Prognostic value of ambulatory blood pressure : current evidence and clinical implications

Athletes with systemic hypertension

Hypertension is rare in the young, but its prevalence increases with aging. Currently, about 25% of the population has hypertension and this is expected to increase to up to about 29% in 2025. The overall risk of the hypertensive patient depends not only on blood pressure but also on the presence of other cardiovascular risk factors, target organ damage, and associated clinical conditions. The recommendations for preparticipation screening, sports participation, and follow-up depend on the cardiovascular risk profile of the individual athlete. When antihypertensive treatment is required, calcium channel blockers and blockers of the renin-angiotensin system are currently the drugs of choice.

Ability of blood pressure to predict left ventricular hypertrophy in children with primary hypertension

OBJECTIVE

To determine whether casual blood pressure (BP) or ambulatory BP monitoring (ABPM) measurements obtained at the initial visit of a child with confirmed hypertension (HTN) might predict left ventricular hypertrophy (LVH), possibly obviating the need for echocardiography.

STUDY DESIGN

We conducted a cross-sectional study of 184 children aged 3 to 20 years who were referred for initial evaluation of elevated BP at 3 tertiary care centers. Casual BP and various ambulatory BP variables were analyzed to determine their association with LVH, defined after echocardiography by cardiologist diagnosis or a left ventricular mass index equal to or greater than the sex-specific 95th percentile.

RESULTS

A total of 41% of children who had echocardiograms had LVH. Children with LVH were significantly more likely to be non-white and have a higher body mass index z-score. There was no difference in casual systolic or diastolic BP index in children with hypertension who had LVH and children with hypertension without LVH. Children with systolic or diastolic BP loads > or = 50% were no more likely to have LVH than children with loads < 50%.

CONCLUSION

LVH is common in children with newly diagnosed HTN. The initial examination of these children should include echocardiography, because neither the severity of casual BP elevation nor the presence of abnormal ambulatory BP results at initial diagnosis are predictive of LVH.

Low nocturnal blood pressure is associated with reduced cerebral blood flow in the cohort "Men born in 1914"

BACKGROUND

"Men born in 1914" is a population-based cohort study of the epidemiology of cardiovascular and cerebral disease. Little is known about how diurnal variation in blood pressure (BP) levels influence cerebral perfusion in very elderly populations.

OBJECTIVES

To study the association between systolic (SBP) and diastolic BP (DBP) levels, during the day and at night, expressed through 24 h ambulatory BP monitoring (ABPM) and regional cerebral blood flow (rCBF) disturbances.

METHODS

A cross-sectional study from a population-based cohort of 108 men 81 years of age (born in 1914) was performed in an out-patient university clinic. Cerebral blood flow measurements using (99m)Tc-hexamethylpropyleneamine oxime single photon emission computed tomography and 24 h ABPM were performed. Eleven men were excluded due to incomplete ABPM data.

RESULTS

Mean DBP at night for each tertile was correlated to rCBF for the medial temporal right (P=0.012) and left (P=0.039) regions. Also, DBP during the day was correlated to the medial temporal right region (P=0.025). When analyses were stratified for DBP during the day, subjects with high DBP during the day (greater than 70 mmHg) showed a stronger association between low medial temporal right rCBF and low mean DBP at night (r=0.32, P=0.009) compared with subjects who had a lower daytime DBP. A corresponding positive correlation was noted for the medial temporal left region and daytime SBP, whereas a negative correlation was noted for frontal left region blood flow and SBP at night.

CONCLUSIONS

A significant association was seen between low BP levels, especially at night, and rCBF in subjects with otherwise normal daytime DBP that may indicate a risk for nocturnal cerebral ischemia.

QT interval prolongation in association with impaired circadian variation of blood pressure and heart rate in adolescents with Type 1 diabetes

AIMS

The aim of our study was to assess diurnal blood pressure (BP) and heart rate variability and their possible relationship to the duration of the QT interval in adolescents with Type 1 diabetes.

METHODS

In 48 normotensive, normoalbuminuric diabetic adolescents, with a mean (+/- sd) age of 17.3 (+/- 4.1) years and a mean (+/- sd) diabetes duration of 8.5 (+/- 3.3) years, 24-h ambulatory BP was recorded. In addition, 24-h heart rate (HR) monitoring was performed and QT and corrected QT (QTc) intervals were estimated as indices of autonomic function. The patients were divided into two groups according to the absence of a decrease (non-dippers) or the presence of a decrease (dippers) in nocturnal diastolic BP (DBP).

RESULTS

In comparison with the dippers, the non-dippers showed reduced mean 24-h HR (79.6 vs. 84.0 beats/min, P = 0.05) and reduced mean daytime HR (81.3 vs. 86.0 beats/min, P = 0.05). The QT interval was prolonged in the non-dippers (366.3 vs. 347.5 ms, P = 0.015), and end systolic (28.7 vs. 25.9 mm, P = 0.004) and end diastolic left ventricular diameters (47.8 vs. 45.5 mm, P = 0.037) were greater. In stepwise multiple regression, HR variables were the most important factors affecting DBP ratio or the duration of the QT interval.

CONCLUSIONS

In conclusion, normotensive diabetic adolescents with impaired nocturnal BP reduction also have impaired autonomic function tests, in association with prolonged QT interval and increased left ventricular diameters. These findings suggest that diabetic adolescents who have the 'non-dipper' phenomenon may need close follow-up for the possible development of vascular complications, such as cardiac arrhythmias and left-ventricular hypertrophy.

Predictors of significant short-term increases in blood pressure in a community-based population

BACKGROUND

Blood pressure predicts the risk of cardiovascular disease events in a linear, graded manner. Factors associated with significant short-term increases in blood pressure are not well established. We aimed to identify predictors of a significant increase in blood pressure over a 1-year period among nonhypertensive, community-dwelling adults.

METHODS

From the community-based Heart Strategies Concentrating on Risk Evaluation study, 509 nonhypertensive adults (mean age 58 years; 68% were female; 24% were black) had baseline and 1-year assessments of blood pressure. Demographics, medical history, anthropometrics, lipids/lipoproteins, physical activity, and psychologic status were measured at both intervals. A "significant" increase in blood pressure was defined as an increase in systolic blood pressure of greater than 20 mm Hg, diastolic blood pressure of greater than 10 mm Hg, or initiation of antihypertensive medication.

RESULTS

At 1 year, 22% of participants had a significant increase in blood pressure. In multivariable analysis, baseline body mass index (BMI) and a greater than 5% increase in weight or waist circumference were associated with a significant increase in blood pressure (adjusted relative risk 2.09; 95% confidence interval, 1.35-3.21). The adverse effect of an increase in weight and waist circumference on blood pressure was evident in subgroup analyses by age, race, baseline BMI, and regular exercise.

