Nocturnal Blood Pressure, Morning Blood Pressure Surge, and Cerebrovascular Events

Role of cerebral microbleeds in acute ischemic stroke and atrial fibrillation

Cerebral microbleeds (CMBs) are commonly detected in the brains of patients with acute ischemic stroke (AIS). With the development of neuroimaging, clinicians are paying more attention to the presence of CMBs. CMBs were found to significantly increase the risk of intracranial hemorrhagic transformation and hemorrhage in patients with AIS, especially in patients with concurrent atrial fibrillation (AF). Additionally, the presence of CMBs is thought to be a symbol of a high risk of recurrent ischemic stroke (IS). A few researchers have found that the presence of CMBs has no significant effect on the prognosis of patients with AIS. Therefore, the current views on the role of CMBs in the prognoses of patients with IS are controversial. The use of anticoagulants and other drugs has also become a dilemma due to the special influence of CMBs on the prognosis of these patients. Due to the large number of patients with AF and CMBs, many studies have been conducted on the effects of CMBs on these patients and subsequent pharmacological treatments. However, at present, there are no relevant guidelines to guide the secondary preventive treatment of patients with stroke, CMBs, and AF. In this paper, we summarized the role of CMBs in AIS combined with AF and relevant preventive measures against the recurrence of stroke and the occurrence of intracerebral hemorrhage to help clarify the specifics of drug therapies for this group of patients.

Development and validation of prediction models for hypertension risks: A cross-sectional study based on 4,287,407 participants

Objective

To develop an optimal screening model to identify the individuals with a high risk of hypertension in China by comparing tree-based machine learning models, such as classification and regression tree, random forest, adaboost with a decision tree, extreme gradient boosting decision tree, and other machine learning models like an artificial neural network, naive Bayes, and traditional logistic regression models.

Methods

A total of 4,287,407 adults participating in the national physical examination were included in the study. Features were selected using the least absolute shrinkage and selection operator regression. The Borderline synthetic minority over-sampling technique was used for data balance. Non-laboratory and semi-laboratory analyses were carried out in combination with the selected features. The tree-based machine learning models, other machine learning models, and traditional logistic regression models were constructed to identify individuals with hypertension, respectively. Top features selected using the best algorithm and the corresponding variable importance score were visualized.

Results

A total of 24 variables were finally included for analyses after the least absolute shrinkage and selection operator regression model. The sample size of hypertensive patients in the training set was expanded from 689,025 to 2,312,160 using the borderline synthetic minority over-sampling technique algorithm. The extreme gradient boosting decision tree algorithm showed the best results (area under the receiver operating characteristic curve of non-laboratory: 0.893 and area under the receiver operating characteristic curve of semi-laboratory: 0.894). This study found that age, systolic blood pressure, waist circumference, diastolic blood pressure, albumin, drinking frequency, electrocardiogram, ethnicity (uyghur, hui, and other), body mass index, sex (female), exercise frequency, diabetes mellitus, and total bilirubin are important factors reflecting hypertension. Besides, some algorithms included in the semi-laboratory analyses showed less improvement in the predictive performance compared to the non-laboratory analyses.

Conclusion

Using multiple methods, a more significant prediction model can be built, which discovers risk factors and provides new insights into the prediction and prevention of hypertension.

Time point of nocturnal trough systolic blood pressure as an independent predictor of cardiovascular events

