with office hypertension had significantly (P < 0.01) higher blood pressure values (146/97 mmHg) than did the normotensive controls (128/81 mmHg). The conventional analysis as well as the rhythm analysis of the ABPM data revealed no difference between the two groups with respect to the 24 h, daytime or night-time mean values and SD. However, the rhythm analysis showed a higher maximum and a lower minimum value for systolic and diastolic blood pressures in the patients with office hypertension, resulting in a greater amplitude both of systolic and of diastolic blood pressure due to a significantly (P < 0.005 and P < 0.05) higher maximum minus minimum value (38/32 mmHg) compared with those of normotensive controls (29/28 mmHg). The early morning rise in systolic and diastolic blood pressures was significantly (P < 0.008 and P < 0.03) greater in the patients with office hypertension (11/9 versus 7/7 mmHg) and intersected the curve of the normotensive controls at approximately 0600 h. No significant differences in heart rate at any time were observed between the groups. The urinary excretion of noradrenaline and dopamine was significantly (P < 0.01 and P < 0.05) increased during daytime for the office hypertensives. CONCLUSION: Patients with office hypertension, who by definition do not yet have established hypertension, already exhibit abnormal regulation both of systolic and of diastolic blood pressure during the morning period and daytime, with a significantly greater early morning rise compared with normotensive subjects and a greater blood pressure amplitude (amplitude hypertension) due to lower blood pressure during night-time and higher blood pressure during the day with increased sympathetic activation. Office hypertension seems to be the earliest manifestation of hypertension.     

Appropriate time interval to repeat ambulatory blood pressure monitoring in patients with white-coat resistant hypertension

Resistant hypertension is defined as uncontrolled office blood pressure, despite the use of ≥3 antihypertensive drugs. Ambulatory blood pressure monitoring (ABPM) is mandatory to diagnose 2 different groups, those with true and white-coat resistant hypertension. Patients are found to change categories between controlled/uncontrolled ambulatory pressures without changing their office blood pressures. In this way, ABPM should be periodically repeated. The aim of this study was to evaluate the most appropriate time interval to repeat ABPM to assure sustained blood pressure control in patients with white-coat resistant hypertension. This prospective study enrolled 198 patients (69% women; mean age: 68.9±9.9 years) diagnosed as white-coat resistant hypertension on ABPM. Patients were submitted to a second confirmatory examination 3 months later and repeated twice at 6-month intervals. Statistical analyses included Bland-Altman repeatability coefficients and multivariate logistic regression. Mean office blood pressure was 163±20/84±17 mm Hg, and mean 24-hour blood pressure was 118±8/66±7 mm Hg. White-coat resistant hypertension diagnosis presented a moderate reproducibility and was confirmed in 144 patients after 3 months. In the third and fourth ABPMs, 74% and 79% of patients sustained the diagnosis. In multivariate regression, a daytime systolic blood pressure ≤115 mm Hg in the confirmatory ABPM triplicated the chance of white-coat resistant hypertension status persistence after 1 year. In conclusion, a confirmatory ABPM is necessary after 3 months of the first white-coat-resistant hypertension diagnosis, and the procedure should be repeated at 6-month intervals, except in patients with daytime systolic blood pressure ≤115 mm Hg, in whom it may be repeated annually.     

The effect of antihypertensive treatment with dihydropyridine calcium antagonists on white-coat hypertension

OBJECTIVE: To investigate the interrelations between blood pressure variables and treatment effects in white-coat and established hypertensive patients. DESIGN: A substudy on data from a randomized clinical trial on two dihydropyridine calcium antagonists, in which treatment intensity relied on office blood pressure, but with ambulatory blood pressure recordings performed before and after treatment. PATIENTS: Ninety-two hypertensive patients from general practices. RESULTS: Office and ambulatory blood pressures were only poorly correlated (r = 0.27-0.49). There was no significant correlation between treatment effects evaluated in terms of office and ambulatory blood pressures. Seventeen patients were classified as white-coat hypertensives; these differed in that their office blood pressure declined more with placebo, but similarly when administered active treatment, whereas their ambulatory blood pressure was not affected. An initial ambulatory blood pressure amounting to 127.4/84.8 mmHg was associated with no ambulatory treatment effect on average. CONCLUSION: These findings expose the shortcomings of office blood pressure measurements and strengthen the conception that white-coat hypertensives should not be treated pharmacologically.     

