White coat effect in treated and untreated patients with high office blood pressure. Relationship with pulse wave velocity and left ventricular mass index.

OBJECTIVE: To evaluate in hypertensive patients whether the white coat effect is associated with target-organ damage and whether it is modified by anti-hypertensive therapy. METHODS: In a cross-sectional study we evaluated blood pressure (BP) measured in the office and by 24-h ambulatory blood pressure monitoring (ABPM), carotid-femoral pulse wave velocity (PWV) as an index of aortic stiffness, and left ventricular mass index (LVMI) in 88 subjects (aged 49 +/- 2 years) with white-coat hypertension (WCH, office BP > 140/90, daytime BP < 130/84 mmHg), 31 under antihypertensive therapy, 57 untreated, and in 115 patients with office and ambulatory hypertension (HT, aged 51 +/- 2 years, office BP > 140/90, daytime BP > 135/85), 65 under antihypertensive therapy, 50 untreated. In a longitudinal study in 15 patients with HT and in 11 patients with WCH we evaluated the influence of antihypertensive therapy (> 6 months) on office and ambulatory BP and on PWV. RESULTS: The intensity of the white coat effect (office BP-daytime BP) was greater in WCH than in HT. Taking all subjects, the white coat effect did not correlate with PWV (r = 0.08, ns) or with LVMI (r = 0.01, ns), whereas daytime BP correlated significantly with PWV (r = 0.41, p < 0.01) and with LVMI (r = 0.32, p < 0.05). WCH subjects showed lower PWV and LVMI than HT subjects. Treated and untreated WCH, with similar office and daytime BP, showed similar values of PWV and LVMI. Treated and untreated HT showed similar office BP values but treated HT showed lower daytime BP and PWV values. In the longitudinal study, antihypertensive therapy significantly reduced daytime BP and PWV values in the 15 HTs, whereas in the 11 WCH it did not alter daytime BP or PWV values. CONCLUSIONS: 1. In both WCH and HT (treated and untreated) the intensity of the white coat effect does not reflect either the severity of hypertension measured by target organ damage or the efficacy of antihypertensive treatment. 2. In WCH antihypertensive therapy does not improve either ambulatory BP values or damage to target organs.     

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.     

Birth weight, hypertension and "white coat" hypertension: size at birth in relation to office and 24-h ambulatory blood pressure

We investigated the association of size at birth with hypertensive status defined by office blood pressure (BP) and 24-h ambulatory BP monitoring in a historical cohort study of 736 men born 1920-1924 and examined at age 70 years. Office BP was measured after 10-min supine rest with a sphygmomanometer, ambulatory BP was recorded with Accutracker 2, and anthropometric and other measurements were taken at a clinic. Birth weight and gestational age were abstracted from the men's birth records. A total of 24% of the men were treated for hypertension at the time of the study. Among not treated subjects, there was a weak positive association of birth weight with daytime and 24-h diastolic ambulatory BP. In subjects treated for hypertension, both office and ambulatory BP were inversely related to birth weight, although these associations were not statistically significant. Birth weight did not show significant association with sustained hypertension (elevated office and daytime ambulatory BPs) but showed a strong and statistically significant inverse association with "white coat" hypertension (elevated office BP and normal daytime ambulatory BP) when adjusted for concurrent body mass index (odds ratios 1.91, 1.59, 1 and 1.21 from lowest to highest quartile of birth weight, P-value for trend 0.035). We conclude that BP measured by 24-h-ambulatory monitoring is not related to birth weight in a pattern previously reported for office BP and that factors related to growth in utero are particularly related to higher risk of "white coat" hypertension.     

Identification of subjects with white-coat hypertension and persistently normal ambulatory blood pressure