CONCLUSIONS

Baseline BMI and a greater than 5% increase in weight or waist circumference over 1 year are associated with a significant increase in blood pressure. These data emphasize the need for weight maintenance. They also serve to stratify individuals who may benefit from close clinical observation and preventive intervention.

Circadian variation of blood pressure: the basis for the chronotherapy of hypertension

Ambulatory blood pressure (BP) measurements present a close correlation with target organ damage and cardiovascular events, including myocardial infarction, stroke and cardiovascular mortality. With the use of this measurement technique, a significant circadian variation has been shown to characterize BP. This circadian BP variation, although affected by a variety of external factors, represents the influence of internal factors such as ethnicity, gender, autonomic nervous system tone, vasoactive hormones, and hematologic and renal variables. In most individuals, BP presents a morning increase, a small post-prandial valley, and a deeper descent during nocturnal rest. However, under certain pathophysiological conditions, the nocturnal BP decline may be reduced or even reversed. This cannot be determined by traditional clinical or home BP assessments. Subjects with a diminished nocturnal BP decline (non-dipper pattern) have a significantly worse prognosis than the ones with a normal dipper pattern. In particular, the non-dipper circadian BP pattern represents a risk factor for left ventricular hypertrophy, microalbuminuria, cerebrovascular disease, congestive heart failure, vascular dementia and myocardial infarction. The normalization of the circadian BP pattern to a dipper profile is a novel therapeutic goal, and accumulating medical evidence suggests this can delay the progression towards the renal and cardiovascular pathology known to be a consequence of the non-dipper BP pattern. The features of the circadian BP profile have direct implications for improving the drug-delivery of antihypertensive therapies as well as the qualification of patients for medication trials and assessment.

Rosiglitazone reduces office and diastolic ambulatory blood pressure following 1-year treatment in non-diabetic subjects with insulin resistance

OBJECTIVE

Rosiglitazone (RSG) has been reported to reduce blood pressure (BP) in patients with type-2 diabetes, but similar effects in non-diabetic people with insulin resistance is less clear. Our aim was to test the long-term BP-lowering effects of RSG compared with placebo.

METHODS

We recruited participants for BP evaluation of RSG treatment from a larger intervention trial. Office BP was recorded in 355 non-diabetic subjects with insulin resistance randomized to receive either RSG or placebo for 52 weeks. Ambulatory BP monitoring (ABPM; Spacelab 90207) was performed in a subgroup of 24 subjects (RSG: n = 11; placebo n = 13).

RESULTS

After 1 year, the office BP decreased by -3.1 mmHg systolic (p<0.05) and -3.8 mmHg diastolic (p<0.001) in the RSG group versus placebo. In patients treated with RSG, at 1 year there was a trend for a reduction from baseline for mean 24-h diastolic BP (DBP), daytime DBP and night-time DBP (-4.39, -5.26 and -2.93 mmHg, respectively). However, only daytime DBP was significantly lower in the RSG group compared with control (adjusted mean difference: -4.41 mmHg, p = 0.007). There was also a non-significant trend for a reduction in mean 24-h systolic BP (SBP), daytime SBP and night-time SBP (-2.70, -2.51 and -3.35 mmHg, respectively).

CONCLUSIONS

RSG treatment for 1 year was associated with a small but significant decrease in diastolic 24-h ambulatory diastolic BP, and both systolic and diastolic office BPs in non-diabetic people with insulin resistance.

Do we need out-of-office blood pressure in every patient?

PURPOSE OF REVIEW

The limitations affecting office blood pressure readings have spurred the development of techniques for measuring blood pressure out of a clinical environment. The increasing use of home and ambulatory blood pressure monitoring has allowed the identification of specific blood pressure patterns related either to a discrepancy between office and out-of-office blood pressure or to alterations in the 24-h blood pressure profiles. This review offers an update on the most recent data published on the above issues.

RECENT FINDINGS

A critical overview is provided on recent data published on blood pressure patterns suggested to have clinical relevance. These include white coat hypertension, the so-called masked hypertension, enhanced overall blood pressure variability over 24 h, a steeper morning blood pressure surge and a blunted or an excessive blood pressure fall at night.

SUMMARY

All of these different conditions have been variably reported to carry prognostic implications, and may represent specific targets for antihypertensive treatment. Their identification and management require information on out-of-office blood pressure, which suggests that self blood pressure monitoring at home or 24-h ambulatory blood pressure monitoring should be used more frequently in clinical practice, following the indications issued in recent guidelines.

Circadian Blood Pressure Variation and Antihypertensive Medication Adjustment in Normoalbuminuric Type 2 Diabetes Patients

BACKGROUND/AIMS

The aim of the study was to assess the effect of an antihypertensive treatment adjustment on 24-hour blood pressure variation in type 2 diabetes patients.

METHODS

The study group included 59 hypertensive type 2 diabetes patients subjected to a single one-step antihypertensive agent dose adjustment (increase or decrease). Ambulatory blood pressure monitoring was performed at baseline and 4-6 weeks after the treatment modification. Controls were 41 matched patients, in whom antihypertensive treatment remained unchanged.

RESULTS

At baseline, 45 (76%) study group patients and 29 (71%) controls were 'non-dippers'; a similar number of patients in both groups converted to 'dipping' or vice versa: 11 (19%) from the study group and 7 (17%) controls. 'Converters' from the study group were significantly younger (47.5 +/- 3.9 vs. 56.4 +/- 12.2 years; p < 0.05) and had lower 24-hour systolic blood pressure than 'non-converters': 113.7 +/- 7.2 vs. 127.7 +/- 20.3 mm Hg (p < 0.01).

CONCLUSION

A single one-step antihypertensive medication adjustment does not affect 'dipping' status in type 2 diabetes patients. However, the assessment of blood pressure variation should be made with greater caution in younger type 2 diabetes subjects with low systolic blood pressure.

A comparative study of an ambulatory blood pressure measuring device and a wrist blood pressure monitor with a position sensor versus a mercury sphygmomanometer

BACKGROUND

Self-measurements of blood pressure (BP) and 24-hour BP measurements are better predictors of cardiovascular mortality and morbidity than office BP measurements. The objective of this study was to compare the accuracy and precision of a wrist BP monitor with a position sensor (Omron 637IT) and of an ambulatory BP measuring monitor (ABPM; Nissei DS-250) with a mercury sphygmomanometer.

METHODS

A total of 139 patients (69 women and 70 men) were included in the study. The BP of each subject was first measured with a mercury device using the same (left) arm. After this, the wrist monitor was used for BP measurement. Upon completion of the BP readings, 24-hour BP monitoring was performed using Nissei DS-250 monitors. Mean and standard deviations were calculated for all devices. In order to assess the agreement between the measurement methods, the Bland-Altman method and graphics were utilized.

