Ambulatory blood pressure monitoring in elderly hypertensive patients

Ambulatory blood pressure monitoring in elderly persons provides the clinician with the opportunity to determine blood pressure outside the office more accurately. Recent technologic developments in the recorders have greatly improved the feasibility of their use and the accuracy of their recordings. Correlations of the blood pressures obtained by ambulatory blood pressure recorders with standard mercury sphygmomanometers indicate that the measurements are accurate and may improve the assessment of risks related to hypertensive cardiovascular diseases. Clinicians should be aware of the applications of ambulatory blood pressure monitoring and alert to situations in which it can be useful in clinical decision making.     

Captopril improves impaired endothelium-dependent vasodilation in hypertensive patients.

Animal studies suggest that some angiotensin converting enzyme inhibitors augment endothelium-dependent vasorelaxation. We aimed to determine if captopril augments endothelium-dependent vasodilation in middle-aged hypertensive patients. By using strain-gauge plethysmography, forearm vasodilation evoked with intra-arterial acetylcholine (4, 8, 16, and 24 micrograms/min) or nitroprusside (0.2, 0.4, 0.8, and 1.2 micrograms/min) was examined before and after captopril administration (25 mg per os). Before captopril, forearm vasodilation with acetylcholine was less in hypertensive patients (n = 12) than in age-matched (n = 7) or young (n = 7) normotensive subjects, but forearm vasodilation with nitroprusside did not differ among the three groups. Captopril improved forearm vasodilation in hypertensive patients (n = 7) with acetylcholine but nitroprusside did not. In contrast, nifedipine (10 mg per os) did not alter forearm vasodilation with acetylcholine or nitroprusside in hypertensive patients (n = 5). The decreases in mean blood pressure caused by captopril and nifedipine in hypertensive subjects were comparable. Captopril did not alter forearm vasodilation with acetylcholine or nitroprusside in young normotensive subjects (n = 7). These results suggest that captopril in hypertensive patients may acutely improve impaired endothelium-dependent forearm vasodilation that does not result from reduction in blood pressure per se.     

原发性高血压合并脑微出血患者动态血压特征

目的 对原发性高血压（高血压）患者合并脑微出血的动态血压特征进行探讨.方法 选取80例高血压患者作为研究对象,并将其中有脑微出血的42例患者列为观察组,未合并有脑微出血的38例患者列为对照组.对两组患者的动态血压值进行观察和比较.结果 两组收缩压、舒张压比较,差异无统计学意义（P＞0.05）.两组的随测血压值均比24动态血压监测（ABMP）值高,差异有统计学意义（P＜0.05）.观察组的收缩压夜间下降率、舒张压夜间下降率均低于对照组,差异有统计学意义（P＜0.05）.结论 高血压患者的血压在夜间降低是引发脑微出血相关因素,因此在临床治疗期间,需对血压的动态节律变化加以注意.     

Ambulatory blood pressure monitoring in hypertensive adolescents

The purpose of this study was to determine the ability of ambulatory blood pressure monitoring to identify youths with chronic blood pressure elevation. Nineteen adolescent boys were studied, ten had 5-year average systolic or diastolic pressures above the 95th percentile, nine had normal pressure. A Del Mar Avionics Pressurometer III system recorded an average of 121 readings on each subject. The coefficients of variation for pressure were similar for hypertensive and normotensive individuals. During classes, eight of the ten hypertensive youths had elevated pressures in over half of the measurements. Also during these classes eight of ten hypertensive boys had average systolic or diastolic pressure above the 95th percentile, whereas only one of nine normotensive boys had average pressures above this level. We suggest that schooltime ambulatory pressures may be most useful in classifying the blood pressure trend in a youth.     

Ambulatory blood pressure variability and brachial-ankle pulse wave velocity in untreated hypertensive patients

