Ambulatory monitoring of blood pressure as a predictor of cardiovascular risk

Publication guidelines for human heart rate and heart rate variability studies in psychophysiology-Part 1: Physiological underpinnings and foundations of measurement

This Committee Report provides methodological, interpretive, and reporting guidance for researchers who use measures of heart rate (HR) and heart rate variability (HRV) in psychophysiological research. We provide brief summaries of best practices in measuring HR and HRV via electrocardiographic and photoplethysmographic signals in laboratory, field (ambulatory), and brain-imaging contexts to address research questions incorporating measures of HR and HRV. The Report emphasizes evidence for the strengths and weaknesses of different recording and derivation methods for measures of HR and HRV. Along with this guidance, the Report reviews what is known about the origin of the heartbeat and its neural control, including factors that produce and influence HRV metrics. The Report concludes with checklists to guide authors in study design and analysis considerations, as well as guidance on the reporting of key methodological details and characteristics of the samples under study. It is expected that rigorous and transparent recording and reporting of HR and HRV measures will strengthen inferences across the many applications of these metrics in psychophysiology. The prior Committee Reports on HR and HRV are several decades old. Since their appearance, technologies for human cardiac and vascular monitoring in laboratory and daily life (i.e., ambulatory) contexts have greatly expanded. This Committee Report was prepared for the Society for Psychophysiological Research to provide updated methodological and interpretive guidance, as well as to summarize best practices for reporting HR and HRV studies in humans.

Leptin Receptor Gene Gln223Arg Polymorphism Is Not Associated with Hypertension: A Preliminary Population-Based Cross-Sectional Study

Hypertension is responsible for high morbidity and mortality as one of the most important cardiometabolic risk factors. The aim of the study was to investigate whether the Gln223Arg in the leptin receptor (LEPR) influences the prevalence of hypertension. A cross-sectional study was carried out in individuals aged ≥ 18 years. Polymorphism identification was performed using PCR-RFLP analysis. Participants with blood pressure ≥ 140/90 mmHg or medication use were considered hypertensive. Frequencies, means, cross-tabulations, and multivariate models were produced to study differences in hypertension prevalence by genotypes. The study includes 470 participants. The frequency of GG polymorphism variant was 10.43%, 46.81% AG, and 42.77% AA. The distribution of hypertension frequency by LEPR genotypes was the following: AA 43.8%, AG 40.4%, and GG 40.8%; there were no significant differences between groups. Comparative analysis which used multivariate Poisson regression adjusted by many potential confounders (age, sex, schooling, smoking, alcohol intake, obesity, and family history of parental obesity) did not modify this result. In this large sample of population-based study, the association of the LEPR Gln223Arg gene polymorphism with hypertension was not observed.

Urinary albumin, protein excretion and circadian blood pressure in patients with fibromyalgia

Recent evidence suggests that patients with fibromyalgia (FM) have increased oxidative stress, inflammation, endothelial dysfunction and autonomic dysfunction. These factors are also shown to be responsible for increased urinary albumin and protein excretion and deranged circadian blood pressure (BP). However, no study has examined the 24-h urinary albumin excretion (UAE), 24-h urinary protein excretion (UPE) and 24-h ambulatory BP measurements in FM patients. The sociodemographic, laboratory parameters, depressive symptoms, sleep problems and 24-h ambulatory BPs were measured for all patients. Diagnosis of FM was based on the criteria for the classification of FM by the American College of Rheumatology. After diagnosis of FM, these patients underwent to complete the Fibromyalgia Impact Questionnaire (FIQ). In total, 30 patients with FM and 61 patients without FM were included. Among FM patients, the average number of tender points was 13.1 ± 1.57 and the mean FIQ score was 57.9 ± 8.86. The number of tender points did not show any correlation with office and ambulatory BPs. There were also no correlations between the number of tender points, UPE and UAE. The stepwise linear regression did not show any relation between UPE and FM. However, 24-h UAE was independently correlated with office systolic BP (P 0.008) and the presence of FM (P 0.045). The logistic regression analysis revealed no association between FM and non-dipping status. We suggest that circadian blood pressure and UPE are not independently associated with FM. However, UAE was related with the presence of FM. Studies are needed to confirm our findings and to highlight pathophysiologic mechanisms.

Simple renal cysts and circadian blood pressure: are they related to each other in patients with hypertension?

Previous studies have shown that the presence of simple renal cysts was related to hypertension. However, the relationship between simple renal cysts and circadian blood pressure was not studied before. Our study population comprised of newly diagnosed patients with essential hypertension. Medical history, physical examination and office blood pressure measurements, laboratory analysis, ambulatory blood pressure measurements, renal ultrasonography, and 24-h urine specimens were collected. In total, the study included 190 patients (male/female ratio 77/113; mean age 50.3 ± 11.3). Overall, 127 (66.8%) patients were dippers and 92 (48.4%) had at least one simple renal cyst. Thirty-five patients had solitary cysts and 57 patients had multiple cysts. Cysts were bilateral in 47 of patients. Most of ambulatory blood pressure recordings were higher in patients with at least one simple cyst when compared to patients without cysts. In multivariate logistic regression analysis, serum uric acid (P: 0.047, OR: 1.287, CI: 1.011-1.658), lower creatinine clearance (P: 0.001, OR: 1.030, CI: 1.012-1.049), presence of diabetes (P: 0.029, OR: 2.451, CI: 1.094-5.491), and presence of at least one cyst in each kidney (P: 0.002, OR: 3.087, CI: 1.533-6.212) were found to be independently related to nocturnal non-dipping. In conclusion, the presence of simple renal cysts is related to higher ambulatory BP and is associated with non-dipping phenomenon in patients with essential hypertension.

Noninvasive Psychophysiological Ambulatory Recordings

Rapid technical developments have greatly facilitated noninvasive 24-hour recording of physiological signals at relatively low costs, including blood pressure, activity of the autonomic nervous system, respiratory behavior, and activity of the hypothalamic-pituitary-adrenocortical axis. Ambulatory noninvasive recordings can be used to study the baseline levels of these physiological variables as well as their reactivity to naturalistic stressors. Levels and reactivity can be compared across groups differing in exposure to risk factors (e.g., stress, genotypes) or used to sharpen the clinical profile of individual subjects (e.g., in panic or somatoform disorders). The focus of the current paper is on the importance of a priori choices in study design and data analysis strategies when ambulatory recording specifically targets the reciprocal relationship between physiological and psychological events. These choices are illustrated with ambulatory-assessed indices of the cardiac autonomic nervous system, blood pressure, respiration, and cortisol secretion.

