[Variations in the prevalence and patient profile of white-coat syndrome, according to its definition using self-measurement of blood pressure at home]

Proportion of isolated clinical hypertension in primary care settings. Comparison of target organ damage in patients with isolated clinical hypertension and patients with sustained arterial hypertension

The aim of this study was to determine the proportion of isolated clinical hypertension (ICH) in newly diagnosed hypertensive patients, and to compare the incidence of target organ damage (TOD) in ICH and sustained hypertension patients. Participants. In a multi-centre study involving 14 primary care centres in Girona, Spain, 140 researchers recruited 214 newly diagnosed hypertensive patients 15-75 years of age, without history of cardiovascular events. Period of study. 2004-6. Method. Self-blood pressure monitoring (SBPM) and ambulatory blood pressure monitoring (ABPM). Evaluation. Anamnesis including blood pressure, physical examination and analysis (creatinine, albumin/creatinine index), electrocardiogram (left ventricular hypertrophy) and retinography (fundus damage). Results. In 129 (60.3%) subjects with sustained hypertension and 85 (39.7%) with ICH, no significant differences were found relative to gender, age, body mass index or blood pressure (155/90 vs 154/90 mmHg, respectively). Cholesterol levels were significant differences between both groups (5.97 mmol/l in sustained hypertension vs 5.64 mmol/l in ICH, p = 0.029). The proportion of ICH was approximately 40%. TOD incidence in sustained hypertensives was similar to that of ICH patients.

[Prevalence of white-coat hypertension and masked hypertension in the general population, through home blood pressure measurement]

OBJECTIVE

To determine the prevalence of white-coat hypertension (WCH) and masked hypertension (MH) in the general population, by means of home blood pressure measurement (HBPM).

DESIGN

Cross-sectional, descriptive study.

SETTING

Four primary care centres.

PARTICIPANTS

A sample of 1400 individuals over 18 years old, selected from the Municipal Register of Inhabitants (Huelva, Spain) and randomised and stratified by age and gender.

MAIN MEASUREMENTS

Two blood pressure (BP) measurements in clinic (CBP) and 12 measurements in a week of BP by HBPM were performed (OMRON 705-CP). Pressure was seen as normal when CBP means were <140/90 mm Hg and HBPM was <135/85 mm Hg. WCH was defined as when CBP was >140/90 mm Hg and HBPM <135/85 mm Hg, and hypertension when CBP was >140 mm Hg and HBPM >135/85 mm Hg or patients were in treatment for hypertension. MH was when CBP was <140/90 mm Hg and at home was >135 mm Hg and/or 85 mm Hg.

RESULTS

A total of 1153 individuals (82.35% of the sample) with mean age of 45.4 (SD, 16.1) were included: 560 men and 593 women. The prevalence of MH was 8.9% (CI+/-1.6) in the general population and 9.8% (CI+/-3.2) in individuals with hypertension. WCH prevalence was 3.6% (CI+/-1.05) overall and 12.8% (CI+/-3.6) in hypertense patients, with its prevalence increasing steadily as age groups rose (P = .001).

CONCLUSIONS

The prevalence of WCH in the general population is low, whereas the prevalence of MH is high.

Role of endothelin in regulation of resistance, fluid-exchange, and capacitance functions of the systemic circulation

This article reviews data at the in vivo whole animal and human level. The importance of both flow and pressure recordings and of the methods used to record these variables is emphasized. Exogenous administration of endothelin-1 evokes a transient depressor response mediated by endothelial endothelinB receptors, but the predominate effect of endothelin-1 is a sustained increase in blood pressure resulting from increases in total peripheral resistance. Resistance in the superior mesenteric, renal, and hindquarter vascular beds of animals and forearm resistance in humans is increased. Both endothelinA and, to a lesser extent, endothelinB receptors on vascular smooth muscle mediate the increases in resistance. Endothelin-1 evokes decreases in the precapillary/postcapillary resistance ratio, resulting in increased capillary pressure and net transcapillary filtration. Endothelin-1 evokes increases in mean circulatory filling pressure in animals and in constriction of the human dorsal hand vein. This venoconstrictor activity is mediated primarily through endothelinA and to a lesser extent endothelinB receptors. Endogenously generated endothelin contributes to the hemodynamic effects of angiotensin and vasopressin in certain animal models of hypertension. Antagonists of endothelin evoke modest hemodynamic changes in healthy humans and in some healthy animals, and they decrease vascular resistance dramatically in several salt-sensitive rat models of hypertension and also in some hypertensive human subjects. Thus, endogenously generated ET appears to play a modest role in the healthy organism, but it likely plays a major role in many pathophysiological states as described in companion articles in this issue.