OBJECTIVE: To assess the spontaneous changes in clinic blood pressure, ambulatory blood pressure (ABP) and left ventricular structure in untreated subjects with white-coat hypertension (WCH). DESIGN: A prospective observational study. PATIENTS AND METHODS: In 83 untreated subjects with WCH, 24 h non-invasive ABP monitoring and echocardiographic studies of the left ventricle were repeated after 0.5-6.5 years (mean 2.5) in the absence of antihypertensive drug treatment. WCH was defined by an average daytime ABP < 131/86 mmHg in women and < 136/87 mmHg in men. Ambulatory hypertension was defined by higher ABP values. RESULTS: In the whole population, the clinic blood pressure, ABP and left ventricular mass did not change from baseline to the follow-up visit, whereas the peak A: peak E ratio (where A is the velocity of transmitral blood flow after atrial contraction and E is the velocity during passive left ventricle filling) increased from 0.86 to 0.93. Sixty-three per cent of subjects remained in the WCH category at follow-up study; the remaining 37% shifted to the ambulatory hypertension category. The former group showed no changes in clinic blood pressure, ABP, left ventricular mass and peak A: peak E ratio. The clinic blood pressure of those who developed ambulatory hypertension did not change, whereas their ABP and peak A: peak E ratio increased and their left ventricular mass increased slightly but not significantly. The left ventricular mass increased from baseline to follow-up study by 6.2% in those who developed ambulatory hypertension and decreased by 1.6% in those who remained in the WCH category. The changes in left ventricular mass were associated with the changes in average 24 h systolic blood pressure, but not with the changes in clinic blood pressure. In a stepwise logistic regression analysis, average daytime diastolic blood pressure was the sole variable to enter the model and the probability of ambulatory hypertension at follow-up study was 20.0%percnt; in those with basal daytime ABP <130/80 mmHg, versus 81% in those with higher basal daytime blood pressure levels. CONCLUSION: After 0.5-6.5 years, WCH spontaneously evolved into ambulatory hypertension in 37% of subjects, with an accompanying rise in left ventricular mass. The probability of ambulatory hypertension increased with the baseline values of ABP, rather than with those of clinic blood pressure. WCH might be a prehypertensive state (particularly in subjects with higher baseline ABP levels) and should be defined by low levels of daytime ABP, possibly lower than 130/80 mmHg.     

24-h Ambulatory blood pressure in patients with ECG-determined left ventricular hypertrophy: left ventricular geometry and urinary albumin excretion-a LIFE substudy

This study was undertaken to evaluate the relationships among left ventricular (LV) geometric patterns and urinary albumin excretion in patients with hypertension and electrocardiographic (ECG) LV hypertrophy. In 143 patients with stage II-III hypertension, 24-h ambulatory blood pressure (BP) monitoring, single urine albumin determination, and echocardiography were performed after 14 days of placebo treatment. Mean age was 68+/-7 years, 35% were women, body mass index was 28+/-5 kg/m(2), LV mass index (LVMI) was 125+/-26 g/m(2), and 24% had microalbuminuria. The mean office BP was 176+/-15/99+/-8 mmHg and the mean daytime ambulatory BP was 161+/-18/92+/-12 mmHg. Ambulatory BP, but not office BP, was higher among albuminuric compared to normoalbuminuric patients. In patients with established hypertension, daytime pulse pressure and office BP were different in the four patterns of LV geometry, with the highest pressure in those with abnormal geometry. Furthermore, microalbuminuria was more frequent in hypertensive patients with LV hypertrophy than in those with either normal geometry or concentric remodelling. White coat hypertensives (10%) showed lower LVMI and no microalbuminuria compared to patients with established hypertension. There were no differences in the prevalence of nondippers (26%) among the four LV geometric patterns or in microalbuminuria. In conclusion, increased daytime pulse pressure and office BP were associated with increased prevalence of abnormal LV geometry. Microalbuminuria was more frequent in groups with concentric and eccentric LV hypertrophy. Ambulatory BP, but not office BP, was higher in albuminuric than normoalbuminuric patients. With regard to the relationship among BP, LV geometric patterns, and urine albumin excretion in this population, 24-h ambulatory BP did not provide additional information beyond the office BP.     

Nurse-recorded and ambulatory blood pressure predicts treatment-induced reduction of left ventricular hypertrophy equally well in hypertension: results from the Swedish irbesartan left ventricular hypertrophy investigation versus atenolol (SILVHIA) study