White-coat hypertension and sex

OBJECTIVES: To compare, by sex, selected behavioral and biologic characteristics among normotensive, white-coat hypertensive, and essential hypertensive patients, and to assess the similarities and differences in these characteristics between men and women diagnosed as having white-coat hypertension. METHODS: The subjects of this study were 764 men (80 normotensives, 112 white-coat hypertensives, and 572 essential hypertensives) and 442 women (53 normotensives, 81 white-coat hypertensives and 308 essential hypertensives) who were a nonrandom subset of a larger cohort of patients being assessed to determine the prognostic significance of ambulatory blood pressure measurements. Physician-measured technician-measured and ambulatory (average awake and asleep) blood pressures, daytime blood pressure variability, the difference between awake and sleeping blood pressures, cholesterol levels, plasma renin activity (PRA) and anthropometric and demographic characteristics were compared across the patient classifications within each sex group and between male and female white-coat hypertensives using one-way analysis of variance. Student's t tests and chi squared analysis. RESULTS: Among men, cholesterol levels of normotensives were significantly lower than those of either white-coat or essential hypertensives (P < 0.05 and P < 0.01, respectively). White-coat hypertensives were significantly younger than the essential hypertensives. The ambulatory and technician-measured blood pressures of the white-coat hypertensives were similar to those of the normotensives, as were most measures of variability of blood pressure. Among women, there were no differences in cholesterol level; however, white-coat hypertensives had lower PRA than did the essential hypertensives (P < 0.01) In contrast to the men, women with white-coat hypertension were similar in age to those with essential hypertension, and 10 years older than normotensives (P < 0.01). The ambulatory blood pressures of white-coat hypertensives were similar to those of normotensives, but their technician-measured blood pressures were intermediate between those of the normotensive and essential hypertensive groups. The daily variability of diastolic blood pressure among the white-coat-hypertensive women was greater than that of the normotensive women and similar to that of the essential hypertensive women. For all other measures of variability, data for white-coat-hypertensive women were similar to those for the normotensive women. There was no anthropometric or demographic difference among the patients either for men or for women. White-coat-hypertensive women were older than white-coat-hypertensive men and had higher systolic blood pressures and variabilities of blood pressure (P < 0.05). They also had lower PRA. CONCLUSIONS: These results are consistent with the ideas that the phenomenon of white-coat hypertension is similar for the two sexes, women may exhibit white-coat hypertension at a greater age than do men, and women with white-coat hypertension may further exhibit a broader white-coat effect, reflected in blood pressures measured by other medical personnel.     

Cardiovascular risk in white-coat and sustained hypertensive patients

We compared cardiovascular outcome between patients with white-coat and sustained hypertension who had previously participated in the Ambulatory Blood Pressure Monitoring and Treatment of Hypertension (APTH) trial. Baseline characteristics, including office and ambulatory blood pressure (BP), were measured during the 2-month run-in period of the APTH trial. During follow-up, information on the occurrence of major cardiovascular events (death, myocardial infarction, stroke and heart failure), achieved office BP and treatment status was obtained. At entry, 326 patients had sustained hypertension (daytime ambulatory BP ≥140 mmHg systolic and/or ≥90 mmHg diastolic) and 93 had daytime ambulatory BP below these limits and were classified as white-coat hypertensives. During 2088 patientyears of follow-up (median follow-up 5.3 years), all major cardiovascular events ( n = 22) occurred in the patients with sustained hypertension (rate 12.7 per 1000 patient-years, p = 0.02 for between-group difference). Furthermore, multiple Cox regression confirmed that after adjustment for important covariables, daytime ambulatory BP - but not office BP at entry - significantly and independently predicted cardiovascular outcome. After additional adjustment for office BP, daytime ambulatory BP still predicted the occurrence of major cardiovascular events. Although white-coat hypertension was less frequently associated with antihypertensive drug treatment during follow-up, it carried a significantly better prognosis than sustained hypertension.     

