Blood pressure variability in relation to outcome in the International Database of Ambulatory blood pressure in relation to Cardiovascular Outcome

Effect of lidocaine on intraoperative blood pressure variability in patients undergoing major vascular surgery

BACKGROUND

Dynamic fluctuations of arterial blood pressure known as blood pressure variability (BPV) may have short and long-term undesirable consequences. During surgical procedures blood pressure is usually measured in equal intervals allowing to assess its intraoperative variability, which significance for peri and post-operative period is still under debate. Lidocaine has positive cardiovascular effects, which may go beyond its antiarrhythmic activity. The aim of the study was to verify whether the use of intravenous lidocaine may affect intraoperative BPV in patients undergoing major vascular procedures.

METHODS

We performed a post-hoc analysis of the data collected during the previous randomized clinical trial by Gajniak et al. In the original study patients undergoing elective abdominal aorta and/or iliac arteries open surgery were randomized into two groups to receive intravenous infusion of 1% lidocaine or placebo at the same infusion rate based on ideal body weight, in concomitance with general anesthesia. We analyzed systolic (SBP), diastolic (DBP) and mean arterial blood (MAP) pressure recorded in 5-minute intervals (from the first measurement before induction of general anaesthesia until the last after emergence from anaesthesia). Blood pressure variability was then calculated for SBP and MAP, and expressed as: standard deviation (SD), coefficient of variation (CV), average real variability (ARV) and coefficient of hemodynamic stability (C10%), and compared between both groups.

RESULTS

All calculated indexes were comparable between groups. In the lidocaine and placebo groups systolic blood pressure SD, CV, AVR and C10% were 20.17 vs. 19.28, 16.40 vs. 15.64, 14.74 vs. 14.08 and 0.45 vs. 0.45 respectively. No differences were observed regarding type of surgery, operating and anaesthetic time, administration of vasoactive agents and intravenous fluids, including blood products.

CONCLUSION

In high-risk vascular surgery performed under general anesthesia, lidocaine infusion had no effect on arterial blood pressure variability.

TRIAL REGISTRATION

ClinicalTrials.gov; NCT04691726 post-hoc analysis; date of registration 31/12/2020.

Prognostic Relevance of Short-Term Blood Pressure Variability. The Spanish ABPM Registry

BACKGROUND

The prognostic relevance of short-term blood pressure (BP) variability in hypertension is not clearly established. We aimed to evaluate the association of short-term BP variability, with all-cause and cardiovascular mortality in a large cohort of patients with hypertension.

METHODS

We selected 59 124 patients from the Spanish Ambulatory Blood Pressure Monitoring Registry from 2004 to 2014 (median follow-up: 9.7 years). Systolic and diastolic BP SD and coefficient of variation from daytime and nighttime, weighted SD, weighted coefficient of variation, average real variability (mean of differences between consecutive readings), and BP variability ratio (ratio between systolic and diastolic 24-hour SD) were calculated through baseline 24-hour ambulatory BP monitoring. Association with all-cause and cardiovascular mortality were assessed by Cox regression models adjusted for clinical confounders and BP.

RESULTS

Patients who died during follow-up had higher values of BP variability compared with those remaining alive. In adjusted models systolic and diastolic daytime and weighted SD and coefficient of variation, average real variability, as well as systolic nighttime SD and BP variability ratio were all significantly associated with all-cause and cardiovascular mortality. Hazard ratios for 1-SD increase in the systolic components ranged from 1.05 to 1.12 for all-cause mortality and from 1.07 to 1.17 for cardiovascular mortality. A daytime SD≥13 mm Hg, a nighttime and a weighted SD≥12 mm Hg, and an average real variability ≥10 mm Hg, all systolic, were independently associated with mortality.

CONCLUSIONS

Short-term blood pressure variability shows a relatively weak but significant association with all-cause and cardiovascular mortality in patients with hypertension.

Association of Variability and Hypertensive Loads in 24-h Blood Pressure With Mortality and Cardiovascular Risk

BACKGROUND

Evidence shows that high 24-h blood pressure (BP) variability increases cardiovascular risk. We investigated whether 24-h BP variability relates to mortality and cardiovascular risk due to inherent variability and/or hypertensive loads in 24-h BP.

METHODS

A total of 1,050 participants from the Maracaibo Aging Study (mean age, 66 years; women, 67.2%) underwent 24-h ambulatory BP monitoring and were followed between 2001 and 2016. To evaluate inherent BP variability, we used average real variability (ARV) as it captures variability among consecutive BP readings. 24-h systolic BP load was the proportion (%) of systolic BP readings ≥130 mm Hg during the daytime and ≥110 during the nighttime. Our primary endpoint was total mortality and major adverse cardiovascular endpoints (MACE). Statistics included Cox proportional models.

RESULTS

During a median follow-up of 8.3 years, 299 participants died and 210 experienced MACE. Each +2 mm Hg (corresponding to 1-standard deviation) higher 24-h systolic ARV (mean value, 9.0 ± 2.0 mm Hg) was associated with higher hazard ratios (HRs) for mortality by 1.28-fold (95% confidence interval [CI], 1.14-1.43) and for MACE by 1.24-fold (95% CI, 1.08-1.42). Each 30% higher 24-h systolic BP load (median value, 63%) was associated with mortality and MACE with HRs of 1.29 (95% CI, 1.15-1.46) and 1.28 (95% CI, 1.10-1.48); respectively. After models were additionally adjusted by BP level, only ARV was associated with mortality (HR, 1.17; 95% CI, 1.04-1.33) and MACE (HR, 1.16; 95% CI, 1.00-1.34).

CONCLUSIONS

High ARV and hypertensive loads in 24-h systolic BP were associated with mortality and cardiovascular risk, however, only ARV is associated independently of the BP level.

Circadian blood pressure dysregulation in children with obstructive sleep apnea

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) adversely affects normal blood pressure (BP) and may disrupt circadian BP patterns. We sought to examine 24-hour circadian BP rhythms in children with OSA and healthy controls.

METHODS

Children 5-14 years with OSA and healthy controls underwent 24-hour BP monitoring and actigraphy to quantify sleep. Shape invariant statistical models compared circadian BP patterns (e.g. times of BP peaks, time arrived at peak BP velocity [TAPV]) in the OSA and control groups.