Type D personality as a prognostic factor in heart disease: assessment and mediating mechanisms

Type D personality, a synergy between negative affectivity and social inhibition, has established itself as a serious risk factor for morbidity and mortality in patients suffering from cardiovascular disease. In this review, we summarize studies on the validity of the assessment methods of Type D, emphasizing its role as an independent vulnerability factor in the progression of cardiovascular disease. We further present evidence on the physiological characteristics that accompany the 2 psychological traits negative affectivity and social inhibition and may mediate the relation between personality and prognosis in heart disease. Further research needs to determine the mechanisms by which Type D affects the course and outcome of cardiovascular disease as well as how Type D patients may benefit from psychosocial intervention.

Is HOMA index a predictor of nocturnal nondipping in hypertensives with newly diagnosed type 2 diabetes mellitus?

OBJECTIVE

Insulin resistance is involved in glucose intolerance, type 2 diabetes mellitus and hypertension. We aimed to analyze relationship between insulin resistance and nocturnal nondipping.

METHODS

Patients underwent physical and biochemical evaluation, clinic and ambulatory blood pressure measurements. The homeostasis model assessment (HOMA) index was calculated.

RESULTS

Ninety-six essential hypertensive patients, of whom 42 were dippers, with newly diagnosed type 2 diabetes mellitus were included. Nighttime average heart rate and mean arterial pressure of nondippers were higher than dippers (P<0.0001 and 0.001). Nondippers had higher fasting plasma glucose, serum insulin levels and HOMA indices than dipper patients (P=0.006, <0.0001 and <0.0001). Ten dippers and 36 nondippers were insulin resistant (P<0.0001). Clinic (r=+0.22, P=0.031), daytime average (r=+0.27, P=0.007), nighttime average (r=+0.33, P=0.001), 24-h average systolic (r=+0.25, P=0.015) and nighttime average diastolic blood pressures (r=+0.31, P=0.002) were positively correlated with homeostasis model assessment index. Nighttime mean arterial pressure and heart rates (daytime, nighttime, 24-h average) showed positive correlation with homeostasis model assessment index. In multivariate analysis, high homeostasis model assessment index was associated with increased nondipping risk (odds ratio: 1.85, confidence interval: 1.24-2.76, P=0.003). After adjustment of several factors, average nighttime systolic (P<0.0001), diastolic (P<0.0001) and 24-h diastolic blood pressure (P=0.029) and heart rate (P=0.001) measurements of insulin resistant patients were higher than nonresistant patients.

CONCLUSIONS

Insulin resistance is related with diurnal blood pressure variation. The HOMA index may be a predictor of nocturnal nondipping in patients with essential hypertension and newly diagnosed type 2 diabetes mellitus.

Comparison of time and frequency domain measures of RSA in ambulatory recordings

The extent to which various measures of ambulatory respiratory sinus arrhythmia (RSA) capture the same information across conditions in different subjects remains unclear. In this study the root mean square of successive differences (RMSSD), peak valley RSA (pvRSA), and high frequency power (HF power) were assessed during ambulatory recording in 84 subjects, of which 64 were retested after about 3 years. We used covariance structure modeling to test the equality of the correlations among three RSA measures over two test days and three conditions (daytime sitting or walking and nighttime sleep) and in groups with low, medium, and high mean heart rate (HR), or low, medium, and high mean respiration rate (RR). Results showed that ambulatory RMSSD, pvRSA, and HF power are highly correlated and that their correlation is stable across time, ambulatory conditions, and a wide range of resting HR and RR values. RMSSD appears to be the most cost-efficient measure of RSA.

Noise perception, heart rate and blood pressure in relation to aircraft noise in the vicinity of the Frankfurt airport

The aim of this study was to evaluate subjective noise perception and objective parameters of circulation in the vicinity of the Frankfurt airport. Two areas were selected in which aircraft noise was the predominant source of noise (and was) created by planes induced by take off but not during landing. Data of residents living in the two areas were observed over a period of twelve weeks, one area being exposed to air traffic noise for three quarters of the given time, the other for one quarter of the time.

METHODS

Fifty three volunteers (age 50-52 +/- 15 y) monitored their blood pressure and heart rate over a period of three months by using an automatic device with digitized readings. They also protocolled their own subjective perception of noise and sleep quality. Thirty one probands were living West of the airport (West group) and were exposed to a nocturnal equivalent continuous air traffic noise level of L(eq(3)) = 50 dB(A) outside, during flight direction 25 to the West. Twenty two probands were living East of the airport (East group) and were exposed to L(eq(3)) = 50 dB (A) during flight direction 07 to the East. During the opposite flight directions air craft noise corresponded to L(eq(3)) = 40 dB(A) in both areas. Frankfurt airport operates direction 25 for about 75% of the time on average and direction 07 for 25% of the time.

RESULTS

The average blood pressure was significantly higher in the West group with higher noise exposure. Morning systolic blood pressure was 10 mmHg and diastolic pressure 8 mmHg higher in the West group. Throughout the observation period, the East group showed a parallel between daily changes in noise and subjective noise perception. In the West group such a parallel did not appear. This reaction was considered to be the consequence of the high noise exposure of the West group.

CONCLUSIONS

It is concluded that a population exposed to a nocturnal equivalent continuous air traffic noise level of L(eq(3)) = 50 dB(A) for three quarters of a given time has a higher average blood pressure compared to a population exposed to the same equal energy noise level for only one quarter of the time. Within the East group a parallel between noise exposure and noise perception was observed, while in the West group this parallel did not appear. The difference is considered to be the consequence of higher noise stress levels in the West group. The data are in accordance with recent epidemiological studies and indicate that a nocturnal aircraft noise of L(eq(3)) = 50 dB(A) can have negative effects on subjective noise perception and on objective parameters of circulation.

Applications of 24-hour Noninvasive Ambulatory Blood Pressure Monitoring

Casual blood pressure (CBP) measurements using a standard sphygmomanometer have traditionally constituted the principal modality for the assessment and management of hypertension. However, CBP measurement has shortcomings. Ambulatory blood pressure monitoring (ABPM) provides abundant information on blood pressure (BP), including heart rate, all BP readings for test periods, BP average, BP variability, BP load, load index, distribution pattern of BP, reduction percentage of BP, trough/peak ratio, and summary statistics for overall 24-hour, daytime and nighttime periods. Over the last three decades, ABPM has evolved from a research device to an established and valuable clinical tool for assessment and management of hypertension. This technology has been proven to be useful in terms of the distribution pattern of BP, characterization of BP profiles in normotensive and hypertensive patients, evaluation of patients with mild or labile hypertension, physiologic and psychologic factors for fluctuation of BP, load index study, study of white coat hypertension, etiology of hypertension, prognosis of hypertension, and assessment of antihypertensive management. Nevertheless, the technology remains underused due to lack of insurance reimbursement in most countries. Accordingly, insurance reimbursement is crucial to promote increased utility of ABPM. Clinicians should be familiar with the role of this technology in the care of patients with abnormal BP. This review is an attempt to increase clinicians' understanding of ABPM and the appropriate use of this technology.