RESULTS

The mean systolic BP measured by the mercury device was 133.2+/-18.4 mmHg and the diastolic BP was 85.4+/-12.5 mmHg, whereas the digital device measured systolic BP as 135.7+/-17.2 mmHg and diastolic BP as 87.0+/-12.5 mmHg. The 24-hour BP measurement was 134.6+/-16.6 mmHg for systolic BP and 85.6+/-11.1 mmHg for diastolic BP. The difference with regard to systolic BP between the mercury and the Omron devices was -2.5+/-5.3 mmHg, which is within the AAMI standard. However, while the mean values of the differences between the mercury and ABPM devices remained under 5 mmHg, their standard deviation was above +/- 8 mmHg. For diastolic BP, the difference between all of the devices was below 5+/-8 mmHg.

CONCLUSIONS

The wrist BP monitor produced results consistent with those of the mercury sphygmomanometer when both were compared with the results of the ABPM. As BP measurement with these devices is a practical and repeatable method, they can be used instead of ABPM in the diagnosis and monitoring of hypertension. However, there is a need for further comparative studies.

Association of clinic and ambulatory blood pressure with vascular damage in the elderly: the EPICARDIAN study

OBJECTIVES

In middle-aged adults, vascular damage correlates better with ambulatory than with clinic blood pressure. This study aimed to determine whether vascular damage evaluated by carotid ultrasonography in the elderly is also more closely related to ambulatory than to clinic blood pressure, and which blood pressure variables are better associated with vascular damage.

METHODS

Cross-sectional study of 292 randomly selected >65 years old participants who underwent 24-h noninvasive ambulatory blood pressure monitoring. Blood pressure variables analyzed were (a) clinic blood pressure: systolic and diastolic blood pressure, pulse pressure; (b) ambulatory blood pressure monitoring: mean values of systolic and diastolic blood pressure, systolic and diastolic blood pressure load, pulse pressure, as well as variability, evaluated within 24 h, diurnal and nocturnal periods; and day-night blood pressure difference. A clinical history, physical examination, carotid ultrasonography and laboratory tests were performed. To estimate the relationship between blood pressure and vascular damage, univariate and multivariate analyses were performed.

RESULTS

Mean age: 73+/-6 years, 45% men, 76.7% hypertensive patients. In the simple regression analysis, the best significant correlations (P<0.05) were common carotid intima-media thickness with 24-h and nocturnal pulse pressure (r=0.32), and common carotid diameter with 24-h systolic blood pressure load (r=0.47). In the multivariate analysis, the significant associations (P<0.05) were (a) linear regression: nocturnal pulse pressure with common carotid intima-media thickness, and diurnal pulse pressure as well as 24-h systolic blood pressure load with common carotid diameter; (b) logistic regression, adjusted odds ratio: nocturnal pulse pressure and nocturnal diastolic blood pressure load with the presence of carotid atherosclerotic plaques 1.03 and 0.98, respectively.

CONCLUSIONS

In the elderly, ambulatory blood pressure monitoring is better associated with carotid damage than clinic blood pressure. Systolic blood pressure variables are the best associated, blood pressure load and pulse pressure being better associated with carotid damage than the mean levels of ambulatory blood pressure.

The value of home blood pressure monitoring

Home blood pressure (BP) monitoring has become popular and acceptable. The value of home BP monitoring has been recognized, because it has some potential advantages over office BP. Home BP monitoring is more accurate and reproducible, has a better prognostic value, and increases patients' compliance with treatment. Home BP monitoring should be performed with an adequate device, following a standardized procedure. The automated arm-cuff-oscillometric devices are recommended currently, and home BP should be measured at least twice daily, in the morning and in the evening. Home BP monitoring has revealed the phenomena of "white-coat hypertension," "masked hypertension," and "morning hypertension," and it is useful for their management. In the future, home BP monitoring will be an essential aspect of clinical practice.

A comparison of the trough-to-peak ratio of cardio-selective beta-blockers in patients with newly diagnosed hypertension

INTRODUCTION

The drug can be administered once a day, if the trough-to-peak ratio (T/P) exceeds 50-66%. The objective of this work was to determine and compare the T/P ratio for betaxolol hydrochloride and for extended-release metoprolol tartrate.

METHODS

An open, randomized, prospective, comparative clinical study. The 24-h ambulatory blood pressure was measured with a SpaceLab 90207 automatic instrument (Redmond, Washington, USA) before and after 3 months of beta-blocker treatment. In order to determine the peak value, the individual maximum hourly mean blood pressure reduction was determined in the 3 to 6-h post-dose interval. For the determination of the trough value, the individual hourly mean blood pressure decrease in the 23-h post-dose interval, minimal 30 min after getting up in the morning was used. The T/P ratio was calculated as the mean of individual T/P ratios with statistical description of standard deviation (SD) and 95% confidence intervals (CIs).

RESULTS

Betaxolol hydrochloride reduced the mean peak systolic blood pressure value by 17.87+/-8.32 mmHg, the mean peak diastolic blood pressure value by 16.07+/-6.65 mmHg, the mean trough systolic blood pressure value by 11.83+/-5.98 mmHg and the mean trough diastolic blood pressure value by 11.33+/-6.74 mmHg. The mean T/P ratio was calculated as 72.84+/-33.32% (95% CI, 60.40-85.285%) for systolic blood pressure and as 71.57+/-29.35% (95% CI, 60.62-82.53%) for diastolic blood pressure. Metoprolol reduced the mean peak systolic blood pressure value by 16.70+/-10.54 mmHg, the mean peak diastolic blood pressure value by 14.20+/-8.67 mmHg, the mean trough systolic blood pressure value by 11.30+/-9.12 mmHg and the mean trough diastolic blood pressure value by 10.00+/-8.38 mmHg. The mean T/P ratio was calculated as 70.59+/-31.66% (95% CI, 58.76-82.41%) for systolic blood pressure and as 66.95+/-31.60% (95% CI, 55.15-78.75%) for diastolic blood pressure.

CONCLUSION

The T/P ratio determined for betaxolol hydrochloride and extended-release metoprolol tartrate is higher than 66%. This ratio guarantees a satisfactory 24-h effect of both the above-mentioned drugs.

Different effects of ambulatory blood pressure monitoring on subjective and objective sleep quality

OBJECTIVE

To determine whether ambulatory blood pressure monitoring affects objective and subjective sleep quality in patients tested at home.

METHODS

Seventy consecutive patients (40 women and 30 men, aged 53+/-15 years), having ambulatory blood pressure monitoring to monitor the efficacy of antihypertensive treatment or to distinguish between hypertension or white-coat hypertension had an evaluation of their sleep quality on a first night with ambulatory blood pressure monitoring and the three following nights without ambulatory blood pressure monitoring. Ambulatory blood pressure monitoring was performed with an auscultatory device with a measure every 15 min during 24 h. Sleep evaluation criteria were both subjective (sleep quality score and sleep questionnaire) and objective (wrist actigraphy monitoring). Sleep parameters during night 1 with ambulatory blood pressure monitoring were compared with those during night 4 without ambulatory blood pressure monitoring. Usual quality of sleep of the patients was assessed by the mean sleep quality score over 7 consecutive days.