OBJECTIVE : To compare the relationships of treatment-induced reductions of left ventricular hypertrophy to the changes in clinic and ambulatory blood pressure (BP). DESIGN : Double-blind and randomized treatment with irbesartan or atenolol for 48 weeks. PATIENTS : Patients with hypertension and left ventricular hypertrophy (n = 66) with a seated diastolic BP 90-115 mmHg (average of three measurements one minute apart by nurses). MAIN OUTCOME MEASURES : Registrations of echocardiographic left ventricular (LV) mass. Clinic and ambulatory BP. RESULTS : In the total material, nurse-measured BP was reduced by 23 +/- 15/16 +/- 7.7 mmHg and 24-h ambulatory BP fell 20 +/- 15/14 +/- 8.5 mmHg by treatment. The correlation between the change in nurse-measured BP and LV mass index (LVMI) induced by treatment was r = 0.35, P = 0.004 for systolic BP and r = 0.26, P = 0.03 for diastolic BP. Corresponding values for 24-h ambulatory BP were r = 0.29, P = 0.02 and r = 0.35, P = 0.004, respectively, with similar correlations for day- and night-time ambulatory BP. The nurse-recorded BP was slightly higher than ambulatory BP (systolic clinic - systolic 24-h ambulatory BP = 5 mmHg). Using 130/80 mmHg as a cut-off value for normal 24-h ambulatory BP, eight subjects had normal diastolic or systolic ambulatory BP, or both. Interestingly, these patients also experienced LVMI regression following treatment (low/normal ABP, -13 +/- 21 g/m2; remaining patients, -18 +/- 22 g/m2, P > 0.5). CONCLUSIONS : In patients with hypertension and left ventricular hypertrophy, ambulatory BP is not superior to carefully standardized nurse-recorded seated BP in terms of associations with treatment-induced changes in LV mass.     

Diagnostic criteria of white coat hypertension (WCH): consequences for the implications of WCH for target organs

In a sample comprising 51 normotensive subjects and 51 subjects with in-clinic arterial hypertension [blood pressures (BPs) > or = 140/90 mmHg), we investigated the prevalence of target organ damage [left ventricular hypertrophy (LVH) and retinal vasculopathy] in white coat hypertension (WCH) groups defined using: (a) the "optimal ambulatory BP" criterion of the Seventh International Consensus Conference (in-clinic BPs >140/90 mmHg, daytime mean BPs < 130/80 mmHg) and (b) the "normal ambulatory BP" criterion proposed in 1997 by Verdecchia and co-workers (in-clinic BPs >140/ 90 mmHg, daytime mean BPs < 135/85 mmHg), and we compared the results with those obtained for the normotensive group and for a WCH group defined as in a 1996 study of the same data. We found that the newer criteria did not alter the conclusions reached in 1996: namely, that WCH constitutes a state of risk intermediate between normotension and sustained hypertension, which demands in-depth evaluation and active monitoring, if not immediate therapy. We also found that when the WCH group was defined as those patients with in-clinic BPs > or = 140/90 mmHg and 24-h mean BPs < 121/78 mmHg, the prevalence of target organ damage was similar to that found in the control group. We conclude that if WCH status is to imply absence of elevated risk of target organ damage, then the ambulatory BP threshold defining WCH should be lower than the upper limit of ambulatory BPs among subjects who are normotensive in the clinic. The desirability of predicting target organ damage in both hypertensive and normotensive subjects using criteria combining in-clinic BPs, daytime mean ambulatory BPs and night-time mean ambulatory BPs is suggested.     

White Coat Hypertension: to Treat or Not to Treat?

Definition of white coat hypertension (WCH) traditionally relies on elevated office blood pressure (BP) during repeated visits concomitant with normal out-of-office BP values, as assessed by home and/or 24-h ambulatory BP monitoring measurements. Accumulating evidence focusing on the association of WCH with target organ damage and, more importantly, with cardiovascular events indicates that the risk conveyed by this condition is intermediate between normotension and sustained hypertension. This article will review a number of issues concerning WCH with particular emphasis on the following: (1) prevalence and clinical correlates, (2) association with target organ damage and cardiovascular events, (3) therapeutic interventions. Data will refer to the original WCH definition, based on out-of-office BP determined by 24-h ambulatory BP monitoring; at variance from home BP measurement, this approach rules out the potentially confounding effect of a clinically relevant abnormal BP phenotype such as isolated nocturnal hypertension.     

White coat hypertension in type 1 diabetic patients without nephropathy

The aim of our study was to determine the prevalence of white coat hypertension (WCH) in type 1 diabetic patients. Therefore, ambulatory blood pressure monitoring (ABPM) and 24-h urinary albumin excretion (UAE) were determined in 47 patients with type 1 diabetes mellitus (27 with new diagnosis of hypertension by office blood pressure (BP) measurement and 20 with normotension). WCH was diagnosed in 20 patients (74%). Patients with WCH presented higher values of systolic and diastolic BP and UAE than normotensive patients. The results indicate that in type 1 diabetes mellitus WCH is very frequent. Thus, WCH may represent a potential risk for the development of diabetic complications, mainly diabetic nephropathy.     