RESULTS

The analytic sample included 219 children (mild OSA: n = 52; moderate-to-severe OSA (MS-OSA): n = 50; controls: n = 117). In the morning, the MS-OSA group had earlier TAPV for DBP than controls (51 minutes, p < 0.001). TAPV in the evening was earlier for the MS-OSA group than controls (SBP: 95 minutes, p < 0.001; DBP: 28 minutes, p = 0.028). At mid-day, SBP and DBP velocity nadirs were earlier for the MS-OSA group than controls (SBP: 57 minutes, p < 0.001; DBP: 38 minutes, p < 0.01). The MS-OSA group reached most BP values significantly earlier than controls; the largest differences were 118 minutes (SBP) and 43 minutes (DBP) (p < 0.001). SBP and DBP were elevated in the MS-OSA group (hours 18-21 and 7--12, respectively, p < 0.01) compared to controls. The MS-OSA group was prone to "non-dipping" compared to controls (SBP: odds ratio [OR] = 2.16, 95% CI: 1.09, 4.29; DBP: OR = 3.45, 95% CI: 1.21, 10.23).

CONCLUSIONS

Children with MS-OSA had changes in circadian BP patterns, namely earlier TAPV and BP peaks and nadirs than controls. Circadian disturbances in BP rhythms may be key to mapping the natural history of BP dysregulation in children with OSA.

Short-term blood pressure variability as a potential therapeutic target for kidney disease

Short-term blood pressure variability (BPV) measured with ambulatory blood pressure (BP) monitoring has been demonstrated to be significant in predicting various clinical outcomes. Short-term BPV is distinguished from long-term BPV based on the time interval in which BP fluctuations are measured. Increased short-term BPV has been linked to detrimental effects on the microvascular structure and contributes to subclinical organ damage in the heart, blood vessels, and kidneys, regardless of the average 24-h BP levels. Short-term BPV can be defined by various measures, including calculated metrics (standard deviation, coefficient of variation, average real variability, weighted standard deviation, variability independent of the mean) or dipping patterns. Nevertheless, the additional role of short-term BPV beyond the predictive value of average 24-h BPs or established risk factors for cardiovascular disease and kidney disease remains unclear. In particular, longitudinal studies that evaluate the association between short-term BPV and kidney function impairment are limited and no conclusive data exist regarding which short-term BPV indicators most accurately reflect the prognosis of kidney disease. The issue of how to treat BPV in clinical practice is another concern that is frequently raised. This paper presents a review of the evidence for the prognostic role of short-term BPV in kidney outcomes. Additionally, this review discusses the remaining concerns about short-term BPV that need to be further investigated as an independent risk modifier.

Sex Differences in Ambulatory Blood Pressure Levels and Subtypes in a Large Italian Community Cohort

BACKGROUND

Sex differences in blood pressure control are recognized. We systematically investigated sex differences in specific components of ambulatory blood pressure (ABP), including variability, day-night changes, morning surge, and hypertension types.

METHODS

We analyzed ABPs of 52 911 participants (45.6% male, 54.4% female, 37.0% treated for hypertension) visiting 860 Italian community pharmacies. Sex differences in ABP levels and patterns were evaluated in the whole group and 4 risk groups (antihypertensive-treated patients, patients with diabetes, dyslipidemia, or cardiovascular disease).

RESULTS

Average 24-hour, day-time, and night-time blood pressure values were consistently higher in males than females (P<0.001). Variability in ABP was higher in females, except during the night. Nondippers and an abnormal morning surge were more common among males (odds ratio and 95% CI, 1.282 [1.230-1.335] and 1.244 [1.159-1.335]; P<0.001). The prevalence of 24-hour and masked hypertension was higher in males (odds ratio and 95% CI, 2.093 [2.019-2.170] and 1.347 [1.283-1.415]; P<0.001) and that of white-coat hypertension in females (0.719 [0.684-0.755]; P<0.001). Ambulatory heart rate mean values were higher (P<0.001) in females. Day-time HR variability was higher and night-time heart rate variability lower in females (P<0.001). Sex differences in ABP levels and patterns detected in the whole population were replicated in all risk groups, except for the prevalence of abnormal morning surge (between sexes difference in antihypertensive-treated participants only).

CONCLUSIONS

Females show better ABP control than males, but with an increased blood pressure variability and a greater prevalence of white-coat hypertension. These findings support tailored management of hypertension.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03781401.

Position of 24-hour ambulatory blood pressure monitoring in modern practice

Currently, 24-hour ambulatory blood pressure (BP) monitoring (ABPM) is the gold standard for diagnosing hypertension (HTN) and evaluating the effectiveness of antihypertensive therapy. The method provides information about some BP parameters that cannot be obtained in any other way. ABPM is reasonable in any patient with a documented increase in BP, especially if specific BP phenotypes are suspected: white coat HTN and masked HTN. Antihypertensive therapy under the ABPM, on average, is more economical and is not associated with overprescribing of drugs and their combinations. Based on the ABPM data, calculating a number of additional indicators of the 24-hour BP profile is possible, but their scope is still limited to the research field. In the conclusion on ABPM data, the results of office BP measurement and antihypertensive therapy should be indicated.

Results of the prospective observation in routine practice of hypertensive patients with concomitant chronic respiratory diseases. Part II. Predictors of adverse events

Aim. To study the predictors of adverse events in hypertensive (HTN) patients, including those with chronic respiratory diseases (CRDs).

Material and methods. Regression analysis evaluated clinical and anamnestic data and blood pressure (BP) in outpatients with stage II-III HTN (n=156): 49 patients had asthma, 20 — chronic obstructive pulmonary disease; age — 63,4±8,8 years, women — 72,4%, followup duration 29,3±8,0 months. The outcomes included in the composite primary endpoint (EP) were registered in 32 patients (death, major cardiovascular events and complications), while the secondary EPs were registered in 57 patients (hospitalizations, emergency calls, temporary disability due to cardiovascular disease/CRD, hypertensive crisis, exacerbation of CRD, pneumonia, respiratory failure), and tertiary EP — in 76 (other significant diseases/conditions, including increased blood pressure without hypertensive crisis, requiring correction of regular therapy).

Results. Predictors of primary EPs were the decrease level of nocturnal diastolic BP (DBP) (β=-5,335, p=0,026), nocturnal DBP variability (β=1,796, p=0,007), blood leukocyte level (β=0,241, p=0,039); secondary EPs — systolic blood pressure ≥170 mm Hg in history (β=1,305-1,641, p=0,037-0,017), statin use (β=-0,997, p=0,037), CRD (β=0,734, p=0,023), blood platelet level (β=-0,008, p=0,022); tertiary EPs — only CRD (β=1,082, p<0,0001).