Devices for ambulatory and home monitoring of blood pressure, lipids, coagulation, and weight management, part 1

PURPOSE

The equipment and methods used for ambulatory and home monitoring of blood pressure, lipids, coagulation, and weight management are discussed.

SUMMARY

Over 100 million people in the United States have one or more chronic diseases, such as diabetes, hypertension, and asthma. With the goal to improve health while reducing costs and the overall health care burden, ambulatory and home monitoring by pharmacists and patients are receiving more attention. Ambulatory and home monitoring of blood pressure, cholesterol, coagulation, and weight management (including devices for assessing overweight and obese patients, heart rate monitors, and pedometers) are convenient for clinicians and patients. Such monitoring provides pharmacists with an opportunity to differentiate their practices. Studies suggest that patients who are involved in ambulatory and home monitoring take a more active role in their health and may have better adherence to prescribed diet and medication regimens. Studies also show that ambulatory and home monitoring, if done correctly, provide clinicians with a large quantity of reliable readings for future therapeutic decisions. Devices are also a means for pharmacists to increase their provision of pharmacy services. Ambulatory monitoring is billable in many clinic settings, and the devices can be a profitable addition to prescription services.

CONCLUSION

Many devices are available to assist patients and clinicians in monitoring blood pressure, lipids, coagulation, and weight management. Familiarity with the devices will help in their proper selection and use.

Morning versus evening administration of a calcium channel blocker in combination therapy for essential hypertension by ambulatory blood pressure monitoring analysis

Patients with moderate to severe hypertension may need more than two antihypertensive drugs in combination to achieve ideal blood pressure (BP) control. The purpose of this study was to compare the efficacy and safety of administering the antihypertensive agents either all together in the morning or separately with two agents in the morning and one calcium channel blocker (CCB) in the evening. Twenty-four-hour ambulatory BP monitoring (ABPM) was performed among 15 patients (mean, 59 years) with moderate to severe essential hypertension. All patients received at least 3 antihypertensive drugs for ideal BP control. Two treatment regimens were given to each patient: Regimen 1: All antihypertensive agents were given once a day in the morning; Regimen 2: All antihypertensive agents were given in the morning, except the CCB which was given at 4:00 pm. After receiving regimen 1 for 4 weeks, each patient underwent 24-hour ABPM to analyze the BP control. After the first ABPM, each patient was switched to regimen 2. After 4 weeks of treatment with regimen 2, each patient underwent the second ABPM measurement. The pretreatment mean systolic and diastolic BP were 179.6 +/- 21.7 and 107.4 +/- 19.9 mmHg, respectively. Between the two regimens, there was no significant difference in the mean 24-hour BP (126.1 +/- 5.8/73.3 +/- 3.8 versus 130.2 +/- 6.2/75.1 +/- 4.7 mmHg), daytime BP (128.2 +/- 6.5/75.3 +/- 3.8 versus 132.4 +/- 5.8/77.2 +/- 4.4 mmHg), nighttime BP (125.2 +/- 4.9/72.4 +/- 3.3 versus 130.9 +/- 6.2/73.8 +/- 4.1 mmHg), and 24-hour heart rate (65.1 +/- 3.8 versus 64.2 +/- 3.4 bpm). The circadian BP and heart rate profiles were almost identical between regimen 1 and regimen 2. We conclude that in patients with moderate to severe hypertension treated with at least 3 antihypertensive agents, administering a CCB simultaneously with other antihypertensive agents in the morning or separately in the evening did not affect the 24-hour BP control.

Heritability of daytime ambulatory blood pressure in an extended twin design

The present study estimated the genetic influences on ambulatory systolic and diastolic blood pressure, and on hypertensive status derived from ambulatory levels, in a family sample of 535 twins and 257 singleton siblings. This "extended twin design" was used to explicitly test the possibility that results obtained in singleton siblings are different from those obtained in twins. To examine the effects of excluding (medicated) hypertensive subjects, the genetic analyses were first performed under strict exclusion (medication and/or blood pressure >135/85 mm Hg), then without the medicated subjects, and, finally, without any exclusion. For the latter analysis, the untreated blood pressure values in subjects using antihypertensive medication were estimated by augmenting the observed blood pressure by the published efficacy of the specific antihypertensive medication used. No evidence was found for differential means, variances, or covariances of ambulatory blood pressure in singletons compared with twins. This indicates that estimates of heritability of ambulatory blood pressure from twin studies can be generalized to the singleton population. Heritability of hypertension, defined as a mean daytime blood pressure >135/85 mm Hg or antihypertensive medication use, was 61%. Genetic contribution to ambulatory blood pressure was highest when all subjects were included (systolic, 44% to 57%; diastolic, 46% to 63%) and lowest under strict exclusion (systolic, 32% to 50%; diastolic, 31% to 55%). We conclude that exclusion of (medicated) hypertensives removes part of the true genetic variance in ambulatory blood pressure.

Use of a mild sedative helps to identify true non-dippers by ABPM: a study in patients with diabetes mellitus and hypertension

BACKGROUND

The interplay between the continuity or quality of sleep and diurnal variation in blood pressure has not been directly examined before. We examined the influence of a mild, non-hypotensive sedative on nocturnal dipping.

DESIGN

This was a randomized, single-blind study.

SETTING

The study took place in an out-patient clinic in an academic hospital.

INTERVENTION

Zolpidem 10 mg or placebo was given randomly for the first or second night, and ambulatory blood pressure monitoring was instigated for 48 h.

PATIENTS

The population under study comprised 96 male patients with type 2 diabetes mellitus and hypertension (mean age 54 +/- 6 years, mean blood pressure 158/94 +/- 9/6 mmHg).

MAIN OUTCOME MEASURE

Nocturnal dipping (nocturnal blood pressure >/= 10% lower than daytime pressure) was found in 71% of the patients taking the sedative compared with 27% of those on placebo (P=0.001).

RESULTS

On placebo, non-dippers and dippers had similar profiles of cardiovascular risk parameters. In contrast, non-dippers taking zolpidem had significantly higher values for most cardiovascular risk parameters compared with dippers: higher systolic blood pressure, higher low-density lipoproteins, lower high-density lipoproteins, higher serum creatinine, a higher urinary albumin:creatinine ratio, higher serum insulin and insulin resistance.

CONCLUSION

The use of a mild sedative during ambulatory blood pressure monitoring may help to identify the patients with a very high cardiovascular risk. These are the patients with a blunted nocturnal hypotension despite sedation.

Association between serum leptin levels and 24-hour blood pressure in obese women

OBJECTIVE

To assess the relationship between serum leptin and 24-hour blood pressure (BP) in obese women, according to body fat distribution.

