Is 44-hour better than 24-hour ambulatory blood pressure monitoring in hemodialysis?

The aim of this study is to evaluate if hemodialysis (HD) patients with similar blood pressure (BP) in the whole inter-HD period could have different target organ lesions and survival if the behavior of BP differs from the first to the second day of the inter-HD period. The present study compares 44-hour ambulatory BP monitoring (ABPM) patterns in 45 HD patients. Three BP patterns emerged: group A (n = 15) had similar BPs throughout (138 ± 11/88 ± 12 in the first 22 h vs. 140 ± 11/87 ± 12 mm Hg in the second 22-hour period); group B (n = 15) had a significant systolic BP rise from the first to the second period (132 ± 15/80 ± 12 vs. 147 ± 12/86 ± 13 mm Hg, p < 0.05); group C (n = 15) had significantly higher BPs (p < 0.05) than the other 2 groups throughout the whole inter-HD period, with no significant change between the 2 halves (172 ± 14/108 ± 12 vs. 173 ± 18/109 ± 14 mm Hg). Ventricular mass and survival during the 30-month follow-up period were statistically significantly better in group A, intermediate in group B and worse in group C. The data suggest that a 44-hour ABPM is more accurate than a 24-hour one in evaluating organ lesion and prognosis in HD patients. Copyright © 2006 S. Karger AG.

Ambulatory blood pressure monitoring in adolescent untreated hypertensive patients.

Ambulatory blood pressure profiles were obtained with the portable semi-automatic blood pressure recorder Remler M2000 in groups of 20 adolescents, 20 young and 20 middle-aged adults and 20 elderly untreated patients, all considered by their physician to be hypertensive. It was found that adolescents who are hypertensive when seeing their physician are more often normotensive outside the physician's office than adult and elderly patients under similar conditions. The increased heart rate variability which was detected in adolescents was not associated with an enhanced blood pressure variability.

Ambulatory blood pressure monitoring in children with obstructive sleep apnea and primary snoring

Objective: To evaluate the systemic blood pressure (BP) during daytime and nighttime in children with sleep breathing disorders (SBD) and compare parameters of BP in children with diagnosis of obstructive sleep apnea syndrome (OSA) to those one with primary snoring (PS).Methods: Children, both genders, aged from 8 to 12 years, with symptoms of SBD realized an overnight polysomnography followed by a 24 h recording of ambulatory BP.Results: All subjects presented with a history of snoring 7 nights per week. Children who have apnea/hipoapnea index >= four or a apnea index >= one presented a mean BP of 93 +/- 7 mmHg and 85 +/- 9 mmHg diurnal and nocturnal respectively whereas children who have a apnea/hipoapnea < four or a apnea index < one presented 90 +/- 7 mmHg and 77 +/- 2 mmHg. Eight children out of fourteen, from OSA group, lost the physiologic nocturnal dipping of the blood pressure. Among OSA children 57% were considered non-dippers. Two (16%) have presented absence of nocturnal dipping among children with primary snoring. The possibility of OSA children loosing physiologic blood pressure dipping was 6.66 higher than the possibilities of patients from PS group.Discussion: Our results indicate that children with sleep apnea syndrome exhibit a higher 24 h blood pressure when compared with those of primary snoring in form of decreased degree of nocturnal dipping and increased levels of diastolic and mean blood pressure, according to previous studies in literature. OSA in children seems to be associated to the development of hypertension or other cardiovascular disease. (C) 2012 Elsevier B.V. All rights reserved.

