Diastolic Blood Pressure Ratio Research Articles

Blood pressure postural changes variability is associated with cognitive decline: the S.AGES cohort

AbstractBackgroundOver the past decade, higher blood pressure (BP) variability has been associated with cognitive decline (CD). To date, only one study investigated the specific impact of visit‐to‐visit BP postural changes variability on dementia but its association with cognition is still unknown. We aimed to investigate the association between BP postural changes variability and cognitive function in noninstitutionalized subjects aged ≥ 65 years.MethodThe S.AGES (Sujets Âgés) cohort followed for three years noninstitutionalized subjects aged ≥ 65 years without major neurocognitive impairment at inclusion. At each visit, an orthostatic systolic BP (SBP) ratio was calculated using the formula (sitting SBP/standing SBP) x 100. An orthostatic diastolic BP ratio was computed using the same method. Subjects with a SBP ratio > 100% had sitting SBP > standing SBP. We assessed the visit‐to‐visit BP postural changes variability according to several indicators: standard deviation, coefficient of variation (CV), variation independent of mean, residual standard deviation, average real variability, and successive variation. Cognitive performances were evaluated using the Mini‐Mental State Examination. Linear mixed models were used for the analyses.ResultWe included 2,974 subjects (mean age 78 years, women 56%). After adjustment for age, sex, education, baseline body mass index, smoking, alcohol intake, atrial fibrillation, congestive heart failure, transient ischemic attack or stroke, coronary artery disease, type 2 diabetes, dyslipidemia, seated SBP/DBP and antihypertensive treatment, greater visit‐to‐visit systolic BP postural changes variability was significantly associated with CD over time (adjusted β [95% CI] = ‐0.17 [‐0.29; ‐0.06], p = 0.004 for CV). Similar results were found for visit‐to‐visit diastolic BP postural changes variability (adjusted β [95% CI] = ‐0.14 [‐0.25; ‐0.03], p = 0.017 for CV).ConclusionGreater visit‐to‐visit BP postural changes variability was associated with CD. Further studies are needed to assess whether controlling orthostatic BP instability over time could be a promising interventional target to preserve cognition among older adults.

Myocardial perfusion and function dichotomy in growth restricted preterm infants.

Compared to preterm appropriate for gestational age (AGA) fetuses, fetuses with fetal growth restriction (FGR) have earlier visualisation of coronary artery blood flow (CABF) but impaired cardiac function. This dichotomy remains uncharacterised during postnatal life. This study compared CABF and cardiac function in preterm FGR infants, against AGA infants during the postnatal period. FGR was defined as birthweight < 10th centile for gestation and sex with absent/reversed antenatal umbilical artery Doppler. Diastolic CABF was measured in the left anterior descending coronary artery. Twenty-eight FGR infants were compared with 26 AGA infants (gestation and birthweight, 29.7 ± 1.3 vs 29.9 ± 1 weeks, P = 0.6 and 918 ± 174 vs 1398 ± 263g, P < 0.001, respectively). Echocardiography was performed in the second week of life. FGR infants had higher CABF (velocity time integral, 2.4 ± 0.9 vs 1.6 ± 0.8 cm, P = 0.002). Diastolic function was impaired (↑ trans-mitral E/A ratio in FGR infants; 0.84 ± 0.05 vs 0.79 ± 0.03, P = 0.0002) while the systolic function was also affected (mean velocity of circumferential fibre shortening [mVCFc], 1.9 ± 0.3 vs 2.7 ± 0.5 circ/s, P < 0.001). Indexing CABF to cardiac function noted significant differences between the groups (CABF: E/A [FGR vs AGA], 2.9 ± 1.1 vs 2.1 ± 1, P = 0.01 and CABF: mVCFc [FGR vs AGA], 1.3 ± 0.5 vs 0.6 ± 0.3, P < 0.001). Diastolic blood pressure (BP) was significantly higher, and CABF to diastolic BP ratio trended higher in FGR infants (30 ± 2 vs 25 ± 3 mmHg, P < 0.001 and 0.08 ± 0.03 vs 0.06 ± 0.03, P = 0.059, respectively). Greater CABF in FGR infants did not translate into better cardiac function. This dichotomy may be a persistent response to fetal hypoxaemia (fetal programming) and/or reflection of altered cardiac architecture.