Nocturnal trough systolic blood pressure (NTSBP) and Time Point of Nocturnal Trough Systolic Blood Pressure (T‐NTSBP) were important parameters of nocturnal blood pressure, the predictive values of which are unclear for stroke outcome. This study aimed to examine the relationship between NTSBP/T‐NTSBP and stroke outcome. The authors used data from a nationwide ambulatory blood pressure monitoring cohort study conducted in China, which recruited 2348 ischemic stroke and transient ischemic attack (TIA) patients. NTSBP was defined as the lowest SBP during nighttime (22:00–6:00), and T‐NTSBP was defined as the corresponding time point of NTSBP. The associations between NTSBP/T‐NTSBP and stroke outcome (stroke recurrence and combined vascular event [CVE]) at 90 days or 1 year were analyzed using cox regression models. According to NTSBP classified by quartile, hazard ratio (HR) with 95% confidence interval (CI) for NTSBP quartile 4 (>129 mm Hg) was 2.727 (1.148–6.478) for CVE at 90‐day, compared with quartile 1 (≤102 mm Hg). However, an attenuated association between NTSBP and CVE was observed at 1 year. In addition, we observed the group of T‐NTSBP at 4:00–6:00 had a lowest CVE incidence at 90 days among four groups (22:00–23:59, 00:00–1:59 2:00–3:59, 4:00–6:00). After multivariable adjustment, T‐NTSBP was significantly associated with CVE incidence at 90 days (T‐NTSBP at the 4:00–6:00 versus the 22:00–23:59 group: HR, 0.433; 95%CI, 0.190–0.986), independent of NTSBP and average nocturnal SBP. Both of NTSBP and T‐NTSBP were important predictors for short‐term cardiovascular risk in ischemic stroke and TIA patients.

Effect of non-dipper pattern on echocardiographic myocardial work parameters in normotensive individuals

BACKGROUND

It is known that non-dipper pattern (NDP) is associated with adverse outcomes in hypertensive patients. However, there is insufficient data on the outcome of NDP in normotensive individuals. Using myocardial work (MW) analysis, as a new echocardiographic examination method, this study aimed to determine the early myocardial effects of NDP in normotensive individuals.

METHODS

This study included 70 normotensive individuals who were followed by ambulatory blood pressure monitoring (ABPM). The subjects were divided into two groups according to dipper pattern (DP) and NDP. Conventional, strain, and MW findings were compared between the groups by making echocardiographic evaluations.

RESULTS

The demographic characteristics, laboratory parameters, and measurements of cardiac chambers, and left ventricular (LV) walls were similar between the groups. There was no statistical difference between the groups in terms of LV 3-2-4 chambers strains and global longitudinal strain (GLS) values. LVMW parameters, global work index (GWI), and global constrictive work (GCW) were not statistically different between groups (2012 ± 127, 2069 ± 137, p = 0.16; 2327 ± 173, 2418 ± 296, p = 0.18, respectively). However, global waste work (GWW) and global work efficiency (GWE) parameters were different between the groups (144 ± 63.9, 104 ± 24.8, p < 0.001; 93.2 ± 3.17, 95.4 ± 1.28, p < 0.001, respectively). In regression analysis, GWW was independently associated with NDP. GWW model showed better results with higher likelihood chi-square and R² values than GLS model in discriminating the predictable capability for NDP status.

CONCLUSION

The results of MW analysis in this study showed that GWW values were higher and the GWE values were lower in normotensive individuals with NDP.

Increasing incidence of macular edema in excessive morning blood pressure surge in patients with retinal vein occlusion

Morning blood pressure surge (MBPS) had been known to be associated with hypertensive target organ injury and vascular events. Retinal vein occlusion (RVO) is also known to be related with underlying cardiovascular risk factors. This study investigated the effect of MBPS on patients with RVO. In total, 76 patients with RVO who had undergone systemic cardiovascular examination including a 24-hour ambulatory blood pressure monitoring, carotid artery intima media thickness, and pulse wave velocity were evaluated between January 2015 and February 2019. The MBPS was calculated as follows: mean systolic blood pressure measured over two hours after awakening minus mean systolic blood pressure measured during the one hour that included the lowest sleep blood pressure. Macular edema was significantly more prevalent in the MBPS group compared with the non-MBPS group. After adjusting for confounding factors, multivariate regression analyses revealed that MBPS independently predicted macular edema in patients with RVO [Odds ratio 4.75, 95% confidence interval 1.136–16.6, p = 0.015]. In conclusion, evaluating blood pressure patterns, especially MBPS, using 24-hour ambulatory blood pressure monitoring may be useful for assessing and predicting ophthalmologic outcome and may facilitate better blood pressure control in patients with RVO.