Conclusion. Patients with HTN need complex multifactorial prevention. It is necessary to improve the control of office and ambulatory blood pressure, blood lipids, especially in the presence of CRD, to improve the control of CRDs themselves. The method of 24-hour blood pressure monitoring should be used more often in routine practice, including assessing the degree of nocturnal blood pressure reduction and its variability.

A multicenter prospective study of home blood pressure measurement (HBPM) during pregnancy in Japanese women

In the near future, hypertensive disorders of pregnancy (HDP) have been diagnosed by home blood pressure monitoring (HBPM) instead of clinic BP monitoring. A multicenter study of HBPM was performed in pregnant Japanese women in the non-high risk group for HDP. Participants were women (n = 218), uncomplicated pregnancy who self-measured and recorded their HBP daily. Twelve women developed HDP. HBP was appropriate (100 mmHg in systole and 63 mmHg in diastole), bottoming out at 17 to 21 weeks of gestation. It increased after 24 weeks of gestation and returned to non-pregnant levels by 4 weeks of postpartum. The upper limit of normal HBP was defined as the mean value +3 SD for systolic and mean +2 SD for diastolic with reference to the criteria for non-pregnant women. Using the polynomial equation, the hypertensive cut-off of systolic HBP was 125 mmHg at 15 weeks and 132 mmHg at 30 weeks of gestation, while it for diastolic HBP was 79 mmHg at 15 weeks and 81 mmHg at 30 weeks of gestation. Systolic HBP in women who developed HDP was higher after 24 weeks of gestation, and diastolic HBP was higher during most of the pregnancy compared to normal pregnancy. When the variability of individual HBP in women developed HDP compared to normal pregnant women was examined using the coefficient of variation (CV), the CV was lower in HDP before the onset of HDP. HBPM can be used not only for HDP determination, but also for early detection of HDP.

Does Blood Pressure Variability Affect Hypertension Development in Prehypertensive Patients?

BACKGROUND

Blood pressure variability (BPV) is associated with end organ damage and cardiovascular outcomes in hypertensive patients. Prehypertensive patients frequently develop hypertension (HT). The purpose of the present study was to evaluate the effect of BPV on the development of HT.

METHODS

Two hundred and seven prehypertensive patients from the Cappadocia cohort were monitored over 2 years, and 24-hour ambulatory blood pressure monitoring (ABPM), office BP, and home BP measurements were subsequently performed at 4- to 6-month intervals. BPV was calculated as average real variability (ARV) from 24-h ABPM data, home BP, and office BP measurements at first visit. The relationship was evaluated between baseline ARV and the development of HT.

RESULTS

HT was diagnosed in 25.60% of subjects. Baseline 24-hour ABPM systolic blood pressure (SBP)ARV and diastolic blood pressure (DBP)ARV and home SBPARV were significantly higher in patients who developed HT than the other patients (P 0.006, 0.001 and 0.006, respectively). Baseline 24-hour ABPM SBPARV and home SBPARV exceeding the 90th percentile were identified as parameters affecting development of HT at logistic regression analysis.

CONCLUSION

In conclusion, our prospective observational cohort study showed that short-term BPV in particular can predict the development of HT in the prehypertensive population.

Relationship between morning blood pressure surge and the frontal plane QRS-T angle in newly diagnosed hypertensive patients

BACKGROUND

Morning blood pressure surge (MBPS) plays an important role in target organ damage and major adverse cardiac events. The frontal QRS-T [f(QRS-T)] angle is the electrocardiographic marker and index of ventricular arrhythmogenic events. We aimed to investigate the relationship between MBPS and the f(QRS-T) angle, which is an indicator of ventricular repolarization disorder, in patients with newly diagnosed HT.

METHODS

Between June 2020 and March 2021, 263 patients with newly diagnosed HT who were admitted to our outpatient clinic were prospectively included in the study. According to ambulatory blood pressure monitoring (ABPM), the patients were categorized into two groups: Group-I: low-value MBPS (<37 mm Hg), and group-II: high-value MBPS (≥37 mm Hg). The f(QRS-T) angle calculated from the 12-lead electrocardiogram and all other data were compared between the groups.

RESULTS

A total of 186 newly diagnosed HT patients who met the inclusion criteria were included in the study. The average f(QRS-T) angle in Groups I and 2 was 21° ± 16° and 51° ± 30°, respectively (P < .001). According to multivariate regression analysis, T peak-end and MBPS were found to be independent predictors of the f(QRS-T) angle.

CONCLUSIONS

As a result of our study, we found that the f(QRS-T) angle was widened in patients with exaggerated MBPS. The cause of increased cardiovascular outcomes in patients with exaggerated MBPS may be explained by widened in the f(QRS-T) angle that is a ventricular repolarization parameter.

Cardiovascular Risk Factors: It's Time to Focus on Variability!

Atherosclerotic heart disease remains a leading cause of morbidity and mortality worldwide. While extensive research supports cardiovascular risk factor reduction in the form of achieving evidence-based blood pressure, lipid, glucose, and body weight targets as a means to improve cardiovascular outcomes, residual risk remains. Emerging data have demonstrated that the intraindividual variability of these risk factor targets potentially contribute to this residual risk. It may therefore be time to define risk factor by not only its magnitude and duration as done traditionally, but perhaps also by the variability of that particular risk factor over time.

Increased Arterial Stiffness Amplifies the Association Between Home Blood Pressure Variability and Cardiac Overload

Increased blood pressure (BP) variability, an index of hemodynamic stress, leads to cardiac overload and worse cardiovascular prognosis. The association between day-by-day home BP variability and NT-proBNP (N-terminal pro-B-type natriuretic peptide) as an index of cardiac overload may be amplified by increased arterial stiffness as assessed by brachial-ankle pulse wave velocity (baPWV). J-HOP (Japan Morning Surge-Home Blood Pressure) Study participants who were selected from a practitioner-based population with at least one cardiovascular risk factor underwent home BP monitoring, and their BP levels and SD, coefficient of variation, and average real variability as indexes of systolic BP variability were assessed. We analyzed 2115 individuals without prevalent heart failure and divided them into lower (<1800 cm/s, n=1464) and higher (≥1800 cm/s, n=651) baPWV groups. The higher baPWV group had significantly higher SD SBP , CV SBP , ARV SBP values, and NT-proBNP levels than the lower baPWV group (all P <0.001). In the higher baPWV group, a multiple linear regression analysis revealed that the SD SBP was associated with the NT-proBNP level after adjustment for traditional cardiovascular risk factors including the average home systolic BP (coefficient per 1 SD increase, 0.049 [95% CI, 0.018–0.081]; P =0.002). Similar trends were found for CV SBP ( P =0.003) and ARV SBP ( P =0.004). However, these associations were not found in the lower baPWV group. There was an interaction between all indexes of systolic BP variability and the NT-proBNP level according to lower or higher baPWV group (all P <0.05). Arterial stiffness amplified the association between home BP variability and cardiac overload.