Blood pressure (BP) variability is estimated as the standard deviation of 24-h ambulatory BP. The present study was performed to determine the effect of the mean 24-h ambulatory BP values and standard deviations on arterial wall stiffness assessed by brachial-ankle pulse wave velocity (baPWV). Brachial-ankle pulse wave velocity, carotid intima-media thickness (IMT), urinary albumin excretion (UAE) and 24-h ambulatory BP were measured before the start of antihypertensive therapy in 203 newly diagnosed hypertensive patients (53.3+/-0.7 years old; clinic systolic/diastolic BP: 154+/-1/98+/-1 mm Hg), and univariate and multivariate regression analyses of these clinical and biological parameters were performed. Univariate regression analyses revealed a significant association between mean baPWV values and the standard deviations of ambulatory systolic/diastolic BP. Mean ambulatory systolic/diastolic BP values were also associated with UAE, and the standard deviations of ambulatory systolic BP were associated with maximum carotid IMT. Quintile analyses showed that patients with a mean 24-h ambulatory mean BP value and standard deviation below 110 and 20 mm Hg, respectively, had the lowest baPWV. Moreover, the multivariate regression analyses confirmed a significant correlation between baPWV and the standard deviation of 24-h ambulatory systolic BP. In conclusion, untreated hypertensive patients with a higher 24-h ambulatory systolic BP variability had stiffer arterial walls. Ambulatory systolic BP variability may be involved in stiffening of the arteries of hypertensive patients.     

Cocoa reduces blood pressure and insulin resistance and improves endothelium-dependent vasodilation in hypertensives

Consumption of flavanol-rich dark chocolate (DC) has been shown to decrease blood pressure (BP) and insulin resistance in healthy subjects, suggesting similar benefits in patients with essential hypertension (EH). Therefore, we tested the effect of DC on 24-hour ambulatory BP, flow-mediated dilation (FMD), and oral glucose tolerance tests (OGTTs) in patients with EH. After a 7-day chocolate-free run-in phase, 20 never-treated, grade I patients with EH (10 males; 43.7+/-7.8 years) were randomized to receive either 100 g per day DC (containing 88 mg flavanols) or 90 g per day flavanol-free white chocolate (WC) in an isocaloric manner for 15 days. After a second 7-day chocolate-free period, patients were crossed over to the other treatment. Noninvasive 24-hour ambulatory BP, FMD, OGTT, serum cholesterol, and markers of vascular inflammation were evaluated at the end of each treatment. The homeostasis model assessment of insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), and insulin sensitivity index (ISI) were calculated from OGTT values. Ambulatory BP decreased after DC (24-hour systolic BP -11.9+/-7.7 mm Hg, P<0.0001; 24-hour diastolic BP -8.5+/-5.0 mm Hg, P<0.0001) but not WC. DC but not WC decreased HOMA-IR (P<0.0001), but it improved QUICKI, ISI, and FMD. DC also decreased serum LDL cholesterol (from 3.4+/-0.5 to 3.0+/-0.6 mmol/L; P<0.05). In summary, DC decreased BP and serum LDL cholesterol, improved FMD, and ameliorated insulin sensitivity in hypertensives. These results suggest that, while balancing total calorie intake, flavanols from cocoa products may provide some cardiovascular benefit if included as part of a healthy diet for patients with EH.     

Ambulatory blood pressure monitoring and hypertensive target-organ damage in children

In contrast to the large number of studies relating high blood pressure to morbidity and mortality in adulthood, relatively few studies evaluating outcomes of children with hypertension have been conducted. Results of recent studies evaluating hypertensive target-organ injury in childhood suggest that early abnormalities, including left ventricular hypertrophy, glomerular hyperfiltration, and retinopathy, occur more commonly than had formerly been believed, and in children with mild elevations of blood pressure. Ambulatory blood pressure monitoring may be an important tool for use in evaluating hypertensive target organ damage in children and adolescents.     

Ambulatory blood pressure recording to identify hypertensive patients who truly need therapy

Ambulatory blood pressure profiles were obtained with the Remler system, a portable semi-automatic blood pressure recorder, in 245 untreated patients considered by their physician to be hypertensive. The average blood pressures recorded during the usual daily activities of the patients were > 140 mmHg for the systolic and > 89 mmHg for the diastolic in only 96 (39%) and 107 (44%) of them respectively. Blood pressure monitoring in ambulatory patients appears to be useful for the practitioner to detect those patients who require antihypertensive therapy. Possibly, unnecessary therapy of only seemingly hypertensive patients may be avoided by this technique.     

Calcium antagonist isradipine improves abnormal endothelium-dependent vasodilation in never treated hypertensive patients.