Clinic and ambulatory heart rate in sustained and white-coat hypertension

BACKGROUND: Sustained and white-coat hypertensives show hypertension in the office setting but different blood pressure values outside the clinical environment. So far, only a few incomplete data on heart rate are available inside and outside the clinical setting in these groups of patient. The aim of this study was to evaluate clinic and ambulatory heart in sustained hypertensives, white-coat hypertensives and normotensives. METHODS: We selected 236 sustained hypertensives, 236 white-coat hypertensives and 236 normotensives matched for age, gender and body mass index, and with a similar occupation. The subjects had been submitted to clinic evaluation and the non-invasive monitoring of blood pressure and heart rate. White-coat hypertension was defined as clinic hypertension and a daytime blood pressure of less than 135/85 mmHg. RESULTS: The clinic heart rate was significantly higher in sustained hypertensives and white-coat hypertensives than in normotensives (76 +/- 11 versus 75.5 +/- 10 versus 70 +/- 9 beats/min [bpm], respectively, P < 0.05). The daytime heart rate was significantly higher in sustained hypertensives than in white-coat hypertensives and normotensives (79.4 +/- 10 versus 74.6 +/- 8.5 versus 74.5 +/- 8.5 bpm, respectively, P < 0.05), as were the night-time heart rate (67 +/- 8.5 versus 63 +/- 8 versus 63 +/- 8 bpm, respectively, P < 0.05) and 24 h heart rate (76.3 +/- 9 versus 72 +/- 7.8 versus 72 +/- 8 bpm, respectively, P < 0.05). When men and women were analyzed separately, the same trend was observed. CONCLUSIONS: The clinic heart rate is similar in sustained and white-coat hypertensives, but the ambulatory heart rate is lower in white-coat hypertensives. As ambulatory heart rate is more representative of 24 h heart rate load and may be a better indicator of the detrimental effect of heart rate, our findings suggest that white-coat hypertensives are at lower cardiovascular risk than sustained hypertensives.     

Factors influencing white-coat effect

BACKGROUND: The transient blood pressure (BP) rise during clinical visits is usually referred to as white-coat effect (WCE). The aim of the present study was to investigate factors that may influence the WCE. METHODS: A total of 2004 subjects underwent office BP measurements and 24-h ambulatory BP monitoring (ABPM) on the same day. The WCE was estimated as the difference between office and average daytime ambulatory BP (ABP). According to the office and daytime BP values, the study population was divided into normotensives (NTs), white-coat hypertensives (WCHs), masked hypertensives (MHTs), and sustained hypertensives (SHTs). Statistical analyses were performed using one-way analysis of variance and multiple linear regression models. RESULTS: The mean systolic and diastolic WCE was 9 +/- 16 and 7 +/- 12 mm Hg, respectively. In the entire group of patients, multiple linear regression models revealed independent determinants of systolic WCE in the following rank order: office systolic BP (SBP) (beta = 0.727; P < 0.001), female gender (beta = 0.166; P < 0.001), daytime SBP variability (beta = 0.128; P < 0.001), age (beta = 0.039, P = 0.020), and smoking (beta = 0.031, P = 0.048). A 1.0 mm Hg increase in daytime SBP variability correlated with an increment of 0.589 mm Hg (95% confidence intervals, 0.437-0.741) in the systolic WCE. The regression analyses for diastolic WCE revealed the same factors as independent determinants. A 1.0 mm Hg increase in daytime diastolic BP (DBP) variability was independently associated with an increment of 0.418 mm Hg (95% confidence intervals, 0.121-0.715) in the diastolic WCE. CONCLUSIONS: Factors such as gender, age, smoking, office BPV and daytime BPV may exert an important influence on the magnitude of the WCE.     