The presence of the NOS3 gene polymorphism for intron 4 mitigates the beneficial effects of exercise training on ambulatory blood pressure monitoring in adults

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ambulatory blood pressure monitoring in children with obstructive sleep apnea and primary snoring

Objective: To evaluate the systemic blood pressure (BP) during daytime and nighttime in children with sleep breathing disorders (SBD) and compare parameters of BP in children with diagnosis of obstructive sleep apnea syndrome (OSA) to those one with primary snoring (PS). Methods: Children, both genders, aged from 8 to 12 years, with symptoms of SBD realized an overnight polysomnography followed by a 24 h recording of ambulatory BP. Results: All subjects presented with a history of snoring 7 nights per week. Children who have apnea/hipoapnea index >= four or a apnea index >= one presented a mean BP of 93 +/- 7 mmHg and 85 +/- 9 mmHg diurnal and nocturnal respectively whereas children who have a apnea/hipoapnea < four or a apnea index < one presented 90 +/- 7 mmHg and 77 +/- 2 mmHg. Eight children out of fourteen, from OSA group, lost the physiologic nocturnal dipping of the blood pressure. Among OSA children 57% were considered non-dippers. Two (16%) have presented absence of nocturnal dipping among children with primary snoring. The possibility of OSA children loosing physiologic blood pressure dipping was 6.66 higher than the possibilities of patients from PS group. Discussion: Our results indicate that children with sleep apnea syndrome exhibit a higher 24 h blood pressure when compared with those of primary snoring in form of decreased degree of nocturnal dipping and increased levels of diastolic and mean blood pressure, according to previous studies in literature. OSA in children seems to be associated to the development of hypertension or other cardiovascular disease. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

Prediction of hypertensive crisis based on average, variability and approximate entropy of 24-h ambulatory blood pressure monitoring

Approximate entropy (ApEn) of blood pressure (BP) can be easily measured based on software analysing 24-h ambulatory BP monitoring (ABPM), but the clinical value of this measure is unknown. In a prospective study we investigated whether ApEn of BP predicts, in addition to average and variability of BP, the risk of hypertensive crisis. In 57 patients with known hypertension we measured ApEn, average and variability of systolic and diastolic BP based on 24-h ABPM. Eight of these fifty-seven patients developed hypertensive crisis during follow-up (mean follow-up duration 726 days). In bivariate regression analysis, ApEn of systolic BP (P<0.01), average of systolic BP (P=0.02) and average of diastolic BP (P=0.03) were significant predictors of hypertensive crisis. The incidence rate ratio of hypertensive crisis was 14.0 (95% confidence interval (CI) 1.8, 631.5; P<0.01) for high ApEn of systolic BP as compared to low values. In multivariable regression analysis, ApEn of systolic (P=0.01) and average of diastolic BP (P<0.01) were independent predictors of hypertensive crisis. A combination of these two measures had a positive predictive value of 75%, and a negative predictive value of 91%, respectively. ApEn, combined with other measures of 24-h ABPM, is a potentially powerful predictor of hypertensive crisis. If confirmed in independent samples, these findings have major clinical implications since measures predicting the risk of hypertensive crisis define patients requiring intensive follow-up and intensified therapy.

Home blood pressure monitoring and control in a group of hypertensive patients

This qualitative study was performed with 71 hypertensive patients, with the objectives to compare outpatient and home blood pressure monitoring (HBPM), to assess blood pressure control, and characterize white-coat hypertension. A nurse performed the outpatient blood pressure measurement. The home blood pressure monitoring was carried out over seven days. White-coat hypertension was quantified as a difference between the outpatient measurement and home blood pressure monitoring in the ranges from 1 to 5, 6 to 10 and > 10 mmHg. The outpatient blood pressure measurement was significantly higher (p<0.05) than the home blood pressure measurement. Pressure control corresponded to 9.9% in the outpatient measurement and 23.9% in the home blood pressure measurement. The white-coat effect > 10 mmHg was 57.7% for systolic and 32.4% for diastolic pressure, in the range from 6 to 10 mmHg. Home blood pressure measurement provided a better assessment of hypertensive patients' control.