The Ratio of Diastolic and Systolic Arterial Pressure is Associated with Pulse Pressure.

Pulse pressure (PP) is defined as the difference between systolic blood pressure (SBP) and diastolic blood pressure (DBP). The metric PP is not unique, as numerous combinations of SBP and DBP yield the same value for PP. Therefore, we introduced the PP companion (PPC) which is calculated using the Pythagorean theorem. Only the combination of PP and PPC offers unique characterization. Interestingly, PPCwas found to be associated with mean arterial pressure (MAP). Another mathematical construct frequently used in hemodynamic studies refers to the ratio of DBP and SBP, or DBP/SBP, denoted as Prat. As Prat and PP share the same companion (C), we investigated the association between PratC and MAP, as well as the connection between PP and Prat. Various patient cohorts were included: A) 52 heart failure patients (16 women), B) 88 patients (11 women) with acute cardiac syndromes, C) 257 patients (68 men) diagnosed with atherosclerosis or any of various types of autoimmune disease, and D) 106 hypertensives (51 men). Linear regression analysis resulted in the following correlations: A: R (PratC, MAP) = 0.94, R (PP, Prat) = -0.91 B: R (PratC, MAP) = 0.98, R (PP, Prat) = -0.85 C: R (PratC, MAP) = 0.97, R (PP, Prat) = -0.86 D: R (PratC, MAP) = 0.92, R (PP, Prat) = -0.82 We conclude that Prat carries no substantial incremental value beyond PP, while both Prat and PP are incomplete metrics, requiring simultaneous consideration of MAP. Clinical Relevance- Various ratio-based metrics have been introduced in hemodynamic studies without paying attention to missing components or even redundant candidates. Here we present a uniform method to provide comprehensive insight.

Abstract P011: Blood Pressure Postural Changes Variability Is Associated With Cognitive Decline: The S.ages Cohort

Introduction: Over the past decade, higher blood pressure (BP) variability has been associated with cognitive decline (CD). To date, only one study investigated the specific impact of visit-to-visit BP postural changes variability on dementia but its association with cognition is still unknown. We aimed to investigate the association between BP postural changes variability and cognitive function in noninstitutionalized subjects aged ≥ 65 years. Methods: The S.AGES (Sujets Å;gés) cohort followed for three years noninstitutionalized subjects aged ≥ 65 years without major neurocognitive impairment at inclusion. At each visit, an orthostatic systolic BP (SBP) ratio was calculated using the formula (sitting SBP/standing SBP) x 100. An orthostatic diastolic BP ratio was computed using the same method. Subjects with a SBP ratio &gt; 100% had sitting SBP &gt; standing SBP. We assessed the visit-to-visit BP postural changes variability according to several indicators: standard deviation, coefficient of variation (CV), variation independent of mean, residual standard deviation, average real variability, and successive variation. Cognitive performances were evaluated using the Mini-Mental State Examination. Linear mixed models were used for the analyses. Results: We included 2,974 subjects (mean age 78 years, women 56%). After adjustment for age, sex, education, baseline body mass index, smoking, alcohol intake, atrial fibrillation, congestive heart failure, transient ischemic attack or stroke, coronary artery disease, type 2 diabetes, dyslipidemia, seated SBP/DBP and antihypertensive treatment, greater visit-to-visit systolic BP postural changes variability was significantly associated with CD over time (adjusted β [95% CI] = -0.17 [-0.29; -0.06], p= 0.004 for CV). Similar results were found for visit-to-visit diastolic BP postural changes variability (adjusted β [95% CI] = -0.14 [-0.25; -0.03], p= 0.017 for CV). Conclusion: Greater visit-to-visit BP postural changes variability was associated with CD. Further studies are needed to assess whether controlling orthostatic BP instability over time could be a promising interventional target to preserve cognition among older adults.

Association Between Genetic Variation in Blood Pressure and Increased Lifetime Risk of Peripheral Artery Disease.

