Physiological, psychological, and behavioral factors and white coat hypertension

Patients with hypertension in the clinic but not during daily activities ("white coat" hypertension) may be at lower risk of hypertensive morbidity and mortality than patients with hypertension in both settings ("persistent" hypertension). We hypothesized that the white coat phenomenon was due to greater blood pressure reactivity to the stress of a clinic visit and that, as a consequence, white coat hypertensive patients would display greater blood pressure reactivity to exercise and mental stress, as well as increased emotional reactivity and higher levels of anger, anxiety, or depression. We studied 89 patients with essential hypertension between 29 and 59 years old with ambulatory blood pressure monitoring, treadmill exercise testing with oxygen consumption measurement, mental stress testing (including mental arithmetic, public speaking, and video game tasks), and psychological testing (State-Trait Anxiety Scale, Cook-Medley Hostility Scale, Center for Epidemiologic Studies Depression Scale, emotional reactivity scale). We defined white coat hypertension as a mean ambulatory systolic blood pressure of 135 mm Hg or less and diastolic 85 mm Hg or less and persistent hypertension as a mean ambulatory systolic blood pressure of 140 mm Hg or more or diastolic 90 mm Hg or more. Forty-nine patients were classified as persistent hypertensives and 20 as white coat hypertensives. No significant differences were seen in demographic or clinical characteristics, fitness level, blood pressure response to exercise or mental stress, or psychological characteristics, except that white coat hypertensive patients had lower systolic blood pressures in the clinic and during exercise and greater variability of clinic diastolic blood pressures.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reproducibility of postexercise ambulatory blood pressure in Stage I hypertension

The accuracy and reproducibility of ambulatory blood pressure monitoring used in intervention and treatment studies is essential to assure the desired health outcomes. The reproducibility of ambulatory variables in pharmacological studies has been reported, however, the reproducibility of ambulatory blood pressure variables associated with exercise has not been reported. Thus, the purpose of this study was to investigate the reproducibility of the postexercise ambulatory blood pressure in Stage I hypertensive adults. It was hypothesized that the reproducibility of the ambulatory blood pressure variables would not be different following two corresponding exercise and control treatments. A total of 18 Stage I hypertensive adults (142.1+/-3.15/91.6+/-1.80 mmHg) performed four randomized, 24 h AmBP monitoring sessions: two following a 50 min treadmill walk (50% VO(2) peak) and two on control days. Variables measured were: (1) average systolic and diastolic pressures for 24 h, daytime (06:00-22:00 h) and night time (22:00-06:00 h) and (2) systolic and diastolic load for the same time periods. Both a nonsignificant paired t-test and an excellent intraclass correlation were used to define reproducibility of the variables between the 1st and 2nd exercise trials and between the 1st and 2nd control trials. Reproducibility was found for all the control variables except for nighttime diastolic load. Reproducibility was found for all the systolic and diastolic exercise variables. Ambulatory blood pressure measurements, including average systolic and diastolic blood pressures and systolic and diastolic loads for 24 h, daytime and night time periods are reproducible following exercise.     

Conventional and ambulatory blood pressure measurement in older patients with isolated systolic hypertension:second progress report on the ambulatory blood pressure monitoring project in the Syst-Eur trial

OBJECTIVES: To compare clinic and ambulatory blood pressure measurement and the reproducibility of these measurements in older patients with isolated systolic hypertension.PATIENTS: A total of 477 patients aged >/= 60 years with isolated systolic hypertension on clinic measurement were monitored during the placebo run-in phase of the Syst-Eur trial. METHODS: The time-weighted 24 h blood pressure, clock time day and night blood pressure, the cumulative sum-derived crest and trough blood pressure and the high and low blood pressure levels of the square-wave model were computed. The daily alteration between the high and low blood pressure spans was quantified using the clock time day-night difference, the cumulative sum-derived circadian alteration magnitude, the Fourier amplitude and the difference between the high and low blood pressure levels of the square-wave model. RESULTS: The daytime ambulatory systolic blood pressure was, on average, 21 mmHg lower than the clinic blood pressure, whereasthe diastolic blood pressure was, on average, similar with both techniques of measurement. In the 132 patients who underwent repeat measurements, clinic blood pressure levels and the parameters describing the difference betgween the daily high and low blood pressure spans were equally reproducible. However, both were less reproducible than the ambulatory blood pressure levels. The repeatability coefficients, expressed as percentages of near maximum variation, were 50 and 51% for the clinic systolic and diastolic blood pressures, 30 and 33% for the mean 24 h systolic and diastolic blood pressures and between 44 and 54% for the parameters describing the daily alteration between the high and low blood pressure spans. CONCLUSION: In older patients with isolated systolic hypertension, clinic and ambulatory systolic blood pressure may differ greatly; the prognostic significance of this difference remains to be elucidated. Furthermore, the level of blood pressure in these patients is more reproducible by ambulatory measurement than it is by clinic measurement.     