RESEARCH METHODS AND PROCEDURES

A cross-sectional study was carried out in a population of 70 nondiabetic, normotensive, obese women (40 with android and 30 with gynoid type of obesity) and 20 nonobese healthy women as a control group. All subjects underwent 24-hour ambulatory BP monitoring. Blood samples were collected for serum leptin and plasma insulin measurements. Total cholesterol and high-density lipoprotein cholesterol were also measured.

RESULTS

Serum leptin levels were significantly higher in obese subjects than in controls, and they were more elevated in android obese women than in gynoid ones. Leptin levels were positively related to body mass index (BMI), insulin, and waist and hip circumferences in the android group. Among gynoid subjects, leptin levels showed positive associations with BMI and insulin. In women with android obesity, strong positive correlations (p < 0.001) were found between leptin levels and 24-hour systolic BP (SBP), daytime SBP, nighttime SBP, 24-hour diastolic BP (DBP), and daytime DBP. Multiple regression analyses, including age, insulin and leptin concentrations, BMI, and waist and hip circumferences on 24-hour and daytime SBP and DBP, showed that only leptin levels contributed to the variability of BP.

CONCLUSIONS

Our study shows that serum leptin levels are directly related to 24-hour BP levels in normotensive women with android fat distribution, independently of BMI.

Dissecting the genetic architecture of the cardiovascular and renal stress response

We review the evidence for a genetic basis of the cardiovascular and renal stress response. A bio-behavioral model of stress-induced hypertension is presented that explains how repeated exposure to stress in combination with genetic susceptibility might lead to the development of hypertension. In this model, we focus on three underlying physiological systems that mediate the stress response of the heart, vasculature and kidney: the sympathetic nervous system (SNS), the renin-angiotensin-aldosterone system (RAAS) and the endothelial system (ES). We then review the evidence for a genetic influence on cardiovascular reactivity to psychological stress and stress-induced sodium retention using data from twin and family studies and a limited number of candidate gene studies. Finally, by describing the underlying physiological systems of our model and their genetic underpinning we emphasize the importance of inclusion of genetic measurements in any future studies testing the reactivity hypothesis.

Large waist circumference and risk of hypertension

OBJECTIVE

To examine the relationship between 24 h ambulatory blood pressure monitoring and three commonest anthropometric measurements for obesity--body mass index (BMI), waist-to-hip ratio (WHR) and waist circumference (W).

DESIGN

Cross-sectional survey among outpatients at the Obesity Research Center.

SUBJECTS AND METHODS

Four-hundred and sixty-one overweight or obese subjects, non-diabetic, otherwise healthy, aged 20-70 y, of either sex, were consecutively recruited. All subjects underwent 24 h ambulatory blood pressure monitoring. The population study was separated in normotensive and hypertensive males and females and the possible risk factors for hypertension (W, WHR, BMI and age) were subdivided into different classes of values.

RESULTS

Logistic regression shows that W is the most important anthropometric factor associated with the hypertensive risk. Among males with W> or =102 cm the odds ratio (OR) for hypertension is three times that of males with W<94 cm using casual BP measure (OR 3.04), nearly four times higher using 24 h BP mean (OR 3.97), and even five times higher using day-time BP mean (OR 5.19). Females with W> or =88 cm have a risk for hypertension twice that of females with W<80 cm, whatever BP measurement was take (casual, 24 h or day-time). Males with WHR> or =0.96 and females with WHR> or =0.86 show significant OR for hypertension only by 24 h BP measurement and by day-time BP measurement. BMI seems to have no significant relationship to hypertensive risk. Age shows a significant relationship to hypertensive risk only considering males aged > or =55 y and females aged > or =50 y.

CONCLUSION

The waist circumference seems to have a strong association with the risk of hypertension, principally by the ambulatory BP monitoring, when compared with casual BP measurement.

Clinical study to investigate the predictive parameters for the onset of atrial fibrillation in patients with essential hypertension

BACKGROUND

The risk factors involved in the onset of atrial fibrillation (AF) are well known, but the predictive clinical and paraclinical parameters for the onset of AF in hypertensive patients have not been investigated specifically.

METHODS AND RESULTS

We retrospectively analyzed 97 consecutive patients with hypertension and no known history of AF or cardiovascular events who attended the cardiology outpatient clinic. The analysis was based on clinical data, the noninvasive ambulatory 24-hour measurement of blood pressure (AMBP), a standard 12-lead electrocardiogram, and a Doppler echocardiogram. After a mean follow-up of 25 +/- 3 months, 19 (19. 5%) patients had AF, 3 (15.8%) of whom had a cerebrovascular accident. The patients with AF were older than the others and their AMBP showed higher mean systolic diurnal and nocturnal blood pressures, though no differences in the clinical blood pressure readings were present. On the electrocardiogram, the maximum duration of the P wave and its dispersion were more prolonged in the patients with AF. On the Doppler echocardiogram, left ventricular mass and left atrial dimension were higher in the patients with AF, and the A-wave velocity of diastolic mitral flow was reduced in these patients. In the multivariate analysis, age (odds ratio 3.28, P <.001), diurnal systolic blood pressure (odds ratio 1.35, P <.01) and nocturnal systolic blood pressure (odds ratio 1.16, P <.01), maximum duration of the P wave (odds ratio 2.09, P <.01), dispersion of the P wave (odds ratio 2.52, P <.001), echocardiographic left ventricular mass (odds ratio 1.43, P <.01), left atrial dimension (odds ratio 2.81, P <.001), and velocity of the A wave (odds ratio 2. 24, P <.01) were independent predictors for the onset of AF. After correction for age, maximum duration of the P wave (odds ratio 1.34, P <.01), dispersion of the P wave (odds ratio 1.63, P <.001), and the velocity of the A wave (odds ratio 1.42, P <.01) remained independent predictors for the onset of AF.

CONCLUSIONS

In patients with hypertension, age and the level of diurnal and nocturnal systolic blood pressures measured by 24-hour AMBP are important independent predictors for the onset of AF. Independent of age, increases in left atrial dimension and left ventricular mass, prolongation of the maximum duration and dispersion of the P wave and reduced A-wave velocity are also predictors for the onset of AF.

Microalbuminuria in essential hypertension: significance, pathophysiology, and therapeutic implications

Some patients with essential hypertension manifest greater than normal urinary albumin excretion (UAE). The significance of this association, which is the object of this review, is not well established. Hypertensive patients with microalbuminuria manifest greater levels of blood pressure, particularly at night, and higher serum levels of cholesterol, triglycerides, and uric acid than patients with normal UAE. Levels of high-density lipoprotein cholesterol, on the other hand, were lower in patients with microalbuminuria than in those with normal UAE. Patients with microalbuminuria manifested greater incidence of insulin resistance and thicker carotid arteries than patients with normal UAE. After a follow-up of 7 years, we observed that 12 cardiovascular events occurred among 54 (21.3%) patients with microalbuminuria and only two such events among 87 patients with normal UAE (P < 0.0002). Stepwise logistic regression analysis showed that UAE, cholesterol level, and diastolic blood pressure were independent predictors of the cardiovascular outcome. Rate of creatinine clearance from patients with microalbuminuria decreased more than that from those with normal UAE. In conclusion, these studies suggest that hypertensive individuals with microalbuminuria manifest a variety of biochemical and hormonal derangements with pathogenic potential, which results in hypertensive patients having a greater incidence of cardiovascular events and a greater decline in renal function than patients with normal UAE.