Exploring the cardiovascular disease continuum: blood pressure and target organ damage

Introduction The objectives of this thesis are to: (1) examine how ambulatory blood pressure monitoring (ABPM) refines office blood pressure (BP) measurement; (2) determine if absolute ambulatory BP or dipping status is better associated with target organ damage (TOD); (3) explore the association of isolated nocturnal hypertension (INH) with TOD; and (4) investigate the association of night-time BP with ultrasound markers of cardiovascular damage. Methods Data from the Mitchelstown Cohort Study was analysed to deliver objectives 1 and 2. Objective 3 was addressed by a systematic review and analysis of data from the Mitchelstown Study. A sample of participants from the Mitchelstown Study underwent an echocardiogram for speckle tracking analysis and carotid ultrasound to achieve objective 4. Results ABPM reclassifies hypertension status in approximately a quarter of individuals, with white coat and masked hypertension prevalence rates of 11% and 13% respectively. Night-time systolic BP is better associated with TOD than daytime systolic BP and dipping level. In multi-variable models the odds ratio (OR) for LVH was 1.4 (95% CI 1.1 -1.8) and for albumin:creatinine ratio ≥ 1.1 mg/mmol was 1.5 (95% CI 1.2 – 1.8) for each 10 mmHg rise in night-time systolic BP. The evidence for the association of INH with TOD is inconclusive. Night-time systolic BP is significantly associated with global longitudinal strain (GLS) (beta coefficient 0.85 for every 10 mmHg rise, 95% CI 0.3 – 1.4) and carotid plaques (OR 1.9 for every 10 mmHg rise, 95% CI 1.1 – 3.2) in univariable analysis. The findings persist for GLS in sex and age adjusted models but not in multivariable models. Discussion Hypertension cannot be effectively managed without using ABPM. Night-time systolic BP is better associated with TOD than daytime systolic BP and dipping level, and therefore, may be a better therapeutic target in future studies.

Ambulatory blood pressure measurement and antihypertensive therapy.

The traditional basis for assessing the effect of antihypertensive therapy is the blood pressure reading taken by a physician. However, several recent trials have been designed to evaluate the blood pressure lowering effect of various therapeutic agents during the patients' normal daytime activities, using a portable, semi-automatic blood pressure recorder. The results have shown that in a given patient, blood pressure measured at the physician's office often differs greatly from that prevailing during the rest of the day. This is true both in treated and untreated hypertensive patients. The difference between office and ambulatory recorded pressures cannot be predicted from blood pressure levels measured by the physician. Therefore, a prospective study was carried out in patients with diastolic blood pressures that were uncontrolled at the physician's office despite antihypertensive therapy. The purpose was to evaluate the response of recorded ambulatory blood pressure to treatment adjustments aimed at reducing office blood pressure below a pre-set target level. Only patients with high ambulatory blood pressures at the outset appeared to benefit from further changes in therapy. Thus, ambulatory blood pressure monitoring can be used to identify those patients who remain hypertensive only when facing the physician, despite antihypertensive therapy. Ambulatory monitoring could thus help to evaluate the efficacy of antihypertensive therapy and allow individual treatment.

Circadian blood pressure during the early course of type 1 diabetes. Analysis of 1,011 ambulatory blood pressure recordings in 354 adolescents and young adults

OBJECTIVE Little information is available on the early course of hypertension in type 1 diabetes. The aim of our study, therefore, was to document circadian blood pressure profiles in patients with a diabetes duration of up to 20 years and relate daytime and nighttime blood pressure to duration of diabetes, BMI, insulin therapy, and HbA1c. RESEARCH DESIGN AND METHODS Ambulatory profiles of 24-h blood pressure were recorded in 354 pediatric patients with type 1 diabetes (age 14.6 +/- 4.2 years, duration of diabetes 5.6 +/- 5.0 years, follow-up for up to 9 years). A total of 1,011 profiles were available for analysis from patients not receiving antihypertensive medication. RESULTS Although daytime mean systolic pressure was significantly elevated in diabetic subjects (+3.1 mmHg; P < 0.0001), daytime diastolic pressure was not different from from the height- and sex-adjusted normal range (+0.1 mmHg, NS). In contrast, both systolic and diastolic nighttime values were clearly elevated (+7.2 and +4.2 mmHg; P < 0.0001), and nocturnal dipping was reduced (P < 0.0001). Systolic blood pressure was related to overweight in all patients, while diastolic blood pressure was related to metabolic control in young adults. Blood pressure variability was significantly lower in girls compared with boys (P < 0.01). During follow-up, no increase of blood pressure was noted; however, diastolic nocturnal dipping decreased significantly (P < 0.03). Mean daytime blood pressure was significantly related to office blood pressure (r = +0.54 for systolic and r = +0.40 for diastolic pressure); however, hypertension was confirmed by ambulatory blood pressure measurement in only 32% of patients with elevated office blood pressure. CONCLUSIONS During the early course of type 1 diabetes, daytime blood pressure is higher compared with that of healthy control subjects. The elevation of nocturnal values is even more pronounced and nocturnal dipping is reduced. The frequency of white-coat hypertension is high among adolescents with diabetes, and ambulatory blood pressure monitoring avoids unnecessary antihypertensive treatment.