White‐Coat Isolated Systolic Hypertension Is a Risk Factor for Carotid Atherosclerosis

The clinical importance of white‐coat hypertension (WCH) remains a controversial issue. The aim of this study was to evaluate the association of isolated systolic, isolated diastolic, and systolic/diastolic WCH with common carotid artery intima‐media thickness (CCA‐IMT) and to compare each subgroup of WCH against other blood pressure (BP) phenotypes in terms of CCA‐IMT values. A total of 1382 consecutive patients underwent 24‐hour ambulatory BP monitoring and carotid artery ultrasonographic measurements. According to the type of elevated office BP, WCH was divided into three groups: isolated systolic, isolated diastolic, and systolic/diastolic WCH. Patients with isolated systolic WCH (n=112) had significantly higher CCA‐IMT values (0.737 mm) than those with isolated diastolic WCH (n=66) (0.685 mm) and nonsignificantly greater compared with those with systolic/diastolic WCH (n=228) (0.708 mm). Patients with isolated systolic WCH had CCA‐IMT values similar to those with hypertension, patients with isolated diastolic WCH had similar values to those with normotension, and patients with systolic/diastolic WCH had an intermediate risk between normotension and hypertension.     

Left ventricular systolic and diastolic function assessed with two-dimensional and Doppler echocardiography in “white coat” hypertension

Objectives. The aim of this study was to investigate left ventricular function in subjects with “white coat” hypertension, defined as office arterial diastolic pressure ≥90 and ambulatory daytime pressure < 140/90mm Hg.Background. The white coat arterial pressure response may, by influencing left ventricular function, have a confounding effect in studies of heart disease.Methods. Two-dimensional and Doppler echocardiography, combined with the calibrated subclavian arterial pulse tracing, were used to assess variables of left ventricular function in 26 subjects with white coat hypertension, as well as 22 subjects with previously untreated ambulatory hypertension (office arterial diastolic pressure ≥90 and <115 mm Hg and ambulatory daytime diastolic pressure ≥90 mm Hg) and 32 normotensive subjects.Results. In subjects with white coat hypertension, systolic arterial pressure during the echocardiographic examination was significantly higher than ambulatory daytime systolic pressure. This pressure response was positively related to the ratio of the systolic to diastolic pulmonary venous flow peak velocities and to the peak velocity of flow reversion during atrial systole; it was inversely related to the ratio of early to late mitral flow peak velocities. Left ventricular stroke volume, ejection fraction and velocity of circumferential fiber shortening did not differ in the study groups, but left ventricular external work and end-systolic wall stress were increased in the white coat group.Conclusions. The arterial pressure response in subjects with white coat hypertension is associated with increased left ventricular external work, increased end-systolic wall stress and alterations of left ventricular filling but normal ejection fraction and velocity of circumferential fiber shortening.     

Relationship between left ventricular mass and blood pressure in treated hypertension

This study evaluated prospectively whether there is still a relationship between left ventricular mass and blood pressure once hypertension is treated and determined the relative importance of daytime vs night-time blood pressure, systolic vs diastolic blood pressure and office vs ambulatory blood pressure. A total of 649 patients (305 or 47% female) with essential hypertension, treated with antihypertensive drugs for at least 3 months, underwent office blood pressure measurement and both daytime and night-time ambulatory blood pressure measurement, electrocardiography and echocardiography. Correlations were made between blood pressure values and parameters of left ventricular mass. Electrocardiographic voltage criteria and even more so echocardiographic parameters correlate significantly albeit weakly (r < or = 0.28) with blood pressure in treated hypertension. Correlations are consistently higher when systolic blood pressure is considered. Overall, the best correlations are found between 24-h ambulatory systolic or night-time blood pressure and the Sokolow-Lyon voltage as well as the echocardiographic age and body mass index adjusted left ventricular mass. In conclusion, once hypertension is treated, the relationship between blood pressure and left ventricular mass is low. Nevertheless, in this the largest single centre study of its kind, echocardiographic parameters of left ventricular mass in treated hypertensive subjects correlate better with blood pressure than electrocardiographic parameters. Parameters of hypertrophy are more closely related to systolic blood pressure than to diastolic blood pressure. In accordance with the finding that dippers have a better prognosis than non-dippers, night-time blood pressure consistently correlates better with left ventricular mass than daytime blood pressure.     