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TARGET DIASTOLIC BLOOD PRESSURE RANGE ACCORDING TO THE AGE CATEGORY AND PRESENCE OF PRIOR CARDIOVASCULAR DISEASE DURING ANTIHYPERTENSIVE TREATMENT

Objective: The evidence supporting European Society of Cardiology (ESC) recommended target diastolic blood pressure (DBP) in range 70–79 mm Hg is scarce. The study was aimed to evaluate optimal DBP according to age category (&lt; 65 years, 65–80 years, &gt; 80 years) and presence of cardiovascular disease (CVD). Design and method: Analysis was performed using Systolic Blood Pressure Intervention Trial (SPRINT) data shared by National Heart, Lung and Blood Institute. On-treatment DBP was computed as a mean of DBP measurements made in period from 6th month of participation to the end of the study, when BP was stable. Composite outcome event (CE) included myocardial infarction and other acute coronary syndrome, stroke, heart failure decompensation and cardiovascular death. Adjusted Cox proportional models were used to establish association between DBP and hazard ratio according to age category and presence of CVD. Results: Data of 8890 SPRINT participants (aged 67.8 ± 9.4 years) with available data were analysed. 3139 (35.3%) were female and 1773 (19.9%) were diagnosed with prior CVD. There was 3049 (42.8%) participants younger than 65 years, 3288 (46.2%) in age 65–80 years and 780 (11%) older than 80 years in group without prior CVD. There was 583 (32.9%) participants younger than 65 years, 891 (50.3%) in age 65–80 years and 299 (16.9%) older than 80 years in group with prior CVD. There was 293 (4.1%) CE events in group without prior CVD and 168 (9.5%) CE events in participants with prior CVD. Figure 1 presents the relationship between DBP and hazard ratio according to age category and presence of CVD. Conclusions: Optimal DBP range for patients with hypertension and CVD younger than 80 years is similar to the recommended interval 70–79 mm Hg. Similar DBP target should be recommended for younger than 65 years adults with hypertension but without prior CVD. DBP range 70–79 mm Hg should be reconsidered as a treatment target in subjects without prior CVD older than 65 years and in subjects with prior CVD older than 80 years.

Ankle pulse pressure to diastole ratio as a novel non-invasive costless screening tool for subclinical atherosclerosis

Atherosclerosis develops gradually as a subclinical condition and eventually becomes clinically apparent as heart disease or stroke. The degree of decreased arterial compliance affects both pulse pressure (PP) and diastolic blood pressure (DBP). These relations would be clear in the distal periphery. We propose that the ankle PP/ankle DBP ratio (APPD) can uncover the ongoing subclinical vascular risk. Based on the elastic chamber theory, APPD = (Cs-Cd)/(Cd-C0) in which Cs, Cd, and C0 represent arterial compliance at systolic pressure, diastolic pressure, and zero-pressure. For a given ventricular ejection, the value of Cs-Cd (i.e. PP) positively differs in the same person from brachium to ankle based on the distance from the heart, degree of arterial stiffness, and the local arterial function. On the other hand, the decreased arterial compliance increases the speed of reflected pulse waves to the heart resulting in earlier ventricular ejection by which the value of Cd-C0 (i.e. DBP) decreases over the arterial tree. In the same person, studies of ankle-brachial blood pressure (BP) differences revealed that PP greatly differed from brachium to ankle while DBPs were of minimal change or almost equivalent. However, DBP would be lower in those with arterial stiffness compared to others of the same age. Accordingly, APPD increases as arterial compliance decreases. Moreover, decreased APPD after a certain limit would reflect either local arterial stenosis or a compromised left ventricular function. When we divided ankle PP by ankle DBP, we could control the diversity of ankle PP as being not related to the BP level and possibly fluctuates in the same person. Additionally, APPD will indicate the extra rapid reflected pulse wave given in decreased DBP. Since increased common carotid artery intima-media thickness (CIMT) is a well-established marker of atherosclerosis, we initially studied 115 subjects apparently free form vascular diseases and had not taken a drug that can affect BP on the day of the study, aged 40–60 years, without a history of stroke, coronary heart disease or peripheral vascular disease to evaluate the relation between APPD and CIMT. The association was statistically significant even after adjusting for age, sex and important covariates and the area under the receiver operating characteristic curve was 0.902 ± 0.031. Therefore, the potential applicability of APPD as a tool for subclinical atherosclerosis was greatly proven.