Risk Factor Variability and Cardiovascular Outcome: JACC Review Topic of the Week

Until recently, intraindividual visit-to-visit variability of cardiovascular risk factors has been dismissed as random fluctuation. This simplistic concept was challenged by demonstrating that visit-to-visit blood pressure variability, independent of average blood pressure, was a powerful risk factor for stroke. Subsequently, variability of other cardiovascular risk factors such as cholesterol, glycemia, and body weight was documented to increase risk independent of their absolute values. Variability of these risk factors has been demonstrated to be a powerful predictor for all-cause and cardiovascular mortality, stroke, coronary artery disease, heart failure, end-stage renal disease, and dementia. With the notable exception of heart rate, cardiovascular risk factors must now be defined by 2 components: the magnitude and duration of sustained risk factor elevation and, equally important, the variability of the same risk factor over time.

Prognostic Relevance of Short-Term Blood Pressure Variability: The Spanish ABPM Registry

The prognostic relevance of short-term blood pressure (BP) variability in hypertension is not clearly established. We aimed to evaluate the association of short-term BP variability, assessed through ambulatory BP monitoring, with total and cardiovascular mortality in a large cohort of patients with hypertension. We selected 63 910 subjects from the Spanish ABPM Registry from 2004 to 2014, with a median follow-up of 4.7 years. Systolic and diastolic BP SD from 24 hours, daytime, and nighttime, weighted SD (mean of daytime and nighttime SD weighted for period duration), average real variability (mean of differences between consecutive readings), variation independent of the mean, and BP variability ratio (ratio between systolic and diastolic 24-hour SD) were calculated through 24-hour ambulatory BP monitoring performed at baseline. Association with total and cardiovascular mortality (obtained through death certificates) were assessed by Cox regression models adjusted for clinical confounders and BP. Patients who died during follow-up had higher values of BP variability compared with those remaining alive. In fully adjusted models, daytime, nighttime, and weighted SD, systolic and diastolic, as well as diastolic average real variability, were all significantly associated with total and cardiovascular mortality. Hazard ratios for 1 SD increase ranged from 1.05 to 1.09 for total mortality and from 1.07 to 1.12 for cardiovascular mortality. A nighttime systolic SD ≥12 mm Hg was independently associated with total (hazard ratio: 1.13 [95% CI, 1.06-1.21]) and cardiovascular mortality (hazard ratio: 1.21 [95% CI, 1.09-1.36]). We conclude that short-term BP variability is independently associated with total and cardiovascular mortality in patients with hypertension.

Effect of antihypertensive treatment on 24-h blood pressure variability: pooled individual data analysis of ambulatory blood pressure monitoring studies based on olmesartan mono or combination treatment

Objective:

To evaluate the impact of olmesartan alone or combined with one to three antihypertensive drugs on 24-h blood pressure variability (BPV) and on distribution of BP reduction in a pooled individual data analysis of 10 double-blind, randomized, ambulatory BP monitoring (ABPM) studies.

Methods:

ABPMs were performed before and after 6–12 weeks of treatment with placebo (n = 119), active control monotherapy [n = 1195, angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), dihydropyridine calcium channel blockers (DCCBs)] olmesartan monotherapy (n = 1410), active control dual combination [n = 79, DCCB + thiazide diuretic (TD)], olmesartan dual combination (n = 637, DCCB or TD), and triple combination therapy (n = 102, DCCB+TD). 24-h BPV was calculated as unweighted or weighted SD of the mean BP, and average real variability. BP control was assessed by smoothness index and treatment-on-variability index.

Results:

The greatest effect on 24-h systolic BPV/diastolic BPV was observed under olmesartan triple [−2.6/−1.9; −1.9/−1.3; −1.4/−1.3 mmHg] and active control dual combination [−1.8/−1.4; −1.9/−1.5; −1.2/−1.1 mmHg]. Smoothness indexes and treatment-on-variability indexes were significantly (P = 0.0001) higher under olmesartan dual (1.53/1.22, 1.67/1.29, 2.05/1.59), olmesartan triple (2.47/1.85, 2.80/2.06, 3.64/2.67), or active control dual combination (1.70/1.26, 1.85/1.33, 2.29/1.65) than under monotherapies (control: 0.86/0.73, 0.80/0.65, 1.01/0.82; olmesartan: 1.02/0.86, 0.95/0.78, 1.23/1.00). They were also greater in patients receiving high-dose olmesartan monotherapy or high-dose olmesartan dual combination than in the corresponding low-dose group.

Conclusion:

Olmesartan plus a DCCB and/or a TD produces a larger, more sustained, and smoother BP reduction than placebo and monotherapies, a desirable feature for a more effective prevention of the cardiovascular consequences of uncontrolled hypertension.

Association of short-term blood pressure variability with cardiovascular mortality among incident hemodialysis patients

Objective: To investigate the association of short-term blood pressure variability (BPV) with cardiovascular mortality in hemodialysis (HD) patients, using a reliable index called average real variability (ARV), and to assess the factors associated with ARV in incident HD population.

Methods: A total of 103 HD patients were recruited, with 44-h ambulatory blood pressure monitoring performed after the midweek HD session. Systolic BPV was assessed by SD, coefficient of variation (CV), and ARV, respectively. Laboratory data were obtained from blood samples before the midweek HD. All patients were followed up for 24 months.

Results: According to the median of BPV indices, the comparisons between patients with the low and high values were conducted. Kaplan–Meier analysis showed the survival curves corresponding to median of SD and CV exhibit similar performance for the low and high groups (p = .647, p = .098, respectively). In contrast, patients with higher ARV had a lower survival rate than those with lower ARV (77.8% vs. 98.0%, p = .002). After adjustment for demographics and clinical factors, ARV (HR: 1.143; 95% CI: 1.022–1.279, p = .019) and high-sensitivity C-reactive protein (HR: 1.394; 95% CI: 1.025–1.363, p = .021) were associated with increased risk of cardiovascular mortality in HD patients. Age and interdialytic weight gain (IDWG) were related factors for ARV (β = 0.065, p = .005; β = 0.825, p = .003, respectively).