Clinical Implications of White Coat Hypertension

Objective: To determine the clinical implications of mild white coat hypertension (WCH).

Subjects and methods: We studied 102 subjects (54 men, 48 women). 51 of whom were normotensive and 51 slightly hypertensive. None had ever received antihypertensive therapy. An ambulatory blood pressure (ABP) record (Accutracker II), a 24-h electrocardiogram and an echocardiogram were obtained from each, and each was examined by funduscopy. WCH subjects were compared with sustained hypertension (SH) subjects and with normotensives.

Results: Fifty-three percent of the hypertensives qualified as WCH. The ultrasonographic characteristics and the ABP variables of the WCH group differed significantly from those of normotensives, but not from those of the SH group. The prevalence of left ventricilar hypertrophy (LVH) in the SH group (62.5%) did not differ significantly from its prevalence in the WCH group (40.7%). but the prevalence among normotensives (17.6%) was significantly lower than in either of the other two groups. The WCH and SH groups did not differ significantly as regards the prevalence of hypertensive retinopathy (33.3%) in the former, 58.3% in the latter). For no non-LVH, nonretinopathic subject, whether norniotensive or hypertensive, were more than 18% of daytime diastolic ABP measurements ≥90mmHg. Ultrasonographic findings were no better correlated with ABP than with in-clinic BP measurements. Fundus findings correlated well with in-clinic BP and with numerous ABP parameters. Retinopathy, with or without LVH, was efficiently predictable among hypertensives on the basis of body mass index and the 24-h maximum of systolic BP.

Conclusions: Myocardiac remodelling and vascular retinopathy develop early and in parallel in hypertensives, and both developments appear to involve determinants including body mass index and 24-h maximum systolic BP. WCH subjects, as defined by current ABP-based criteria, have cardiac and retinovascular Characteristics different to normotensive subjects. Stricter criteria are needed to discriminate between hypertensives with and without the systemic developments that constitute the immediate source of risk to the hypertensive individual.     

White-coat effect in normotension and hypertension

OBJECTIVES: The difference between clinic and daytime ambulatory blood pressure is referred to as the white-coat effect. In this study, we investigated (i) the magnitude of the white-coat effect in subjects with different daytime ambulatory blood pressure levels, and (ii) the association of the white-coat effect with left ventricular mass. METHODS: A total of 1581 subjects underwent clinic blood pressure readings, 24-h ambulatory blood pressure monitoring and left ventricular echocardiographic assessment. Their mean daytime systolic blood pressure varied from 88.0 to 208.9 mmHg and their mean daytime diastolic blood pressure from 40.3 to 133.0 mmHg. RESULTS: A negative correlation was found between the systolic or diastolic white-coat effect and the systolic or diastolic daytime ambulatory blood pressure (r = -0.22, P < 0.000 and r = -0.50, P < 0.000, respectively). Left ventricular mass significantly correlated with ambulatory blood pressure (P < 0.001), but there was no association between left ventricular mass and clinic blood pressure or white-coat effect. Furthermore, the white-coat effect was reversed at the highest level of systolic or diastolic daytime ambulatory blood pressure (systolic over 170 mmHg or diastolic over 100 mmHg) when systolic or diastolic daytime ambulatory blood pressure was higher than systolic or diastolic clinic blood pressure (ambulatory blood pressure hypertension). CONCLUSIONS: The white-coat effect shows an inverse association with daytime ambulatory blood pressure level (systolic or diastolic), being significantly more prominent for levels below 140/80 mmHg for systolic/diastolic daytime ambulatory blood pressure and reversed with daytime ambulatory blood pressure levels above 170/100 mmHg.     