The white-coat effect in treated hypertension

OBJECTIVE: To determine the occurrence of the white-coat effect in patients already receiving antihypertensive therapy. METHODS: A review of data from several studies in which the prevalence of a white-coat effect was determined in different populations of patients receiving antihypertensive therapy. RESULTS: In an initial series of 71 treated hypertensive patients being studied in a tertiary care centre, we noted a white-coat effect (office minus ambulatory blood pressure >/= 20/10 mmHg) in 52 patients. This finding was confirmed in a larger series of similar patients with 106 of 152 having a white-coat effect. A white-coat effect was also more common in women (70 of 87) than in men (36 of 65). Similar findings were observed in untreated hypertensive patients in the community with 91 of 147 patients having a white-coat effect on the basis of routine office blood pressure readings taken by family physicians. CONCLUSION: The white-coat effect is common in patients being administered antihypertensive therapy and should be considered as part of their management in clinical practice.     

Ambulatory blood pressure monitoring of chronically dialyzed pediatric patients.

BACKGROUND: Background Ambulatory blood pressure monitoring (ABPM) has been shown to be more representative of blood pressure levels in adult patients than are casual measurements of blood pressure. OBJECTIVE: To evaluate, by means of ABPM, the behavior of blood pressure in children with chronic renal failure submitted to continuous ambulatory peritoneal dialysis and compare the results with casual blood pressure monitoring measurements. DESIGN: Evaluation of blood pressures in chronically dialyzed pediatric patients by ABPM. METHODS: Ten pediatric patients, treated by continuous ambulatory peritoneal dialysis were evaluated by ABPM using the oscillometric SpaceLabs 90207 monitor, every 10 min during the day and every 15 min during the night, for 24h. RESULTS: Six of 10 patients were found normotensive by office measurement of blood pressure; four of 10 patients were found hypertensive by casual measurements of blood pressure. With ABPM we obtained a mean success rate of 92.5%, confirmed hypertension in all the patients classified hypertensive in terms of office readings and reclassified six of six patients from normotensive to hypertensive. The mean systolic and diastolic physiologic falls in blood pressure at night were respectively by 10 and 15%. At the time of the ABPM study end-organ damage was present in two patients judged to be normotensive in terms of office blood pressures. CONCLUSION: Casual recordings of blood pressure are not representative of average blood pressure in dialyzed pediatric patients. ABPM seems to be a useful diagnostic aid for assessing treatment of hypertension in children with end-stage renal disease.     

Reverse white-coat effect as an independent risk for left ventricular concentric hypertrophy in patients with treated essential hypertension

Recent studies have shown that the converse phenomenon of white-coat hypertension called 'reverse white-coat hypertension' or 'masked hypertension' is associated with poor cardiovascular prognosis. We assessed the hypothesis that this phenomenon may specifically influence left ventricular (LV) structure in treated hypertensive patients. A total of 272 outpatients (mean age, 65 years) with chronically treated essential hypertension and without remarkable white-coat effect were enrolled. Patients were classified into two groups according to office and daytime ambulatory systolic blood pressure (SBP); that is subjects without (Group 1: office SBP > or =daytime SBP, n=149) and with reverse white-coat effect (Group 2: office SBP相似文献   

The white-coat hypertension response

This study was designed to determine the clinical characteristics of hypertensive patients whose blood pressures are substantially higher in the medical office than in their natural environments. Thirty-nine percent of patients enrolled in a nonpharmacologic hypertension treatment program had systolic or diastolic office blood pressures (OBPs) that were at least 10 mm Hg higher than their ambulatory blood pressures (ABPs). Although these white-coat responders (WCRs) had higher systolic OBPs than did non-white-coat responders (NRs), both their systolic (p<0.02) and their diastolic (p<0.0001) ABPs were significantly lower than those of NRs. Furthermore, patients with white-coat hypertension did not have greater blood pressure reactivity in their natural environments, suggesting that their blood pressure elevations may be specific to the medical setting. White-coat hypertensives were older (p<0.005), had less angry dispositions (p<0.01), and reported less overt anger expression (p<0.005). They were also taking more antihypertensive medications than were the other patients in the study (p<0.001).     

AMBULATORY BLOOD PRESSURE MONITORING AND CLINICAL CHARACTERISTICS OF THE TRUE AND WHITE-COAT RESISTANT HYPERTENSION

The resistant hypertension has been differentiated in true resistant hypertension and white-coat resistant hypertension by using ambulatory blood pressure monitoring. White-coat resistant hypertension was defined as high clinic blood pressure, despite triple treatment for at least 3 months, but day-time blood pressure values < 135/85 mmHg. The aim of this study was to evaluate the presence of different clinical characteristics between two types of resistant hypertension.

