Does blood pressure variability modulate cardiovascular risk?

Correlation of blood pressure levels at different time periods throughout the day with total CSVD burden and MRI imaging markers

Purpose

Hypertension is an important risk factor for atherosclerotic cerebral small vessel disease (CSVD). Higher blood pressure is associated with a higher CSVD burden and the presence of relevant magnetic resonance imaging (MRI) markers. However, the effect of blood pressure level on CSVD burden and imaging markers including white matter hyperintensity (WHM), lacune, enlarged perivascular spaces (EPVS), and cerebral microbleed (CMB) remains unknown. The purpose of this study was to investigate the correlation between blood pressure level and CSVD burden at different time periods throughout the day.

Methods

In total, 144 in-patients with CSVD (66.4 ± 9.8 years, 50% male) were enrolled and underwent brain MRI, and 24-h ambulatory blood pressure was assessed. Patients were categorized into five groups according to their MRI-evaluated total CSVD burden scores (0-4). Spearman's correlation analysis was performed to examine the correlation between blood pressure levels at different time periods and the total CSVD score or the markers of periventricular WMH, deep WMH, lacune, EPVS, and CMB.

Results

Of the 144 patients, 83.3% (120/144) harbored one or more CSVD markers of interest. The systolic blood pressure (SBP) of 24-h, daytime, nighttime, and morning differed significantly among the five groups. The SBP levels increased significantly with the total CSVD scores during 24 h (P = 0.018), daytime (P = 0.018), and nighttime (P = 0.035). Spearman's correlation analysis demonstrated that the SBP of 24 h, daytime, nighttime, and morning and the diastolic blood pressure (DBP) of 24 h and morning positively and significantly correlated with the total CSVD score (P < 0.05). A logistic regression analysis indicated that both morning SBP and DBP were independent risk factors for total CSVD burden (OR = 1.13, 95% CI: 1.02-1.23, P = 0.015; OR = 1.19, 95% CI: 1.06-1.33, P = 0.005). Spearman's correlation analysis indicated a significant positive correlation between morning SBP and higher deep WMH Fazekas score (r = 0.296, P < 0.001), EPVS grade in the basal ganglia (r = 0.247, P = 0.003), and the presence of lacune (r = 0.173, P = 0.038) and CMB (r = 0.326, P < 0.001). Morning DBP only correlated positively with the presence of CMB (r = 0.292, P < 0.001).

Conclusion

Higher SBP signficantly correlated with total CSVD burden in patients with atherosclerotic CSVD. Early morning blood pressure level is an important indicator to reflect the severity of CSVD patients.

Effect of systolic blood pressure fluctuations during resuscitation on postoperative complications following meningioma surgery: A retrospective observation study

It is unclear whether blood pressure variability in the post-anesthesia care unit is associated with postoperative complications. This study aims to characterize the impact of blood pressure fluctuations on postoperative complications and postoperative length of stay after meningioma surgery. Adult meningioma patients undergoing general anesthesia were retrospectively recruited. The principal exposure was blood pressure variability in the post-anesthesia care unit, calculated by noninvasive blood pressure measurements. The primary outcome was major postoperative complications, defined as II or higher in the Clavien-Dindo classification grades. Secondary outcomes included healthcare resource utilization parameters among patients. Multivariable logistic regression was used and adjusted for potential confounding variables. Data sensitivity analyses were performed via different variable transformations and propensity score matching analyses. A total of 578 patients qualified for the study, and 161 (27.9%) cases experienced postoperative complications. The multivariable analysis found that increased systolic blood pressure variability in the post-anesthesia care unit was associated with postoperative complications (adjusted odds ratio [aOR] = 1.15; 95% confidence interval [CI], 1.09-1.22, P < .001) and prolonged postoperative length of stay (adjusted regression coefficients [β] = 1.86; 95% CI, 0.58-3.13, P = .004). Patients with postoperative complications had a higher frequency of intensive care admission (44.1% vs 15.3%), major postoperative interventions (6.6% vs 0%), and 30-day readmission (5.0% vs 0.7%). Systolic blood pressure fluctuations during resuscitation have an independent impact on postoperative complications and postoperative length of stay following meningioma surgery.

Association between Twenty-Four-Hour Ambulatory Blood Pressure Variability and Cerebral Small Vessel Disease Burden in Acute Ischemic Stroke

Objective. This study is aimed at investigating the association between the twenty-four-hour ambulatory blood pressure variability monitoring (ABPM) and cerebral small vessel disease (cSVD) burden in acute ischemic stroke (AIS) patients. Methods. 115 AIS patients with demographics, vascular risk factors, 24 h ABPM, and brain magnetic resonance imaging (MRI) were retrospectively enrolled. 3.0 T MRI was used to assess cSVD burden by combining four MRI markers including white matter hyperintensities (WMHs), cerebral microbleeds (CMBs), perivascular spaces (PVS), and lacunes. Correlation analysis was conducted to detect whether ABPM was associated with cSVD burden in AIS patients. Results. 115 AIS patients with mean age $68.77\pm 10.26$ years and 75.7% male were enrolled in this study. 112 AIS patients (97.4%) had at least one cSVD marker. Spearman correlation analysis indicated that hypertension was positively correlated with cSVD burden ( $\rho =0.21$ , $P=0.07$ ). High-density lipoprotein (HDL) was negatively correlated with cSVD burden ( $\rho =-0.21$ , $P=0.02$ ). Blood pressure variability such as 24 h mean SBP ( $\rho =0.23$ , $P=0.01$ ), day mean SBP ( $\rho =0.23$ , $P=0.01$ ), and night mean SBP ( $\rho =0.20$ , $P=0.04$ ) was positively correlated with higher cSVD burden. Ordinal logistic regression analysis demonstrated that higher 24 h SBP SD and day mean SBP were independent risk factors for cSVD after controlling for other confounders. Conclusions. Higher BPV was significantly related to total cSVD burden in AIS patients. 24 h SBP SD and day mean SBP were independent risk factors for cSVD burden in AIS patients but not DBP or DBP variability.

Day and night blood pressure variability among older persons in South-Western Nigeria

BACKGROUND

Hypertension is the largest contributor to the global burden of disease. Emerging risk factors for cardiovascular disease include blood pressure variability (BPV), but evidence on BPV is lacking among older Nigerians. We reported BPV in a cohort of older persons at the University College Hospital (UCH), Ibadan.

METHODS

We conducted a retrospective cohort study of respondents aged >50 years within the Ibadan Ambulatory Blood Pressure Registry at the UCH, Ibadan, Nigeria. Socio-demographic characteristics, lifestyle habits and anthropometric measurements were obtained.