Ambulatory blood pressure monitoring in elderly patients with isolated systolic hypertension.

OBJECTIVES: This study compared clinic and ambulatory blood pressure measurement and the reproducibility of these measurements in older patients with isolated systolic hypertension (ISH). PATIENTS: Eighty-seven patients aged greater than or equal to 60 years with ISH on clinic measurement were followed in the placebo run-in phase of the Syst-Eur trial. METHODS: Clinic blood pressure was defined as the mean of two blood pressure readings on each of three clinic visits (six readings in total). Ambulatory blood pressure was measured over 24 h using non-invasive ambulatory blood pressure monitors. RESULTS: Daytime ambulatory systolic pressure was, on average, 21 mmHg lower than the clinic blood pressure, whereas diastolic pressure was, on average, similar with both techniques of measurement. In the 42 patients who had repeat measurements, clinic blood pressure levels nad the amplitude of the diurnal blood pressure profile (fitted by Fourier analysis) were equally reproducible. However, both were less reproducible than ambulatory blood pressure levels. The repeatability coefficients, expressed as per cent of near maximum variation (four times the standard deviation of a given measurement), were 52% and 45% for the clinic systolic and diastolic pressures, 56% and 42% for the amplitude of the diurnal profile, and 29% and 26% for mean 24-h pressures. CONCLUSIONS: In older patients with ISH, clinic and ambulatory systolic blood pressure measurements may differ largely: the prognostic significance of this difference remains to be elucidated. Furthermore, in these patients the level of pressure is more reproducible by daytime ambulatory blood pressure measurement than by clinic measurement.     

Conventional and ambulatory measurements of blood pressure in old patients with isolated systolic hypertension: baseline observations in the Syst-Eur trial

OBJECTIVES: To compare clinic and am measurements of blood pressure in old patients with isolated systolic hypertension and their reproducibilities. PATIENTS: In total 610 patients aged >/= 60 years with isolated systolic hypertension detected by clinic measurement were monitored during the placebo run-in phase of the Syst-Eur trial. METHODS: The time-weighted 24 h blood pressure, clock-time day and night blood pressures, the cumulative-sum-derived crest and trough blood pressures and the high and low blood pressure levels according to the square-wave model were computed. The daily alteration between the high and low spans of blood pressure was quantified using the day-night difference, the cumulative-sum-derived magnitude of circadian alteration, the Fourier amplitude and the difference between the high and low blood pressure levels of the square-wave model. RESULTS: The daytime am systolic blood pressure was, on average, 21 mmHg lower than the clinic systolic blood pressure, whereas diastolic pressure was, on average, similar with both techniques of measurement. Clinic levels of blood pressure in the 141 patients who underwent repeat measurements and the parameters describing the difference between the daily high and low spans of blood pressure were equally reproducible. However, both were less reproducible than the ambulatory blood pressure levels. The reproducibility coefficients, expressed as percentages of near maximum variation, were 49 and 50% for the clinic systolic and diastolic blood pressures, 30 and 32% for the mean 24 h systolic and diastolic blood pressures and 45-55% for the parameters describing the daily alteration between the high and low spans of blood pressure. CONCLUSION: Values of blood pressure in old patients with isolated systolic hypertension were more reproducible for ambulatory than they were for clinic measurements. Levels in patients selected because they have a high clinic blood pressure may be substantially higher with conventional than they are with daytime ambulatory measurement. The prognostic significance of this difference for the present patients is currently under investigation.     