RESULTS

The sleep quality score was significantly higher for night 4 than for night 1 (7.3+/-2.1 vs. 5.3+/-2.3; P<0.0001). In contrast, actigraphy parameters (actual sleep time, mean activity score, and fragmentation index) were similar on night 1 and night 4 (6.7+/-1.2 vs. 6.9+/-1.2, 13.2+/-9.8 vs. 12.1+/-8.4, and 31.0+/-14.5 vs. 29.9+/-14.3, respectively). Subjective sleep quality was significantly altered by ambulatory blood pressure monitoring in good sleepers (mean sleep quality score > or =7, 73% of patients) but not in poor sleepers. The effect of ambulatory blood pressure monitoring on subjective sleep quality did not differ between dippers and nondippers.

CONCLUSIONS

Objective sleep quality as assessed by wrist actigraphy is not significantly altered by ambulatory blood pressure monitoring, whereas subjective sleep quality is adversely affected in good sleepers.

Blood pressure recordings within and outside the clinic and cardiovascular events in chronic kidney disease

BACKGROUND

Blood pressure (BP) measured outside the clinic correlates better with cardiovascular outcomes in patients with essential hypertension. To assess the role of out-of-clinic BP recordings in predicting cardiovascular events in patients with chronic kidney disease (CKD), a prospective cohort study was conducted in 217 veterans with CKD.

METHODS

BP was measured outside the clinic at home and by 24-hour ambulatory recordings, and in the clinic by 'routine' and standardized methods. Patients were followed over a median of 3.4 years to assess the combined end-point of total mortality, myocardial infarction or stroke.

RESULTS

Average (+/-SD) home BP was 147.0 +/- 21.4/78.3 +/- 11.6 mm Hg, 24-hour ambulatory BP 133.5 +/- 16.6/73.1 +/- 11.1 mm Hg and in-clinic BPs were 155.2 +/- 25.6/84.7 +/- 14.2 mm Hg by the standardized method, and 144.5 +/- 24.2/75.4 +/- 14.7 mm Hg by the 'routine' method. A 1 SD increase in systolic BP increased the hazard ratio (HR) of the composite end-point by 1.16 (95% CI 0.89-1.50) for routine BP, 1.57 (95% CI 1.19-2.09) for standardized BP, 1.66 (95% CI 1.27-2.17) for home BP, and 1.42 (95% CI 1.10-1.84) for 24-hour ambulatory BP recording. The HR of the composite end-point was only significant for hypertension defined by 24-hour ambulatory BP monitoring (HR 2.22 (95% CI 1.23-4.01)). Adjusted for the propensity scores, BP measured by the ambulatory technique was not an independent predictor of cardiovascular events. Non-dipping was associated with increased cardiovascular risk, but not when adjusted for other risk factors.

CONCLUSION

Risk factors that differentiate hypertension or non-dipping appear to confer a cardiovascular risk in CKD.

The interplay between haemodynamic load, brain natriuretic peptide and left atrial size in the early stages of essential hypertension

OBJECTIVE

Left atrial (LA) enlargement is an index of adverse cardiovascular events. We sought to investigate any possible correlation between haemodynamic load, neurohumoral factors and LA size in the early stages of essential hypertension.

METHODS

We studied 94 consecutive middle-aged subjects, with newly diagnosed stage I-II essential hypertension without left ventricular (LV) hypertrophy and 34 age and sex-matched normotensive individuals. Ambulatory blood pressure (BP) monitoring, plasma levels of brain natriuretic peptide (BNP), metabolic profile and left atrial volume index (LAVI), an echocardiographic measurement of LA volume indexed for the body surface area, constituted the work-up of all subjects.

RESULTS

Hypertensive compared with normotensive subjects had significantly increased office and ambulatory systolic and diastolic BP (P < 0.0001 for all cases) as well as body mass index and waist-to-hip ratio (P < 0.05 for both cases). BNP levels were greater in hypertensive compared with normotensive subjects but were not statistically significant (20.4 versus 17.1 pg/ml, P = NS). Hypertensive compared with normotensive subjects also had significantly increased LV mass index (105 versus 84 g/m, P < 0.0001), LA diameter (39 versus 36 mm, P < 0.0001), and LAVI (22 versus 19 ml/m, P < 0.05). In the hypertensive population, LAVI exhibited significant positive relationships with office systolic BP, ambulatory pulse pressure, LV mass index and BNP. In multiple linear regression analysis only LV mass index and BNP were significantly associated with LAVI (beta = 0.298, P = 0.030 and beta = 0.322, P = 0.009, respectively).

CONCLUSIONS

Increased LAVI, closely associated with LV mass index and BNP, was still found in the early stages of essential hypertension. However, the clinical significance of these findings remains to be elucidated in future studies.

Infradian awake and asleep systolic and diastolic blood pressure rhythms in humans

BACKGROUND

Blood pressure shows 24-h rhythms with a significant seasonal fluctuation.

OBJECTIVES

To characterize 2-month to 12-month infradian rhythms in the mean awake and asleep systolic blood pressure (SBP) and diastolic blood pressure (DBP) in humans.

METHODS

A total of 1689 participants underwent 24-h ambulatory blood pressure monitoring during different periods of the year. The mean daily temperature, humidity, barometric pressure and wind velocity values for the same time span and geographical location were obtained. Fourier analysis was used to fit 12-month, 6-month, 4-month, 3-month and 2-month rhythms to the mean awake and asleep SBP and DBP and to metereological variables.

RESULTS

The awake mean SBP and DBP values showed significant 12-month and 3-month rhythms (respectively, R2 = 55%, P < 0.001 and R2 = 45% P < 0.001), with a peak in July (winter) and a trough-peak difference of 6.2 +/- 1.6 mmHg (P < 0.001, SBP) and 4.2 +/- 1.5 mmHg (P < 0.001, DBP). In contrast, asleep blood pressure means showed mainly 3-month rhythms (SBP, R2 = 19%, P < 0.02; DBP, R2 = 43% P < 0.02). Mean daily temperature and humidity showed at 12-month, 6-month, 4-month, 3-month and 2-month rhythms, barometric pressure showed 12-month and 6-month rhythms, and wind velocity showed 12-month and 3-month rhythms. Minimal temperature values and maximal humidity values coincided with elevated blood pressure values.

CONCLUSION

Awake blood pressure means exhibited mainly circannual fluctuations while asleep blood pressure means showed principally 3-month rhythms. Infradian blood pressure variations correlated with some meteorological variables.