Conclusions: Greater ARV was independently associated with increased risk of cardiovascular mortality in HD patients. Age and IDWG were independent related factors for ARV.

Understanding short-term blood-pressure-variability phenotypes: from concept to clinical practice

Clinic blood pressure (BP) is recognized as the gold standard for the screening, diagnosis, and management of hypertension. However, optimal diagnosis and successful management of hypertension cannot be achieved exclusively by a handful of conventionally acquired BP readings. It is critical to estimate the magnitude of BP variability by estimating and quantifying each individual patient's specific BP variations. Short-term BP variability or exaggerated circadian BP variations that occur within a day are associated with increased cardiovascular events, mortality and target-organ damage. Popular concepts of BP variability, including "white-coat hypertension" and "masked hypertension", are well recognized in clinical practice. However, nocturnal hypertension, morning surge, and morning hypertension are also important phenotypes of short-term BP variability that warrant attention, especially in the primary-care setting. In this review, we try to theorize and explain these phenotypes to ensure they are better understood and recognized in day-to-day clinical practice.

Diurnal blood pressure changes

The definition of diurnal blood pressure changes varies widely, which can be confusing. Short-term blood pressure variability during a 24-h period and the dipping status of diurnal blood pressure can be captured by ambulatory blood pressure monitoring, and these metrics are reported to have prognostic significance for cardiovascular complications. Morning blood pressure surge also indicates this risk, but its effect may be limited to populations with specific conditions. Meanwhile, the combined use of conventional office blood pressure and out-of-office blood pressure allows us to identify people with white-coat and masked hypertension. Current home devices can measure nocturnal blood pressure during sleep more conveniently than ambulatory monitoring; however, we should pay attention to blood pressure measurement conditions regardless of whether they are in a home, ambulatory, or office setting. The relatively poor reproducibility of diurnal blood pressure changes, including the nocturnal fall of blood pressure, is another underestimated issue to be addressed. Although information on diurnal blood pressure changes is expected to be used more effectively in the future, we should also keep in mind that blood pressure levels have remained central to the primary and secondary prevention of blood pressure-related cardiovascular diseases in clinical practice.

Relationship Between Blood Pressure Variability and Cognitive Function in Elderly Patients With Good Blood Pressure Control

BACKGROUND

Although higher blood pressure (BP) levels and BP variability have been associated with cognitive impairment, data are sparse regarding the relationship between BP variability and cognitive function in elderly patients with well BP control.

METHODS

We analyzed 232 ambulatory patients with one or more cardiovascular risk factors. All patients underwent ambulatory BP monitoring and the Japanese version of the Montreal Cognitive Assessment (MoCA-J).

RESULTS

The mean age was 77.7 ± 8.3 years; 33.6% were male, and 85.3% were taking antihypertensive drugs. The average 24-hour BP level was 118.7 ± 10.0/68.3 ± 6.4 mm Hg. When we divided the weighted SD of systolic BP (SBP) as a measure of BP variability into quartiles, the top quartile group (≥19.6 mm Hg) had a significantly lower total MoCA-J score (15.4 [95% confidence interval 14.2-16.7] vs. 17.9 [17.2-18.6], P = 0.001) and lower scores on several domains, visuoexecutive (2.2 [1.9-2.6] vs. 2.8 [2.6-2.9], P = 0.012), abstraction (1.0 [0.7-1.2] vs. 1.3 [1.1-1.4], P = 0.015), attention (2.8 [2.4-3.1] vs. 3.6 [3.4-3.8], P = 0.001), and naming (2.1 [1.9-2.3] vs. 2.5 [2.4-2.6], P = 0.001) than quartiles 1 through 3 combined, after adjustment for age and 24-hour SBP. These associations were not found in the quartiles of 24-hour SBP.

CONCLUSIONS

In elderly patients with well ambulatory BP control, higher BP variability but not average ambulatory BP level was associated with cognitive impairment.

Relationship Between Short-Term Blood Pressure Variability and Incidence of Acute Kidney Injury in Critically Ill Patients

BACKGROUND/AIMS

Blood pressure (BP) variability is associated with cardiovascular events, and cerebral and renal damage. The aim of this study was to investigate any potential relationship between short-term BP variability and incidence of acute onset conditions, such as acute kidney injury (AKI), in critically ill patients.

METHODS

BP was monitored to analyze its variability in critically ill patients in present study. Short-term BP variability was assessed as average real variability (ARV), standard deviation (SD) and coefficient of variation (CV) of 24-hour BP.

RESULTS

A total of 565 patients were included, 41.2% (n=233) of which presented with AKI after admission (AKI stage I, n = 94; stage II, n = 37; stage III, n = 102). The mean APACHE II score was 21.5 for all patients. ARV of 24 h systolic BP was significantly higher in patients with AKI (p<0.001). This association remained (p=0.006) after adjustment for potential confounders. The incidence of AKI increased with the ARV from 14.0% (ARV ≤6 mmHg) to 73.9% (ARV >14 mmHg). A weak association was also found between BP variability and hospital mortality in critically ill patients.

CONCLUSION

BP variability is correlated with the incidence of AKI in critically ill patients.

Methodology and technology for peripheral and central blood pressure and blood pressure variability measurement: current status and future directions - Position statement of the European Society of Hypertension Working Group on blood pressure monitoring and cardiovascular variability

Office blood pressure measurement has been the basis for hypertension evaluation for almost a century. However, the evaluation of blood pressure out of the office using ambulatory or self-home monitoring is now strongly recommended for the accurate diagnosis in many, if not all, cases with suspected hypertension. Moreover, there is evidence that the variability of blood pressure might offer prognostic information that is independent of the average blood pressure level. Recently, advancement in technology has provided noninvasive evaluation of central (aortic) blood pressure, which might have attributes that are additive to the conventional brachial blood pressure measurement. This position statement, developed by international experts, deals with key research and practical issues in regard to peripheral blood pressure measurement (office, home, and ambulatory), blood pressure variability, and central blood pressure measurement. The objective is to present current achievements, identify gaps in knowledge and issues concerning clinical application, and present relevant research questions and directions to investigators and manufacturers for future research and development (primary goal).