Impact of obesity on 24-hour ambulatory blood pressure and hypertension

The purpose of the present study was to determine the relationship between body mass index (BMI) and parameters derived from 24-hour ambulatory blood pressure monitoring including mean 24-hour daytime and nighttime systolic and diastolic blood pressures, 24-hour daytime and nighttime pulse pressure, mean 24-hour daytime and nighttime heart rate, dipping and nondipping status. 3216 outpatient subjects who visited our hypertension center and were never treated with antihypertensive medication underwent 24-hour blood pressure monitoring. BMI was significantly correlated with clinic systolic and diastolic blood pressures. Significant correlations were also found between BMI and mean 24-hour daytime and nighttime systolic blood pressure, 24-hour daytime and nighttime pulse pressure, and mean 24-hour daytime and nighttime heart rate. In multivariate regression analysis, clinic systolic, diastolic blood pressure, mean 24-hour systolic blood pressure, 24-hour pulse pressure, and high-density lipoprotein were independently correlated with BMI. The incidence of white coat hypertension was higher in overweight and obese patients than in normal weight subjects. Confirmed ambulatory blood pressure hypertension was also found to be higher in overweight and obese individuals compared with normal weight subjects. Our data also highlight the higher incidence of nondipping status in obesity. These findings suggest that obese patients had increased ambulatory blood pressure parameters and altered circadian blood pressure rhythm with increased prevalence of nondipping status.     

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.     

Repeated measurements of non-invasive ambulatory blood pressure: distinction between reproducibility and the proper effect of placebo

OBJECTIVE: To determine whether non-invasive ambulatory blood pressure is more reproducible and less affected by the placebo treatment than are clinic blood pressure measurements. METHOD: Thirty-four essential hypertensive outpatients were randomly allocated after a 4-week preselection period in two groups in a cross-over study design. One group received placebo for 4 weeks while the other formed the control group (reproducibility), then the treatments were exchanged for another 4 weeks. Clinic and ambulatory blood pressures were measured at three different times for each patient, namely bnefore the random allocation to groups and at the end of each period, using a mercury sphygmomanometer and 24 h non-invasive ambulatory blood pressure monitoring. RESULTS: Administration of placebo was accompanied by a significant reduction in systolic and diastolic clinic blood pressures (by 3.4+/-13 and 3.6+/-8 mmHg, respectively), but not in 24 h, daytime and night-time blood pressures. Circadian hourly blood pressure and heart rate curves were virtually superimposable. In the 13 placebo responder patients selected on the basis of clinic blood pressure, placebo decreased the clinic blood pressure and also reduced systolic and diastolic ambulatory blood pressures, mainly during the day period (by 5.2+/-6.2 and 4.89+/-7.8 mmHg, respectively). This effect is specific and related to the placebo administration because repetition of the measurements without any treatment showed no significant difference. To characterize at baseline the placebo responder patients, comparison with the non-placebo responders showed lower baseline values of ambulatory systolic blood pressure recorded during 24 h daytime and night-time in the placebo responder group. CONCLUSION: The 24 h ambulatory blood pressure average is not affected by placebo in the present group of patients but that a placebo effect occurs mainly during the daytime in patients who decreased their clinic blood pressure under placebo (placebo responders); the placebo-induced reduction in blood pressure is related to a specific effect of placebo and is independent from any alerting reaction or reproducibility hypothesis. This study clearly indicates the necessity of including placebo and ambulatory blood pressure monitoring in the therapeutic and pharmacological trials of antihypertensive drugs.     

Relationship between 24 h ambulatory central blood pressure and left ventricular mass – Rationale and design of a prospective multicenter study

The prognostic superiority of ambulatory over clinic blood pressure has been repeatedly proven. However, due to the mechanical properties of the arterial system, systolic and pulse pressures are higher in the brachial artery than in the ascending aorta. It seems logical that central pressures are more relevant to cardiovascular disease than peripheral (brachial) pressures, and indeed, using clinic blood pressures, it has been shown that central systolic and pulse pressures are more closely associated with hypertensive end-organ damage than their brachial counterparts. Moreover, antihypertensive drugs can have differential effects on central versus brachial blood pressures. All these effects have been described on the basis of clinic blood pressure measurements. Recent advances in technology allow the estimation of central systolic blood pressure from brachial pulse waves recorded with a regular brachial oscillometric blood-pressure cuff, using a transfer-function like algorithm (ARCSolver). This method has been invasively validated and allows the recording of 24 h ambulatory central blood pressure profiles. Our multicenter study now aims for the first time to investigate the relationship between central ambulatory blood pressure monitoring and hypertensive end-organ damage (left ventricular mass) in untreated adults.     

