Clinical Significance of Nocturnal Blood Pressure Monitoring

Although there are certain technical problems in determining nocturnal BP by ambulatory BP monitoring, the information provided on nocturnal BP has possible clinical significance. Short-term BP variability, an elevated BP during sleep and amplitude and sleep of nocturnal BP decline might be responsible for cardiovascular mortality. Furthermore, circadian BP variation might also be responsible for cardiovascular morbidity and mortality. The nocturnal BP level, even in extreme dippers with diurnal hypertension, is equivalent to or higher than that in normotensive subjects. Antihypertensive effects of drugs with different pharmacologic properties positively correlate with basal ambulatory BP. Therefore, there is a critical BP level at which the antihypertensive effect disappears. The critical BP level for each drug is in normal BP range but not in the hypotensive range. Therefore, an antihypertensive regimen would be safe even in extreme-dipper hypertension without excessive nocturnal hypotension, and might even be beneficial because of the decreasing amplitude and speed of the nocturnal BP decline. We conclude that an antihypertensive drug regimen should control BP throughout a 24-h period regardless of circadian BP variation.     

INSUFFICIENT DURATION OF ACTION OF ANTIHYPERTENSIVE DRUGS MEDIATES HIGH BLOOD PRESSURE IN THE MORNINGIN HYPERTENSIVE POPULATION:THE OHASAMA STUDY

Blood pressure (BP) usually peaks in the morning. The circadian variation of the onset of cardiovascular disease mimics this circadian BP variation. To examine the determinants of the BP difference between the self-recorded BP in the morning (home BP) and daytime average ambulatory BP a cross sectional study was done in the general population of Ohasama, Japan. 1207 subjects ≥20 years measured both home (more than 14 times) and ambulatory BPs (326 treated for hypertension and 881 untreated subjects). The prevalence of subjects with the systolic BP difference (home BP in the morning?daytime ambulatory BP) of ≥10?mmHg (high morning BP) was 5.6% in untreated normotensives, 2.9% in untreated hypertensives, and 25.8% in treated hypertensives. This trend was also observed for diastolic pressure. Multiple regression analysis demonstrated that age, male sex, and use of antihypertensive drugs were positively associated and day-night difference of BP was negatively associated with the high morning BP, respectively. These results suggest an insufficient duration of antihypertensive action of widely used antihypertensive drugs in Japan from the 1980s to 1990s. The amplitude of the day-night difference of ambulatory BP in subjects with a high morning BP was lower (non-dipping) than that without high morning BP. The high morning BP is not necessarily accompanied by hypertension but might be mediated, at least in part, by an insufficient duration of action of antihypertensive drugs. The high morning BP accompanies so-called non-dipper pattern of circadian BP variation. An insufficient duration of action of drugs may partly mediate non-dipping in subjects with antihypertensive medication.     

Insufficient duration of action of antihypertensive drugs mediates high blood pressure in the morning in hypertensive population: the Ohasama study

Blood pressure (BP) usually peaks in the morning. The circadian variation of the onset of cardiovascular disease mimics this circadian BP variation. To examine the determinants of the BP difference between the self-recorded BP in the morning (home BP) and daytime average ambulatory BP a cross sectional study was done in the general population of Ohasama, Japan. 1207 subjects > or = 20 years measured both home (more than 14 times) and ambulatory BPs (326 treated for hypertension and 881 untreated subjects), The prevalence of subjects with the systolic BP difference (home BP in the morning - daytime ambulatory BP) of > or = 10 mmHg (high morning BP) was 5.6% in untreated normotensives, 2.9% in untreated hypertensives, and 25.8% in treated hypertensives. This trend was also observed for diastolic pressure. Multiple regression analysis demonstrated that age, male sex, and use of antihypertensive drugs were positively associated and day-night difference of BP was negatively associated with the high morning BP, respectively. These results suggest an insufficient duration of antihypertensive action of widely used antihypertensive drugs in Japan from the 1980s to 1990s. The amplitude of the day-night difference of ambulatory BP in subjects with a high morning BP was lower (non-dipping) than that without high morning BP. The high morning BP is not necessarily accompanied by hypertension but might be mediated, at least in part, by an insufficient duration of action of antihypertensive drugs. The high morning BP accompanies so-called non-dipper pattern of circadian BP variation. An insufficient duration of action of drugs may partly mediate non-dipping in subjects with antihypertensive medication.     