The importance of using 24‐hour and nighttime blood pressure for the identification of white coat hypertension: Data from the Jackson Heart Study

We calculated the prevalence of white coat hypertension (WCH) using out‐of‐clinic blood pressure (BP) in the daytime period; daytime and 24‐hour periods; and daytime, 24‐hour, and nighttime periods among 199 African Americans with clinic‐measured systolic/diastolic BP ≥140/90 mm Hg in the Jackson Heart Study. Left ventricular mass index (LVMI) was measured among participants with WCH and 374 participants with sustained normotension (ie, non‐hypertensive clinic, daytime, 24‐hour, and nighttime BP). The prevalence of WCH was 29.6%, 21.1%, and 10.6% using daytime BP; daytime and 24‐hour BP; and daytime, 24‐hour, and nighttime BP, respectively. Compared with sustained normotension, LVMI was higher when WCH was defined using daytime BP (adjusted mean difference [95% CI] 5.0 [?0.2, 10.1] g/m²), but not when defined using daytime and 24‐hour BP or daytime, 24‐hour, and nighttime BP (adjusted mean difference [95% CI] 3.9 [?1.9, 9.7] and 0.4 [?7.3,8.2] g/m², respectively). Using only daytime BP overestimates the prevalence of WCH among African Americans.     

Clinical implications of white coat hypertension: an ambulatory blood pressure monitoring study

Within routine clinical practice, white coat hypertension (where blood pressure is persistently higher in the presence of the doctor or nurse but normal outside the medical setting) makes the diagnosis and management of hypertension difficult. There are conflicting data regarding the prevalence and significance of white coat hypertension. This study has used ambulatory blood pressure monitoring to detect the presence of white coat hypertension in 186 patients referred to an out-patient hypertension unit. The presence of white coat hypertension was defined as an average office blood pressure (measured on three occasions over a 2-month period) of >140/90 mm Hg and an ambulatory awake blood pressure < or = 136/86 mm Hg. The prevalence of white coat hypertension in those patients with borderline hypertension (diastolic blood pressure 90-99 mm Hg) and those with mild-to-moderate hypertension (diastolic blood pressure > or = 100 mm Hg) was determined. Echocardiography was used to assess left ventricular mass index in patients with and without white coat hypertension. The prevalence of white coat hypertension in the total group was 23%. However, the prevalence was higher (33%) in those patients with borderline hypertension compared to 9% of those patients with mild-to-moderate hypertension. There was a statistically significant increase in left ventricular mass index in patients with no evidence of white coat hypertension (125 gm/m2) compared to those with white coat hypertension (102 gm/m2). We conclude that, if office blood pressure is used to identify patients with hypertension who may require treatment, some patients will be incorrectly diagnosed and may be treated inappropriately. We recommend that ambulatory blood pressure monitoring is used in the routine assessment of all newly diagnosed hypertensive patients. Furthermore, we recommend echocardiography in patients with borderline hypertension as some will already have an increased left ventricular mass index.     

Characteristics of white coat hypertension in Chinese Han patients with type 2 diabetes mellitus

Objectives: This study documented the prevalence and clinical features of white coat hypertension (WCH) among Chinese Han patients with type 2 diabetes mellitus (T₂DM). Methods: Clinic and ambulatory blood pressure (BP) measurements were compared in 856 patients with T₂DM to determine the frequency of WCH (WCH was defined as clinical blood pressure ≥140/90?mmHg and daytime blood pressure <135/85?mmHg and/or 24-h ambulatory BP (ABP) mean value of <130/80?mmHg on ambulatory BP monitoring (ABPM). Weight, waist circumference (WC), body mass index (BMI), waist to height ratio (WHtR), fasting blood glucose, glycosylated hemoglobin level and circadian BP patterns were also measured to find clinical features predictive of WCH in T₂DM. Results: The prevalence of WCH was 7.36% (63/856) in the overall population, 6.13% (29/473) in male and 8.88% (34/383) in female (p?2DM, male WC were independent protective factors, whereas female sex, smoking and alcohol consumption were independent risk factors for WCH in T₂DM. Non-dippers and reverse dippers made up larger proportion of the WCH group (p?Conclusion: WCH is relatively common among T₂DM patients, it is a unique condition distinct from essential hypertension (EH), and WCH patients also exhibit significant differences in clinical parameters.     