RESULTS

Among 639 respondents, 332 (52.0%) were female. The blood pressure (BP) variables were strongly associated with age. Compared with younger age groups, mean diastolic BP (DBP) was less at an older age, whereas mean pulse pressure was greater. During the wake-up and sleep periods, mean DBP and mean arterial BP were less with each increasing age category, whereas mean pulse pressure was larger with each increasing age category. BP dipping, systolic, diastolic and mean arterial BP decreased with age. Overall, timed BPV increased significantly with increasing age. The prevalence of white-coat hypertension was greater among older participants than younger participants. Most respondents in the 50-59 years' age group were non-dippers (55.8%), whereas 33.7% of older respondents were reverse-dippers.

CONCLUSION

Older persons experienced a greater abnormal circadian blood variation and greater BPV than younger people. In Nigeria, follow-up data are needed to determine the prognostic significance of these data in this population.

Acupuncture for Hypertension in Animal Models: A Systematic Review and Meta-Analysis

OBJECTIVE

The aim of this study was to summarize and evaluate the efficacy of acupuncture in hypertension animal study.

METHODS

Studies were searched from six databases, including Medline, Embase, Chinese National Knowledge Infrastructure, Wanfang Data, VIP information database, and Chinese Biomedical Literature Database. Study quality of each included study was evaluated according to the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines, and the risk of bias was evaluated by the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) tool. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were selected as outcomes. Meta-analyses were performed using Stata 12.0 software. The effect size was calculated by combining SBP/DBP/MAP data with the random effects model, respectively.

RESULTS

67 studies containing 1522 animals were included. According to the ARRIVE guideline, 8 items were assessed as poor and 4 items were assessed as excellent. According to the SYRCLE tool, all studies were judged as having high risk of bias. Compared with the hypertension group, the pooled results showed significant antihypertension effects of acupuncture for SBP, DBP, and MAP. Similarly, compared with the sham-acupuncture group, the pooled results showed significant antihypertension effects of acupuncture for SBP, DBP, and MAP.

CONCLUSION

Although pooled data suggested that the acupuncture group was superior to the hypertension group or sham-acupuncture group for SBP/DBP/MAP, the presentation of poor methodological quality, high risk of bias, and heterogeneity deserves cautious interpretation of the results.

Preserved glycemic control and baroreflex efficacy in young adult hypertensive female obese Zucker rats

Obese Zucker rats (OZRs) develop hypertension and hyperinsulinemia by 3 mo of age. Male OZRs also have diminished baroreflex-mediated activation of nucleus tractus solitarius (NTS) and bradycardia, which are improved by correcting their hyperglycemia. Conversely, 3-mo-old female OZRs and lean Zucker rats (LZRs) have equivalent baroreflex-mediated bradycardia that is impaired in 6-mo-old OZRs. We hypothesized that 3-mo-old female OZRs maintain NTS activation and baroreflexes coincident with glycemic control. We also hypothesized that 6-mo-old female OZRs develop impaired baroreflexes with hyperglycemia and diminished NTS activation. In 12- to 16-wk-old females, sympathetic nerve activity (SNA) and arterial pressure (AP) were higher in OZRs than LZRs. However, baroreflex-mediated inhibition of SNA and bradycardia were equivalent in female OZRs and LZRs. Unlike deficits in male OZRs, female OZRs and LZRs had no differences in phenylephrine-induced c-Fos expression in NTS or decreases in SNA and AP evoked by glutamate into NTS. Compared with hyperglycemia in male OZRs (217.9 ± 34.4 mg/dL), female OZRs had normal fed blood glucose levels (108.2 ± 1.6 mg/dL in LZRs and 113.6 ± 3.5 mg/dL in OZRs) with emerging glucose intolerance. Conscious 24- to 27-wk-old female OZRs had impaired baroreflex-mediated bradycardia, but fed blood glucose was modestly elevated (124.2 ± 5.2 mg/dL) and phenylephrine-induced c-Fos expression in NTS was comparable to LZRs. These data suggest that better glycemic control in 3-mo-old female OZRs prevents diminished NTS activation and baroreflexes, supporting the notion that hyperglycemia impairs these responses in male OZRs. However, 6-mo-old female OZRs had impaired baroreflex efficacy without diminished NTS activation or pronounced hyperglycemia, suggesting baroreflex deficits develop by different mechanisms in female and male OZRs.

Coconut Oil Supplementation Does Not Affect Blood Pressure Variability and Oxidative Stress: A Placebo-Controlled Clinical Study in Stage-1 Hypertensive Patients

Exploring an alternative to improve the clinical management of hypertension, we tested the hypothesis that food supplementation with coconut oil (EVCO), alone or combined with aerobic exercise training, could exert an antihypertensive effect (primary outcome) in patients with stage 1 hypertension. Forty-five hypertensive volunteers of both genders participated in a placebo-controlled clinical trial. The volunteers were submitted to 24-hour ambulatory blood pressure monitoring, analysis of blood pressure variability (BPV), measurement of serum malondialdehyde (MDA) and nutritional assessment. Results indicate that EVCO consumption had no adverse effects. The supplementation did not increase the caloric intake compared with placebo, and the dietary constituents were similar between groups, except for the saturated fats, especially lauric acid. The analysis of blood pressure indicated absence of antihypertensive effect of EVCO alone or combined with physical training. Furthermore, no effects on blood pressure variability and oxidative stress were observed in the supplemented hypertensive patients. Thus, despite the results observed in pre-clinical studies, the current clinical study did not provide evidence to support the use of coconut oil as an adjuvant in the management of hypertension in humans.

Twenty-Four-Hour Ambulatory Blood Pressure Variability Associated With Cerebral Small Vessel Disease MRI Burden and Its Progression in Inpatients With Cerebrovascular Disease

Background: Lacunar infarcts, white matter lesions, cerebral microbleed, enlarged perivascular space and brain atrophy are regarded as magnetic resonance imaging (MRI) manifestations of cerebral small vessel disease (cSVD). 24-hour blood pressure variability (BPV) has been reported to relate with cerebral small vessel disease, but the impact of 24-h BPV on the total MRI cSVD burden and its progression in inpatients with cerebrovascular disease has not been investigated yet. Methods: We enrolled inpatients with cerebrovascular disease, who underwent the 24-h ambulatory blood pressure monitoring (ABPM) and the brain MRI scan at baseline and had the follow-up brain MRI images stored in the clinical information system of our hospital. BPV was quantified by the calculation of standard deviation (SD), coefficient of variation (CV), weighted standard deviation (wSD) of blood pressure record. We evaluated the total cSVD score on baseline MRI and the MRI followed-up to obtain the total burden of cSVD. The cSVD burden progression was estimated through the comparison of the total cSVD score on the two MRIs. Results: A total of 140 patients with an average age of 65.6 years were finally enrolled, 82.9% (116/140) of whom had one or more cSVD markers. After a median of 4.4 years follow-up, cSVD score progression were found in 50.7% (71/140) of the patients. Both SD and CV of SBP and DBP during 24-h and daytime as well as the SBP wSD differed significantly among different total cSVD score groups. The SBP SD and CV during 24-h and daytime, the SBP SD in nighttime, the DBP SD and CV during the daytime were significantly higher in the cSVD progression group than those in the cSVD no-progression group. The SBP wSD and the DBP wSD were significantly higher in the cSVD progression group than those in the cSVD no-progression group. Logistic regression analyses revealed that daytime SBP SD and SBP wSD were independent risk factors for total cSVD burden [daytime SBP SD: OR = 1.628, 95% CI = 1.105-2.398 (per 5 mmHg increase in SD), P = 0.014; SBP wSD: OR = 2.248, 95% CI = 1.564-3.230 (per 5 mmHg increase in wSD), P < 0.001)] and SBP wSD was a significant predictor for cSVD progression [OR = 2.990, 95% CI = 1.053-8.496 (per 5 mmHg increase in wSD), P = 0.040]. Conclusion: Higher BPV were significantly related with total cSVD burden in inpatients with cerebrovascular disease. SBP SD during daytime and SBP wSD were independent risk factor for total cSVD burden and SBP wSD was an predictive factor for cSVD progression.