Rationale for time-qualified reference standards for 24-hour blood pressure values and their circadian rhythms in Japanese normotensive adults: a study by the Ambulatory Blood Pressure Monitoring Research Group

The aim of this study was to demonstrate that blood pressure (BP) has to be standardized according to its circadian variability, including the properties shown in its circadian rhythm. The BP time-qualified standards were derived from a sample of 644 clinically healthy normotensive Japanese subjects (320 males, 324 females; age range, 18-93 years), stratified by age-group and gender, who underwent noninvasive ambulatory monitoring according to a fixed protocol. The monitored data series shows that BP exhibits a within-day variability at any age of life in both males and females. Additionally, the monitored data series shows that BP exhibits a significant circadian rhythm at any age of life in both males and females. The age- and sex-related reference limits for the BP within-day variability constitute the time-qualified standards against which both the casual and monitored BP measurements can be compared in order to detect whether or not they are compatible with normotension. The reference limits for the BP circadian rhythm represent the rhythmometric standards against which the BP oscillatory curve can be compared in order to detect whether or not they are compatible with a physiological circadian rhythm.

Lack of age-associated elevations in 24-h systolic and pulse pressures in women who exercise regularly

We tested the hypothesis that the elevations in 24-h arterial systolic (SBP) and pulse (PP) pressures with age in sedentary adult females are absent or smaller in women who exercise regularly. Four groups of healthy normotensive women were studied: premenopausal (n = 12; 29 +/- 1 yr, mean +/- SE) and postmenopausal (n = 20; 62 +/- 1) sedentary, and premenopausal (n = 14; 30 +/- 1) and postmenopausal (n = 12; 58 +/- 1) endurance-exercise trained (distance runners). In the sedentary group, 24-h SBP and PP (Spacelabs ambulatory monitor 90207) were approximately 10 mmHg higher (P < 0.05) in the postmenopausal women than in the premenopausal controls; this was because of higher daytime and nighttime SBP and PP levels in the postmenopausal women. In contrast, 24-h, daytime and nighttime SBP and PP were not different with age in the endurance-trained women. SBP variability and SBP load (% of all recordings > 140 mmHg) generally were greater with age in the sedentary women (e.g., SBP load = 14 +/- 4 vs. 3 +/- 1%, P < 0.05) but not in the endurance-trained women. In the pooled population, 24-h SBP and PP were related to waist-to-hip ratio (measure of abdominal adiposity) (r = 0.48 and 0.49, respectively, P < 0.001) and carotid augmentation index (measure of arterial stiffness) (r = 0.43 and 0.53, P < 0.005). In the sedentary women, accounting for the influence of either of these factors eliminated the significant age-associated differences in 24-h SBP and PP (P > 0.3). Our results suggest that the elevations in 24-h SBP and PP with age in sedentary adult females may not occur in women who regularly perform endurance exercise. This appears to be related to the absence of age-associated increases in abdominal adiposity and arterial stiffness in the exercising women.

Office and laboratory blood pressures as predictors of daily blood pressure level in normotensive subjects and borderline and mild hypertensive subjects

A series of standardized laboratory tests [10 min sitting and supine, 9 min standing, dynamic; cycle ergometer (ERG) and isometric exercise; handgrip (HG)] were performed during intra-arterial blood pressure (BP) recording in 97 healthy unmedicated men, initially classified as normotensive (NT, n = 34), borderline hypertensive (BHT, n = 29) or mildly hypertensive (HT, n = 34) by repeated office blood pressure (OBP) measurements. After testing, a 24-h intra-arterial ambulatory BP (IABP) recording was obtained while subjects performed their normal activities. Day and night periods were analysed as well as 24-h averages for systolic BP (SBP) and diastolic BP (DBP) using Pearson correlations and multiple linear regressions. In normotensive subjects, the supine SBP predicted IABP measurements best (r range 0.39-0.69, P < 0.05-0.001). In multiple regression, supine SBP explained 49% of 24-h SBP variance (F = 12.4, P = 0.001). For BHT, supine SBP was also the best predictor (r range 0.09-0.64, P NS to P < 0.001), and it explained 37% of 24-h SBP variance (F = 15.6, P = 0.0005). In HT, ERG DBP correlated best with IABP (r range 0.52-0.75, P < 0.01-0.001). ERG SBP explained 49% of 24-h SBP (F = 31.0, P = 0.0000) and ERG DBP explained 56% of 24-h DBP (F = 35.4, P = 0.0000) variance. Laboratory BP correlations were generally better with day than with night measurements. OSBP correlated moderately well with IABP in NT, and weakly in BHT and HT; ODBP instead correlated with IABP in NT and HT but not significantly in BHT. In conclusion, OBP is less closely related to IABP than laboratory BP, but even laboratory BP generally explains less than 50% of IABP variance. Stressors such as exercise are useful only in HT. For BHT, the prediction of IABP with laboratory measures was even weaker than in other groups, and thus ambulatory measurements cannot be replaced by short-duration laboratory measurements and stress tests.

Predictors of future ambulatory blood pressure in youth

OBJECTIVE

The objective of this study was to determine the predictors of future ambulatory blood pressure in normotensive youths with family histories of essential hypertension.

STUDY DESIGN

Eighty-eight healthy youths (mean age 10.9 +/- 2.5 years; 52 blacks, 36 whites; 45 boys) were studied. During an initial visit anthropometric variables and hemodynamics were measured at rest and before, during, and after three laboratory stressors: postural change, forehead cold, and video game challenge. The subjects' ambulatory blood pressure was monitored for 24 hours as part of a follow-up evaluation an average of 2.5 years later.

RESULTS

Anthropometric and demographic variables and measures of reactivity to laboratory stressors were related to future daytime and nighttime ambulatory blood pressure.

CONCLUSION

These findings provide important information on the predictors of ambulatory blood pressure and underscore the importance of resting blood pressure and adiposity. These results support the guidelines of the Second Task Force, which recommend the measurement of blood pressure and adiposity in the context of ongoing health care.