Associations of ambulatory blood pressure with urinary caffeine and caffeine metabolite excretions.

Intake of caffeinated beverages might be associated with reduced cardiovascular mortality possibly via the lowering of blood pressure. We estimated the association of ambulatory blood pressure with urinary caffeine and caffeine metabolites in a population-based sample. Families were randomly selected from the general population of Swiss cities. Ambulatory blood pressure monitoring was conducted using validated devices. Urinary caffeine, paraxanthine, theophylline, and theobromine excretions were measured in 24 hours urine using ultrahigh performance liquid chromatography tandem mass spectrometry. We used mixed models to explore the associations of urinary excretions with blood pressure although adjusting for major confounders. The 836 participants (48.9% men) included in this analysis had mean age of 47.8 and mean 24-hour systolic and diastolic blood pressure of 120.1 and 78.0 mm Hg. For each doubling of caffeine excretion, 24-hour and night-time systolic blood pressure decreased by 0.642 and 1.107 mm Hg (both P values <0.040). Similar inverse associations were observed for paraxanthine and theophylline. Adjusted night-time systolic blood pressure in the first (lowest), second, third, and fourth (highest) quartile of paraxanthine urinary excretions were 110.3, 107.3, 107.3, and 105.1 mm Hg, respectively (P trend <0.05). No associations of urinary excretions with diastolic blood pressure were generally found, and theobromine excretion was not associated with blood pressure. Anti-hypertensive therapy, diabetes mellitus, and alcohol consumption modify the association of caffeine urinary excretion with systolic blood pressure. Ambulatory systolic blood pressure was inversely associated with urinary excretions of caffeine and other caffeine metabolites. Our results are compatible with a potential protective effect of caffeine on blood pressure.

Association of left ventricular hypertrophy and stage of hypertension by ambulatory blood pressure monitor

Hypertension in adults is defined by risk for cardiovascular morbidity and mortality, but in children, hypertension is defined using population norms. The diagnosis of hypertension in children and adolescents requires only casual blood pressure measurements, but the use of ambulatory blood pressure monitoring to further evaluate patients with elevated blood pressure has been recommended in the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents. The aim of this study is to assess the association between stage of hypertension (using both casual and 24 hour ambulatory blood pressure measurements) and target organ damage defined by left ventricular hypertrophy (LVH) in a sample of children and adolescents in Houston, TX. A retrospective analysis was performed on the primary de-identified data from the combination of participants in two, IRB approved, cross-sectional studies. The studies collected basic demographic data, height, weight, casual blood pressures, ambulatory blood pressures, and left ventricular measurements by echocardiography on children age 8 to 18 years old. Hypertension was defined and staged using the criteria for ambulatory blood pressure reported by Lurbe et al. [1] with some modification. Left ventricular hypertrophy was defined using left ventricular mass index (LVMI) criteria specific for children and adults. The pediatric criterion was LVMI2.7 > 95th percentile for gender and the adult criterion was LVMI2.7 > 51g/m2.7. Participants from the original studies were included in this analysis if they had complete demographic information, anthropometric measures, casual blood pressures, ambulatory blood pressures, and echocardiography data. There were 241 children and adolescents included: 19.1% were normotensive, 17.0% had white coat hypertension, 11.6% had masked hypertension, and 52.4% had confirmed hypertension. Of those with hypertension, 22.4% had stage 1 hypertension, 5.8% had stage 2 hypertension, and 24.1% had stage 3 hypertension. Participants with confirmed hypertension were more likely to have LVH by pediatric criterion than those who were normotensive [OR 2.19, 95% CI (1.04–4.63)]; LVH defined by adult criterion did not differ significantly in normotensives compared with hypertensives [OR 2.08, 95% CI (0.58–7.52)]. However, there was a significant trend in the increased prevalence of LVH across the six blood pressure categories for LVH defined by both pediatric and adult criteria (p < 0.001 and p = 0.02, respectively). Additionally, the mean LVM indexed by height 2.7 had a significantly increased trend across blood pressure stages from normal to stage 3 hypertension (p < 0.02). Pediatric hypertension is defined using population norms, and although children with mild hypertension are not at increased odds of having target organ damage defined by LVH, those with severe hypertension are more likely to have LVH. Staging hypertension by ambulatory blood pressure further describes an individual's risk for LVH target organ damage. ^