Aldosterone synthase gene (CYP11B2) C-334T polymorphism, ambulatory blood pressure and nocturnal decline in blood pressure in the general Japanese population: the Ohasama Study.

OBJECTIVE: The C-344T polymorphism in the 5'-flanking region of the aldosterone synthase (CYP11B2) gene has been suggested to be associated with hypertension and disturbed circadian blood pressure (BP) rhythm through its effect on aldosterone synthesis. However, previous findings on this topic have been inconsistent. DESIGN: A cross-sectional study. SUBJECTS AND METHODS: We investigated the CYP11B2 C-344T genotype in 802 subjects, aged 40 and over, in a Japanese community, who gave written informed consent and were monitored for 24 h ambulatory BP. RESULTS: The frequencies of the CC, CT, and TT genotypes in these Japanese subjects were 0.14, 0.44, and 0.42, showing a higher frequency of the T allele (0.64) than in Caucasians. Although there was no significant difference in 24 h ambulatory BP levels among the genotypes, the nocturnal decline in BP was significantly greater in the CC homozygous subjects than in other subjects (P = 0.0065 for systolic and P = 0.031 for diastolic decline in nocturnal BP). Detailed analyses demonstrated that this association was significant only in aged (60 years and over) or male subjects. The prevalence of previous cardiovascular disease was significantly less in these subjects with the CC genotype than in those with the TC and TT genotypes, although age, body mass index, male gender, smoking, use of alcohol and antihypertensive medication did not differ among the three genotypes. There was no significant difference among the three genotypes in biochemical and hormonal parameters. CONCLUSION: Although the C-344 T polymorphism of CYP11B2 did not directly influence the level of 24 h BP, the CC genotype was associated with decreased nocturnal BP in elderly or male Japanese. Since prevalence of previous cardiovascular disease was significantly less in homozygous CC subjects, greater nocturnal BP decline in this genotype appears to be beneficial in the circadian BP rhythm.     

Nocturnal blood pressure and cardiovascular disease: a review of recent advances

The accurate measurement, prediction and treatment of high blood pressure (BP) are essential issues in the management of hypertension. Ambulatory blood pressure monitoring (ABPM) has been shown to be superior to clinic BP measurements as ABPM can provide the following important information: (i) the mean BP levels, (ii) the diurnal variation in BP and (iii) the short-term BP variability. Among these parameters, there is increasing evidence that the mean nocturnal BP level is the most sensitive predictor of cardiovascular morbidity and mortality. Furthermore, several studies have shown that less nocturnal BP dipping, defined as less nocturnal BP decline relative to daytime BP, or a high night-day BP ratio was associated with poor prognosis irrespective of the 24-hour BP levels. These findings can be interpreted in at least two ways: namely, high nocturnal BP or less nocturnal BP dipping might be not only a potent risk factor for cardiovascular disease (CVD), but also a marker of pre-existing or concurrent diseases that can lead to nocturnal BP elevation. In this review, we consider the clinical utility of ABPM and in particular focus on the nocturnal BP levels or nocturnal BP dipping as a potent risk factor for CVD. In addition, the clinical management of high nocturnal BP and blunted nocturnal BP dipping with antihypertensive medications is discussed.     

Role of ambulatory blood pressure monitoring for the management of hypertension in Asian populations

Out‐of‐clinic blood pressure (BP) measurement, eg, ambulatory BP monitoring, has a strong association with target organ damage and is a powerful predictor of cardiovascular events compared with clinic BP measurement. Ambulatory BP monitoring can detect masked hypertension or various BP parameters in addition to average 24‐hour BP level. Short‐term BP variability assessed by standard deviation or average real variability, diminished nocturnal BP fall, nocturnal hypertension, and morning BP surge assessed by ambulatory BP monitoring have all been associated with target organ damage and cardiovascular prognosis. Recently, the authors compared the degree of sleep‐trough morning BP surge between a group of Japanese and a group of Western European untreated patients with hypertension and found that sleep‐trough morning BP surge in Japanese persons was significantly higher than that in Europeans. Although Asian persons have been known to have a higher incidence of stroke than heart disease, the difference in characteristics of BP indices assessed by ambulatory BP monitoring might be the cause of racial differences in stroke incidence between Asian and Western populations. This review focuses on Asian characteristics for the management of hypertension using ambulatory BP monitoring.     

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.     

How well does ambulatory blood pressure predict target-organ disease and clinical outcome in patients with hypertension?