The influence of different surgical procedures on hypertension after repair of coarctation

We measured resting and exercise haemodynamics, as well as 24-hour ambulatory blood pressure, so as to study the influence on development of hypertension in children after repair of coarctation by either construction of a subclavian flap or end-to-end anastamosis. The patients in both groups were studied a mean time of 13 years after surgery. Thus, we divided 43 children who had undergone surgical repair of coarctation, and who were not on antihypertensive therapy, into a group of 22 patients who had undergone subclavian flap repair, with a mean age of 14 plus or minus 2.6 years, and another group of 21 patients undergoing end-to-end anastomosis, with a mean age of 13.5 plus or minus 3.9 years. We examined blood pressure at rest and during exercise, along with the measurement of cardiac output using impedance cardiography, and during 24-hour ambulatory monitoring. We recorded systolic and diastolic blood pressures, pulse pressure, cardiac output and total peripheral vascular resistance at rest and at peak exercise. During ambulatory monitoring, we measured mean pressures over 24 hours, in daytime and nighttime, 24-hour pulse pressure, and 24-hour mean arterial pressure. Student's t test was used to judge significance, accepting this when p was less than 0.05. The group repaired using the subclavian flap showed significantly disadvantageous differences for diastolic blood pressure at rest, systolic blood pressure at peak exercise and for 24-hour systolic and diastolic blood pressure, 24-hour mean arterial pressure, and daytime and nighttime systolic blood pressure during ambulatory monitoring. Our findings suggest that, after repair using the subclavian flap in comparison to end-to-end anastomosis, patients show a higher incidence of late hypertension, both during exercise and ambulatory monitoring. The data indicate different residual aortic stiffnesses, these being lower after end-to-end anastomosis, which may be due to the greater resection of the abnormal aortic tissue when coarctation is repaired using the latter technique.     

Evaluation of noninvasive blood pressure monitoring devices Spacelabs 90202 and 90207 versus resting and ambulatory 24-hour intra-arterial blood pressure.

This study evaluated the accuracy of blood pressure values provided by the Spacelabs 90202 and 90207 devices in comparison with intra-arterial recording in 19 subjects at rest and in nine subjects in ambulatory conditions (Oxford method). At rest Spacelabs monitors reflected intra-arterial systolic blood pressure values very closely but overestimated to a considerable extent intra-arterial diastolic blood pressure (Spacelabs-intra-arterial differences, -0.8 +/- 9.2, NS, and 9.1 +/- 8.8 mm Hg, p less than 0.01, for systolic and diastolic blood pressures, respectively). In ambulatory conditions Spacelabs-intra-arterial average differences in 24-hour values were +0.4 +/- 5.1 mm Hg for systolic blood pressure (NS) and +14.0 +/- 2.9 mm Hg for diastolic blood pressure (p less than 0.01) when group data were considered. The performance of both Spacelabs devices was worse when assessed in individual subjects or for each hourly interval. In spite of these differences between noninvasive and intra-arterial absolute blood pressure values, however, Spacelabs 90202 and 90207 monitors were able to faithfully reflect directional hour-to-hour changes in intra-arterial blood pressure (chi 2 = 18.2 and chi 2 = 23.1 for systolic and diastolic blood pressures, respectively, p less than 0.01). No differences were found between the performance of the two Spacelabs devices. Thus, although the absolute accuracy of blood pressure values provided by these monitors in ambulatory subjects is still limited, they seem to be suitable for studies aimed at assessing 24-hour blood pressure profiles quantitatively as well as qualitatively.     

Effect of ambulatory blood pressure monitoring on the diagnosis and cost of treatment for mild hypertension

Detection of mild hypertension by a small number of casual blood pressures may be inaccurate for the determination of average blood pressure. Nonetheless, casual pressures remain the basis for the diagnosis and treatment of hypertensive patients. We compared casual and noninvasive ambulatory blood pressure monitoring in a consecutive series of 60 subjects evaluated for possible mild hypertension on the basis of casual pressures. Ambulatory blood pressure monitoring was performed on days of usual activity. Correlations between casual systolic and average ambulatory systolic pressures or casual diastolic and average ambulatory diastolic pressures were not significant. Nearly half of the subjects had average ambulatory systolic pressures less than 130 mm Hg. Sixty percent had average ambulatory diastolic pressures less than 85 mm Hg. Nearly 40% had both systolic and diastolic pressures less than those limits. A preliminary analysis of the effects of these results on the short-term cost of antihypertensive treatment was made, assuming that treatment could be withheld from those with average ambulatory pressures less than 130/85 mm Hg. This approach suggests that ambulatory blood pressure monitoring need not increase overall cost, if the results of this evaluation are used in the decision to treat.     