Comparison of manual versus automated blood pressure measurements in treated hypertensive patients

This study assesses differences in blood pressure (BP) levels prospectively between office (manual) measurement and ambulatory blood pressure monitoring (ABPM) in 70 treated, essential, hypertensive patients. The objective was to determine whether ABPM is superior to office measurement for assessing adequacy of therapy. Twenty-four patients received monotherapy and 46 received multiple therapy. Thirty-five patients were administered medication in the morning only, whereas 33 were administered medication in the morning and evening both. Mean systolic BP by manual method was identical to that obtained by ABPM (141.98 +/- 14.98 mm Hg versus 141.46 +/- 16.33 mm Hg, respectively). However, mean diastolic BP by manual method was significantly higher than that obtained by ABPM. (90.38 +/- 9.01 mm Hg versus 86.69 +/- 10.65 mm Hg, respectively; P < 0.001). Significant correlations (P < 0.01) were found between the BP levels measured by these two methods, although individual readings differed by 10 mm Hg or more systolic and by 5 mm or more diastolic in many subjects. No significant differences were noted in BP levels measured by either method for patients treated by monotherapy or multiple therapy, and none were noted whether they were taking medication in the morning or in both the morning and evening. In addition, no differences were noted in BP levels using either method for race. Thus, this study shows that the office measurement is grossly similar to ABPM for assessment of adequacy of therapy in treated hypertensive patients whose blood pressure is controlled adequately. However, ABPM is found to be superior to office measurement in identifying hypertensive patients whose blood pressure is not controlled adequately or is uncontrolled.

Effect of regular aerobic exercise on elevated blood pressure in postmenopausal women

The efficacy of aerobic exercise for lowering arterial blood pressure (BP) in postmenopausal women with elevations of 130 to 159/85 to 99 mm Hg has not been established. To determine this, 10 postmenopausal women with high normal resting BP or stage I essential hypertension were studied throughout a 12-week lead-in period (no exercise, n = 5) and/or 12 weeks of moderate-intensity aerobic exercise (walking, n = 9). There were no significant time effects during the lead-in period (all p >0.4). Maximal aerobic capacity (as assessed by maximal oxygen consumption) was unchanged after 12 weeks of exercise, but exercise tolerance (treadmill walking time) increased by approximately 10% (p <0.05). Body weight, dietary intake and composition, and urinary sodium excretion were unchanged before versus after exercise training. After 12 weeks of exercise, systolic and diastolic BP at rest were significantly lowered by 10/7 and 12/5 mm Hg, respectively, in the sitting and standing positions (p <0.001); some (> or = 3 to 5 mm Hg) decrease in BP was observed in every subject. On average, subjects with stage I hypertension had a reduction in BP into the high normal range, whereas subjects with high-normal initial levels had a reduction in BP into the normal range. Borderline significant (p = 0.06 to 0.07) reductions in systolic and diastolic BP were observed by the end of the second and tenth weeks of training, respectively. Ambulatory determined 24-hour levels of BP were unchanged with training, but significant reductions in BP during submaximal exercise occurred. Our results demonstrate that regular aerobic exercise can produce clinically important reductions in resting BP in Caucasian postmenopausal women with mild to moderately elevated initial levels. This effect of exercise is observed in the absence of changes in maximal aerobic capacity, body weight, or dietary intake.

Comparison of enalapril to captopril by 24-hour ambulatory blood pressure monitoring

The efficacy of a once-daily dose of enalapril was compared with a thrice-daily dose of captopril in an open-label, randomized parallel group study of 27 hypertensive patients. The patients were monitored using conventional measurements of blood pressure and with 24-hour ambulatory blood pressure monitoring at baseline and after 12 weeks of therapy. The end points were 24-hour, daytime, and nighttime mean blood pressure values and the percentage of elevated systolic and diastolic measurements, reflecting the "hypertensive load." Enalapril reduced mean 24-hour systolic blood pressure by 18 mmHg and diastolic blood pressure by 11 mmHg. The comparative values for captopril were 9 mmHg and 2 mmHg, respectively. The mean daytime systolic blood pressure was reduced by 20 mmHg with enalapril versus 7 mmHg with captopril; the diastolic values were lowered by 11 mmHg with enalapril versus 4 mmHg with captopril. The mean nighttime systolic blood pressure was lowered by 16 mmHg with enalapril versus 12 mmHg with captopril; the diastolic values were reduced by 10 mmHg with enalapril and 5 mmHg with captopril. No major side effects were recorded in either group. A single daily 20-mg dose of enalapril, therefore, proved to be equipotent or superior to 75 mg of captopril administered in three divided doses.

Blood pressure risks factors in healthy postmenopausal women: physical activity and hormone replacement

The prevalence of cardiovascular disease (CVD) increases with advancing age in women, particularly after menopause. CVD risk is lower in physically active women relative to their sedentary peers, but the responsible mechanisms are not well understood. The aims of this study were to test the hypotheses that 1) physically active postmenopausal women demonstrate more favorable blood pressure (BP)-related risk factors for CVD than do sedentary healthy women and 2) women on hormone replacement therapy (HRT) also have more favorable levels of these CVD risk factors. BP-related CVD risk factors were measured in physically active women (n = 18; age 55 +/- 1 yr; n = 8 on HRT) and in healthy less-active controls (n = 34; age 59 +/- 1 yr; n = 17 on HRT). Maximal oxygen consumption was higher in the active group, whereas waist-to-hip ratio and waist circumference were lower (all P < 0.005). The active women demonstrated marginally lower (5-8 mmHg; P < or = 0.10) levels of casual, 24-h, and daytime systolic BP (SBP). They also tended to have lower (P = 0.11) daytime SBP loads (percentage of BP recordings > 140/90 mmHg) and lower daytime and nighttime BP variabilities (P = 0.04) and a reduced (P < 0.007) SBP response to submaximal exercise. Women on HRT tended to have lower (3-4 mmHg; P = 0.07) levels of 24-h and nighttime diastolic BP (DBP) relative to the nonusers and smaller (P < 0.04) daytime and 24-h DBP loads. Stepwise multiple regression indicated that waist circumference was the primary predictor of most of the SBP-related CVD risk factors while HRT use was the best predictor for DBP loads. These findings indicate that, in general, physically active postmenopausal women demonstrate more favorable SBP-related CVD risk factors relative to their less-active healthy peers, which may be mediated, in party, by their lower levels of abdominal adiposity. In addition, HRT use tends to be associated with lower levels of DBP-related CVD risk factors.