For many years, it has been evident that ambulatory blood pressure monitoring is superior to the measurement of office blood pressure as a predictor of target-organ involvement in patients with hypertension. Until recently, there were far fewer data on the relationship between 24 h ambulatory blood pressure and cardiovascular outcomes such as myocardial infarction, stroke, and cardiovascular death. In 1983, Perloff et al. published their seminal report on awake ambulatory blood pressure as a predictor of cardiovascular outcomes. During the 16 years that have passed since that publication, several additional prospective ambulatory blood pressure studies have been completed, in five different countries. The basis for all these investigations has been to assess the predictive value of ambulatory blood pressure as a determinant of either cardiovascular morbidity (myocardial infarction, cerebrovascular accidents, and vascular surgical procedures) or mortality. With the exception of the Systolic Hypertension in Europe (Syst-Eur) trial, all these studies have been uncontrolled for therapeutic interventions. Typically, the average follow-up period for each trial has been 3-9 years. All these studies have shown that ambulatory blood pressure is a much better predictor of cardiovascular events than the standard office or clinic pressure. In addition, hypertensive patients whose nocturnal (or sleep) blood pressure remains high (that is, those who have a 'non-dipper' circadian blood pressure profile) have a worse outcome than patients whose nocturnal blood pressure decline is at least 10%. These data all support the desirability of increased utilization of 24 h ambulatory blood pressure monitoring in clinical trials of antihypertensive drugs and in the management of hypertensive patients in clinical practice.     

Factors That Affect Blood Pressure Variability: A Community-Based Study in Ohasama,Japan

Factors that affect blood pressure (BP) variability, ie, standard deviation (SD) and variation coefficient (VC: SD/average ambulatory BP) of ambulatory BP, were examined in a community-based sample in northeastern Japan. Screening and ambulatory BPs were measured in 823 subjects ≥20 years of age, and the effects of age and BP on the SD and the VC were examined. In bivariate regression analysis, the SD of ambulatory BP was positively correlated with age and the ambulatory BP. The VC was also correlated with age. Both the SD and the VC were strongly correlated with the magnitude of the nocturnal decline in BP. Ambulatory BP was positively correlated with age and negatively correlated with heart rate and the SD of heart rate. Multivariate analysis demonstrated that the nocturnal decline in BP showed the strongest association with the SD and the VC of 24-h BP. However, age and BP were still independently and positively associated with the SD and the VC of ambulatory BP. Furthermore, pulse pressure and BMI were independently and positively associated with the SD and the VC of ambulatory BP. Since the SD and the VC of 24-h ambulatory BP were determined mainly by the nocturnal decline in BP, this variable appears to be an index of the circadian variation in BP and not an index of short-term BP variability. Pulse pressure, an index of arterial stiffness, was a relatively strong predictor of the SD and the VC of BP. In addition, the SD of heart rate, an index of baroreflex function, decreased with increasing age. Findings suggest that the increase in BP variability in hypertensive and elderly subjects may be explained, in part, by a disturbance of baroreflex function associated with an increase in arterial stiffness due to aging and hypertension.     

Masked nocturnal hypertension and target organ damage in hypertensives with well-controlled self-measured home blood pressure.

It has been reported that masked hypertension, a state in which patients show normal clinic blood pressure (BP) but elevated out-of-clinic BP by self-measured home BP, is a predictor of cardiovascular morbidity much like sustained hypertension. In addition, nocturnal BP is closely associated with cardiovascular disease. This might mean that ambulatory and self-measured home BP monitoring each provide independent information. We performed ambulatory BP monitoring, self-measured home BP monitoring, echocardiography and carotid ultrasonography in 165 community-dwelling subjects. We subclassified the patients according to the ambulatory and self-measured home BP levels as follows: in the masked nocturnal hypertension group, the self-measured home BP level was <135/85 mmHg and the ambulatory nocturnal BP level was >or=120/75 mmHg; in the normotensive group, the self-measured home BP level was <135/85 mmHg and the ambulatory nocturnal BP level was <120/75 mmHg. The intima-media thickness (IMT) and relative wall thickness (RWT) were greater in the masked nocturnal hypertension group than in the normotensive group (IMT: 0.76+/-0.20 vs. 0.64+/-0.14 mm, p<0.05; RWT: 0.50+/-0.14 vs. 0.41+/-0.10, p<0.05). Even in hypertensives with well-controlled self-measured home BP, elevated ambulatory nocturnal BP might promote target organ damage. We must rule out masked hypertension using self-measured home BP monitoring, and we might also need to rule out nocturnal masked hypertension using ambulatory BP monitoring.     