Clinical implications of blood pressure variability (BPV) in pregnancies: a review

Background Hypertension disorder in pregnancy (HDP) is the second most common contributor to maternal morbidity and mortality worldwide. Blood pressure variability (BPV), with the assistance of ambulatory blood pressure monitoring (ABPM), measures blood pressure readings in pregnant women and has the potential to predict the occurrence of pregnancy-induced hypertension (PIH) or preeclampsia (PE) before any symptoms develop. Methodology Studies involving ABPM among pregnant women were identified using electronic databases such as PubMed, Scopus, Google Scholar, ScienceDirect, Medscape, Ovid and ProQuest. These electronic databases were assessed from 1990 to 2018. Keywords used to search for literatures included a combination of BPV matched with pregnancy, pregnant women and HDP, gestational hypertension and/or PE. Results Out of 21,526 articles identified, a total of 10 studies met the criteria. Seven articles used the spectral analysis method while another two articles used a combination of spectral analysis, time domain and a non-linear method for BPV analysis. The final article described BPV as vagal baroreflex. Four articles agreed that high frequency (HF) BPV was mainly dominant from the second trimester until 4 days postpartum in HDP patients. This reflects the dominant features of parasympathetic activities among these patients. Two articles that used time domain also agreed that standard deviation (SD) BPV increased in PE patients. Conclusions In pregnancy, BPV has a strong impact on the knowledge understanding of the disease in clinical fields, allows a superior ability to predict PIH and PE in mid-pregnancy and offers potential value for addressing hypertension in pregnancy.

Orthostatic blood pressure variability is associated with lower visual contrast sensitivity function: Findings from The Irish Longitudinal Study on Aging

BACKGROUND

Hypertension is established to cause vascular end-organ damage. Other forms of dysregulated blood pressure (BP) behaviour, such as orthostatic hypotension have also been associated with cardiovascular (CV) events. The eye is potentially vulnerable to dysregulated systemic BP if ocular circulation autoregulation is impaired. We investigated whether phenotypes of abnormal BP stabilisation after orthostasis, an autonomic stressor, had a relationship with contrast sensitivity (CS), an outcome measure of subtle psychophysical visual function.

METHODS

This was a cross-sectional study from wave 1 of The Irish Longitudinal Study on Ageing (TILDA). From beat-to-beat orthostatic BP (BP), measured by digital photoplethysmography during active stand, 4 phenotypes have been defined 1) normal stabilisation 2) orthostatic hypotension, 3) orthostatic hypertension 4) BP variability. Contrast sensitivity was measured using a Functional Visual Analyzer. Multivariable linear regression models investigated the relationship between orthostatic BP phenotypes and contrast sensitivity in 4289 adults aged ≥50 years adjusting for, demographics, cardiovascular risk factors, self-reported eye pathologies, objective hypertension and antihypertensives. A sensitivity analysis adjusted for age-related macular degeneration, glaucoma, diabetic retinopathy and maculopathy identified on retinal photographs. Finally models were compared, adjusting for alternative measures of cataract versus not, to examine the potential effect of cataract on any associations.

RESULTS

Systolic orthostatic BP variability was associated with worse contrast sensitivity, in the primary and the sensitivity analysis. Adjusting for alternative measures of clinical cataract attenuated the association by 18%.

CONCLUSIONS

Orthostatic BP variability is associated with worse contrast sensitivity, independent of hypertension and retinal pathology and may be a cardiovascular biomarker of early ocular pathology.

Twenty-four-hour ambulatory blood pressure variability is associated with total magnetic resonance imaging burden of cerebral small-vessel disease

Background

Lacunae, brain atrophy, white matter hyperintensity, enlarged perivascular space and microbleed are magnetic resonance imaging (MRI) markers of cerebral small-vessel disease (cSVD). Studies have reported that higher blood pressure variability (BPV) predicted cardiovascular risk in hypertensive patients; however, the association between BPV and the total MRI burden of cSVD has not been investigated. In this study, we aimed to explore this relationship between BPV and cSVD MRI burden.

Methods

We prospectively recruited patients who attended our hospital for annual physical examination. Twenty-four-hour ambulatory BP monitoring was performed using an automated system. BPV was quantified by SD, weighted SD, and coefficient of variation. One point was awarded for the presence of each marker, producing a score between 0 and 5. Spearman correlation and ordinal logistic regression analyses were used to test the relationship between BPV and total cSVD MRI burden.

Results

A total of 251 subjects with an average age of 68 years were enrolled in this study, and 52.6% were male; 163 (64.94%) had one or more markers of cSVD. Correlation analysis indicated that higher systolic BP (SBP) levels and BPV metrics of SBP were positively related to higher cSVD burden. Ordinal logistic regression analyses demonstrated that higher SBP levels and SBP variability were independent risk factors for cSVD. There were no significant differences in 24-hour, day and night diastolic BP levels or BPV metrics of diastolic BP among the five subgroups.

Conclusion

Twenty-four-hour, day and night SBP levels and SBP variability were positively related to cSVD burden. Higher SBP levels and SBP variability were independent risk factors for cSVD.

Pre-end-stage renal disease visit-to-visit systolic blood pressure variability and post-end-stage renal disease mortality in incident dialysis patients

OBJECTIVES

Higher SBP visit-to-visit variability (SBPV) has been associated with increased risk of adverse events in patients with chronic kidney disease, but the association of SBPV in advanced nondialysis-dependent chronic kidney disease with mortality after the transition to end-stage renal disease (ESRD) remains unknown.