Outcome-Driven Thresholds for Increased Home Blood Pressure Variability

Increased blood pressure (BP) variability predicts cardiovascular disease, but lack of operational thresholds limits its use in clinical practice. Our aim was to define outcome-driven thresholds for increased day-to-day home BP variability. We studied a population-based sample of 6238 individuals (mean age 60.0±12.9, 56.4% women) from Japan, Greece, and Finland. All participants self-measured their home BP on ≥3 days. We defined home BP variability as the coefficient of variation of the first morning BPs on 3 to 7 days. We assessed the association between systolic/diastolic BP variability (as a continuous variable and in deciles of coefficient of variation) and cardiovascular outcomes using Cox regression models adjusted for cohort and classical cardiovascular risk factors, including BP. During a follow-up of 9.3±3.6 years, 304 cardiovascular deaths and 715 cardiovascular events occurred. A 1 SD increase in systolic/diastolic home BP variability was associated with increased risk of cardiovascular mortality (hazard ratio, 1.17/1.22; 95% confidence interval, 1.06-1.30/1.11-1.34; P=0.003/<0.0001) and cardiovascular events (hazard ratio, 1.13/1.14; 95% confidence interval, 1.05-1.21/1.07-1.23; P=0.0007/0.0002). Compared with the average risk in the whole population, risk of cardiovascular deaths (hazard ratio, 1.66/1.84; 95% confidence interval, 1.27-2.17/1.42-2.37; P=0.0002/<0.0001) and events (hazard ratio, 1.46/1.42; 95% confidence interval, 1.21-1.76/1.17-1.71; P<0.0001/0.0004) was increased in the highest decile of systolic/diastolic BP variability (coefficient of variation>11.0/12.8). Increased home BP variability predicts cardiovascular outcomes in the general population. Individuals with a systolic/diastolic coefficient of variation of day-to-day home BP >11.0/12.8 may have an increased risk of cardiovascular disease. These findings could help physicians identify individuals who are at an increased cardiovascular disease risk.

Relationships between 24-h blood pressure variability and 24-h central arterial pressure, pulse wave velocity and augmentation index in hypertensive patients

Twenty-four-h blood pressure variability (BPV) predicts cardiovascular complications in hypertension, but its association with pulse wave indices (central arterial pressure, pulse wave velocity (PWV) and augmentation index (AIx)) is poorly understood. In the present study, we assessed the degree of the effect of 24-h BPV on 24-h pulse wave indices. Brachial blood pressure was measured non-invasively over the 24 h with an electronic, oscillometric, automated device (BPLab) in 661 uncomplicated treated or untreated hypertensive patients. Digitalized oscillometric waveforms were analyzed with a validated algorithm to obtain pulse wave indices. Twenty-four-h BPV was calculated as the unweighted (SDu) or weighted s.d. (SDw) of the mean blood pressure or as the average real variability (ARV). Twenty-four-h systolic BPV showed a direct and significant relationship with the central arterial systolic pressure (r=0.28 SDu, r=0.40 SDw, r=0.34 ARV), PWV (r=0.10 SDu, r=0.21 SDw, r=0.19 ARV) and AIx (r=0.17 SDu, r=0.27 SDw, r=0.23 ARV). After adjustment for age, sex, body mass index, antihypertensive treatment and 24-h systolic blood pressure, the relationship lost some power but was still significant for all measures, except for the AIx. Pulse wave indices were higher in patients with high BPV than in those with low BPV: after adjustment, these differences were abolished for the AIx. The diastolic BPV showed a weak association with the pulse wave indices. In conclusion, in hypertensive patients, 24-h systolic BPV is moderately and independently associated with 24-h central arterial pressure and stiffness.

Increased Blood Pressure Variability Prior to Chronic Kidney Disease Exacerbates Renal Dysfunction in Rats

Increased blood pressure variability (BPV), which can be experimentally induced by sinoaortic denervation (SAD), has emerged as a new marker of the prognosis of cardiovascular and renal outcomes. Considering that increased BPV can lead to organ-damage, the goal of the present study was to evaluate the effects of SAD on renal function in an experimental model of chronic kidney disease (CKD). SAD was performed in male Wistar rats 2 weeks before 5/6 nephrectomy and the animals were evaluated 4 weeks after the induction of CKD. Our data demonstrated that BPV was increased in SAD and CKD animals and that the combination of both conditions (SAD+CKD) exacerbated BPV. The baroreflex sensitivity index was diminished in the SAD and CKD groups; this reduction was more pronounced when SAD and CKD were performed together. 5/6 nephrectomy led to hypertension, which was higher in SAD+CKD animals. Regarding renal function, the combination of SAD and CKD resulted in reduced renal plasma and blood flow, increased renal vascular resistance and augmented uraemia when compared to CKD animals. Glomerular filtration rate and BPV were negatively correlated in SAD, CKD, and SAD+CKD animals. Moreover, SAD+CKD animals presented a higher level of glomerulosclerosis when compared to all other groups. Cardiac and renal hypertrophy, as well as oxidative stress, was also further increased when SAD and CKD were combined. These results show that SAD prior to 5/6 nephrectomy exacerbates renal dysfunction, suggesting that previous augmented BPV should be considered as an important factor to the progression of renal diseases.

Regional Fat Distribution and Blood Pressure Level and Variability: The Dallas Heart Study

Our aim was to investigate the associations of regional fat distribution with home and office blood pressure (BP) levels and variability. Participants in the Dallas Heart Study, a multiethnic cohort, underwent 5 BP measurements on 3 occasions during 5 months (2 in home and 1 in office) and quantification of visceral adipose tissue, abdominal subcutaneous adipose tissue, and liver fat by magnetic resonance imaging, and lower body subcutaneous fat by dual x-ray absorptiometry. The relation of regional adiposity with short-term (within-visit) and long-term (overall visits) mean BP and average real variability was assessed with multivariable linear regression. We have included 2595 participants with a mean age of 44 years (54% women; 48% black), and mean body mass index was 29 kg/m(2) Mean systolic BP/diastolic BP was 127/79 mm Hg and average real variability systolic BP was 9.8 mm Hg during 3 visits. In multivariable-adjusted models, higher amount of visceral adipose tissue was associated with higher short-term (both home and office) and long-term mean systolic BP (β[SE]: 1.9[0.5], 2.7[0.5], and 2.1[0.5], respectively; all P<0.001) and with lower long-term average real variability systolic BP (β[SE]: -0.5[0.2]; P<0.05). In contrast, lower body fat was associated with lower short-term home and long-term mean BP (β[SE]: -0.30[0.13] and -0.24[0.1], respectively; both P<0.05). Neither subcutaneous adipose tissue or liver fat was associated with BP levels or variability. In conclusion, excess visceral fat was associated with persistently higher short- and long-term mean BP levels and with lower long-term BP variability, whereas lower body fat was associated with lower short- and long-term mean BP. Persistently elevated BP, coupled with lower variability, may partially explain increased risk for cardiac hypertrophy and failure related to visceral adiposity.