Evaluation of white coat hypertension in children: importance of the definitions of normal ambulatory blood pressure and the severity of casual hypertension

To better describe the phenomenon of white coat hypertension (WCH) in children, we reviewed our single-center experience using ambulatory blood pressure monitoring to determine: 1) how the choice of threshold limits for defining ambulatory hypertension affects the determination of WCH, and 2) whether the severity of casual hypertension predicts the occurrence of WCH. Using the same daytime ambulatory blood pressure (ABP) data from 71 children (age 11.9 ± 3.4 years) with persistently elevated casual blood pressure (BP), the prevalence of WCH was compared using 95th percentile BP limits from the Task Force on High Blood Pressure in Children (TF) and from normative pediatric daytime ambulatory BP (ABP) data. To quantify casual hypertension severity, average clinic BP was divided by the patient-specific TF 95th percentile BP to generate a BP index (ie, BP index of 1.1 = 10% above 95th percentile). The WCH prevalence was lower by normative ABP criteria than by TF criteria (31% v 59%, P < .001), but did not vary significantly by age, gender, race, or body mass index. Logistic regression showed that higher systolic BP index (P < .001) or diastolic BP index (P < .01) was associated with a lower probability of WCH. Specifically, as systolic BP index increased from 1.0 to 1.2, the estimated probability of WCH decreased from 87% to 15%, respectively. These data suggest that the use of the lower TF limits, derived solely from resting BP measurements, may overestimate WCH prevalence in ambulatory children. In addition, these data confirm in children the finding in adults that WCH is highly prevalent when casual hypertension is borderline or mild, but uncommon when moderate or severe.     

Ambulatory blood pressure monitoring to study white coat syndrome in patients with hypertension seen in primary care

INTRODUCTION AND OBJECTIVES: The white coat phenomenon is said to occur when the difference between systolic/diastolic blood pressure measured during visits to the doctor's office and in ambulatory recordings is greater than 20/10. These absolute differences, known as the white coat effect, may lead to normotensive patients being classified as having white coat hypertension (WCH). We used ambulatory blood pressure monitoring (ABPM) to monitor the prevalence and response (white coat effect, white coat hypertension or white coat phenomenon) in patients during pharmacological treatment for grade 1 or 2 hypertension, and 4 weeks after treatment was suspended under medical supervision. PATIENTS AND METHOD: Ambulatory blood pressure monitoring was used in 70 patients with hypertension that was well controlled with treatment. Blood pressure was recorded during treatment (phase 1) and 4 weeks after treatment was stopped (phase 2). RESULTS: 18 (26%) of the 70 patients did not participate in phase 2 because when medication was withdrawn, their blood pressure values became unacceptable and it was necessary to restart treatment. The white coat effect was significantly stronger in phase 1, and the prevalence of white coat phenomenon and white coat hypertension did not differ significantly between phases. At the end of phase 2 the prevalence of white coat hypertension was 33%. CONCLUSIONS: Withdrawal of antihypertensive medication in patients with well controlled grade 1 or grade 2 hypertension did not significantly modify the prevalence of white coat phenomenon or white coat hypertension. The white coat effect was greater while patients were on pharmacological treatment. One third of our patients were considered to have been mistakenly diagnosed as having hypertension.     

Prevalence and clinical significance of a greater ambulatory versus office blood pressure ('reversed white coat' condition) in a general population

BACKGROUND: Attention has recently been directed to a condition termed 'reversed white coat' because of an average 24 h ambulatory blood pressure (BP) uncharacteristically greater than office BP. No data are available, however, on the prevalence of this condition in the general population, as well as on its relationship to BP, age, gender, antihypertensive treatment and cardiac organ damage. METHODS: In 3200 individuals (participation rate 64%), randomly selected to be representative of the residents of Monza (Milan, Italy) for sex and decades of age (25 to 74 years), we measured office BP (average of three measurements, sphygmomanometry), ambulatory BP (automatic readings every 20 min, Spacelabs 90207) and left ventricular mass (echocardiography). RESULTS: A 'reversed white coat' condition (identified when 24-h average ambulatory systolic, diastolic or mean were higher than the corresponding office values) was seen in 15% (diastolic) to 26% (systolic) of the population as a whole. Prevalence was greater (34-40%) when the difference between office and daytime BP was considered but in both instances it remained less than the prevalence of the white-coat phenomenon. A reversed white-coat condition was similarly frequent in males and females and showed a steep reduction with age and increasing office BP values. Prevalence was greater in hypertensive subjects in whom treatment achieved BP control than in untreated or unsatisfactorily treated individuals. Within each quartile of 24-h or office BP, left ventricular mass index adjusted for demographic and biochemical values was similar in reversed white coat versus the remaining subjects. The absence of any association with left ventricular hypertrophy scores against the clinical significance of this phenomenon.