METHODS

Among 17 729 US veterans transitioning to dialysis between October 2007 and September 2011, we assessed SBPV calculated from the SD of at least three intraindividual outpatient SBP values during the last year prior to dialysis transition (prelude period). Outcomes included factors associated with higher prelude SBPV and post-transition all-cause, cardiovascular, and infection-related mortality, assessed using multivariable linear regression and Cox and competing risk regressions, respectively, adjusted for demographics, comorbidities, medications, cardiovascular medication adherence, SBP, BMI, estimated glomerular filtration rate, and type of vascular access.

RESULTS

Modifiable clinical factors associated with higher prelude SBPV included higher SBP, use of antihypertensive medications and erythropoiesis-stimulating agents, inadequate cardiovascular medication adherence, and catheter use. After multivariable adjustment, higher prelude SBPV was significantly associated with higher post-ESRD all-cause and infection-related mortality, but not cardiovascular mortality [hazard/subhazard ratios (95% confidence interval) for the highest (vs. lowest) quartile of SBPV, 1.08 (1.01-1.16), 1.02 (0.89-1.15), and 1.41 (1.10-1.80) for all-cause, cardiovascular, and infection-related mortality, respectively].

CONCLUSION

High pre-ESRD SBPV is potentially modifiable and associated with higher all-cause and infection-related mortality following dialysis initiation. Further studies are needed to test whether modification of pre-ESRD SBPV can improve clinical outcomes in incident ESRD patients. VIDEO ABSTRACT:.

The relationship between ambulatory blood pressure variability and enlarged perivascular spaces: a cross-sectional study

OBJECTIVES

Recent studies reported that 24-hour ambulatory blood pressure variability (ABPV) was associated with lacunar infarction and white matter hyperintensities (WMH). However, the relationship between ABPV and enlarged perivascular spaces (EPVS) has not been investigated. Thus, our study aimed to investigate whether ABPV is associated with EPVS by 24-hour ambulatory blood pressure monitoring (ABPM).

DESIGN

We conducted this study as a cross-sectional study.

SETTINGS

The study was based on patients who presented for physical examinations in our hospital from May 2013 to June 2016.

PARTICIPANTS

Patients with both brain MRI scans and 24-hour ABPM were included and patients with acute stroke, a history of severe stroke and some other severe diseases were excluded. A total of 573 Chinese patients were prospectively enrolled in this study.

PRIMARY AND SECONDARY OUTCOME MEASURES

EPVS in basal ganglia (BG) and white matter (WM) were identified on MRI and classified into three categories by the severity. WMH were scored by the Fazekas scale. Coefficient of variation (CV) and SD were considered as metrics of ABPV. Spearman correlation analysis and ordinal logistic regression analysis were used to assess the relationship between ABPV and EPVS.

RESULTS

There were statistical differences among the subgroups stratified by the severity of EPVS in BG in the following ABPV metrics: SD and CV of systolic blood pressure (SBP), CV of diastolic blood pressure (DBP) in 24 hours, daytime and nighttime and SD of DBP in nighttime. The above ABPV metrics were positively associated with the degree of EPVS. The association was unchanged after adjusting for confounders. Spearman correlation analysis showed ABPV was not related to the degree of EPVS in the WM.

CONCLUSION

ABPV was independently associated with EPVS in BG after controlling for blood pressure, but not in the WM. Pathogenesis of EPVS in BG and WM might be different.

[Relationship between blood pressure variability and combined cardiovascular events in 5-10 years in hypertensive patients]

OBJECTIVE

To explore the relationship between blood pressure variability (BPV) and combined cardiovascular events in 5-10 years in patients with hypertension.

METHODS

A total of 367 hypertensive patients treated in our hospital from January, 2000 to January, 2005 were analyzed, and their BPV was assessed in comparison with 145 normotensive individuals. The hypertensive patients were classified into high BPV group and low BPV group, and the general clinical data and biochemical profiles were compared. The relationship between BPV and combined cardiovascular events of the patients within 5-10 years were explored.

RESULTS

Compared with the normotensive individuals, the hypertensive patients showed significantly increased standard deviation and coefficient of variation of 24-h systolic blood pressure (SBP), 24-h diastolic blood pressrue (DBP), daytime SBP, daytime DBP, night-time SBP and night-time DBP (P<0.01). The percentages of drinking, smoking, diabetes and coronary heart disease were significantly higher in patients with high BPV than those with lower BPV (P<0.01 or 0.05); uric acid, homocysteine, urinary protein/creatinine ratio and urinary microalbumin increased more significantly in patients with high BPV (P<0.01 or 0.05). In addition, the combined cardiovascular events in 5-10 years were significantly higher in the patients with higher BPV than those with lower BPV (P<0.01 or 0.05). Logistic multivariate logistic regression analysis showed that alcohol, diabetes, coronary heart disease, uric acid and homocysteine were independent risk factors for cardiovascular events in hypertensive patients (P<0.01 or 0.05).

CONCLUSION

In hypertensive patients, BPV is closely correlated with the long-term combined cardiovascular events, and a high BPV is associated with a greater likeliness of combined cardiovascular events.

Visit-to-Visit Blood Pressure Variability and Mortality and Cardiovascular Outcomes Among Older Adults: The Health, Aging, and Body Composition Study

BACKGROUND

Level of blood pressure (BP) is strongly associated with cardiovascular (CV) events and mortality. However, it is questionable whether mean BP can fully capture BP-related vascular risk. Increasing attention has been given to the value of visit-to-visit BP variability.

METHODS

We examined the association of visit-to-visit BP variability with mortality, incident myocardial infarction (MI), and incident stroke among 1,877 well-functioning elders in the Health, Aging, and Body Composition Study. We defined visit-to-visit diastolic BP (DBP) and systolic BP (SBP) variability as the root-mean-square error of person-specific linear regression of BP as a function of time. Alternatively, we counted the number of considerable BP increases and decreases (separately; 10mm Hg for DBP and 20mm Hg for SBP) between consecutive visits for each individual.

RESULTS

Over an average follow-up of 8.5 years, 623 deaths (207 from CV disease), 153 MIs, and 156 strokes occurred. The median visit-to-visit DBP and SBP variability was 4.96 mmHg and 8.53 mmHg, respectively. After multivariable adjustment, visit-to-visit DBP variability was related to higher all-cause (hazard ratio (HR) = 1.18 per 1 SD, 95% confidence interval (CI) = 1.01-1.37) and CV mortality (HR = 1.35, 95% CI = 1.05-1.73). Additionally, individuals having more considerable decreases of DBP (≥10mm Hg between 2 consecutive visits) had higher risk of all-cause (HR = 1.13, 95% CI = 0.99-1.28) and CV mortality (HR = 1.30, 95% CI = 1.05-1.61); considerable increases of SBP (≥20mm Hg) were associated with higher risk of all-cause (HR = 1.18, 95% CI = 1.03-1.36) and CV mortality (HR = 1.37, 95% CI = 1.08-1.74).