Sleep-Wake Concordance in Couples Is Inversely Associated With Cardiovascular Disease Risk Markers.

To determine whether interdependence in couples' sleep (sleep-wake concordance i.e., whether couples are awake or asleep at the same time throughout the night) is associated with two markers of cardiovascular disease (CVD) risk, ambulatory blood pressure (BP) and systemic inflammation. This community-based study is a cross-sectional analysis of 46 adult couples, aged 18-45 years, without known sleep disorders. Percent sleep-wake concordance, the independent variable, was calculated for each individual using actigraphy. Ambulatory BP monitors measured BP across 48 h. Dependent variables included mean sleep systolic BP (SBP) and diastolic BP (DBP), mean wake SBP and DBP, sleep-wake SBP and DBP ratios, and C-reactive protein (CRP). Mixed models were used and were adjusted for age, sex, education, race, and body mass index. Higher sleep-wake concordance was associated with lower sleep SBP (b = -.35, SE = .01) and DBP (b = -.22, SE = .10) and lower wake SBP (b = -.26, SE = .12; all p values < .05). Results were moderated by sex; for women, high concordance was associated with lower BP. Men and women with higher sleep-wake concordance also had lower CRP values (b = -.15, SE = .03, p < .05). Sleep-wake concordance was not associated with wake DBP or sleep/wake BP ratios. Significant findings remained after controlling for individual sleep quality, duration, and wake after sleep onset. Sleep-wake concordance was associated with sleep BP, and this association was stronger for women. Higher sleep-wake concordance was associated with lower systemic inflammation for men and women. Sleep-wake concordance may be a novel mechanism by which marital relationships are associated with long-term CVD outcomes.

Circadian Blood Pressure Rhythm Is Changed by Improvement in Hypoalbuminemia and Massive Proteinuria in Patients with Minimal Change Nephrotic Syndrome

Background: Proteinuria and nighttime blood pressure (BP) elevation are notable risk markers of chronic kidney disease and correlate closely with each other. However, daily urinary protein excretion (UPE) always fluctuates. In patients with minimal change nephrotic syndrome (MCNS), serum albumin concentrations (SAC) decrease but fluctuate less than UPE. We evaluated whether SAC is a reliable marker for proteinuria, and compared the relations among circadian BP changes, SAC, and UPE. Methods: In patients with MCNS (12 men and 11 women, 43 ± 18 years), blood and spot urine samples were collected on three consecutive days before treatment, and 24-hour BP was also measured on the three days. Then, an intervention study was conducted in the patients to examine circadian BP changes induced by treatment. Sleeping/waking BP ratio was analyzed as an indicator of circadian BP rhythm. Results: In the three-day measurements before treatment, mean coefficient of variation, an index of dispersion of data, for SAC was 7.4 ± 7.4%, which was markedly lower (p < 0.01) than 35.7 ± 15.4% for UPE. SAC correlated inversely with sleeping/waking systolic and diastolic BP ratios on all three days, whereas UPE did not correlate significantly with sleeping/waking diastolic BP ratio on day 3. Sleeping/waking systolic and diastolic BP ratios were 96 ± 5 and 95 ± 6%, and were higher (p < 0.05) than in healthy subjects (89 ± 8 and 88 ± 10%). Treatment improved hyperproteinuria and hypoalbuminemia, and was accompanied by decreases (p < 0.05) in sleeping and waking systolic/diastolic BP ratio to 91 ± 8 and 89 ± 9%. Conclusion: These findings suggest that reduced SAC in patients with proteinuria is associated with disrupted circadian BP rhythm.

Oscillometric blood pressure estimation by combining nonparametric bootstrap with Gaussian mixture model