Prognostic importance of ambulatory blood pressure recordings in patients with chronic kidney disease

Ambulatory systolic blood pressure (BP) correlates better with risk factors for progression of chronic kidney disease (CKD) compared to clinic measured BP, but its role in predicting end-stage renal disease (ESRD) and death in patients with CKD is unknown. In a cohort study of 217 Veterans with CKD BP was measured by ambulatory monitoring and in the clinic. Twenty-four hour ambulatory BP was 133.5 +/- 16.6/73.1 +/- 11.1 mm Hg and clinic BP was 155.2 +/- 25.6/84.7 +/- 14.2 mm Hg. The composite renal end point of ESRD or death over a median follow-up of 3.5 years occurred in 75 patients (34.5%), death occurred in 52 patients (24.0%), and ESRD in 36/178 patients (20.2%). Thirty-nine patients died before reaching ESRD. One standard deviation (s.d.) increase in systolic BP increased the risk of composite outcome to 1.69 (95% confidence interval (CI) 1.32-2.17) for standard clinic measurement and to 1.88 (95% CI 1.48-2.39) for 24 h ambulatory BP recording. One s.d. increase in 24 h ambulatory systolic BP increased the risk of ESRD to 3.04 (95% CI 2.13-4.35) and to 2.20 (95% CI 1.43-3.39) when adjusted for standard clinic systolic BP. Non-dipping was associated with increased risk of total mortality and composite end point. In patients with CKD, BPs obtained by ambulatory monitoring are a stronger predictor of ESRD or death compared to BPs obtained in the clinic. Systolic ambulatory BP and nondipping are independent predictors for ESRD after adjusting for clinic BP. However, adjustment for other risk factors for CKD progression removes the independent prognostic value of ambulatory BP.

Efficacy of Combination Therapy With Amlodipine Besylate/Benazepril Hydrochloride for Lowering Systolic Blood Pressure in Stage 2 Hypertension

The Systolic Evaluation of Lotrel Efficacy and Comparative Therapies (SELECT) study compared daily treatment with combination amlodipine besylate/benazepril hydrochloride 5/20 mg, amlodipine besylate 5 mg, and benazepril hydrochloride 20 mg in 505 patients aged 55 years of age or older with stage 2 hypertension (systolic blood pressure [BP] > or =160 and < or =200 mm Hg and diastolic BP > or =60 and < or =100 mm Hg). BP and pulse pressure were assessed by conventional office BP measurements and 24-hour ambulatory BP monitoring. In this analysis, combination therapy was associated with significantly greater reductions in mean 24-hour BP, pulse pressure, and mean ambulatory BP during various time intervals compared with either monotherapy in the intent-to-treat population, in those with isolated and predominantly systolic hypertension, and in dippers and nondippers. Adverse event rates were low and similar in all treatment groups. This study demonstrated that combination therapy is superior to monotherapy in older patients with stage 2 systolic hypertension and is well tolerated.

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.

Adolescents' attachment orientation influences ambulatory blood pressure responses to everyday social interactions

OBJECTIVES

Adult attachment theory provides a useful framework for understanding how early developmental experiences affect social processes, associated physiological stress responses, and ultimately, health across the lifespan. The current study examined the effects of attachment orientation on physiological responses to naturalistic social interactions in adolescents.

METHODS

Two-hundred five black (49%) and white high school students (14-16 years; 50% boys) completed a measure of anxious and avoidant attachment, and underwent 1.5 days of ambulatory blood pressure and heart rate (AmBP and AmHR) monitoring while they tracked social experiences.

RESULTS

As predicted, individuals with higher avoidant attachment reported fewer interactions with friends (t [299] = -3.18, p < .01) and more anxious adolescents experienced less pleasant interactions both during (t [299] = -3.59, p < .01) and outside of school hours (t [298] = -3.59, p < .01). Individuals who were higher in anxious attachment showed augmented ambulatory diastolic and systolic blood pressure (AmDBP, AmSBP; both p < .05) in conjunction with current or recent interactions with friends. More avoidant adolescents exhibited augmented AmDBP responses to social conflict (p < .05).

CONCLUSIONS

The current findings suggest that adolescent attachment orientation may shape later physical health through influences on the nature of, and physiological responses to, social interactions in everyday life.

Improving patient outcomes with ambulatory blood pressure monitoring in elderly with hypertension

PURPOSE

The purpose of this article is to review the current knowledge regarding ambulatory blood pressure monitoring (ABPM) use in clinical practice and to provide example cases for its use in a hypertension (HTN) specialty clinic.

DATA SOURCES

Published research trials, medical literature, and cases from the Center for Senior Hypertension.

CONCLUSIONS

The knowledge of ABPM benefits to using ABPM are substantial and improves the care and management of many conditions, including white coat HTN, white coat normotension, resistant, borderline, episodic, paroxysmal HTN, and finally orthostatic hypotension. Third-party payers only cover ABPM for "white coat" HTN.

IMPLICATIONS FOR PRACTICE

This article reviews previous studies and explains the benefit to changing our current practice to match the knowledge we have gained through research through case studies.

High prevalence of newly detected hypertension in hospitalized patients: the value of inhospital 24-h blood pressure measurement

OBJECTIVE

Screening for hypertension in hospitalized patients could reduce the number of individuals with unrecognized hypertension. We hypothesized that 24-h blood pressure monitoring is an adequate tool to detect unrecognized hypertension among inpatients.

METHODS

Clinically stable inpatients in the Department of Internal Medicine, Department of Visceral Surgery and Department of Orthopaedics were included in the cross-sectional study. Every patient underwent inhospital 24-h blood pressure measurement. Previously unknown hypertension was defined as 24-h blood pressure of at least 125/80 mmHg in the absence of known hypertension. Forty-two patients had an additional 24-h blood pressure measurement after discharge, to compare mean inhospital and outpatient 24-h blood pressure values.

RESULTS

In 314 consecutive inpatients, 24-h blood pressure measurement was performed. Among 139 patients without known hypertension, 53 were hypertensive. The mean routine and 24-h blood pressures in these patients were 135/77 and 137/82 mmHg, respectively. Thirty-seven of these patients had normal routine blood pressure and could be detected only by 24-h blood pressure measurement. Patients with unknown hypertension had a marked cardiovascular risk profile, 26 being at high or very high cardiovascular risk. However, documented cardiovascular disease was present in only seven patients, suggesting that effective treatment could prevent a considerable number of cardiovascular events. The agreement between inhospital and outpatient 24-h blood pressure measurement in 42 patients was good.

CONCLUSIONS

By performing inhospital 24-h blood pressure measurement, a considerable number of patients with previously unknown hypertension can be detected.

Diurnal blood pressure pattern in patients with primary aldosteronism

BACKGROUND

The aim of the study was to evaluate diurnal blood pressure (BP) profiles in patients with primary aldosteronism and to compare them to those in subjects with essential hypertension. The effects of specific therapy on the circadian BP profiles have been studied.

MATERIALS AND METHODS

Sixty-four patients with primary aldosteronism were included in the study. Thirty of them revealed an aldosterone-producing adenoma (APA) and 34 had idiopathic hyperaldosteronism (IHA) due to bilateral adrenal hyperplasia.