CONCLUSIONS

Visit-to-visit DBP variability and considerable changes in DBP and SBP were risk factors for mortality in the elderly.

Exaggerated sympathoexcitatory reflexes develop with changes in the rostral ventrolateral medulla in obese Zucker rats

Obesity leads to altered autonomic reflexes that reduce stability of mean arterial pressure (MAP). Sympathoinhibitory reflexes such as baroreflexes are impaired, but reflexes that raise MAP appear to be augmented. In obese Zucker rats (OZR) sciatic nerve stimulation evokes larger increases in MAP by unknown mechanisms. We sought to determine the autonomic underpinnings of this enhanced somatic pressor reflex and whether other sympathoexcitatory reflexes are augmented. We also determined whether their final common pathway, glutamatergic activation of the rostral ventrolateral medulla (RVLM), was enhanced in male OZR compared with lean Zucker rats (LZR). Sciatic nerve stimulation or activation of the nasopharyngeal reflex evoked larger rises in splanchnic sympathetic nerve activity (SNA) (79% and 45% larger in OZR, respectively; P < 0.05) and MAP in urethane-anesthetized, ventilated, paralyzed adult OZR compared with LZR. After elimination of baroreflex feedback by pharmacological prevention of changes in MAP and heart rate, these two sympathoexcitatory reflexes were still exaggerated in OZR (167% and 69% larger, respectively, P < 0.05). In adult OZR microinjections of glutamate, AMPA, or NMDA into the RVLM produced larger rises in SNA (∼61% larger in OZR, P < 0.05 for each drug) and MAP, but stimulation of axonal fibers in the upper thoracic spinal cord yielded equivalent responses in OZR and LZR. In juvenile OZR and LZR, sympathoexcitatory reflexes and physiological responses to RVLM activation were comparable. These data suggest that the ability of glutamate to activate the RVLM becomes enhanced in adult OZR and may contribute to the development of exaggerated sympathoexcitatory responses independent of impaired baroreflexes.

Preferable effects of olmesartan/calcium channel blocker to olmesartan/diuretic on blood pressure variability in very elderly hypertension: COLM study subanalysis

OBJECTIVE

The aims of this subanalysis of the COLM trial [NCT00454662] were to compare visit-to-visit variability (VVV) of blood pressure (BP) between age groups and between two treatment combinations, that is, the angiotensin II receptor blocker, olmesartan combined with a calcium channel blocker (CCB), or a diuretic and to investigate the effect of VVV of BP on cardiovascular events in elderly hypertensive patients.

METHODS

Hypertensive patients ages 65-84 years with a history of and/or risk factors for cardiovascular disease were randomized to receive treatment with olmesartan along with either a CCB or a diuretic for at least 3 years. This subanalysis comprised 4876 patients who had their office BP measured at least three occasions (median nine occasions) during the follow-up period. VVV of BP was defined by several metrics including the within-individual standard deviation of every visit during the follow-up period.

RESULTS

VVV of SBP was larger in the very elderly group (75-84 years) than in the elderly group (65-74 years). VVV of SBP was smaller in the olmesartan along with CCB group than in the olmesartan along with diuretic group, especially in very elderly patients and also isolated systolic hypertensive patients. The incidence rate of primary endpoint increased along with an increment in the SD of SBP in all of the age and treatment groups.

CONCLUSION

VVV of SBP may mediate the preferable effect of combination of angiotensin II receptor blocker along with CCB on cardiovascular events in the very elderly and also isolated systolic hypertensive patients.

Polyphenols: a Promising Nutritional Approach to Prevent or Reduce the Progression of Prehypertension

Diet plays a crucial role in maintaining healthy blood pressure. Functional foods are increasingly popular among health-conscious consumers to reduce cardiovascular risk factors and improve vascular health. In particular, dietary polyphenols represent an extraordinary inventory of structurally different compounds that may represent promising candidate chemical entities to prevent or delay the onset of hypertension. In recent years, it has been recognized that prehypertension may be a predictor of clinical hypertension and consequently of cardiovascular risk. Moreover, prehypertension status is associated with increased levels of several inflammatory markers and it is also characterized by structural changes, including endothelial dysfunction and arteriolar hypertrophy. Despite the low bioavailability of polyphenols and the lack of clinical data from nutritional intervention studies, the antihypertensive role of polyphenols to control blood pressure and reduce inflammation and endothelial dysfunction has been subject of recent debate. The purpose of this article is to discuss the potential benefits of dietary polyphenols as a promising and effective nutritional strategy for the management of prehypertension.

Quantification of peripheral and central blood pressure variability using a time-frequency method

Systolic blood pressure variability (BPV) is associated with cardiovascular events. As the beat-to-beat variation of blood pressure is due to interaction of several cardiovascular control systems operating with different response times, assessment of BPV by spectral analysis using the continuous measurement of arterial pressure in the finger is used to differentiate the contribution of these systems in regulating blood pressure. However, as baroreceptors are centrally located, this study considered applying a continuous aortic pressure signal estimated noninvasively from finger pressure for assessment of systolic BPV by a time-frequency method using Short Time Fourier Transform (STFT). The average ratio of low frequency and high frequency power band (LF_PB/HF_PB) was computed by time-frequency decomposition of peripheral systolic pressure (pSBP) and derived central aortic systolic blood pressure (cSBP) in 30 healthy subjects (25-62 years) as a marker of balance between cardiovascular control systems contributing in low and high frequency blood pressure variability. The results showed that the BPV assessed from finger pressure (pBPV) overestimated the BPV values compared to that assessed from central aortic pressure (cBPV) for identical cardiac cycles (P<;0.001), with the overestimation being greater at higher power.

Phenotypes of orthostatic blood pressure behaviour and association with visual acuity

BACKGROUND

Manifestations of neurocardiovascular instability (NCVI), including orthostatic hypotension (OH) orthostatic hypertension (OHTN) and impaired blood pressure variability (BPV), have been associated with cardiovascular (CV) events. The eye is highly vascular and we propose an ideal target end organ to investigate pathological implications of NCVI.

OBJECTIVE

To identify and define clinically applicable phenotypes of orthostatic blood pressure (BP) behaviour, analogous to OH, OHTN, and orthostatic BPV and to investigate their relationship to vision.

METHODS

Wave one data from the Irish Longitudinal Study on Ageing (TILDA) were used. Orthostatic BP (OBP) phenotypes were identified and defined from beat-to-beat BP data, measured by digital photoplethysmography during an active stand (AS) lasting 110 s (s). Visual acuity (VA) was assessed using the Early Treatment Diabetic Retinopathy Study (EDTRS) LogMAR chart. The relationship between OBP phenotypes and VA in 4355 adults aged ≥50 years was investigated through multivariate linear regression models.