Home blood pressure measurement: reproducibility and relationship with left ventricular mass.

OBJECTIVE: To evaluate the reproducibility and relationship with left ventricular mass index of home blood pressure in comparison with ambulatory and office blood pressures. METHODS: We measured home, ambulatory and office blood pressures of 84 previously untreated hypertensive patients, aged 60-74 years, from primary care, at baseline and after 12 weeks, without active intervention in between. Left ventricular mass index was determined echocardiographically during week 12. RESULTS: Decreases in systolic and diastolic blood pressures were found after 12 weeks for mean home and office blood pressures (P<0.05), but not for mean ambulatory blood pressure. The coefficients of reproducibility for systolic and diastolic ambulatory blood pressures were 26.4 and 16.0, respectively. Correlation coefficients for correlation of left ventricular mass index to ambulatory blood pressure (0.51 and 0.36) were higher than the correlation coefficients for home (0.31 and 0. 16) and office (0.32 and 0.21) blood pressures, for systolic and diastolic values, respectively. However, we could find no statistically significant difference among the correlation coefficients for all three types of measurements. CONCLUSIONS: Home blood pressure was considerably less reproducible than ambulatory blood pressure and no different from office blood pressure in this respect. The relationship with left ventricular mass index appeared to be stronger for ambulatory than it was for home and office blood pressures, although not statistically significant so.     

Noninvasive ambulatory blood pressure monitoring in patients with recently detected systemic hypertension

Noninvasive ambulatory blood pressure monitoring and Doppler echocardiography were used in a recent study evaluating persons aged 18 to 50 years who were initially found to have mild hypertension by casual blood pressure determination. Ambulatory blood pressure recordings were performed on a day of usual activity in 54 subjects; a subgroup of 24 patients had evaluation of left ventricular dimensions and diastolic filling patterns by Doppler echocardiography. Average ambulatory systolic pressures of 42% of subjects were greater than or equal to 130 mm Hg. Only 35% had average diastolic pressures greater than or equal to 85 mm Hg, and 57% had either systolic or diastolic pressures greater than or equal to 130/85 mm Hg. Correlation between casual and ambulatory pressures was not significant. No subject had left ventricular hypertrophy determined by echocardiography. Abnormal left ventricular diastolic filling was noted in 38% of those patients with average ambulatory pressures greater than or equal to 130/85 mm Hg, but in no patients with average pressures less than 130/85 mm Hg (p less than 0.05). These results suggest that ambulatory blood pressure monitoring may be a specific method for detecting those patients with mild hypertension who may have early and potentially reversible cardiac abnormalities.     

Value of home blood pressures as predictor of target organ damage in mild arterial hypertension

BACKGROUND: Home blood pressure measurement has gained increasing importance for the management of hypertensive patients. The aim of our study was to compare levels of clinic (CBP), ambulatory (ABP), and home blood pressure (HBP) measurements, and their relationships with various indexes of target organ damage in I-II grade essential hypertension. DESIGN AND METHODS: Thirty-eight essential hypertensives underwent evaluation of clinic, ambulatory and home blood pressures. Each patient recorded HBP for 2 days with a digital BP monitor three times daily, the first time on the same day during which ABP monitoring was simultaneously performed. Moreover, in all subjects electrocardiogram recording, echocardiographic study, microalbuminuria assay and fundus oculi examination were obtained. RESULTS: The average HBPs obtained on the first day, in particular systolic values, were quite similar to mean daytime ambulatory BP recorded on the same day. Clinic BP, both systolic and diastolic, showed no significant correlation with left ventricular mass index (LVMI) and with albumin excretion rate (AER), whereas a correlation barely significant was observed with an index of global target organ damage (GTODi), including cardiac, renal and retinal parameters. On the contrary, home blood pressures, especially those recorded on the second day, correlated significantly, and more tightly than clinic BP, with LVMI, AER and GTODi. CONCLUSIONS: Our study seems to justify the adoption of home BP monitoring in the management of hypertensive patients, as a useful complement to clinical readings, and may provide additional prognostic information.     