RESULTS

We did not find any significant differences in ambulatory BP monitoring (ABPM) between patients with APA and IHA. However, the circadian BP variation in the patients with primary hyperaldosteronism due to APA was preserved, while the patients with IHA showed lower nocturnal decline in comparison with patients with essential hypertension. There was a significant decline in office and ambulatory BP levels after treatment in the patients with both APA and IHA. The awake-sleep BP difference in patients with APA remained unchanged after surgical treatment, while in patients with IHA the night-time systolic and diastolic BP decline was significantly higher after spironolactone treatment.

CONCLUSIONS

Primary hyperaldosteronism due to APA was associated with normal circadian BP variability and the surgical treatment led to highly significant decline in all BP parameters but had no influence on the extent of nocturnal BP variation. Spironolactone therapy restored normal nocturnal BP decline in patients with IHA. Reduction of night-time BP decline in patients with IHA is more likely to be related to the duration of the disease rather than to the aldosterone levels.

Assessment of the white-coat effect

BACKGROUND

A limitation of blood pressure measurements made in the physician's office is the transient elevation in pressure seen in many patients that does not appear to be linked to target organ damage or prognosis. This has been labeled the 'white-coat effect' (WCE), computed as the difference between blood pressure measurements taken by the physician and the ambulatory level or resting measures. It is unclear, however, which resting measure is most appropriate. The awake ambulatory blood pressure is the most widely used. However, while arguably the most useful measure for prediction of clinical outcomes, it is less appropriate for use as a resting measure, because it is influenced by many factors, including posture and physical activity level. Resting levels taken in the clinic may also be elevated, and will therefore underestimate the WCE.

METHODS

We addressed this question by taking resting measures in a non-medical setting on the day before patients were seen at a Hypertension Clinic (day 1), and comparing these with resting measures taken on the following day, in the clinic before the patient saw the physician.

RESULTS

As predicted, the day 1 resting levels were lower than those taken in the clinic prior to seeing the physician (P < 0.05 and P < 0.001 for systolic and diastolic pressures, respectively) in both normotensive and hypertensive patients. Using the day 1 resting levels, the estimated WCE for hypertensive patients was 5.3/6.9 mmHg (systolic/diastolic blood pressures), compared with estimates, using the clinic resting levels, of 0.3/0.5 mmHg. The pattern of changes was different in normotensive patients and hypertensive patients, with the physician pressures being slightly lower than day 1 pressures in the former, and substantially higher in the latter. Heart rate changes were similar and modest in both groups.

CONCLUSION

The WCE may not just be limited to that narrow interval in which the patient actually sees the physician, but may generalize to the clinic setting, rendering a clinic 'resting' level invalid. While it is strongly positive in most hypertensive patients, it is frequently negative in normotensive patients. Our results suggest that improved methods of measuring blood pressure in the clinic setting are unlikely to resolve the confounding influence of the WCE, and that greater reliance will need to be placed on out-of-office monitoring.

Medición de la presión arterial en el domicilio

Measurement of blood pressure (BP) by the own patient at home has become a popular procedure. Both a great offer of simple electronic devices and publication of multiple studies supporting its usefulness for the diagnosis and control of hypertension have contributed to this fact. In fact, this technique has various advantages over the conventional clinical measurement such as a higher reproducibility, better representation of the usual BP profile of the patient, greater correlation with target organs damage and greater morbimortality predictive value. Besides, there is a potential benefit on the control of patients under antihypertensives and, maybe, a reduction in health expenses at long-term follow-up. Currently, the main hypertension societies recommend the home measurement of BP in some clinical situations. However, it cannot be considered an alternative to the clinical measurement but rather a complementary technique in the evaluation of the hypertensive patient. Here we review the indications and limitations of this procedure in clinical practice.

Psychosocial Stress and Cardiovascular Risk: What is the Role of Daily Experience?

We describe an ecological momentary assessment (EMA) protocol designed to measure daily life experiences along several psychosocial dimensions (Social Conflict, Task Demand, Decisional Control, Negative Affect, and Arousal) hypothesized to be relevant for cardiovascular disease risk. In a large community sample, these assessments have been administered in conjunction with ambulatory blood pressure (ABP) monitoring and measures of subclinical cardiovascular disease. Several results have emerged that support the promise of this approach. First of all, each of these dimensions of experience appears to be a trigger for cardiovascular activation, with movement on each scale being associated with significant within-person changes in heart rate and blood pressure in the natural environment. Second, there appear to be individual differences in physiological responsiveness to these dimensions of daily experience, with such differences being associated in some cases with laboratory-based assessments of cardiovascular reactivity, as might be expected. Third, EMA ratings are associated in several instances with (between-person) stable individual differences in ABP readings. And finally, we have found that some of the characteristics defined by our EMA ratings are related to measures of subclinical atherosclerosis. Such effects appear to be mediated, in part, by ABP. The advantages of using EMA measures for capturing the effects of psychosocial stressors are highlighted by comparing the predictive validity of these daily life assessments to traditional global self-reports. We conclude by describing future plans for use of this type of assessment protocol for helping us to characterize psychosocial characteristics relevant to cardiovascular disease risk. Personality and social processes during daily living may have an important impact not only on psychological functioning but also on physical health and disease. In this article we review our recent work involving the assessment of daily experience as a means of better understanding the role of psychosocial stress in cardiovascular disease risk. First, we outline the rationale for our interest in daily experience sampling for examining these processes, and we describe the methods we have adopted for this purpose. Next, we review findings from a recent study in which we have used these approaches to examine the role of psychosocial stress on ABP and atherosclerosis in a community-dwelling sample. We compare our approach to more traditional (global self-report and laboratory-observation) methods for examining these relationships in humans, and we discuss potential future directions for use of daily experience sampling in studies of health and behavior.

The reproducibility of dipping status: beyond the cutoff points

A limited reproducibility has been ascribed to 24-h ambulatory blood pressure monitoring, especially in relation to the dipper and nondipper phenomena. This study examined the reproducibility of 24-h ambulatory blood pressure monitoring in three recordings of pressure at intervals of 8-15 days in 101 study participants (73% treated hypertensive patients) residing in the city of Recife, Pernambuco, Brazil. SpaceLabs 90207 monitors were used, and the minimum number of valid measurements was 80. No significant differences were found between the mean systolic and diastolic pressures, between the second and third recordings when the normotensive and hypertensive patients were assessed jointly (P=0.44). Likewise, no significant differences were present when the normotensive patients were analyzed separately (P=0.96). In the hypertensive group, a significant difference existed between only the first and second ambulatory blood pressure readings (135.1 vs. 132.9 mmHg, respectively; P=0.0005). Regarding declines in pressure during sleep, no significant differences occurred when continuous percentage values were considered (P=0.27). The values obtained from 24-h ambulatory blood pressure monitoring are reproducible when tested at intervals of 8-15 days. Small differences, when significantly present, always involved the first ambulatory blood pressure monitoring. The reproducibility of the dipper and nondipper patterns is of greater complexity because it considers cutoff points rather than continuous ones to characterize these states.