Background: Blood pressure (BP) is one of the most important vital indicators and plays a key role in determining the cardiovascular activity of patients.Methods: This paper proposes a hybrid approach consisting of nonparametric bootstrap (NPB) and machine learning techniques to obtain the characteristic ratios (CR) used in the blood pressure estimation algorithm to improve the accuracy of systolic blood pressure (SBP) and diastolic blood pressure (DBP) estimates and obtain confidence intervals (CI). The NPB technique is used to circumvent the requirement for large sample set for obtaining the CI. A mixture of Gaussian densities is assumed for the CRs and Gaussian mixture model (GMM) is chosen to estimate the SBP and DBP ratios. The K-means clustering technique is used to obtain the mixture order of the Gaussian densities.Results: The proposed approach achieves grade “A” under British Society of Hypertension testing protocol and is superior to the conventional approach based on maximum amplitude algorithm (MAA) that uses fixed CR ratios. The proposed approach also yields a lower mean error (ME) and the standard deviation of the error (SDE) in the estimates when compared to the conventional MAA method. In addition, CIs obtained through the proposed hybrid approach are also narrower with a lower SDE.Conclusions: The proposed approach combining the NPB technique with the GMM provides a methodology to derive individualized characteristic ratio. The results exhibit that the proposed approach enhances the accuracy of SBP and DBP estimation and provides narrower confidence intervals for the estimates.

Improved Measurement of Blood Pressure by Extraction of Characteristic Features from the Cuff Oscillometric Waveform.

We present a novel approach to improve the estimation of systolic (SBP) and diastolic blood pressure (DBP) from oscillometric waveform data using variable characteristic ratios between SBP and DBP with mean arterial pressure (MAP). This was verified in 25 healthy subjects, aged 28 ± 5 years. The multiple linear regression (MLR) and support vector regression (SVR) models were used to examine the relationship between the SBP and the DBP ratio with ten features extracted from the oscillometric waveform envelope (OWE). An automatic algorithm based on relative changes in the cuff pressure and neighbouring oscillometric pulses was proposed to remove outlier points caused by movement artifacts. Substantial reduction in the mean and standard deviation of the blood pressure estimation errors were obtained upon artifact removal. Using the sequential forward floating selection (SFFS) approach, we were able to achieve a significant reduction in the mean and standard deviation of differences between the estimated SBP values and the reference scoring (MLR: mean ± SD = −0.3 ± 5.8 mmHg; SVR and −0.6 ± 5.4 mmHg) with only two features, i.e., Ratio2 and Area3, as compared to the conventional maximum amplitude algorithm (MAA) method (mean ± SD = −1.6 ± 8.6 mmHg). Comparing the performance of both MLR and SVR models, our results showed that the MLR model was able to achieve comparable performance to that of the SVR model despite its simplicity.

Relation between blood pressure and mortality risk in an older population: role of chronological and biological age.

The relation between high blood pressure (BP) and mortality risk in older individuals (above 65years of age) is still debated. Some data suggest that this relation is inverted in certain subgroups of (biologically) older individuals. We therefore investigated whether the association between BP and mortality is dependent on chronological age and on physical and cognitive function as indicators of biological age. The relationship between BP and all-cause mortality was investigated in 1466 older participants (aged 65years and older; mean age 75.8years) of the Longitudinal Ageing Study Amsterdam using multiple adjusted Cox proportional hazard models. Analyses were stratified for age, gait speed and mini mental state examination score. A total of 1008 participants died after a median (range) follow-up of 10.6 (0.2; 15.9) years. Low diastolic blood pressure (DBP) was associated with an increased all-cause mortality risk: hazard ratio (HR) of low DBP (≤70mmHg) compared to normal DBP (71-90mmHg) was 1.36 [95% confidence interval (CI) 1.15; 1.61]. This relation was particularly strong in the oldest old (individuals aged >80years) and in those who had lower levels of both physical and cognitive functioning: HRs (95% CIs) of low versus normal DBP were 1.58 (1.26; 1.98) and 1.45 (1.18; 1.77), respectively. In a large population-based cohort of older adults, low DBP was associated with an increased all-cause mortality risk, especially in the oldest old and in biologically old individuals.