Is It Daily, Monthly, or Yearly Blood Pressure Variability that Enhances Cardiovascular Risk?

Variability is a phenomenon common to most biological processes that we can measure and is a particular feature of blood pressure (BP). Variability causes concern for many physicians regarding its clinical meaning and potential impact on cardiovascular risk. In this review, we assess the role of different time periods of blood pressure variability (BPV) in cardiovascular risk stratification. We review the indices of BPV derived from ambulatory blood pressure measurement (ABPM), home blood pressure measurement (HBPM), or at the clinic setting with the intention of providing a clear message for clinical practice. BPV, either derived from ABPM or HBPM, does not consistently augment cardiovascular risk prediction over and beyond that of average BP, particularly in low-risk individuals. That said, it would seem that certain medications such as calcium channel blockers may have a beneficial effect on visit-to-visit BPV and perhaps reduce the associated cardiovascular risk. This highlights the benefits in using combination therapy which might couple a number of therapeutic benefits such as the reductions of mean blood pressure and BPV. Overall, we should remain aware that the average BP level remains the main modifiable risk factor derived from BP measurements and continue to improve the control of hypertension and adverse health outcomes.

Effect of salt intake on beat-to-beat blood pressure nonlinear dynamics and entropy in salt-sensitive versus salt-protected rats

Blood pressure exhibits substantial short- and long-term variability (BPV). We assessed the hypothesis that the complexity of beat-to-beat BPV will be differentially altered in salt-sensitive hypertensive Dahl rats (SS) versus rats protected from salt-induced hypertension (SSBN13) maintained on high-salt versus low-salt diet. Beat-to-beat systolic and diastolic BP series from nine SS and six SSBN13 rats (http://www.physionet.org) were analyzed following 9 weeks on low salt and repeated after 2 weeks on high salt. BP complexity was quantified by detrended fluctuation analysis (DFA), short- and long-range scaling exponents (αS and αL), sample entropy (SampEn), and traditional standard deviation (SD) and coefficient of variation (CV(%)). Mean systolic and diastolic BP increased on high-salt diet (P < 0.01) particularly for SS rats. SD and CV(%) were similar across groups irrespective of diet. Salt-sensitive and -protected rats exhibited similar complexity indices on low-salt diet. On high salt, (1) SS rats showed increased scaling exponents or smoother, systolic (P = 0.007 [αL]) and diastolic (P = 0.008 [αL]) BP series; (2) salt-protected rats showed lower SampEn (less complex) systolic and diastolic BP (P = 0.046); and (3) compared to protected SSBN13 rats, SS showed higher αL for systolic (P = 0.01) and diastolic (P = 0.005) BP Hypertensive SS rats are more susceptible to high salt with a greater rise in mean BP and reduced complexity. Comparable mean pressures in sensitive and protective rats when on low-salt diet coupled with similar BPV dynamics suggest a protective role of low-salt intake in hypertensive rats. This effect likely reflects better coupling of biologic oscillators.

The relationship between blood pressure variability and Pooled Cohort Risk Assessment Equations 10-year cardiovascular risk score

BACKGROUND

Recent attention has focused on the clinical significance of blood pressure variability (BPV) in explaining the adverse cardiovascular consequences of hypertension. We therefore analyze the impact of 24 h BPV on the development of future cardiovascular disease determined by The Pooled Cohort Risk Assessment Equations 10-year risk calculator.

MATERIALS AND METHODS

We analyzed 250 adult patients, ages 40-80 years old. The ambulatory blood pressure monitoring was recorded automatically. We defined the mean blood pressure values, SD, and coefficient of variation (CV) of blood pressure on the basis of the recorded 24 h ambulatory blood pressure monitoring values as an indicator for BPV.Patients were divided into two groups according to their Pooled Cohort Risk Assessment Equations 10-year risk profile (<7.5 and ≥7.5%).

RESULTS

Besides the mean systolic blood pressure (SBP), parameters showing the BPV such as SD and CV of mean blood pressures were also significantly higher in patients with an elevated 10-year risk score compared with others. Only CV of SBP and pulse pressure showed a clear association with the 10-year risk in multivariate logistic regression analysis. The results suggested that each 1% increase in CV of SBP could lead to a 1.258-fold increase in The Pooled Cohort Risk Assessment Equations 10-year risk score.

CONCLUSION

In the present study, we found that independent of baseline SBP, increased CV of SBP within 24 h was associated with increased cardiovascular risk, as assessed by The Pooled Cohort Risk Assessment Equations 10-year risk calculator.

The Effects of Nocturnal Dip and Blood Pressure Variability on Paracentral Scotoma in Early Open-Angle Glaucoma

PURPOSE

To evaluate the effect of nocturnal dip and blood pressure (BP) variability on paracentral scotoma in early open-angle glaucoma.

METHODS

The present study included 72 early normal-tension glaucoma (NTG) patients and 34 early primary open-angle glaucoma (POAG) patients. Nocturnal dip and weighted standard deviation (wSD) were determined by 24-hour ambulatory BP monitoring (24-hr ABPM). The mean deviation (MD) and pattern deviation (PD) were measured with visual field. Correlations between nocturnal dip and/or BP variability and paracentral scotoma were assessed using Student's t-test, Pearson's correlation test, and linear logistic regression analysis.

RESULTS

The systolic and diastolic nocturnal dip and paracentral scotoma occurrence demonstrated a statistically significant correlation in the early NTG group (systolic nocturnal dip: p=0.047, diastolic nocturnal dip: p=0.011). In the early NTG group, the subgroup with paracentral scotoma had a greater nocturnal dip than those patients without paracentral scotoma (systolic nocturnal dip: p=0.000; diastolic nocturnal dip: p=0.000). In the early NTG group, the subgroup with paracentral scotoma had higher wSD of SBP than the patients without paracentral scotoma (p=0.003). In the logistic regression analysis of the factors that can affect paracentral scotoma SBP dip and SBP, wSD appeared to significantly affect the occurrence of paracentral scotoma in the early NTG group.

CONCLUSIONS

Early NTG patients with paracentral scotoma have nocturnal dip and large BP variability. Therefore, in early glaucoma patients, particularly in early NTG with paracentral scotoma, nocturnal dip and BP variability should be assessed with 24-hr ABPM.