Association Between Hemodynamic Profile During Laboratory Stress and Ambulatory Pulse Pressure

Hemodynamic responses underlying blood pressure reactivity to laboratory stress are theoretically linked to cardiovascular pathophysiology. The present study investigated whether a vascular response predicted ambulatory pulse pressure, a known risk factor for cardiovascular disease. A new model of hemodynamic profile, previously developed by the authors, was applied to 24-h ambulatory data from 30 female and 34 male healthy young adults. Of these, 40 were monitored during a naturalistic stressor (university examination). For females, hemodynamic profile significantly predicted nighttime systolic blood pressure, and 24-h, day-, and nighttime diastolic blood pressure, but not ambulatory pulse pressure. A vascular or mixed hemodynamic profile significantly predicted 24-h and daytime ambulatory pulse pressure in males. The findings are consistent with theories of pathogenic mechanisms involving vascular changes and suggest that, for males, a vascular or mixed hemodynamic profile measured during laboratory stress may be a risk marker for cardiovascular disease, by its association with ambulatory pulse pressure.

Convenience of ambulatory blood pressure monitoring: comparison of different devices

OBJECTIVE

Twenty-four-hour ambulatory blood pressure monitoring has emerged as an important tool supporting physicians in the diagnosis and management of arterial hypertension. Compared with office measurements and self-measurements, however, ambulatory blood pressure monitoring shows the lowest patients' acceptance. The present study compares the convenience of different monitors in order to examine whether the patients benefit from new technologies.

METHODS

In a prospective randomized study, we compared the side effects of the Spacelabs 90207 with the I.E.M. Mobilograph monitor in 250 patients by means of a questionnaire that covered the following aspects: restriction in everyday activities, noise, sleep disturbance, pain and mobility. Complaints were measured by a five-point scale ranging from 'no complaints at all' to 'severe complaints'.

RESULTS

In all, 205 patients returned completed surveys (101 patients of the I.E.M. group, 104 patients of the Spacelabs group), yielding an 82% final response rate. The overall mean complaint score was significantly higher in the Spacelabs group than in the I.E.M group (2.24 vs. 1.78; P<0.001). The Mobilograph revealed less discomfort in every single question and differences were significant for restrictions in everyday activities, noise, pain, disturbance of the patient's or the patient's partner's sleep and restrictions in walking. Sleep disturbance was the aspect with the highest difference in the two groups.

CONCLUSION

The present work confirms that ambulatory blood pressure monitoring monitors are cumbersome to wear. Devices, however, differ in their comfort. Monitors with an improved convenience might lead to a higher patients' acceptance of this powerful diagnostic tool.

Arterial hypertension and cardiovascular prognosis after successful repair of aortic coarctation: a clinical model for the study of vascular function

Despite successful surgical repair, aortic coarctation is associated with unfavourable prognosis mainly due to cardiovascular disease. Late timing of repair and arterial hypertension represent adverse prognostic factors. Arterial hypertension can recur after coarctation repair, despite the absence of residual obstruction, with a prevalence of up to 45%. Furthermore, even subjects with normal blood pressure values at rest may show an abnormal blood pressure elevation during exercise and daily life activities. The pathophysiology of such abnormal blood pressure behaviour is unclear. Different mechanisms have been proposed: resetting of the renin-angiotensin system, neurological dysfunction and impaired vascular reactivity and/or elastic properties. Several studies have supported these hypotheses, although the suggestion of a causative role of vascular dysfunction persisting late after coarctation repair has recently become more popular. Further studies are needed to investigate this issue; this particular syndrome may represent an important study model for the understanding of systolic hypertension.

Aggressive hypertension management in patients of advancing and advanced age

Many older patients are not being aggressively managed for hypertension. Healthcare providers are often hesitant to start or even aggressively titrate antihypertensive medication, especially in the aged. Multiple studies have demonstrated that morbidity and mortality can be significantly reduced by appropriate intervention in all age groups. There are some clinical situations, however, where the provider must approach cautiously, such as in patients with a wide pulse pressure or those with a propensity toward adverse reactions. The data are clear that in the United States, undertreatment, rather than overtreatment, appears to be the issue. This article reviews studies that support the aggressive treatment of hypertension. The nuances of aging, which often influence the healthcare provider's treatment decisions, are also discussed. Suggestions for reasonable approaches to these difficult cases will be considered.

Does the reduction in systolic blood pressure alone explain the regression of left ventricular hypertrophy?

Systolic blood pressure (SBP) is an important determinant of the development and regression of left ventricular hypertrophy (LVH) in hypertensive humans. However, comparative assessments with other BP components are scarce and generally limited in size. As part of the Progetto Ipertensione Umbria Monitoraggio Ambulatoriale (PIUMA), 743 hypertensive subjects underwent echocardiography and 24-h ambulatory BP monitoring before and after an average of 3.9 years of treatment. The changes in left ventricular mass showed a significant direct association with the changes in 24-h SBP (r=0.40), diastolic blood pressure (DBP) (r=0.33) and pulse pressure (PP) (r=0.35). Weaker associations were found with the changes in clinic BP (r=0.32, 0.31 and 0.16, respectively). In a multivariate linear regression analysis, the changes in 24-h SBP were the sole independent determinants of the changes in left ventricular mass (LVM) according to the following equation: percentage changes in LVM=0.73 x (percentage changes in 24-h SBP) -0.48 (P<0.0001). For any given reduction in 24-h SBP, the reduction in LVM did not show any association with the changes in DBP and PP, either clinic or ambulatory. These data indicate that SBP is the principal determinant of LVH regression in hypertensive humans.

Blood pressure changes in acute haemorrhagic stroke

The relationship between hypertension and cerebrovascular disease is well established. As blood pressure is a dynamic and continually distributed variable, 24 h ambulatory blood pressure monitoring may be valuable as a risk stratifying tool in determining the "hypertensive load" as assessed by the presence of dipping or non-dipping status of an individual. Indeed, the association between reduced nocturnal blood pressure dipping and increased target organ damage is well established. Raised blood pressures are often seen in those presenting with strokes, although the precise mechanisms are uncertain. The relationship between intracerebral haemorrhage, which accounts for up to 15% of strokes in Caucasians, and blood pressure patterns is not well known. Understanding these inherent diurnal rhythms of blood pressure variation could help us unravel their significance and impact on cerebrovascular disease.

Arterial stiffness assessed by pulse wave analysis in essential hypertension: relation to 24-h blood pressure profile

BACKGROUND

Arterial stiffness is a risk factor for cardiovascular morbidity and mortality and appears to be increased in arterial hypertension. The purpose of the present study was to relate systemic arterial stiffness assessed by pulse wave analysis to variables of 24-h ambulatory blood pressure monitoring (ABPM) in patients with essential hypertension.