Increased blood pressure variability during the subacute phase of ischemic stroke is associated with poor functional outcomes at 3 months

Thus far, it is well known that increased blood pressure variability may exacerbate stroke outcomes. Blood pressure in the acute phase would be influenced by both reactive hypertension to stroke and intrinsic blood pressure reactivity. Thus, we aimed to evaluate the association between blood pressure variability and outcomes at 3 months using ambulatory blood pressure monitoring in ischemic stroke patients in the subacute phase after reactive hypertension subsided. We retrospectively examined 626 consecutive patients with acute ischemic stroke who underwent 24-hour ambulatory blood pressure monitoring during the subacute phase of stroke (median, 9 days from onset). The variability in blood pressure was evaluated by assessing the standard deviation and coefficient of variation of systolic and diastolic blood pressure. The primary outcome was functional status at 3 months. A poor outcome was defined as a modified Rankin scale score of 3 or more and a good outcome as 2 or less. We assessed the functional outcome at 3 months in 497 patients (79.4%). The mean systolic and diastolic blood pressure levels were not associated with functional outcome. The multivariable analysis revealed that increases in the standard deviations of systolic and diastolic blood pressure, coefficient of variation of diastolic blood pressure, and morning blood pressure surge were associated with poor outcome. Blood pressure variability during the subacute phase of ischemic stroke can be a useful prognostic indicator of poor functional outcome at 3 months in patients with acute ischemic stroke.

Targeting blood pressure for stroke prevention: current evidence and unanswered questions

High blood pressure (BP) is the leading modifiable risk factor of stroke worldwide. Although randomized clinical trials have demonstrated the beneficial effect of BP reduction on stroke risk, there are still insufficiently explored issues concerning the optimal personalized management of BP in stroke patients in terms of thresholds to be achieved and drug classes to be prescribed. Few data are available about BP control in specific clinical contexts such as in older patients, in various stroke subtypes, or in association with co-morbidities such as diabetes. In addition, although drug trials based their conclusions on achieved mean BP values, recent findings indicate that aspects such as circadian variations of BP and BP variability should be taken into account as well. This article aims to highlight current knowledge about BP control in stroke prevention and to provide new perspectives to be addressed in future studies so as to guide clinicians in their day-to-day practice.

Dynamic Cerebral Autoregulation Remains Stable During the Daytime (8 a.m. to 8 p.m.) in Healthy Adults

Many functions of the human body possess a daily rhythm, disruptions of which often lead to disease. Dynamic cerebral autoregulation (dCA) stabilizes the cerebral blood flow to prompt normal neural function. However, whether dCA is stable across the day remains unknown. This study aimed to investigate the daily rhythm of dCA. Fifty-one healthy adults (38.294 ± 13.279 years, 40 females) were recruited and received six dCA measurements per individual that were conducted at predefined time points: 8:00, 9:00, 11:00, 14:00, 17:00, and 20:00. Although the blood pressure fluctuated significantly, there was no statistical difference in phase difference and gain (autoregulatory parameters) across the six time points. This study demonstrates that dCA remains stable during the interval from 8 a.m. to 8 p.m. and underscores the importance of stable dCA in maintaining cerebral blood flow and neural function.

Morning Blood Pressure Surge Relates to Autonomic Neural Activity in Young Non-Dipping Adults: The African-PREDICT Study

BACKGROUND

It is well established that an exaggerated morning blood pressure surge (MBPS) is associated with an increased risk for cardiovascular disease development in hypertensive individuals. However, in non-dipping individuals, a lower surge was reportedly associated with increased cardiovascular risk. Sympathetic nervous system activity is involved in 24-hour blood pressure fluctuations, including night-time dipping and the MBPS. To better understand this interaction, we investigated associations of MBPS with heart-rate variability and baroreceptor sensitivity in young healthy dippers and non-dippers.

METHODS

We included black and white men and women (n=827), aged 20-30 years and determined the MBPS using two formulas: the sleep-trough and dynamic morning surge. For autonomic function we determined baroreceptor sensitivity and heart-rate variability.