Superiority of ambulatory over clinic blood pressure measurement in predicting mortality: the Dublin outcome study

The purpose of this study was to determine if ambulatory blood pressure measurement predicted total and cardiovascular mortality over and beyond clinic blood pressure measurement and other cardiovascular risk factors; 5292 untreated hypertensive patients referred to a single blood pressure clinic who had clinic and ambulatory blood pressure measurement at baseline were followed up in a prospective study of mortality outcome. Multiple Cox regression was used to model time to total and cause-specific mortality for ambulatory blood pressure measurement while adjusting for clinic blood pressure measurement and other risk factors at baseline. There were 646 deaths (of which 389 were cardiovascular) during a median follow-up period of 8.4 years. With adjustment for gender, age, risk indices, and clinic blood pressure, higher mean values of ambulatory blood pressure were independent predictors for cardiovascular mortality. The relative hazard ratio for each 10-mm Hg increase in systolic blood pressure was 1.12 (1.06 to 1.18; P<0.001) for daytime and 1.21 (1.15 to 1.27; P<0.001) for nighttime systolic blood pressure. The hazard ratios for each 5-mm Hg increase in diastolic blood pressure were 1.02 (0.99 to 1.07; P=NS) for daytime and 1.09 (1.04 to 1.13; P<0.01) for nighttime diastolic pressures. The hazard ratios for nighttime ambulatory blood pressure remained significant after adjustment for daytime ambulatory blood pressure. These results have 2 important clinical messages: ambulatory measurement of blood pressure is superior to clinic measurement in predicting cardiovascular mortality, and nighttime blood pressure is the most potent predictor of outcome.     

Postexercise hypotension induced by low-intensity resistance exercise in hypertensive women receiving captopril

OBJECTIVE: The present study investigated the effect of a single bout of low-intensity resistance exercise on recovery blood pressure in hypertensive women receiving captopril. METHODS: Twelve essential hypertensive women, who were receiving captopril, underwent two experimental sessions: control (C - 40 min of seated rest) and low-intensity resistance exercise (E - six resistance exercises, three sets, 20 repetitions, 40% of one repetition maximum). Clinic blood pressure was measured in the laboratory, before and for 120 min after exercise or rest. Moreover, ambulatory blood pressure was also measured for 21 h after exercise or rest. RESULTS: Clinic blood pressures decreased significantly after exercise (systolic blood pressure =-12+ or -3 mmHg and diastolic blood pressure =-6+ or -2 mmHg, P<0.05), but not after rest. Mean awake blood pressures (systolic: C=132+ or -5 mmHg vs. E=125+ or -4 mmHg and diastolic: C=83+ or -3 mmHg vs. E=78+ or -2 mmHg, P<0.05) were significantly lower in the E than in the C session, while 21-h (systolic blood pressures: C=128+ or -5 mmHg vs. E=123+ or -4 mmHg; and diastolic blood pressures: C=80+ or -3 mmHg vs. E=76+ or -2 mmHg) and asleep (systolic blood pressures: C=120+ or -7 mmHg vs. E=118+ or -5 mmHg; and diastolic blood pressures: C=73+ or -4 mmHg vs. E=71+ or -3 mmHg) blood pressures did not differ between the experimental sessions. Moreover, there was a positive correlation between blood pressure measured in the C session and blood pressure reduction observed in the E session, showing that blood pressure decrease was greater when blood pressure level was higher. CONCLUSION: In hypertensive women receiving captopril, a single bout of low-intensity resistance exercise reduces blood pressure. This reduction persists for 10 h, during the awake period, while patients were engaged in their daily living activities. It was greater in patients with higher ambulatory blood pressure.     

Reproducibility of nurse-measured, exercise and ambulatory blood pressure and echocardiographic left ventricular mass in borderline hypertension.