Blood pressure level and variability in the prediction of blood pressure after 5-year follow-up

We compared mean intra-arterial ambulatory blood pressure (IAMB), blood pressure (BP) diurnal profiles are variability, and postural measurements with casual sphygmomanometric measurements for the prediction of future BP. We studied 97 healthy, ummedicated men classified as normotensive (NT, n = 34), borderline hypertensive (BHT, n = 29), or mildly hypertensive (HT, n = 34) by repeated casual measurements during the 2 months before IAMB. Five years later, we reassessed 79 subjects (81%) using casual BP measurements and noninvasive ambulatory 24-hour BP monitoring (NAMB). IAMB level generally correlated well with follow-up BP and slightly better with NAMB level than with casual measurements (24-hour IAMB versus follow-up NAMB systolic BP [SBP], r = .64, P < .001; versus diastolic' BP [DBP], r = .52, P < .001). NT and BHT subgroup correlations were of similar strength, but the relationship in the HT subgroup was not significant. Similarly, when we examined daytime and nighttime BP levels, nighttime BP correlated better with follow-up BP in NT and BHT but not in HT. The only measures that were significantly related to follow-up BP in HT were two BP variability measures, SD and the range of variability (RV80: 90th minus 10th percentile), (initial 24-hour IAMB SD and follow-up BP, r = .42 to r = .52, P < .05 to P < .01; RV80 versus follow-up BP, r = .43 to r = .52, P < .05 to P < .01). Correlations of follow-up BP with postural BP were generally weaker than with casual BP or IAMB level. Linear stepwise regressions for SBP and DBP separately (including all IAMB variables) demonstrated that the best single predictor for follow-up BP was 24-hour IAMB SBP level, which explained 41% of follow-up NAMB SBP level variance (F = 52.6, P < .001). However, in a second analysis including casual values, casual SBP alone explained 44% of follow-up NAMB SBP variance (F = 62.5, P < .001), whereas IAMB SBP added only 4% (F = 5.5, P < .05). Predictions of follow-up DBP were always poorer. After 5 years, 70% of NT and 86% of HT were still in their initial classification group, but 67% of BHT had become hypertensive. In these new HT (n = 16), initial IAMB level correlated most strongly with follow-up NAMB level (24-hour SBP, r = .70, P < .01; 24-hour DBP, r = .55, P < .05). The only other significant demographic variable predicting future BP was change in weight over 5 years, which added 10% to the explanation of future casual SBP variance (F = 12.5, P = .0007) and 15% to casual DBP variance (F = 18.0, P = .0001); for NAMB, the percentages were lower. In logistic regression, those NT and BHT who became hypertensive (n = 22) had a 75% probability of becoming hypertensive if they gained 11.7 kg or more during 5 years (X2 = 4.5, P = .03). To conclude, BP tended to increase in all groups, especially in BHT, during follow-up. Nominal differences were observed between casual measurements and BP level measures in the prediction of future BP, and their explanatory value for future BP was generally less than 50%. However, for BHT who became hypertensive, BP level and variability measurements somewhat improved the prediction of follow-up BP. Weight gain was an important additional predictor for future hypertension in both NT and BHT.

The relevance of continuous blood pressure monitoring in examining the relationship of memory efficiency with blood pressure characteristics

The study of the relationship between hypertension and cognitive decline is characterized by various difficulties of realization and, as a consequence, by incongruent results. One of the reasons for these difficulties may be explained by the occasional method of measurement of blood pressure (once a day). This study presents the results obtained in 27 normotensive and mild hypertensive subjects of both sexes (ages between 20 and 77 years) with a continuous blood pressure monitoring for 24 h. A noninvasive sphygmomanometric technique was used employing a portable recorder programmed to take a measure every 30 min. Both objective and subjective measures of memory, measures of attention efficiency, and IQ were correlated to the blood pressure measures. Continuous monitoring data of blood pressure were analyzed according to a model that included a macroscopic descriptive analysis, a microscopic rhythmometric analysis, and a microscopic integrative analyses where the effects of the interaction between level and duration of excess and the time of the day when the excess eventually appeared were considered. Results evidenced no differences in cognitive efficiency between those subjects identified with the traditional occasional measurement of blood pressure as hypertensives of mild severity and the normal subjects. Cognitive efficiency of our subjects was found correlated, independently from the clinical diagnosis, with the time of peak and with the duration of excess of their blood pressure when the results of the analyses on the continuous monitoring of blood pressure were considered.

Association of body mass index and regional fat distribution with blood pressure investigated by 24-hour ambulatory blood pressure monitoring in android-type obese

In 46 female outpatients with android-type obesity, body mass index (BMI) 36.6 +/- 1.0, waist to hip ratio (WHR) > 0.86, and normal glucose tolerance (NGT) who were hypertensive at entry study [blood pressure (BP) > 140/90 mm Hg] and in 10 clinically healthy, nonobese, normotensive women, we evaluated the relationship between BMI, fat mass, WHR, fasting blood glucose, sum of blood glucose levels during oral glucose tolerance test and casual BP levels, 24-h ambulatory BP monitoring (ABP) parameters as the 24-hour mean, day-time mean, night-time mean and, by using a periodic model of cosine regression, MESOR (midline estimating statistic of rhythm), amplitude, acrophase, and baric impact. In android obese women, a negative correlation between ABP levels (day-/night-time, MESOR, and baric impact of systolic BP; night-time and MESOR of diastolic BP) and BMI has been documented. A positive correlation between systolic BP (casual, night-time mean, MESOR, amplitude, and baric impact), diastolic baric impact, and the WHR has been found. No correlation has been demonstrated between ABP monitoring parameters, and BMI, body fat, and WHR in the control group. Our data could suggest that, when enrolling obese subjects, it must be taken into account that obesity is a heterogeneous disorder. There are in fact obese subjects with normal or impaired glucose tolerance, as well as diabetics with moderate to severe obesity and with gynecoid or android-type obesity. In our android obese subjects with NGT, the WHR rather than the BMI was found to be a better predictor of hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Latent overhydration and nocturnal hypertension in diabetic nephropathy

With the aim of studying the diurnal variation in blood pressure in relation to degree of fluid retention, 24-h ambulatory blood pressure monitoring was performed in 31 insulin-dependent diabetic patients with nephropathy. The extracellular volume was calculated from the distribution volume of 51Cr-EDTA after a single injection. The study population was arbitrarily divided into two groups, depending on their extracellular volume. Group 1 included 15 patients with a lower extracellular volume and group 2, 16 patients with a higher extracellular volume. Ambulatory blood pressure was measured with a portable monitor using an oscillometric technique. In all patients, the mean +/- SD 24-h ambulatory blood pressure was 135/79 +/- 14/7 mmHg. Day and night-time blood pressure were 136/81 +/- 14/7 and 133/75 +/- 17/8, respectively (p < 0.02). The ambulatory blood pressure was 135/80 +/- 14/7 in group 1 and 136/78 +/- 15/6 mmHg in group 2. The nocturnal change in blood pressure was significantly greater in group 1 than in group 2, -9/-9 +/- 10/5 mmHg and 1/-3 +/- 10/6 mmHg, respectively (p = 0.005/0.01). There were no other significant differences between the groups than the diurnal blood pressure pattern. There were significant correlations between day ambulatory blood pressure and night ambulatory blood pressure and 24-h ambulatory blood pressure and urinary albumin excretion. There was no correlation between ausculatatory clinic blood pressure on the one hand and albuminuria on the other. Latent fluid retention therefore may contribute to nocturnal hypertension in diabetic nephropathy.