OBJECTIVE: To examine whether middle (two months) and long-term (six months) isradipine sustained-release treatment improves endothelium-dependent vasodilation in never treated hypertensive patients. METHODS: The responses of the forearm vasculature to acetylcholine (7.5, 15 and 30 micrograms/min) and sodium nitroprusside (0.8, 1.6, 3.2 micrograms/min) were evaluated in 12 normotensive controls (seven men and five women, aged 25 to 49 years), and in 12 hypertensives (eight men and four women, aged 20 to 47 years) at baseline and after two and six months of isradipine sustained-release treatment. Drugs were infused into the brachial artery, and forearm blood flow was measured by strain-gauge plethysmography. RESULTS: At baseline, the response to acetylcholine was significantly lower in hypertensives vs controls: at the highest dose (30 micrograms/min), forearm blood flow was 28.6 +/- 2.4 ml/100 ml of tissue per min in the controls vs 8.9 +/- 1.0 ml/100 ml of tissue per min in hypertensive (p < 0.0001). Similarly, vascular resistance was significantly (p < 0.0001) higher in hypertensives: 4.8 +/- 0.5 units (controls) vs 15.1 +/- 1.7 units (hypertensives). After isradipine treatment, the forearm blood flow in hypertensive patients changed from 8.9 +/- 1.0 ml/100 ml of tissue per min to 16.0 +/- 1.2 ml/100 ml of tissue per min (two months; p < 0.0001) and 15.2 +/- 1.4 ml/100 ml of tissue per min (six months; p < 0.0001). Isradipine treatment did not modify the vasodilating effect of sodium nitroprusside. CONCLUSIONS: Our data demonstrate for the first time that the calcium antagonist isradipine improves acetylcholine-induced vasodilation in hypertensives.     

Ambulatory blood pressure characteristics in normotensive and treated hypertensive older people

The objective of this study was to determine the normal values and characteristics of 24-h ambulatory blood pressure (ABP) and to describe the ABP level of treated hypertensive subjects in an older Finnish population. ABP was measured in 502 randomly selected subjects aged 64 years or over living in a Finnish municipality (mean age 70 years, range 64-87 years). A total of 211 subjects did not have blood pressure (BP) affecting medication. ABP measurements were taken every 30 min for 24 h, and the day- and night-time periods were diary-based. The results were that in untreated subjects, the average office BP was 134/82 +/- 16/9 (s.d.) mm Hg for men and 140/81 +/- 18/8 mm Hg for women. The 24-h average BP was 120/75 +/- 14/8 mm Hg (95th percentile upper limit 145/93 mm Hg) for men and 125/75 +/- 15/7 (95th = 154/89 mm Hg) for women. The daytime averages were 127/78 +/- 12/7 mm Hg (95th = 154/99 mm Hg) and 131/78 +/- 15/7 mm Hg (95th = 158/91 mm Hg) for men and women, respectively. The ABP daytime value of 130/83 mm Hg corresponded best to the office BP value of 140/90 mm Hg. All BP values were significantly higher in the treated hypertensive group compared to the normotensive group. Night-time BP was markedly lower than daytime BP, and no difference in circadian variability was found between the normotensive and hypertensive subjects. Both office and ambulatory BPs were significantly higher in women than in men. This study provides sex-specific normal values for ABP in a 64 to 87-year-old age group. The normal values of ABP were markedly lower than the office BP values. Hypertensives, even when treated, tended to have elevated values.     

Ambulatory blood pressure variation and plasma renin activity in hypertensive women

OBJECTIVE: To examine and compare the relationships between the level of plasma renin activity (PRA) and ambulatory blood pressure variability for hypertensive women aged under 45 years (n = 72, aged 36 +/- 6 years) and for women aged over 50 years (n = 175, aged 61 +/- 8 years). METHODS: The 247 white women studied were a nonrandom subset of a larger cohort of patients being assessed to determine the prognostic significance of ambulatory blood pressure measurements. The average awake ambulatory blood pressures (a minimum of 30 readings during at least 8 h), their SD and the coefficient of variation of the awake ambulatory blood pressures (awake SD/average awake blood pressure) of the women were examined by age group and three levels of PRA (less than 1.0, 1.0-4.0, and greater than 4.0 ng/ml per h) using two-way analysis of variance. The PRA was determined at the time of ambulatory monitoring. RESULTS: For the women aged 50 years and older, the average awake diastolic blood pressure was higher among women who had PRA greater than 4.0 ng/ml per h than it was among women who had PRA less than 1.0 ng/ml per h (P < 0.05). The average awake systolic blood pressure and systolic blood pressure variability were greater among women aged over 50 years than they were among women aged 45 years (P < 0.05). There were no significant relationships between the ambulatory blood pressure variability and the PRA, although the systolic blood pressure variability tended to be associated with the PRA among women aged under 45 years. These results contrasted sharply to previously reported findings among men, for whom there was an inverse relationship between the blood pressure and the PRA, particularly among those aged over 45 years, and a powerful positive association between measures of the awake ambulatory diastolic pressure variability and the PRA, again among older men. CONCLUSION: There seems to be a sex difference between hypertensive men and women in the relationship between the PRA and the ambulatory blood pressure variability. This difference might be related to factors associated with the menstrual cycle of women, although other biologic and behavioral influences may also play a role.     