RESULTS

The majority of non-dippers in this population were black (70.4%), presenting lower sleep-trough and dynamic morning surge (all p<0.001). Heart-rate variability was comparable between dippers and non-dippers, whereas baroreceptor sensitivity was higher in non-dippers (p=0.021). Despite a suppressed MBPS profile in non-dippers, we found both sleep-trough (β=-0.25; p=0.039) and dynamic morning surge (β=-0.14; p=0.047) to be inversely and independently associated with 24-hour heart-rate variability (total power). These results were absent in dippers.

CONCLUSIONS

In conclusion, we found a higher night-time blood pressure coupled with lower MBPS in young healthy non-dippers. Furthermore, this lower MBPS was independently and negatively associated with autonomic neural activity, suggesting increased autonomic function involvement in MBPS suppression of non-dippers. The predictive value of suppressed nocturnal dipping pattern should be investigated while taking autonomic neural activity into account.

Homocysteine is Associated with Exaggerated Morning Blood Pressure Surge in Patients with Acute Ischemic Stroke

BACKGROUND

Considerable researches suggest that high level of homocysteine (Hcy) is associated with the risk of ischemic stroke. Ambulatory blood pressure monitoring (ABPM) parameters have also been confirmed associated with cardio-cerebrovascular events. However, the relationship between Hcy and ABPM parameters remains unclear in patients with acute ischemic stroke. In this study, we aim to investigate the association between Hcy level and ABPM parameters in patients with acute ischemic stroke.

METHODS

We enrolled 60 patients with acute ischemic stroke who received ABPM. We calculated ABPM parameters like morning blood pressure surge (MBPS), ambulatory arterial stiffness index, blood pressure variability, and night dipping patterns.

RESULTS

Multivariate logistic regression analysis indicated that patients in the top quartile of Hcy level tended to have a higher level of prewaking and sleep-trough MBPS compared with patients in the lower 3 quartiles after adjusted for age and gender (P = .028 and P = .030, respectively). When treating Hcy as a continuous variable, the linear regression showed the association between Hcy level and both MBPS parameters remained significant (prewaking MBPS, r = .356, P = .022; sleep-trough MBPS, r = .365, P = .017, respectively). However, there is no association between Hcy level and ambulatory arterial stiffness index, blood pressure variability or night dipping patterns (P = .635, P = .348 and P = .127 respectively).

CONCLUSIONS

There is a relationship between the 2 major cerebrovascular risk factors: MBPS and Hcy.

Fixed-dose combination of zofenopril plus hydrochlorothiazide vs. irbesartan plus hydrochlorothiazide in hypertensive patients with established metabolic syndrome uncontrolled by previous monotherapy. The ZAMES study (Zofenopril in Advanced MEtabolic Syndrome)

OBJECTIVE

Whether all antihypertensive drugs are equally effective in patients with metabolic syndrome is still unclear. The goal of the Zofenopril in Advanced MEtabolic Syndrome (ZAMES) study was to investigate whether treatment with the fixed-dose combination of sulphydril-containing angiotensin-converting enzyme inhibitor zofenopril plus hydrochlorothiazide is at least as effective as that with the angiotensin receptor blocker irbesartan plus hydrochlorothiazide in patients with metabolic syndrome and essential hypertension, uncontrolled by a previous monotherapy.

METHODS

We enrolled 721 patients in a multicenter, international (Italy and Romania), randomized, double-blind, parallel group, phase III study. Following a 1-week screening withdrawal period, 482 patients (mean age 59 ± 10 years, 53% men) bearing a SBP at least 140 mmHg and/or DBP at least 90 mmHg plus metabolic syndrome (ATP-III criteria) were randomly allocated to a fixed-dose combination of zofenopril 30 mg plus hydrochlorothiazide 12.5 mg or irbesartan 150 mg plus hydrochlorothiazide 12.5 mg once daily for a cumulative period of 24 weeks. After 8 and 16 weeks, zofenopril and irbesartan doses were doubled in nonnormalized study participants. The study endpoint was the office DBP reduction at study end. In 20% of patients, an ambulatory blood pressure monitoring was performed.