RESULTS

There was a wide fluctuation in the prevalence of OH and OHTN up to 20 s after standing. After 30 s, four distinct OBP phenotypes were identified: in 70 % BP stabilised to within 20/10 mmHg of baseline BP, 4 % had persistent OH, 2 % had persistent OHTN and 25 % had exaggerated orthostatic blood pressure variability BPV. Systolic BPV was associated with worse VA (P = 0.02) as was diastolic BPV (P = 0.03), following adjustment for demographics, health behaviours, self-report eye diseases and diabetes, uncorrected refractive error, objective hypertension and antihypertensives.

CONCLUSIONS

The hypothesis that NCVI may independently modulate CV risk is supported the independent association of exaggerated BPV and worse VA.

Neurocardiovascular instability may modulate end-organ damage: A review of this hypothesis investigating the eye and manifestations of NCVI

Neurocardiovascular instability (NCVI) represents age-related changes in blood pressure and heart rate behaviour. It has been associated with increased leukoaraiosis in the brain and also conditions which are likely to be are related to cerebral end-organ damage, such as stroke and falls. The eye is a 'window' into the brain and cardiovascular (CV) system, changes in retinal microvasculature being independently predictive of cardiovascular events. The eye is highly vascular, having two circulatory systems and as such the ideal target end-organ to investigate NCVI and early end-organ damage. The retinal and choroidal circulations of the eye would be vulnerable to NCVI if ocular vasoregulation becomes impaired with age, particularly given the high metabolic activity of the retina. The choroid is predominantly extrinsically regulated by the autonomic nervous system. In patients with NCVI, autonomic dysfunction is more common and thus impairment of the tightly regulated ocular microcirculation may indeed be compromised. We review the evidence for the hypothesis that NCVI may modulate end-organ cardiovascular pathology and that the eye is the ideal target organ to monitor this.

Day-by-Day Blood Pressure Variability and Functional Outcome After Acute Ischemic Stroke

Background and Purpose—

The relationship between blood pressure (BP) variability and functional outcome in patients with acute ischemic stroke remains unclear. This study aimed to elucidate whether in-hospital day-by-day BP variability is associated with functional outcome after acute ischemic stroke.

Methods—

Using the Fukuoka Stroke Registry, we included 2566 patients with a first-ever ischemic stroke who had been functionally independent before the onset and were hospitalized within 24 hours. BP was measured daily, and its variability was assessed by SD, coefficients of variance, and variations independent of mean. Poor functional outcome was assessed by modified Rankin Scale scores ≥3 at 3 months.

Results—

After adjustment for multiple confounding factors including age, sex, risk factors, stroke features, baseline severity, thrombolytic therapy, antihypertensive agents, and mean BP, day-by-day BP variability during the subacute stage (4–10 days after onset) was independently associated with a poor functional outcome (multivariable-adjusted odds ratios [95% confidence interval] in the top versus bottom quartile of systolic BP variability, 1.51 [1.09–2.08] for SD; 1.63 [1.20–2.22] for coefficients of variance; 1.64 [1.21–2.24] for variations independent of mean). Similar trends were also observed for diastolic BP variability. These trends were unchanged in patients who were not treated with antihypertensive drugs. In contrast, no association was found between indices of BP variability during the acute stage and functional outcome after adjusting for potential confounders.

Conclusions—

These data suggest that intraindividual day-by-day BP variability during the subacute stage is associated with the 3-month functional outcome after acute ischemic stroke.

Impact of intraoperative hypotension and blood pressure fluctuations on early postoperative delirium after non-cardiac surgery

INTRODUCTION

Postoperative delirium is common in older patients. Despite its prognostic significance, the pathophysiology is incompletely understood. Although many risk factors have been identified, no reversible factors, particularly ones potentially modifiable by anaesthetic management, have been identified. The goal of this prospective cohort study was to investigate whether intraoperative hypotension was associated with postoperative delirium in older patients undergoing major non-cardiac surgery.

METHODS

Study subjects were patients >65 years of age, undergoing major non-cardiac surgery, who were enrolled in an ongoing prospective observational study of the pathophysiology of postoperative delirium. Intraoperative blood pressure was measured and predefined criteria were used to define hypotension. Delirium was measured by the Confusion Assessment Method on the first two postoperative days. Data were analysed using t-tests, two-sample proportion tests and ordered logistic regression multivariable models, including correction for multiple comparisons.

RESULTS

Data from 594 patients with a mean age of 73.6 years (sd 6.2) were studied. Of these 178 (30%) developed delirium on day 1 and 176 (30%) on day 2. Patients developing delirium were older, more often female, had lower preoperative cognitive scores, and underwent longer operations. Relative hypotension (decreases by 20, 30, or 40%) or absolute hypotension [mean arterial pressure (MAP)<50 mm Hg] were not significantly associated with postoperative delirium, nor was the duration of hypotension (MAP<50 mm Hg). Conversely, intraoperative blood pressure variance was significantly associated with postoperative delirium.

DISCUSSION

These results showed that increased blood pressure fluctuation, not absolute or relative hypotension, was predictive of postoperative delirium.

Effects of vitamin E, vitamin C and polyphenols on the rate of blood pressure variation: results of two randomised controlled trials

High blood pressure (BP) variability, which may be an important determinant of hypertensive end-organ damage, is emerging as an important predictor of cardiovascular health. Dietary antioxidants can influence BP, but their effects on variability are yet to be investigated. The aim of the present study was to assess the effects of vitamin E, vitamin C and polyphenols on the rate of daytime and night-time ambulatory BP variation. To assess these effects, two randomised, double-blind, placebo-controlled trials were performed. In the first trial (vitamin E), fifty-eight individuals with type 2 diabetes were given 500 mg/d of RRR-α-tocopherol, 500 mg/d of mixed tocopherols or placebo for 6 weeks. In the second trial (vitamin C-polyphenols), sixty-nine treated hypertensive individuals were given 500 mg/d of vitamin C, 1000 mg/d of grape-seed polyphenols, both vitamin C and polyphenols, or neither (placebo) for 6 weeks. At baseline and at the end of the 6-week intervention, 24 h ambulatory BP and rate of measurement-to-measurement BP variation were assessed. Compared with placebo, treatment with α-tocopherol, mixed tocopherols, vitamin C and polyphenols did not significantly alter the rate of daytime or night-time systolic BP, diastolic BP or pulse pressure variation (P>0·05). Treatment with the vitamin C and polyphenol combination resulted in higher BP variation: the rate of night-time systolic BP variation (P= 0·022) and pulse pressure variation (P= 0·0036) were higher and the rate of daytime systolic BP variation was higher (P= 0·056). Vitamin E, vitamin C or grape-seed polyphenols did not significantly alter the rate of BP variation. However, the increase in the rate of BP variation suggests that the combination of high doses of vitamin C and polyphenols could be detrimental to treated hypertensive individuals.