Self-blood-pressure monitoring--a questionnaire study: response, requirement, training, support-group popularity and recommendations

The objective of this study was to survey hypertensive patients' response to, requirement for and training in self-blood pressure monitoring (SBPM). A total of 222 hypertensives were invited to complete a questionnaire even when not participating in the project. Questions supplied information on demographics, monitoring frequency, convenience of attending the surgery, monitor ownership and preference for and ease of self-monitoring. Comments supplied qualitative data. Training group questionnaires supplied similar data as well as SBPM data before and after training. Of 133 respondents, a higher educated, younger, wider age range wanted to participate (76; 57.2%) and tended to self-monitor. However, only an increase in further education (FE) was associated with an increased probability of participation and inclination to self-monitor in the multivariate analyses. A positive relationship exists between age and frequency in both groups. About a sixth of respondents own monitors and ownership is correlated to FE. Although most patients found it convenient to visit the surgery, the percentage finding it convenient was lower in patients attending training sessions than in the original survey, possibly indicating that independence is important for SBPM. Younger, higher-educated patients tended to self-monitor although FE was again the significant factor. Training increased preference for the idea of SBPM, prospective monitor ownership (64.8% of non-owners) and self-monitoring intention (76.1%). Patients found recording card listed cardiovascular disease (CVD) risks valuable and 69.6% (32) wanted to establish a support group. Comments and interviews indicated haphazard knowledge, routines and uncertainty about SBPM. A standardised procedure including patient assessment, SBPM protocol and lifestyle education is needed for SBPM to be successful.

[Predictive factors of hypertension in patients with diagnostic doubts of persistent hypertension]

BACKGROUND

White coat hypertension (WCH) is a prevalent clinical situation which requires a therapeutic management different from persistent hypertension (PH). To distinguish between patients with WCH and uncertain hypertension from patients with PH, an ambulatory blood pressure monitoring (ABPM) is usually indicated, yet it is not available in primary care. Thereby, predictors of WCH on the basis of pre-test (pre-ABPM) clinical characteristics have been suggested. However, little is known about the predictors of PH. The aim of this study was to ascertain predictors of PH in patients referred from the primary care due to suspicion of WCH or uncertain hypertension.

PATIENTS AND METHOD

A 24-hours ABPM was performed in 230 consecutive patients referred from primary care because of suspicion of WCH or uncertain hypertension. WCH was defined as an increased office BP with a mean daytime BP, as measured by ABPM, < 135/85 mmHg. Uncertain hypertension was diagnosed when patients had had episodic (2 or more) office BP >140 and/or 90 mmHg together with normal BP determinations. Patients with increased office BP with a mean daytime BP [by ABPM]3 135/85 mmHg were considered as having PH.

RESULTS

In 178 patients, ABPM was successful. Eighty-six patients (48.3%) had PH and the remainder (92 patients; 51.7%) were considered as having WCH. In the PH group, there were more males (67.4% vs 43.5%; p < 0.001), patients were older (42.8 [11.8] years vs 35.7 [11.2] years), there were more smokers (39.5 vs 26.1%; p = 0.056), they consumed more alcohol (p = 0.001) and coffee (p < 0.001) and they had higher levels of hemoglobin (p = 0.001) and creatinine (p = 0.003) and lower levels of uric acid (p<0.001) than the WCH group. Also they had an office BP and an ambulatory BP higher than WCH patients. A multivariate logistic regression analysis revealed that PH was significantly associated with a male gender (odds ratio [OR] = 3.26; confidence interval [CI]: 1.54-6.88; p = 0.001), office systolic BP > 145 mmHg (OR = 6.53; CI, 2.67-16.11; p < 0.001), age (> 35 years) (OR = 5.03; CI, 2.35-10.78; p < 0.001) and smoking (OR = 3.07; CI, 1.38-6.84; p = 0.005).

CONCLUSIONS

Our findings indicate that in patients referred from primary care due to suspicion of WCH or uncertain hypertension, the prevalence of PH was 48.3%. PH was more frequent among men older than 35 years, smokers and those with an ambulatory systolic BP > 145 mmHg.