Ambulatory blood pressure and left ventricular mass index in hypertensive children

To determine whether ambulatory blood pressure is more predictive of left ventricular hypertrophy than is casual blood pressure in hypertensive children, echocardiography and ambulatory blood pressure data from 37 untreated hypertensive children were analyzed. Left ventricular mass was calculated using the Devereux equation, left ventricular mass index was calculated as left ventricular mass (in grams)/height(2.7) (in meters), and left ventricular hypertrophy was defined as left ventricular mass index >51 g/m(2.7). Average blood pressure, blood pressure load, and blood pressure index (average blood pressure divided by pediatric ambulatory blood pressure 95th percentile) were calculated. Left ventricular mass index was strongly correlated with 24-hour systolic blood pressure index (r=0.43, P=0.008) and was also correlated with 24-hour systolic blood pressure (r=0.34, P=0.037), 24-hour systolic blood pressure load (r=0.38, P=0.020), wake systolic blood pressure load (r=0.37, P=0.025), sleep systolic blood pressure (r=0.33, P=0.048), and sleep systolic blood pressure load (r=0.38, P=0.021). Left ventricular mass index did not correlate with age, weight, clinic blood pressure, or ambulatory diastolic blood pressure. The overall prevalence of left ventricular hypertrophy was 27%. The prevalence of left ventricular hypertrophy was 47% (8 of 17) in patients with both systolic blood pressure load >50% and 24-hour systolic blood pressure index >1.0, compared with 10% (2 of 20) in patients without both criteria (P=0.015). These data suggest ambulatory blood pressure monitoring may be useful for the clinical assessment of hypertensive children by identifying those at high risk for the presence of end organ injury.     

Ambulatory blood pressure, target organ damage and aortic root size in never-treated essential hypertensive patients

The relationship between ambulatory blood pressure (ABP), target organ damage (TOD) and aortic root (AR) size in human hypertension has not been fully explored to date. We investigated the relationship between ABP, different markers of TOD and AR size in never-treated essential hypertensive patients. A total of 519 grade 1 and 2 hypertensive patients (mean age 46+/-12 years) referred for the first time to our outpatient clinic underwent the following procedures: (1) routine examination, (2) 24 h urine collection for microalbuminuria (MA), (3) ambulatory blood pressure monitoring over two 24 h periods within 4 weeks, (4) echocardiography and (5) carotid ultrasonography. AR dilatation was defined by sex-specific criteria (> or =40 mm in men and > or =37 mm in women). AR diameter was increased in 3.7% of patients. Demographic variables (body mass index, age and male gender), average night-time diastolic blood pressure (BP) (but not clinic or average 48 h BP), left ventricular mass index and carotid intima-media (IM) thickness showed an independent association with AR size in both univariate and multivariate analyses. When TOD data were analysed in a categorical way, a stepwise increase in the prevalence of left ventricular hypertrophy (LVH) (I=17.5%, II=27.6%, III=35.8%) and carotid IM thickening (I=20.9%, II=28.8%, III=34.4%), but not in MA (I=6.8%, II=9.1%, III=8.7%) was found with the progression of AR size tertiles. Our results show that (1) AR enlargement in uncomplicated never-treated hypertensive patients has a markedly lower prevalence than traditional markers of cardiac and extracardiac TOD; (2) night-time BP, LVH and carotid IM thickening are independent predictors of AR dimension.     