Blood pressure variability: assessment, predictive value, and potential as a therapeutic target

A large body of evidence has consistently supported the relationship between blood pressure (BP) levels and the risk of cardiovascular complications. In recent years, several independent studies have also indicated that this risk may not only depend on the magnitude of the blood pressure elevation per se but also on the presence of other associated conditions such as increased blood pressure variability. This concept has been supported by a series of reports, most of which post hoc analyses of clinical trials in hypertension, showing that increasing values of BP variability (BPV) (either in the short term, in the midterm, or in the long term) may predict development, progression, and severity of cardiac, vascular, and renal organ damage, as well as cardiovascular events and mortality. Remarkably, studies conducted in populations at high cardiovascular risk have shown increasing values of BPV in the individual subjects (so-called intra- or within-individual BPV) to be strong predictors of cardiovascular morbidity and mortality, even to a larger extent than average BP values. However, in subjects at low to moderate cardiovascular risk, the contribution of BPV to cardiovascular risk prediction over and beyond average BP values has been shown to be only moderate. The aim of this paper is to critically review the evidence addressing the prognostic relevance of different components of BPV addressing a yet open question, i.e., whether routine assessment of BPV in clinical practice should be regarded as an additional target of antihypertensive treatment to improve cardiovascular protection.

Effect of One-Week Salt Restriction on Blood Pressure Variability in Hypertensive Patients with Type 2 Diabetes

Background

Increased short-term blood pressure (BP) variability on 24-hour ambulatory BP monitoring (ABPM) is known to be a risk factor for cardiovascular events. However, very few studies have evaluated the effect of salt restriction on BP variability particularly in hypertensive patients with type 2 diabetes. This study aimed to investigate the effect of salt restriction on systolic BP (SBP) variability.

Methods and Results

10 hypertensive patients with type 2 diabetes and not receiving antihypertensive agents were enrolled in the study. After admission, all patients received a salt-restricted diet and appropriate anti-diabetic treatments and were followed up for 7 consecutive days using ABPM. After the 7-day treatment, the median [interquartile range (IQR)] coefficient of variation (CV) for diurnal SBP variability changed from day 1 to day 7–13.0 [10.8 to 16.8] % to 13.3 [9.1 to 18.9] % (P = 0.959)—and the median [IQR] change between days 1 and 7 was -0.3 [-3.2 to 2.9] %. In addition, CV for BP variability and circadian rhythm of BP varied greatly on a day-by-day basis for 7 days, compared to mean BP values. Interestingly, increased SBP variability was associated with greater day-by-day changes in circadian rhythm of BP.

Conclusions

Salt restriction during 7-day hospitalization led to a -0.3 [-3.2 to 2.9] (median [IQR]) % change from baseline in CV for diurnal SBP variability in 10 hypertensive patients with type 2 diabetes not receiving antihypertensive agents.

Trial Registration

UMIN Clinical Trials Registry UMIN000016243

Sex differences in autonomic function following maximal exercise

Background

Heart rate variability (HRV), blood pressure variability, (BPV) and heart rate recovery (HRR) are measures that provide insight regarding autonomic function. Maximal exercise can affect autonomic function, and it is unknown if there are sex differences in autonomic recovery following exercise. Therefore, the purpose of this study was to determine sex differences in several measures of autonomic function and the response following maximal exercise.

Methods

Seventy-one (31 males and 40 females) healthy, nonsmoking, sedentary normotensive subjects between the ages of 18 and 35 underwent measurements of HRV and BPV at rest and following a maximal exercise bout. HRR was measured at minute one and two following maximal exercise.

Results

Males have significantly greater HRR following maximal exercise at both minute one and two; however, the significance between sexes was eliminated when controlling for VO₂ peak. Males had significantly higher resting BPV-low-frequency (LF) values compared to females and did not significantly change following exercise, whereas females had significantly increased BPV-LF values following acute maximal exercise. Although males and females exhibited a significant decrease in both HRV-LF and HRV-high frequency (HF) with exercise, females had significantly higher HRV-HF values following exercise. Males had a significantly higher HRV-LF/HF ratio at rest; however, both males and females significantly increased their HRV-LF/HF ratio following exercise.

Conclusions

Pre-menopausal females exhibit a cardioprotective autonomic profile compared to age-matched males due to lower resting sympathetic activity and faster vagal reactivation following maximal exercise. Acute maximal exercise is a sufficient autonomic stressor to demonstrate sex differences in the critical post-exercise recovery period.

Cardiovascular risk stratification and blood pressure variability on ambulatory and home blood pressure measurement

Variability is a phenomenon attributed to most biological processes and is a particular feature of blood pressure (BP) that concerns many physicians regarding the clinical meaning and the impact on their clinical practice. In this review, we assessed the role of different indices of BP variability in cardiovascular risk stratification. We reviewed the indices of BP variability derived from ambulatory BP monitoring (day-to-night ratio, morning surge of BP, and short-term BP variability) and home BP measurement (standardized conventional BP measurement and self-BP measurement), and summarized our recent results with the intention to provide a clear message for clinical practice.

CONCLUSION

BP variability, either derived from ambulatory BP measurement or home BP measurement does not substantially refine cardiovascular risk prediction over and beyond the BP level. Practitioners should be aware that BP level remains the main modifiable risk factor derived from BP measurement and contributes to improving the control of hypertension and adverse health outcomes.

The relationship between the 24 h blood pressure variability and carotid intima-media thickness: a compared study

Large blood pressure variability (BPV) will not only harm the target organ but also increase the possibility of the cardiovascular events. Since the damage of vascular system always leads to the alteration of the carotid wall, the structure and function of the carotid artery have been extensively examined in previous studies. In this work we conduct a study (60 subjects, aged 33–79) to evaluate the relationship between BPV and carotid intima-media thickness (IMT) in Shenzhen, which is one large city in the southern area of China. In our study, the blood pressure (BP) was collected using the 24 h ambulatory BP monitoring, and the BPV was evaluated using standard deviation (SD), coefficient of variation (CV), and average real variability (ARV) during 24 h, daytime and nighttime. All the IMT measurements are collected by ultrasound. The results show that both the daytime, and 24 h systolic BPV evaluated by three indices are positively associated with IMT. Among them, daytime systolic BPV evaluated with ARV is the best variable to represent the increasing of carotid IMT. In addition, after adjusting by age, sex, smoking, hypertension, and mean BP and PP values, 24 h diastolic BPV evaluated with SD also presents the favorable performance.