RESULTS

The prevalence of diabetes at baseline was significantly (P < 0.05) greater in the zofenopril plus hydrochlorothiazide group (82%) than in the irbesartan plus hydrochlorothiazide (73%) group. Baseline-adjusted DBP reductions were superimposable (P = 0.370) with zofenopril plus hydrochlorothiazide [n = 231; 9.8 (95% confidence interval: 11.1, 8.4) mmHg] and irbesartan plus hydrochlorothiazide [n = 235; 10.4 (11.8, 9.0) mmHg]. The same was for SBP [17.0 (19.2, 14.8) mmHg zofenopril plus hydrochlorothiazide vs. 18.8 (21.0, 16.6) mmHg irbesartan plus hydrochlorothiazide, P = 0.113]. Rate of normalized and responder patients (SBP/DBP < 140/90 mmHg or SBP reduction more than 20 mmHg or DBP reduction more than 10 mmHg) did not differ at study end (65.8% and 77.5% zofenopril plus hydrochlorothiazide vs. 67.7% and 81.5% irbesartan plus hydrochlorothiazide; P = 0.695, P = 0.301). These results were confirmed in the 69 study participants undergoing ambulatory blood pressure monitoring (35 zofenopril plus hydrochlorothiazide; 34 irbesartan plus hydrochlorothiazide), with a comparable 24-h average BP reduction [BP difference between-treatment: SBP: 0.1 (-5.7, 5.9) mmHg, P = 0.975; DBP: -0.9 (-3.8, 2.0) mmHg, P = 0.541]. Both drugs attained similar BP reductions also in the last 6 h of the dosing interval [between-treatment difference SBP: 0.1 (-7.4, 7.5) mmHg P = 0.990; DBP: -0.9 (-4.4, 2.6) mmHg, P = 0.602]. Metabolic and renal indexes were not altered. Few patients were withdrawn for moderate adverse events (5% zofenopril plus hydrochlorothiazide; 5% irbesartan plus hydrochlorothiazide).

CONCLUSION

This is the first study supporting the comparable antihypertensive and metabolic response to fixed-dose combinations of sulphydril-containing angiotensin-converting enzyme inhibitors (zofenopril) or angiotensin receptor blockers (Irbesartan) with a diuretic in patients with advanced metabolic syndrome and nonresponders to monotherapy. The results of this study can further improve the clinical management of high cardiovascular risk patients with hypertension and metabolic syndrome, because these two drug combinations increase the number of available combinations, which may significantly improve patients' adherence in this special clinical condition that is frequently found in everyday practice.

Secondary Stroke Prevention: Improving Diagnosis and Management with Newer Technologies

Treatment of hypertension, diabetes, high cholesterol, smoking cessation, and healthy lifestyle have all contributed to the decline in the incidence of vascular disease over the last several decades. Patients who suffer an acute stroke are at a high risk for recurrence. Introduction of newer technologies and their wider use allows for better identification of patients in whom the risk of recurrence following an acute stroke may be very high. Traditionally, the major focus for diagnosis and management has focused on patient history, examination, imaging for carotid stenosis/occlusion, and detection of AF and paroxysmal AF (PAF) with 24-48 h cardiac monitoring. This review focuses on the usefulness of three newer investigative tools that are becoming widely available and lead to better prevention. Continuous ambulatory blood pressure measurements for 24 h or longer and 3D Doppler measures of the carotid arteries provide key useful information on the state of vascular health and enhance our ability to monitor the response to preventive therapies. Furthermore, the detection of PAF can be significantly improved with prolonged cardiac monitoring for 3 weeks or longer, enabling the initiation of appropriate prevention therapy. This review will focus on the potential impact and importance of these emerging technologies on the prevention of recurrent stroke in high-risk patients.