Quantitative analysis of the 24-hour blood pressure and heart rate patterns in young men

To characterize the normal nycterohemeral blood pressure and heart rate profiles and to delineate the relative roles of sleep and circadian rhythmicity, we performed 24-hour ambulatory blood pressure monitoring with simultaneous polygraphic sleep recording in 31 healthy young men investigated in a standardized physical and social environment. Electroencephalographic sleep recordings were performed during 4 consecutive nights. Blood pressure and heart rate were measured every 10 minutes for 24 hours starting in the morning preceding the fourth night of recording. Sleep quality was not significantly altered by ambulatory blood pressure monitoring. A best-fit curve based on the periodogram method was used to quantify changes in blood pressure and heart rate over the 24-hour cycle. The typical blood pressure and heart rate patterns were bimodal with a morning acrophase (around 10:00 AM), a small afternoon nadir (around 3:00 PM), an evening acrophase (around 8:00 PM), and a profound nocturnal nadir (around 3:00 AM). The amplitude of the nycterohemeral variations was largest for heart rate, intermediate for diastolic blood pressure, and smallest for systolic blood pressure (respectively, 19.9%, 14.1%, and 10.9% of the 24-hour mean). Before awakening, a significant increase in blood pressure and heart rate was already present. Recumbency and sleep accounted for 65-75% of the nocturnal decline in blood pressure, but it explained only 50% of the nocturnal decline in heart rate. Thus, the combined effects of postural changes and the wake-sleep transition are the major factors responsible for the 24-hour rhythm in blood pressure. In contrast, the 24-hour rhythm of heart rate may reflect an endogenous circadian rhythm, amplified by the effect of sleep. We conclude that modulatory factors different from those controlling nycterohemeral changes in blood pressure influence the 24-hour variation in heart rate.     

Prognostic significance of ambulatory blood pressure.

Measurements of ambulatory blood pressure as an adjunct to casual/clinic blood pressure measurements are currently widely used for the diagnosis and treatment of hypertension. There have been many recent reports on the clinical significance of ambulatory blood pressure. The relationship between ambulatory blood pressure level and target-organ damage uniformly demonstrated on a cross-sectional basis that average ambulatory blood pressure is correlated to target-organ damage. The main limitation of cross-sectional studies, however, is the difficulty of drawing inferences about causality from them. We have been monitoring the prognosis of the Ohasama population and reported that ambulatory blood pressure is superior to casual blood pressure for the prediction of mortality. We also observed that the daytime ambulatory blood pressure is a better predictor for cardiovascular mortality in the general population than is the night-time ambulatory blood pressure. It is widely recognized that casual/clinic blood pressure is less representative of the true blood pressure level than is average ambulatory blood pressure. One reason that clinic blood pressure is a poor predictor of prognosis is that clinic blood pressure includes several biases, including the white-coat effect. For determining white-coat hypertension, measurement of blood pressure in a non-medical setting such as ambulatory blood pressure monitoring is indispensable. We examined the prognostic significance for mortality of white-coat hypertension and reversed white-coat hypertension (clinic blood pressure 相似文献   

Ambulatory blood pressure as a predictor of target organ disease and outcome in the hypertensive patient.

Since the early 1980s, when Perloff and colleagues published their seminal report on awake ambulatory blood pressure as a predictor of cardiovascular outcomes, there have been several additional prospective ambulatory blood pressure studies that have been completed in five different countries. The basis for all of these investigations was to assess the predictive value of ambulatory blood pressure as a determinant of either cardiovascular morbidity (typically myocardial infarction, cerebrovascular accidents, and vascular surgical procedures) or mortality. With the exception of Syst-Eur, all of these studies have been uncontrolled for therapeutic interventions. Typically, the average follow-up period for each trial has been three to nine years. Despite these limitations, all of the studies have shown that ambulatory blood pressure is a far better predictor of cardiovascular events than the standard office or clinic blood pressure. Furthermore, the hypertensive patients whose nocturnal (or sleep) blood pressure remains high (i.e. non-dipper circadian blood pressure profile) have a much worse outcome compared with patients whose nocturnal blood pressure decline is over 10%.     