Improved Confidence Interval Estimation for Oscillometric Blood Pressure Measurement by Combining Bootstrap-After-Jackknife Function with Non-Gaussian Models

Confidence intervals (CIs) are generally not provided along with estimated systolic blood pressure (SBP) and diastolic blood pressure (DBP) measured using oscillometric blood pressure devices. No criteria exist to determine the CI from a small sample set of oscillometric blood pressure measurements. We provide an extended methodology to improve estimation of CIs of SBP and DBP based on a nonparametric bootstrap-after-jackknife function and a Bayesian approach. We use the nonparametric bootstrap-after-jackknife function to reduce maximum amplitude outliers. Improved pseudomaximum amplitudes (PMAs) and pseudoenvelopes (PEs) are derived from the pseudomeasurements. Moreover, the proposed algorithm uses an unfixed ratio obtained by employing non-Gaussian models based on the Bayesian technique to estimate the SBP and DBP ratios for individual subjects. The CIs obtained through our proposed approach are narrower than those obtained using the traditional Studentt-distribution method. The mean difference (MD) and standard deviation (SD) of the SBP and DBP estimates using our proposed approach are better than the estimates obtained by conventional fixed ratios based on the PMA and PE (PMAE).

Low diastolic blood pressure was one of the independent predictors of ischemia-like findings of electrocardiogram in patients who underwent coronary angiography

BackgroundThe underlying cause of a high cardiovascular event rate in the population with low diastolic blood pressure (DBP) has not been fully elucidated. Methods and resultsThe relationship between DBP and ischemia-like findings on electrocardiography (ECG) was investigated in 187 patients who underwent coronary angiography. Patients with conditions affecting ECG (e.g. patients taking digitalis or those with old myocardial infarction, complete right bundle branch block, or hypokalemia) were excluded from the analyses. Ischemia-like ECG was defined as having one or more of the following: borderline Q wave [Minnesota code (MC) I 3], ST depression (MC IV 1–3), negative T wave (MC V 1–3), and complete left bundle branch block (MC VII 1). Based on this definition, 70 of 187 patients (37%) had ischemia-like ECG. Compared with the group without it, the group with ischemia-like ECG included more females (p<0.01), and had lower values of body mass index (p=0.01), DBP (p<0.01), estimated glomerular filtration rate (p<0.01), left ventricular ejection fraction (LVEF; p<0.01), and higher values of age (p<0.01) and left ventricular mass index (LVMI; p<0.01). The severity of coronary artery disease did not differ between the groups. Receiver operating characteristics curve analysis revealed that 74.5mmHg was the optimal cut-off point of DBP to predict ischemia-like ECG (area under curve, 0.63; 95% confidence interval, 0.55–0.71, p=0.003). There were no significant relationships between systolic blood pressure and ischemia-like ECG. A multivariate analysis showed that female sex, low DBP (≤74.5mmHg), LVMI, and LVEF were the significant factors for the ischemia-like ECG. The odds ratio of low DBP was 2.53 (95% confidence interval, 1.19–5.40; p=0.02). ConclusionsLow DBP was one of the significant predictors of the ischemia-like ECG in the present study. Myocardial ischemia may be a part of the cause of high cardiovascular morbidity in the population with low DBP.

Short-term reproducibility of ambulatory blood pressure monitoring in autosomal dominant polycystic kidney disease

Nondipping, defined as a less than 10% decline in Night:Day (N:D) ratio of blood pressure using 24 h ambulatory blood pressure monitoring, is associated with poor cardiovascular outcomes. However, its reproducibility has been questioned in autosomal dominant polycystic kidney disease. Twenty-five of 29 recruited hypertensive or prehypertensive patients with autosomal dominant polycystic kidney disease completed ambulatory blood pressure monitoring on two occasions, 7-15 days apart, on a stable antihypertensive regimen. Daytime and night-time were defined as 6:00-21:59 h and 22:00-5:59 h, respectively. Correlation and concordance coefficients for systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate were determined based on N:D and Asleep:Awake (A:A) ratios. Consistency of dipping was assessed by using Cohen's Kappa statistics. Mean (±standard deviation) for age, estimated glomerular filtration rate, differences in daytime and night-time SBP and DBP were 43.12 years (8.55 years), 63.1 ml/min (20.5 ml/min), 11.74 mmHg (8.2 mmHg), and 10.82 mmHg (6.4 mmHg), respectively. Seventeen of 25 (68%) and 18 of 25 (72%) participants maintained the same dipping category based on D:N or A:A separation. Cohen's Kappa was 0.34 for D:N ratio and 0.38 for A:A ratio. Correlation and concordance coefficients were 0.89 and 0.88 for daytime SBP, 0.91 and 0.91 for daytime DBP, 0.79 and 0.78 for night-time SBP, 0.81 and 0.80 for night-time DBP, 0.58 and 0.56 for N:D ratio of SBP, and 0.56 and 0.53 for N:D ratio of DBP. Coefficients for A:A ratio were almost identical to N:D values except for A:A ratios of SBP (0.69 and 0.67) and DBP (0.48 and 0.45). Repeated measures of SBP and DBP, 7-15 days apart, are highly correlative and concordant in the studied population, but nondipping, even though predominant, was found to be modestly reproducible.