Blood pressure variability, impaired autonomic function and vascular senescence in aged spontaneously hypertensive rats are ameliorated by angiotensin blockade

OBJECTIVE

Elderly hypertensive patients are characterized by blood pressure (BP) variability, impaired autonomic function, and vascular endothelial dysfunction and stiffness. However, the mechanisms causing these conditions are unclear. The present study examined the effect of angiotensin receptor blockers (ARBs) on aged spontaneously hypertensive rats (SHR).

METHODS

We surgically implanted telemetry devices in SHR and WKY at the age of 15 weeks (Young) and 80 weeks (Aged). Aged SHR were orally administered either olmesartan or valsartan once daily at 19:00 h (at the beginning of the dark period (active phase)) for 4 weeks to examine the effects on BP variability, impaired autonomic function, and vascular senescence.

RESULTS

Aging and hypertension in SHR additively caused the following: increased low frequency (LF) power of systolic BP, a decreased spontaneous baroreceptor reflex gain (sBRG), increased BP variability, increased urinary norepinephrine excretion, increased vascular senescence-related beta-galactosidase positive cells and oxidative stress. Treatment with olmesartan or valsartan significantly ameliorated these changes in aged SHR. However, olmesartan ameliorated these changes in aged SHR better than valsartan. The reductions in BP caused by olmesartan in aged SHR were sustained longer than reductions by valsartan. This result indicates longer-lasting inhibition of the AT1 receptor by olmesartan than by valsartan.

CONCLUSION

ARBs ameliorated autonomic dysfunction, BP variability, and vascular senescence in aged SHR. Olmesartan ameliorated the aging-related disorders better than valsartan and was associated with longer-lasting AT1 receptor inhibition by olmesartan. Thus, the magnitude of improvement of these aging-related abnormalities differs for ARBs.

Blood pressure variability and cerebrovascular disease

Variability is an aspect of blood pressure (BP) relatively unknown and poorly evaluated systematically in clinical practice. Although the introduction of intensive BP measurement methods, such as ambulatory blood pressure monitoring provided evidence of the importance of BP variability in the short-term, more recently, however, emphasis has been placed on the relevance of variability of BP in the medium- and long-term. The adverse cardiovascular consequences of high BP not only depend on absolute BP values, but also on BP variability. Independently of mean BP levels, BP variations in the short- and long-term are associated an increased risk of cardiovascular events and mortality. Also, it has been suggested that modulation of such variability may explain the different level protection exerted by different antihypertensive-drug classes.

Genetic and environmental influences on blood pressure variability: a study in twins

OBJECTIVES

Blood pressure variability (BPV) and its reduction in response to antihypertensive treatment are predictors of clinical outcomes; however, little is known about its heritability. In this study, we examined the relative influence of genetic and environmental sources of variance of BPV and the extent to which it may depend on race or sex in young twins.

METHODS

Twins were enrolled from two studies. One study included 703 white twins (308 pairs and 87 singletons) aged 18-34 years, whereas another study included 242 white twins (108 pairs and 26 singletons) and 188 black twins (79 pairs and 30 singletons) aged 12-30 years. BPV was calculated from 24-h ambulatory blood pressure recording.

RESULTS

Twin modeling showed similar results in the separate analysis in both twin studies and in the meta-analysis. Familial aggregation was identified for SBP variability (SBPV) and DBP variability (DBPV) with genetic factors and common environmental factors together accounting for 18-40% and 23-31% of the total variance of SBPV and DBPV, respectively. Unique environmental factors were the largest contributor explaining up to 82-77% of the total variance of SBPV and DBPV. No sex or race difference in BPV variance components was observed. The results remained the same after adjustment for 24-h blood pressure levels.

CONCLUSIONS

The variance in BPV is predominantly determined by unique environment in youth and young adults, although familial aggregation due to additive genetic and/or common environment influences was also identified explaining about 25% of the variance in BPV.

Blood Pressure Variability: Prognostic Value and Therapeutic Implications

Blood pressure variability (BPV) is considered nowadays a novel risk factor for cardiovascular disease. Early findings in sinoaortic denervated rats have clearly shown that enhanced fluctuation of blood pressure induced left ventricular hypertrophy, vascular stiffness, and renal lesion. A large number of clinical trials confirm that short-term and long-term blood pressure variability independently contributes to target organ damage, cardiovascular events, and mortality not only in hypertensive patients but also in subjects with diabetes mellitus and chronic kidney disease. Therefore, amelioration of BPV has been suggested as an additional target of the treatment of cardiovascular diseases. Preliminary evidence obtained from meta-analysis and controlled clinical trials has shown that antihypertensive classes differ in their ability to control excessive BP fluctuations with an impact in the prevention of cardiovascular events. Calcium channel blockers seem to be more effective than other blood pressure lowering drugs for the reduction of short-term and long-term BPV. In order to increase actual knowledge regarding the prognostic value and therapeutic significance of BPV in cardiovascular disease, there is a need for additional clinical studies specifically designed for the study of the relevance of short-term and long-term BPV control by antihypertensive drugs.

Quantifying the speed of fluctuations in systolic blood pressure

Increased blood pressure variability (BPV), even in the absence of hypertension, has been identified as an important independent cardiovascular risk factor (CVRF). However, the role of the speed of changes in systolic blood pressure (SBP; vSBP) on cardiovascular risk needs to be investigated. The objective of this study was to investigate whether subjects with a high cardiovascular risk profile have an increased degree and speed of changes in SBP compared with subjects with low or no risk. Resting beat-to-beat blood pressure (BP) was recorded for 5 min. Standard BPV measures in both time and frequency domains were conducted. The s.d. of SBP (s.d.-SBP) values was used to quantify the degree of BPV. vSBP was assessed by calculating the slopes of oscillatory fluctuations in SBP for different interbeat intervals (IBI). Subjects were allocated to one of four groups according to the number of CVRFs (0, 1, 2, ≥ 3 CVRF). Of 122 subjects, 19.7% had 0 CVRF, 27.0% had 1, 32.0% had 2 and 21.3% had ≥ 3 CVRFs. There was an increase in vSBP across the four risk groups. The vSBP in patients without CVRF was 3.12 (1.09), 1 CVRF 3.23 (1.07), 2 CVRF 4.16 (2.26) and ≥ 3 CVRF 4.22 (1.66; P = 0.015). The s.d.-SBP was not significantly different between the cardiovascular risk groups. The speed of fluctuations in SBP rather than the degree of BPV is pronounced in patients with elevated cardiovascular risk. Increased speed of BP fluctuations may thus be a contributing mechanism to cardiovascular morbidity.