Campodimele study: blood pressure and heart rate pattern in clinically healthy elderly subjects

Noninvasive ambulatory blood pressure (BP) monitoring is a developing method in clinical practice. Its interpretation needs reference standards stratified by age and gender. This study addresses ambulatory BP monitoring in elderly people with the purpose of quantifying the discrete and periodic variability of BP pattern over a 24-h period. The ABPM was performed in 92 clinically healthy subjects (45 men and 47 women) ranging in age from 76 to 102 years. The results refer to the time-qualified mean values with their dispersion, to the circadian rhythm with its parameters, and to the daily baric impact (BI) with its variability. The conclusion is drawn that BP preserves its nychtohemeral variability and circadian rhythmicity despite old age. The daily BP mean level and BI in older people in good health are comparable with those of young subjects, suggesting that humans surviving into old age are characterized by a eugenic control of their pressure regimen.

Pressor reactivity, ethnicity, and 24-hour ambulatory monitoring in children from hypertensive families

We assessed blood pressure responses of a multiethnic (Black and White) sample of 120 children of hypertensive families to orthostasis, video game, forehead cold, and dynamic exercise, and monitored the children's ambulatory pressure 24 hours later. Thirteen children were studied twice (1-year stability). The Black children exhibited higher 24-hour ambulatory systolic and diastolic pressures than the White children. Regardless of ethnicity, peak and mean systolic pressures during each task were generally positively correlated with mean systolic pressure while the children were awake and asleep. Associations between diastolic pressor responses and ambulatory measurements were somewhat dependent upon ethnicity and task. Relatively few reactivity-ambulatory correlations were significant, using pressor reactivity change scores. The children who participated twice exhibited significant 1-year stability for most ambulatory and pressor measurements. Children's pressor responses to laboratory tasks may generalize to the natural environment.

Stress and the heart. Mechanisms, measurement, and management

Unrelieved physical or mental stress and repeated episodic stress are ultimately harmful to the cardiovascular system and thus can be life-threatening. In this article, Dr Eliot describes efforts to quantify the psychophysiologic responses to stress and to identify the components of stress and its clinical consequences. He also explains the importance of controlling the real-life episodic fluctuations in blood pressure that occur daily in response to stress.

Effectiveness of antihypertensive medications in office and ambulatory settings: a placebo-controlled comparison of atenolol, metoprolol, chlorthalidone, verapamil, and an atenolol-chlorthalidone combination

In a double-blind, crossover study, five white men with mild-to-moderate hypertension received placebo and fixed doses of atenolol, metoprolol, chlorthalidone, verapamil, and the combination of atenolol and chlorthalidone in a quasi-random order. Daily dosages were: atenolol, 100 mg; metoprolol, 200 mg; chlorthalidone, 50 mg; verapamil, 240 mg; and the same doses of atenolol and chlorthalidone in combination. Standard office and daytime ambulatory blood pressures were assessed at the end of each month-long trial. Atenolol, metoprolol, chlorthalidone, and verapamil controlled office blood pressure with similar reductions. Verapamil did not lower ambulatory blood pressure at this dose (which is lower than is now commonly used), but reductions in ambulatory blood pressure were similar for atenolol, metoprolol, and chlorthalidone. The combination of atenolol and chlorthalidone maintained blood pressure control more effectively than the single drug treatments in both office and ambulatory settings, and the combined hypotensive effects were additive. However, reductions in the office due to the combination appeared to overestimate hypotensive effectiveness in the ambulatory setting. This study suggests that the effectiveness of commonly prescribed antihypertensive regimens varies according to setting as well as drug, and that assessment of treatment effectiveness can be improved by automated ambulatory blood pressure monitoring.

Utilizing ambulatory blood pressure recordings to evaluate antihypertensive drug therapy

Until recently, the efficacy and pharmacodynamics of antihypertensive agents were assessed by resting blood pressure measurements in the doctor's office or a research clinic. The limitations of the office or clinic blood pressure measurement include the lack of representation (from recording only 1 point of time in the dosing schedule), the effects of the doctor's office on the patient's blood pressure, and, perhaps more relevant, observer bias. Ambulatory monitoring of the blood pressure has gained worldwide acceptance as an alternative method to assess antihypertensive drug efficacy and the time-effect relation of a drug. The ambulatory monitoring devices have been refined and are smaller, more precise, and more reliable than earlier recording models. Although there are no reference standards for analysis of ambulatory blood pressure data, international consensus groups are presently addressing this problem. Key roles for ambulatory blood pressure recordings in clinical trials of antihypertensive agents now include determination of the entry criteria for patients, improving the assessment of peak/trough pharmacodynamics in the patient's own environment (including nocturnal/sleep readings), and evaluating efficacy through calculation of the hypertensive burden, or blood pressure load.

Therapeutic Issues in the Evaluation and Treatment of the Hypertensive Patient: White Coat Hypertension and Once Daily Dosing of Antihypertensive Agents

Pharmacists are an invaluable resource of drug and other treatment information for the primary provider because of their skills in drug literature evaluation and retrieval. The implementation of a home blood pressure monitoring program at the HMO of Delaware has allowed the establishment of excellent relations between medical, nursing, and pharmacy personnel and has allowed the pharmacist to become involved in the decision-making process for many hypertensive patients.

Ambulatory blood pressure monitoring for the assessment of nicardipine as a third drug in severe essential hypertension

The antihypertensive efficacy of sustained-release nicardipine compared to placebo as third-line therapy has been assessed by ambulatory blood pressure monitoring in severely hypertensive patients with clinically unsatisfactory blood pressure control on 50 mg hydrochlorothiazide o.d. and 75 mg captopril b.d. Forty-two patients, 31 m and 11 f, with supine diastolic blood pressure 95-115 mm Hg after a 4 week run-in period on open hydrochlorothiazide and captopril, were randomly allocated to sustained-release nicardipine 45-60 mg/d or placebo. At a visit to the clinic blood pressure and heart rate were measured 12 h after the evening dose by a trained observer unaware of the treatment. Twenty-four hour ambulatory monitoring was performed at the end of baseline and after 8 weeks of blinded medication. There was no significant change in BD at the visit or on ambulatory monitoring in the placebo treated patients. In contrast, nicardipine produced a significant reduction in both blood pressures without affecting heart rate. Nicardipine also decreased the mean 24-h blood pressure by 14/10 mm Hg in patients whose clinical hypertension had been confirmed by ambulatory blood pressure monitoring but by only 3/2 mm Hg in ambulant patients who were normotensive on two-drug therapy. One patient experienced an episode of severe symptomatic hypotension while on nicardipine. Otherwise, the numbers and percentages of patients from each group reporting adverse experiences were similar. It is concluded that nicardipine appears to be an effective antihypertensive agent when used as third line therapy with diuretics and angiotensin converting enzyme inhibitors in patients with severe hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)