Angiotensin-converting enzyme I/D polymorphism and hypertension: the Ohasama study

OBJECTIVE : Angiotensin-converting enzyme (ACE) I/D polymorphism in intron 16 of the ACE gene was analyzed in a general Japanese population in relation to self-blood pressure (BP) measurement at home (home BP) and ambulatory BP monitoring (ABPM) to determine the association between genetic variants of this polymorphism and hypertension. DESIGN : A cross-sectional study. METHODS AND RESULTS : We genotyped the ACE I/D polymorphism in 1245 subjects with home BP and 803 subjects with ABPM in Ohasama, a rural community in Japan. All the subjects were 40 years of age and over, and gave written informed consent for the present genetic analysis. Hypertensive subjects were defined as those receiving antihypertensive drugs and those who had a home BP higher than 135 mmHg in systole and/or higher than 85 mmHg in diastole. The frequencies of the II, ID, and DD genotypes in these Japanese subjects were 0.45, 0.45, and 0.10, indicating a lower frequency of the D allele (0.33) than in Caucasians. There was no significant difference of BP level, prevalence of hypertension or nocturnal decline in BP among the genotypes. There were no differences in the prevalence of previous cardiovascular disease, age, body mass index, male gender, smoking, or biochemical and hormonal parameters among the three genotypes. CONCLUSION : The present results indicate the absence of direct effects of the ACE D-allele on BP level, prevalence of hypertension, prevalence of cardiovascular disease, and circadian BP variation. We conclude there is little association between ACE I/D polymorphism and hypertension in the general Japanese population.     

Variations in 7‐day/24‐h circadian pattern of ambulatory blood pressure and heart rate of type 2 diabetes patients

Aims/Introduction

Diabetes has profound consequences on the cardiovascular system leading to cardiovascular morbidity and mortality in diabetic patients. Blood pressure (BP) has a characteristic and reproducible circadian pattern, with high values during the day and low values at night. A 7-day timed analysis of BP through ambulatory blood pressure monitoring has been used not only to diagnose day and night dipping patterns of blood pressure, but also to measure day-to-day variability and the circadian hyper-amplitude-tension, a condition in which excessive circadian BP amplitude precedes the chronic established hypertension. Our objective was to assess the 7-day/24-h circadian pattern of BP and heart rate in diabetic patients, as it could be helpful in the diagnosis and prevention of cardiovascular morbidity.

Materials and Methods

A total of 50 diabetic patients with type 2 diabetes and 50 non-diabetic participants were recruited for the study. General health records were individually maintained, and 7-day/24-h ambulatory blood pressure monitoring using an ambulatory blood pressure monitor was carried out.

Results

The rhythmic parameters of systolic and diastolic BP, heart rate, double amplitude, acrophase and 3-h fractionated hyperbaric index were found to be significantly high in diabetic patients. A total of 12 participants were diagnosed with circadian hyper-amplitude-tension. These data suggest that diabetic patients have certain variations in the circadian pattern of blood pressure and heart rate, which can result in disturbed vascular events, and thus are at greater risk of cardiovascular morbidity.

Conclusion

Seven-day/24-h monitoring might be useful as an early predictive tool in assessing future cardiovascular risk, guiding treatment and management of these patients.     

Blood Pressure Variability and Autonomic Dysfunction

Purpose of Review

This review considers the relationship between abnormal blood pressure (BP) variability and autonomic dysfunction through an attempt to answer questions about its clinical relevance and pertinence to diabetes and cardiovascular autonomic neuropathy (CAN) and which therapeutic measures can lessen its cardiovascular impact.

Recent Findings

Office, ambulatory, and home BP monitoring identify posture-related, circadian, short-term, and long-term BP variabilities. Abnormal BP variability is a risk marker for organ damage, mortality, and cardiovascular events. Moreover, BP variability changes are common in diabetes and associated with CAN and possibly exacerbated by comorbidities like nephropathy, obstructive sleep apnoea syndrome, and chronic pain. The prognostic role of nondipping and reverse dipping is well documented in diabetes. Some findings suggest the possibility of restoring dipping with the dosage time of antihypertensive agents.

Summary

Diabetes is a favorable scenario for altered BP variability, which might mediate the harmful effects of CAN. Preliminary data suggest the protective effect of targeting BP variability. However, further longitudinal outcome studies are needed. In the meantime, BP variability measures and practical expedients in antihypertensive treatment should be implemented in diabetes.

     

Nighttime Blood Pressure: A Target for Therapy?