Evaluation of Antihypertensive Effect on Essential Hypertension From Acupuncture by Ambulatory Blood Pressure Monitoring

The purpose of this study was to evaluate the antihypertensive effect of acupuncture on patients with mild to moderate essential hypertension by 24-hour ambulatory blood pressure monitoring (ABPM). Fifty patients with mild to moderate essential hypertension were treated with 80 mg telmisartan once a day for four weeks. The 24-hour ABPM was performed before and after the treatment and the trough/peakratio and smoothness index were calculated. The mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) reduced significantly (P < 0.05) in 24-hour period, day-time period and night-time period. The blood pressure loads of SBP and DBP also decreased significantly (P < 0.05). The trough/peak ratio of SBP and DBP was 76% and 72%, respectively. The Smoothness index of SBP and DBP was 1.34±0.13 and 1.16±0.22, respectively. The results showed that compound telmisartan was an effective and safe antihypertensive drug with satisfactory trough/peak ratio and smoothness index.

Unfair Treatment and Trait Anger in Relation to Nighttime Ambulatory Blood Pressure in African American and White Adolescents

To determine if ambulatory blood pressure (ABP) at night relative to day ABP among adolescents is influenced by unfair treatment and trait anger, and whether these associations are stronger in African Americans and adolescents from lower socioeconomic status (SES) families and neighborhoods. A total of 189 healthy white and African American adolescents (ages = 14-16 years, standard deviation = 0.62, 50% female) completed 2 days and 1 night of ABP monitoring and unfair treatment and trait anger questionnaires. SES was measured using 1) parental education and 2) a composite neighborhood SES score based on U.S. Census tract data for neighborhood poverty and education. The night/day ABP ratio was calculated by dividing the night ABP mean (readings from the self-reported bedtime of each participant through 5 AM) by the day ABP mean (8:30 AM until self-reported bedtime). Higher trait anger was associated with a higher night/day diastolic blood pressure (DBP) ratio in the full sample, B = 0.003, SE = 0.001, t = 2.20, p = .03. A significant interaction effect for Race x Unfair Treatment on the night/day DBP ratio, B = 0.01, SE = 0.003, t = 3.17, p = .002, followed by post hoc tests indicated that greater unfair treatment was associated with a higher night/day DBP ratio among African Americans, B = 0.006, SE = 0.002, t = 2.56, p = .01. Further, among African American adolescents living in lower SES neighborhoods, greater unfair treatment predicted a higher night/day DBP ratio, B = 0.008, SE = 0.003, t = 3.15, p = .002, and higher trait anger scores predicted a higher night/day DBP ratio, B = 0.008, SE = 0.002, t = 3.19, p = .002. Trait anger may be a factor leading to elevated nighttime DBP in both African Americans and whites. Unfair treatment and trait anger are important predictors of elevated night/day ABP ratios among African American adolescents living in lower SES neighborhoods. These factors may contribute to the onset of hypertension in African Americans at a younger age.