Ambulatory blood pressure and risk of new‐onset atrial fibrillation in treated hypertensive patients

The aim of this study was to evaluate the influence of clinic and ambulatory blood pressure (BP) on the occurrence of new‐onset atrial fibrillation (AF) in treated hypertensive patients. We studied 2135 sequential treated hypertensive patients aged >40 years. During the follow‐up (mean 9.7 years, range 0.4–20 years), 116 events (new‐onset AF) occurred. In univariate analysis, clinic, daytime, nighttime, and 24‐h systolic BP were all significantly associated with increased risk of new‐onset AF, that is, hazard ratio (95% confidence interval) per 10 mm Hg increment 1.22 (1.11–1.35), 1.36 (1.21–1.53), 1.42 (1.29–1.57), and 1.42 (1.26–1.60), respectively. After adjustment for various covariates in multivariate analysis, clinic systolic BP was no longer associated with increased risk of new‐onset AF, whereas daytime, nighttime, and 24‐h systolic BP remained significantly associated with outcome, that is, hazard ratio (95% confidence interval) per 10 mm Hg increment 1.09 (0.97–1.23), 1.23 (1.10–1.39), 1.16 (1.03–1.31), and 1.22 (1.06–1.40), respectively. Daytime, nighttime, and 24‐h systolic BP are superior to clinic systolic BP in predicting new‐onset AF in treated hypertensive patients. Future studies are needed to evaluate whether a better control of ambulatory BP might be helpful in reducing the occurrence of new‐onset AF.     

Ferulic acid restores endothelium-dependent vasodilation in aortas of spontaneously hypertensive rats

BACKGROUND: Ferulic acid (FA), a phytochemical constituent, has antihypertensive effects, but a detailed understanding of its effects on vascular function remains unclear. The vasoreactivity of FA was assessed using aortic rings isolated from normotensive Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR). METHODS: The effects of FA (10(-5) to 10(-3) mol/L) on vasodilatory responses were evaluated based on contractile responses induced by phenylephrine (10(-6) mol/L) in thoracic aortic rings from male WKY rats and SHR. Basal nitric oxide (NO) bioavailability in the aorta was determined from the contractile response induced by the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME, 10(-4) mol/L). The effects of FA on the production of NADPH-dependent superoxide anion were examined in SHR aortas. The impact of hydroxyhydroquinone, a generator of superoxide anions, on the FA-induced enhancement in acetylcholine-stimulated vasodilation was also investigated. RESULTS: The FA (10(-3) mol/L)-induced relaxation was partially blocked by removal of the endothelium or by pretreating SHR aortas with L-NAME. FA increased NO bioavailability, and decreased NADPH-dependent superoxide anion levels in SHR aortas. Ferulic acid improved acetylcholine-induced endothelium-dependent vasodilation in SHR, but not in WKY. Furthermore, the simultaneous addition of hydroxyhydroquinone significantly inhibited the increase in acetylcholine-induced vasodilation by FA. CONCLUSIONS: Ferulic acid restores endothelial function through enhancing the bioavailability of basal and stimulated NO in SHR aortas. The results explain, in part, the mechanisms underlying the effects of FA on blood pressure (BP) in SHR.     

Ambulatory blood pressure and the metabolic syndrome in normotensive and untreated hypertensive men

Background: Components of the metabolic syndrome are typically intercorrelated in epidemiologic studies and, when combined, predict type 2 diabetes and cardiovascular diseases. However, it remains unclear whether a single construct underlies the various components and which of the components are most closely associated with the underlying syndrome. Here, we use our confirmatory factor analytic model of the metabolic syndrome to examine the extent to which measures of ambulatory blood pressure, reflecting blood pressure variability throughout the day and night, may strengthen the association between blood pressure and the other components of the syndrome. Methods: Participants were a community sample of 358 men (248 with hypertension), ages 40-70, not receiving antihypertensive medications. Confirmatory factor analysis was employed to examine model fit and the strength of association between clinic and ambulatory blood pressure and the metabolic syndrome. Results: The blood pressure factor loaded significantly on the underlying metabolic syndrome but the strength of association was not as great (loading = 0.34, p < 0.01) as those observed for the obesity, insulin resistance and lipid factors. The factor loadings for the ambulatory measures (awake loading = 0.19; sleep loading = 0.16, p values < 0.01) were significant but smaller in magnitude than the loadings for clinic blood pressure. Conclusions: Both clinic and ambulatory measures of blood pressure are significantly associated with the underlying metabolic syndrome using confirmatory factor analytic methods. However, the strength of association appears greater for the clinic measures relative to the ambulatory measures in this study.