Ambulatory blood pressure (BP) monitoring is increasingly used in the evaluation of hypertensive patients. The ability to monitor BP throughout the day and night allows the detection of abnormal nocturnal BP patterns, the most common being a “nondipping” pattern, which is associated with increased cardiovascular risk; its correction appears to have a positive impact on cardiovascular outcome. Antihypertensive treatment should be individually adjusted to control BP during both daytime and nighttime. However, drug-induced lowering of nocturnal BP, if excessive, could amplify the morning BP surge in patients with daytime BP elevation, increasing the risk of developing a cardiovascular event. Ambulatory BP monitoring therefore represents a unique tool to establish the most appropriate antihypertensive drug regimen for the individual patient.     

Prognostic significance for stroke of a morning pressor surge and a nocturnal blood pressure decline: the Ohasama study

There is continuing controversy over whether the pattern of circadian blood pressure (BP) variation that includes a nocturnal decline in BP and a morning pressor surge has prognostic significance for stroke risk. In this study, we followed the incidence of stroke in 1430 subjects aged > or =40 years in Ohasama, Japan, for an average of 10.4 years. The association between stroke risk and the pattern of circadian BP variation was analyzed with a Cox proportional hazards model after adjustment for possible confounding factors. There was no significant association between total stroke risk and the nocturnal decline in BP (percentage decline from diurnal level) or between total stroke risk and the morning pressor surge. The cerebral infarction risk was significantly higher in subjects with a <10% nocturnal decline in BP as compared with subjects who had a > or =10% nocturnal decline in BP (P=0.04). The morning pressor surge was not associated with a risk of cerebral infarction. On the other hand, an increased risk of cerebral hemorrhage was observed in subjects with a large morning pressor surge (> or =25 mm Hg; P=0.04). Intracerebral hemorrhage was also observed more frequently in extreme dippers (those with a > or =20% nocturnal decline in BP) than dippers (those with a 10% to 19% decline; P=0.02). A disturbed nocturnal decline in BP is associated with cerebral infarction, whereas a large morning pressor surge and a large nocturnal decline in BP, which are analogous to a large diurnal increase in BP, are both associated with cerebral hemorrhage.     

Relation Between Nocturnal Decline in Blood Pressure and Mortality: The Ohasama Study

To investigate the relation between nocturnal decline in blood pressure and mortality, we obtained ambulatory blood pressures in 1542 residents aged 40 years or over of a rural Japanese community. Subjects were followed-up for a mean of 5.1 years and were then subdivided into four groups according to the percent decline in nocturnal blood pressure: 1) extreme dippers: percent decline in nocturnal blood pressure ≥ 20% of the daytime blood pressure; 2) dippers: decline of ≥ 10% but < 20%; 3) nondippers: decline of ≥ 0% but < 10%; and 4) inverted dippers: no decline. The relationship between the decline in nocturnal blood pressure and mortality was examined by the Cox proportional hazards regression model adjusted for age, sex, smoking status, previous history of cardiovascular disease, and the use of antihypertensive medication. The mortality risk was highest in inverted dippers, followed by nondippers. There was no difference in mortality between extreme dippers and dippers. This relationship was observed for both treated and untreated subjects, was more pronounced for cardiovascular than for noncardiovascular mortality, and did not change after the data were adjusted for 24-h, daytime, and nighttime blood pressure levels.     

Office and ambulatory blood pressure control in hypertensive patients treated with different two-drug and three-drug combinations

There is scarce information regarding ambulatory blood pressure (BP) achieved in daily practice with a wide range of antihypertensive drug combinations. We looked for differences in office and ambulatory BP among major drug combinations of two and three antihypertensive agents from a different drugs class. A total of 17187 patients treated with six types of two-drug combinations and 9724 treated with six types of three-drug combinations from the Spanish ABPM Registry were analyzed. We compared achieved office and ambulatory BP, as well as office (< 140/90 mmHg) and ambulatory (24-hour BP < 130/80; day BP < 135/85, and night BP < 120/70 mmHg) BP control among groups. The combination of renin-angiotensin system (RAS) blockers with diuretics and the triple combination of RAS blockers with diuretics and calcium channel blockers (CCB) were associated with lower values of 24-hour, daytime and nighttime BP, as well as more pronounced nocturnal BP dip. Compared with such combinations (reference), other double combinations had lower rates of ambulatory BP control. Moreover, triple combinations containing alpha blockers also had lower rates of ambulatory BP control. We conclude that even with similar office BP control, differences exist among antihypertensive two-drug and three-drug combinations with respect to ambulatory BP control achieved during treatment, with RAS blockers/diuretics and RAS blockers/CCBs/diuretics obtaining better control rates. This can help physicians choose among drug combinations in order to obtain further ambulatory BP reductions.