OBJECTIVE: To compare the short-term reproducibility of four diagnostic tests: resting blood pressure, exercise blood pressure, non-invasive daytime ambulatory blood pressure and echocardiographic left ventricular mass. DESIGN: Blinded, prospective test-retest (reliability) study. SETTING: Hypertension research units in two teaching hospitals. PARTICIPANTS: Six normal volunteers and 22 patients with untreated borderline to mild hypertension, mean age 44 years. MAIN OUTCOME MEASURES: The intraclass correlation coefficient (RI) and standard deviation of the difference (SDD) between visits. MAIN RESULTS: The mean blood pressures and left ventricular mass did not differ between visits. Concordance between visits reached RI = 0.86 systolic/0.66 diastolic for ambulatory blood pressure and RI = 0.85 systolic/0.64 diastolic for nurse-measured random-zero sphygmomanometer resting blood pressure. The respective variabilities were SDD = 9/8 and 8/8 mmHg. Submaximal exercise systolic blood pressure (SBP) and echo left ventricular mass showed excellent reliability. Echo left ventricular mass and resting SBP or ambulatory SBP were significantly more reproducible than resting diastolic blood pressure (DBP) or ambulatory DBP. CONCLUSIONS: Despite averaging many readings within each day, clinically important between-visit variations in ambulatory blood pressure remained. The between-visit variability of daytime ambulatory blood pressure was similar to that of resting blood pressure when carefully measured by a research nurse. The echo left ventricular mass appears to be more reproducible over the short term than the current diagnostic standard for hypertension, the resting DBP.     

Isolated office hypertension: are there any markers of future blood pressure status?

BACKGROUND: The introduction of ambulatory blood pressure monitoring into clinical practice has defined a clinical condition called 'isolated office hypertension'. OBJECTIVE: The aim of this study was to evaluate the long-term systolic and diastolic blood pressure changes in patients with isolated office hypertension and to identify the presence of markers capable of identifying which patients will develop sustained hypertension. METHODS: All the 407 patients enrolled had a random office systolic or/and diastolic blood pressure of over 140/90mmHg and a mean daytime ambulatory blood pressure of 130/84mmHg or less. At enrollment, each patient underwent a 'baseline examination' made up of a physical evaluation, a 24h ambulatory blood pressure monitoring, and a mental arithmetic test performed at the end of the 24h ambulatory monitoring. RESULTS: Of the 173 patients finally studied, 102 (58.9%) developed sustained hypertension with an increase in both ambulatory systolic and diastolic blood pressure. At the time of the baseline examination, the patients were divided into two groups. Group A included patients with mean ambulatory systolic and diastolic blood pressures in the first hour of 130/84mmHg or less; group B included patients with mean ambulatory systolic and diastolic pressures in the first hour of greater than 130/84mmHg. During the mental arithmetic test, the systolic and heart rate values increased significantly only in group B patients. Of the 102 patients who had become hypertensive by the time of the follow-up examination, 84 (82%) belonged to group B. CONCLUSION: These data suggest that isolated office hypertension may indeed be a transitional state towards the development of sustained hypertension. Moreover, the mean ambulatory blood pressure value during the first hour can be considered to be a marker of a higher risk of developing sustained hypertension.     

Potassium supplementation reduces clinic and ambulatory blood pressure in elderly hypertensive patients.

OBJECTIVES: To determine the effects of potassium chloride 60 mmol/day supplementation on clinic and 24-h ambulatory blood pressure values in elderly untreated hypertensive patients. DESIGN: A double-blind randomized placebo-controlled crossover study lasting 8 weeks, following a 4-week run-in period. SETTING: Outpatient clinic in a district general hospital. PATIENTS: Eighteen untreated elderly hypertensive patients (mean age 75 years, range 66-79) with a systolic blood pressure of > or = 160 mmHg and/or a diastolic blood pressure of > or = 95 mmHg were recruited from the clinics of local general practitioners and from the current hospital outpatient department. Patients had not received any antihypertensive medication for at least 4 weeks before entry into the study. INTERVENTIONS: Before entry into the study, the daily dietary electrolyte intake of each individual was established and this was maintained during the run-in and intervention periods. Following a 4-week run-in period patients received potassium supplements or matching placebo, each for 4 weeks. MAIN OUTCOME MEASURES: The within-patient changes in clinic and 24-h ambulatory blood pressures at the end of each intervention period. RESULTS: After 4 weeks potassium supplementation compared with placebo there was a significant fall in supine clinic blood pressure, standing and 24-h ambulatory systolic blood pressure. There was no significant change in clinic standing diastolic blood pressure, 24-h ambulatory diastolic blood pressure or pulse rate. Plasma renin activity increased and body weight fell after potassium supplementation. Twenty-four-hour urinary potassium rose significantly, whereas urinary sodium excretion was unchanged. CONCLUSIONS: A 60-mmol daily supplement of potassium chloride reduces clinic and 24-h ambulatory blood pressure in elderly hypertensive patients.