METHODS

Seventy-two subjects with untreated mild to moderate arterial hypertension underwent evaluation with 24-h ambulatory blood pressure monitoring. In the same subjects, applanation tonometry and pulse wave analysis was performed for evaluation of systemic arterial stiffness expressed as augmentation index and estimated aortic pulse wave velocity.

RESULTS

Clinic systolic blood pressure, mean heart rate during 24-h blood pressure monitoring and height were independent predictors of augmentation index and estimated aortic pulse wave velocity. The 41 patients with blunted reduction in nighttime blood pressure (nondippers) showed higher mean systolic blood pressure (p=0.02), lower systolic and diastolic blood pressure variability (p<0.001), higher pulse pressure during 24-h monitoring (p=0.05) and higher estimated aortic pulse wave velocity (p=0.03), indicating stiffer arteries in this group.

CONCLUSIONS

These results suggest that blood pressure change from day- to nighttime is an important determinant of arterial stiffness assessed by pulse wave analysis; this association could contribute to the higher cardiovascular risk in nondippers.

Ambulatory blood pressure level rather than dipper/nondipper status predicts vascular events in type 2 diabetic subjects

To clarify which parameter, diurnal pattern of blood pressure (BP) or level of BP variability, has the stronger predictive value for fatal and nonfatal vascular events, vital status after a mean (+/-SD) follow-up period of 86+/-46 months was determined in 392 type 2 diabetic subjects without any history of vascular disease, in whom the 24-h BP profile had been monitored between 1988 and 1998. After the exclusion of 28 subjects who died during the follow-up period of causes unrelated to diabetes, 364 subjects were recruited for further analysis. A total of 147 first events, including 50 fatal vascular events and 97 nonfatal vascular events, were recorded during the follow-up period. The rates of various vascular events increased with both reduced nocturnal falls in systolic BP (SBP) and levels of all ambulatory BP parameters. The ambulatory BP parameter showing the largest area under the receiver operating characteristic curve (ROCAUC) for fatal events was the mean 24-h pulse pressure (PP), and that for nonfatal events was the mean nighttime SBP; both exceeded the respective values of nocturnal fall in SBP. Furthermore, when dipper and nondipper diabetic subjects were divided into subgroups based on the 24-h PP (54.3 mmHg) and the nighttime SBP (116.5 mmHg) cut-off points derived from the ROC analyses, Kaplan-Meier plots showed that the diabetic subgroups with high ambulatory BP levels had worse outcomes, independent of dipper/nondipper status. Finally, these parameters were applied to the Cox model with the values of nocturnal fall in SBP and other confounding factors, and results showed that mean 24-h PP and mean nighttime SBP predicted fatal and nonfatal vascular events, respectively, more strongly than nocturnal fall in SBP in type 2 diabetic subjects. These findings therefore suggest that ambulatory BP levels in type 2 diabetic subjects have a higher predictive value for organ damage and death compared with diurnal BP patterns or dipper/nondipper status.

Captopril Administered at Night Restores the Diurnal Blood Pessure Rhythm in Adequately Controlled, Nondipping Hypertensives

The aim of our study was to evaluate whether captopril administered at night, can shift the circadian blood pressure (BP) from a nondipper to a dipper pattern in adequately controlled hypertensive patients, who continued their antihypertensive therapy. In a prospective, randomized, double blind, placebo-controlled designed study, we enrolled 121 treated, adequately controlled nondipping hypertensive patients. All patients were randomly assigned to 12.5 mg captopril or placebo treatment administered at night. In case of nondippers, the dosage of captopril or placebo was doubled after two weeks of treatment, while for dippers antihypertensive regimens were not changed. After another two weeks, all patients underwent ambulatory BP monitoring. Our results show that at the end of the active treatment period, the prevalence of a dipping diurnal BP pattern in the captopril group (70%) was significantly higher than that in the placebo group (9.8%, P < 0.001). Nighttime BP, night/day BP ratio, nighttime BP load and 24-h systolic BP were significantly lower after 4 weeks nighttime captopril treatment compared to baseline. In conclusion, the present study demonstrates for the first time that captopril administered at night can restore the diurnal BP rhythm and decrease the elevated night/day BP ratio in appropriately controlled, nondipper hypertensive patients. These results were mainly due to the decrease of nighttime BP.

The normal circadian pattern of blood pressure: implications for treatment

Blood pressure fluctuates over 24 h following a circadian rhythm that reaches a peak in the morning shortly after awakening. The onset of many acute cardiovascular and cerebrovascular events shows a synchronous cyclical pattern, with the highest incidence of morbidity and mortality in the early morning hours. Strong, although circumstantial, evidence suggests that the early morning surge in blood pressure may contribute to the onset of acute cardiovascular episodes. Sustained blood pressure control that blunts the early morning blood pressure surge may help to reduce the incidence of these events. Antihypertensive agents are needed that provide smooth and sustained blood pressure control for the full 24 h, including the risky early morning hours. The angiotensin II receptor blocker telmisartan given once daily, because of its long half-life and mechanism of action, is likely to confer benefit in terms of 24-h blood pressure control and may reduce cardiovascular risk at the time of greatest patient vulnerability.

Changes in financial strain over three years, ambulatory blood pressure, and cortisol responses to awakening

OBJECTIVE

Chronic psychosocial stress has been associated cross-sectionally with ambulatory blood pressure and with salivary cortisol, but there have been few longitudinal studies of the effects of changes in chronic stress. We assessed the influence of changes in financial strain on ambulatory blood pressure and salivary cortisol.

METHODS

Data were analyzed from 160 men and women age 47 to 59 years at the first assessment (T1) who repeated ambulatory monitoring 3 years later (T2). We analyzed change in financial strain as a continuous variable, and specifically compared people who did and did not report an improvement in financial strain.

RESULTS

Change in financial strain was associated with change in ambulatory systolic pressure after controlling for T1 ambulatory systolic pressure, gender, socioeconomic position, age, smoking, body mass index, and T1 financial strain (p = .041). Systolic pressure at T2 was lower in the improved financial strain (121.7 +/- 11.2 mm Hg) than in the worse/no change group (125.5 +/- 11.5 mm Hg; p = .029). The corresponding diastolic pressures averaged 78.5 +/- 7.1 mm Hg and 80.7 +/- 7.9 mm Hg, respectively (p = .061). The cortisol awakening response (difference between waking and 30 minutes later) was lower (p = .048) in men who reported improved financial strain, controlling for T1 cortisol response, socioeconomic position, age, smoking, time of waking, and T1 financial strain. There were no differences in the slope of cortisol decline over the day or in evening values.

CONCLUSION

These longitudinal data extend cross-sectional findings in showing associations between favorable changes in chronic stress and reduced cardiovascular and neuroendocrine activation in everyday life.