The study group consisted of 49 patients with essential hypertension, resistant to an adequate and appropriate triple-drug therapy, that included a diuretic, with all 3 drugs prescribed in near maximal doses and that had persistently elevated clinic blood pressure (>140/90 mm Hg), for at least 3 months. They represented the 2% of 2500 hypertensive outpatients that referred at our Hypertension Unit. Patients with white-coat resistant hypertension (n=19) were older (p<0.05) than those with true resistant hypertension (n=30). The sodium intake (p<0.05) and alcohol intake (p<0.05) were significantly higher in patients with true resistant hypertension than in those with white-coat resistant hypertension. The renin plasma activity and plasma aldosterone were higher (p<0.05) in patients with true resistant hypertension than in those with white-coat resistant hypertension with normal plasma electrolyte balance. There were no significant differences in mean values of office systolic and diastolic blood pressures between white coat resistant hypertensives and true resistant hypertensives (165+17 vs 172+28 and 98+12 vs 102+14 mmHg).

Day-time and night-time ambulatory 24-h-systolic and diastolic blood pressures were significantly higher in the true resistant hypertensive patients when compared with white-coat resistant hypertensives (153+15 vs 124+10 mmHg and 97+9 vs 76+6 mmHg all p<0.001). Day-time and night-time ambulatory 24-h-heart rate were significantly higher in the true resistant hypertensive patients when compared with white-coat resistant hypertensives (79+11 vs 71+9 beats/min;p<0.01; 68+9 vs 60+6 beats/min. p<0.001). The ABP readings were analysed by a Fourier series with 4 harmonics. According to the runs test both two groups of patients showed a circadian rhythm for both systolic and diastolic blood pressure. The nocturnal fall in SBP, DBP and HR was not different in both groups of patients.

In conclusion, our findings showed that true resistant hypertensive patients were characterized both by higher heart rate and higher plasma renin activity values as an expression of a possible increased sympathetic activity. Thus, the combination of ABPM with the assessment of the clinical characteristics allow to differentiate better the true drug-resistant hypertension from the white coat resistant hypertension.     

White-Coat Resistant Hypertension

The aim of this study was to evaluate whether sustained hypertensives with high clinic blood pressure, despite multiple drug treatment, show a true resistant hypertension or a “white-coat effect,” and whether the pretreatment white-coat effect is maintained despite pharmacological therapy. The occurrence of resistant hypertension was determined in 250 consecutive essential hypertensives who had had an ambulatory blood pressure monitoring before treatment assignment. Twenty-seven of 250 hypertensives with persistently high clinic blood pressure despite 3 months of adequate pharmacological therapy underwent further ambulatory blood pressure monitoring. Using our internal standards, seven patients had a true resistant hypertension whereas 20 subjects showed a large white-coat effect (white-coat resistant hypertension), ie, high clinic blood pressure (>140/90) but “normal” ambulatory daytime (<139/90 mm Hg) and 24 h (135/85 mm Hg) blood pressure. Using other cutoff points for ambulatory blood pressure, 134/90 and 135/85 mm Hg for daytime blood pressure, 10 and 13 patients, respectively, were reclassified as true resistant hypertensives and 17 and 14, respectively, were white-coat resistant hypertensives. Interestingly, in white-coat resistant hypertensives the large differences between clinic and ambulatory daytime blood pressure (white-coat effect), recorded before treatment assignment, were not affected by drugs and remained constant over time. Left ventricular mass index in white-coat resistant hypertensives was significantly lower than in truly resistant hypertensives, suggesting that prognosis could differ between these groups. In this study, using either our internal standards or some other cutoffs reported in the literature, the white-coat phenomenon was an important cause of resistant hypertension. The use of ambulatory blood pressure monitoring in these patients may avoid misdiagnosis of resistant hypertension, unnecessary overtreatment, and expensive procedures to look for possible secondary hypertension.