Nighttime blood pressure and white matter hyperintensities in patients with Parkinson disease

Increasing evidence indicates that nocturnal blood pressure level and/or loss of nocturnal blood pressure dips are sensitive markers of cardiovascular morbidity and mortality. Several studies have suggested that blunted heart rate variability and nocturnal decline in heart rate are also associated with target organ damage. These phenomena occur relatively commonly in patients with Parkinson disease (PD); however, few studies have assessed the consequences of these abnormalities in patients with PD. We investigated the influence of circadian changes in blood pressure and heart rate on white matter hyperintensities (WMHs) in patients with PD. The presence of nocturnal hypertension was associated with increased WMH score, and nighttime systolic pressure was closely related with white matter changes. Blunted heart rate variability and nocturnal decline in heart rate were also related to increasing WMH scores. The non-dipping phenomenon did not influence WMHs. These findings suggest that white matter changes are related to circadian autonomic dysfunction, particularly nocturnal hypertension in patients with PD. Therefore, it is important to monitor nocturnal blood pressure status, because modifying these circadian regulatory disturbances can be beneficial to protect against vascular brain damage in patients with PD.

Interaction between chromosome 2 and 3 regulates pulse pressure in the stroke-prone spontaneously hypertensive rat

In an F2 cross between stroke-prone spontaneously hypertensive (SHRSP) and Wistar Kyoto (WKY) rats, we previously identified blood pressure quantitative trait loci (QTL) on rat chromosome (RNO) 2 and a pulse pressure QTL on RNO3. The aims of this study were to confirm the QTL on RNO3 and to investigate interaction between RNO2 and RNO3 loci through the generation and phenotypic assessment of single RNO3 congenic (SP.WKY(Gla)3a) and bicongenic (SP.WKY(Gla)2a/3a) strains. Hemodynamic profiling, vascular function, and renal histology were examined in these newly generated strains along with the previously reported RNO2 congenic strain (SP.WKY(Gla)2a). Our results demonstrate significant equivalent reduction in systolic, diastolic, and pulse pressure phenotypes in SP.WKY(Gla)3a and SP.WKY(Gla)2a rats, whereas greater reductions were observed with the SP.WKY(Gla)2a/3a bicongenic strain achieving blood pressure levels similar to normotensive WKY rats. Epistasis was observed between pulse pressure QTL on RNO2 and 3 at baseline and during 1% salt challenge. Vascular function and renal pathology studies indicate that QTL on RNO3 are responsible for salt-induced kidney pathology, whereas QTL on RNO2 seem to have greater impact on vascular function. RNO3 congenic and bicongenic strains have confirmed the importance of SHRSP alleles in the RNO3 congenic interval on pulse pressure variability and end-organ damage. These strains will allow interrogation of complex gene-gene and gene-environment interactions contributing to salt-sensitive hypertension and renal pathology in the SHRSP rat.

Black tea lowers the rate of blood pressure variation: a randomized controlled trial

BACKGROUND

Measures of blood pressure variation have been associated with cardiovascular disease and related outcomes. The regular consumption of black tea can lower blood pressure, but its effects on blood pressure variation have yet to be investigated.

OBJECTIVE

We aimed to assess the effects of black tea consumption on the rate of ambulatory blood pressure variation.

DESIGN

Men and women (n = 111) with systolic blood pressure between 115 and 150 mm Hg at screening were recruited in a randomized, controlled, double-blind, 6-mo parallel-designed trial designed primarily to assess effects on blood pressure. Participants consumed 3 cups/d of either powdered black tea solids (tea) or a flavonoid-free caffeine-matched beverage (control). The 24-h ambulatory blood pressure level and rate of measurement-to-measurement blood pressure variation were assessed at baseline, day 1, and 3 and 6 mo.

RESULTS

Across the 3 time points, tea, compared with the control, resulted in lower rates of systolic (P = 0.0045) and diastolic (P = 0.016) blood pressure variation by ~10% during nighttime (2200-0600). These effects, which were immediate at day 1 and sustained over 6 mo, were independent of the level of blood pressure and heart rate. The rate of blood pressure variation was not significantly altered during daytime (0800-2000).

CONCLUSIONS

These findings indicate that a component of black tea solids, other than caffeine, can influence the rate of blood pressure variation during nighttime. Thus, small dietary changes have the potential to significantly influence the rate of blood pressure variation. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTR12607000543482.

Association of BP variability with mortality among African Americans with CKD

BACKGROUND AND OBJECTIVES

Increased systolic BP visit-to-visit variability (SBV) may be associated with higher overall mortality and cardiovascular events. However, few studies have examined these associations in patients with CKD, and the relation of SBV with CKD progression and ESRD has not been shown. This study analyzed the association of SBV with overall mortality, cardiovascular mortality, cardiovascular events, and renal events among individuals enrolled in the African American Study of Kidney Disease (AASK) trial.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a prospective observational study of 908 participants during the trial phase of the AASK study, with at least 1 year of BP measurements available and followed for 3-6.4 years. SBV was calculated as the SD of the systolic pressure from five visits occurring 3-12 months after randomization. The association of SBV with risk of overall mortality, cardiovascular mortality, a composite of fatal and nonfatal cardiovascular events, and a composite of renal events was assessed using proportional hazards regression and adjusting for multiple potential confounders.

RESULTS

Greater SBV was associated with higher overall mortality. The adjusted hazard ratio (95% confidence interval) was 2.82 (1.14-6.95) comparing the highest with lowest tertile of SBV. A similar comparison revealed that greater SBV was also associated with cardiovascular mortality (adjusted hazard ratio, 4.91; 1.12-21.50). SBV was associated with both the cardiovascular renal composite endpoints in unadjusted but not adjusted analyses.

CONCLUSIONS

In African Americans with CKD, SBV is strongly and independently associated with overall and cardiovascular mortality.

Cardiovascular risk

Cardiovascular disease is a major, growing, worldwide problem. It is important that individuals at risk of developing cardiovascular disease can be effectively identified and appropriately stratified according to risk. This review examines what we understand by the term risk, traditional and novel risk factors, clinical scoring systems, and the use of risk for informing prescribing decisions. Many different cardiovascular risk factors have been identified. Established, traditional factors such as ageing are powerful predictors of adverse outcome, and in the case of hypertension and dyslipidaemia are the major targets for therapeutic intervention. Numerous novel biomarkers have also been described, such as inflammatory and genetic markers. These have yet to be shown to be of value in improving risk prediction, but may represent potential therapeutic targets and facilitate more targeted use of existing therapies. Risk factors have been incorporated into several cardiovascular disease prediction algorithms, such as the Framingham equation, SCORE and QRISK. These have relatively poor predictive power, and uncertainties remain with regards to aspects such as choice of equation, different risk thresholds and the roles of relative risk, lifetime risk and reversible factors in identifying and treating at-risk individuals. Nonetheless, such scores provide objective and transparent means of quantifying risk and their integration into therapeutic guidelines enables equitable and cost-effective distribution of health service resources and improves the consistency and quality of clinical decision making.