Mixed methods feasibility study for a trial of blood pressure telemonitoring for people who have had stroke/transient ischaemic attack (TIA).

Background Good blood pressure (BP) control reduces the risk of recurrence of stroke/transient ischaemic attack (TIA). Although there is strong evidence that BP telemonitoring helps achieve good control, none of the major trials have considered the effectiveness in stroke/TIA survivors. We therefore conducted a feasibility study for a trial of BP telemonitoring for stroke/ TIA survivors with uncontrolled BP in primary care. Method Phase 1 was a pilot trial involving 55 patients stratified by stroke/TIA randomised 3:1 to BP telemonitoring for 6 months or usual care. Phase 2 was a qualitative evaluation and comprised semi-structured interviews with 16 trial participants who received telemonitoring and 3 focus groups with 23 members of stroke support groups and 7 carers. Results Overall, 125 patients (60 stroke patients, 65 TIA patients) were approached and 55 (44%) patients were randomised including 27 stroke patients and 28 TIA patients. Fifty-two participants (95%) attended the 6-month follow-up appointment, but one declined the second daytime ambulatory blood pressure monitoring (ABPM) measurement resulting in a 93% completion rate for ABPM − the proposed primary outcome measure for a full trial. Adherence to telemonitoring was good; of the 40 participants who were telemonitoring, 38 continued to provide readings throughout the 6 months. There was a mean reduction of 10.1 mmHg in systolic ABPM in the telemonitoring group compared with 3.8 mmHg in the control group, which suggested the potential for a substantial effect from telemonitoring. Our qualitative analysis found that many stroke patients were concerned about their BP and telemonitoring increased their engagement, was easy, convenient and reassuring Conclusions A full-scale trial is feasible, likely to recruit well and have good rates of compliance and follow-up.

Treatment Adherence and Blood Pressure Control in Older Individuals with Hypertension

Background: Non-adherence to treatment has been identified as the main cause of uncontrolled blood pressure (BP), and may represent a greater risk in older individuals. Objective: The aim of this study was to evaluate and compare the rate of adherence to hypertension treatment using different methods, to estimate the BP control rate, and to observe if there is an association between BP control and adherence. Methods: Treatment adherence was evaluated in older patients with hypertension, followed by the public primary health care, through four methods, including the Morisky-Green test (reference), the Attitude regarding the Medication Intake questionnaire (AMI), an evaluation of adherence by the nurse in the office (Nurse Adherence Evaluation - NAE), and at home (Home Adherence Evaluation - HAE). Salt intake was estimated by 24-hour sodium urinary excretion. BP control was assessed by the awake ambulatory blood pressure monitoring. Results: Concordance between the Morisky-Green test and AMI (Kappa=0.27) or NAE (Kappa=0.05) was poor. There was a moderate concordance between the Morisky-Green test and HAE. Eighty percent had controlled BP, including 42% with white-coat effect. The group with lower salt excretion informed to avoid salt intake more times (p<0.001) and had better medication adherence (p<0.001) than the higher salt excretion group. Conclusion: The evaluated tests did not show a good concordance to the Morisky-Green test. Adherence to hypertension treatment was low; however, there was a high rate of BP control when subjects with the white-coat effect were included in the analysis. (Arq Bras Cardiol 2012;99(1):636-641)