Sleep-Disordered Breathing and 24-Hour Blood Pressure Pattern Among Older Adults

To examine the association between sleep-disordered breathing (SDB) and 24-hour blood pressure (BP) pattern among community-dwelling older adults. A convenience sample of 70 community-dwelling older adults, recruited from senior housing, community centers, and learning centers, were admitted to General Clinical Research Center, Emory University Hospital, Atlanta, Ga. Information regarding demographic and clinical history was obtained using questionnaires. Twenty-four-hour BP monitoring in supine position was performed using Spacelabs model 20207. Breathing during sleep was monitored with the use of a modified sleep recording system (Embletta, PDS), which monitors nasal and oral airflow, chest and abdominal movements, and pulse oximetry. Night time-daytime (night-day) BP ratio (average night-time BP divided by daytime BP) was calculated both for systolic and diastolic BPs. Sixty-nine participants, mean age 74.9 +/- 6.4 years (41 [57%] women), completed the study. The mean apnea-hypopnea index (AHI) was 13 +/- 13 per hour of sleep, and 20 participants (29%) had AHI > or =15 per hour of sleep, indicating moderate to severe SDB. Moderate to severe SDB (AHI > or =15 per hour of sleep) was significantly associated with nocturnal hypertension, whereas there was no statistically significant difference in wake-time BP between those with and without moderate to severe SDB. Stepwise multiple regressions showed that AHI independently predicted increased night-day systolic and night-day diastolic BP ratio, even after controlling for nocturia frequency. The results indicate increased BP load associated with increased AHI in this group of older adults. This increased BP load may contribute to increased hypertension-related morbidity and disease burden.

Blood pressure means rather than nocturnal dipping pattern are related to complications in Type 2 diabetic patients

To determine whether systolic and diastolic blood pressure (BP) means, during ambulatory BP monitoring (ABPM), are more strongly correlated with microvascular complications and echocardiographic structural alterations than night-time/daytime (N/D) BP ratio. A cross-sectional study was conducted in 270 Type 2 diabetes mellitus (DM) outpatients who underwent clinical and laboratory investigations, urinary albumin excretion rate (UAER) determination, echocardiography, office and 24-h ABPM (Spacelabs 90207). UAER, after multivariate adjustments, was associated with office BP (systolic: R(2)(a) 0.162, P < 0.001; diastolic: R(2)(a) 0.124, P < 0.001) and ABPM (24-h systolic: R(2)(a) 0.195, P < 0.001; 24-h diastolic: R(2)(a) 0.197, P < 0.001) but not with N/D BP ratios (systolic: R(2)(a) 0.062, P = 0.080; diastolic: R(2)(a) 0.063, P = 0.069). Similar results were observed for echocardiographic parameters. The presence of retinopathy was associated only with night-time BP values [systolic means: odds ratio (OR) 1.13, 95% confidence interval (CI) 1.03-1.24 and diastolic means: OR 1.21, CI 1.04-1.40 and N/D diastolic BP ratio > 0.90, OR 3.21, CI 1.65-6.25]. UAER and echocardiographic structural alterations had more consistent correlations of a greater magnitude with systolic BP means than with N/D BP ratios. The nocturnal BP values appear to be more relevant for diabetic retinopathy. BP measurement in patients with Type 2 DM should take into account the 24-h period rather than focusing on a specific time span of BP homeostasis.

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

The aim of our study was to assess diurnal blood pressure (BP) and heart rate variability and their possible relationship to the duration of the QT interval in adolescents with Type 1 diabetes. In 48 normotensive, normoalbuminuric diabetic adolescents, with a mean (+/- sd) age of 17.3 (+/- 4.1) years and a mean (+/- sd) diabetes duration of 8.5 (+/- 3.3) years, 24-h ambulatory BP was recorded. In addition, 24-h heart rate (HR) monitoring was performed and QT and corrected QT (QTc) intervals were estimated as indices of autonomic function. The patients were divided into two groups according to the absence of a decrease (non-dippers) or the presence of a decrease (dippers) in nocturnal diastolic BP (DBP). In comparison with the dippers, the non-dippers showed reduced mean 24-h HR (79.6 vs. 84.0 beats/min, P = 0.05) and reduced mean daytime HR (81.3 vs. 86.0 beats/min, P = 0.05). The QT interval was prolonged in the non-dippers (366.3 vs. 347.5 ms, P = 0.015), and end systolic (28.7 vs. 25.9 mm, P = 0.004) and end diastolic left ventricular diameters (47.8 vs. 45.5 mm, P = 0.037) were greater. In stepwise multiple regression, HR variables were the most important factors affecting DBP ratio or the duration of the QT interval. In conclusion, normotensive diabetic adolescents with impaired nocturnal BP reduction also have impaired autonomic function tests, in association with prolonged QT interval and increased left ventricular diameters. These findings suggest that diabetic adolescents who have the 'non-dipper' phenomenon may need close follow-up for the possible development of vascular complications, such as cardiac arrhythmias and left-ventricular hypertrophy.