Comparison of bisoprolol to a metoprolol CR/ZOK tablet for control of heart rate and blood pressure in mild-to-moderate hypertensive patients: the CREATIVE study

This open-label study investigated the long action of bisoprolol compared with metoprolol CR/ZOK for controlling the mean dynamic heart rate (HR) and blood pressure (BP) in patients with mild-to-moderate primary hypertension. Patients from seven centers in China were treated with either bisoprolol 5 mg or metoprolol CR/ZOK 47.5 mg once daily for 12 weeks. The primary end points were the mean dynamic HR reduction and the mean dynamic diastolic BP (DBP) control in the last 4 h of the treatment period. Secondary end points included ambulatory monitoring of the BP and HR, safety and compliance. A total of 186 patients, with 93 patients in each group, were enrolled and analyzed. In the last 4 h of the treatment period, patients receiving bisoprolol demonstrated a significantly greater reduction in the mean dynamic HR compared with patients receiving metoprolol CR/ZOK (least squares means (LSmeans) of difference: -3.79 b.p.m.; 97.5% confidence interval (CI): -7.45, -0.14; P=0.0202). Furthermore, in the last 4 h of the treatment period, bisoprolol demonstrated non-inferiority vs. metoprolol CR/ZOK in lowering the mean dynamic DBP (LSmeans of difference: -1.00; 97.5% CI: -4.79, 2.78; P=0.5495). Bisoprolol further significantly lowered the 24-h mean ambulatory, mean daytime and mean nighttime HR. The overall adverse event rate was similar between the two groups. Noncompliance was reported in 3 (3.53%) and 6 (7.32%) patients in the bisoprolol and metoprolol CR/ZOK groups, respectively. In conclusion, bisoprolol provided superior dynamic HR reduction and non-inferior dynamic BP reduction vs. metoprolol CR/ZOK in patients with mild-to-moderate hypertension. No new safety concerns were found.

Morning Blood Pressure Surge as a Predictor of Development of Chronic Kidney Disease

Blood pressure (BP) usually increases upon awakening--a physiological mechanism called morning BP surge (MBPS). BP values above the MBPS threshold are associated with target organ damage, including left ventricular hypertrophy and proteinuria. Despite these data, there have been no studies that have investigated the association between elevated MBPS and the development of incident chronic kidney disease (CKD). In this study, patients with essential hypertension were included and underwent ambulatory BP measurements and MBPS. Patients were followed for a median of 3.33 years. In total, 622 patients were enrolled. The mean age of patients was 57.6±12.4 years, 54.0% were men, 16.7% had diabetes, and 10.6% had prevalent cardiovascular disease. During follow-up, 32 patients developed CKD. Higher MBPS, analyzed both as continuous and categorical variables, was associated with incident CKD in all models. Elevated MBPS is associated with kidney function deterioration and the development of CKD. Studies are needed to further examine underlying mechanisms regarding MBPS and these renal outcomes.

Morning hypertension and night non-dipping in patients with diabetes and chronic kidney disease

Morning hypertension (HTN) and nocturnal non-dipping (ND) are closely associated with target organ damage and cardiovascular events. However, their importance in diabetics with advanced renal disease is unclear. We evaluated the relationships of morning HTN and ND with estimated glomerular filtration rate (eGFR) and proteinuria, and determined the risk of morning HTN and ND according to presence of diabetes mellitus (DM) and chronic kidney disease (CKD) stage. A total of 1312 patients, including 439 with diabetes, were prospectively recruited at 21 centers in Korea. All patients had HTN and an eGFR of 15-89 ml min(-1) per 1.73 m(2). Ambulatory 24-h blood pressure was assessed. The rates of morning HTN (25.2% vs. 13.6%, P<0.001) and ND (58.2% vs. 48.2%, P=0.002) were higher in diabetics than in non-diabetics. eGFR was correlated with ND in all patients (P<0.05) and with morning HTN only in non-diabetics (P=0.005). Proteinuria was related to ND in all patients (P<0.05) and to morning HTN only in diabetics (P=0.001). In a regression analysis, the risk of morning HTN was 2.093 (95% confidence interval (95% CI): 1.070-4.094) for the DMCKD2 group, 1.634 (95% CI: 1.044-2.557) for the CKD3-4-only group and 2.236 (95% CI: 1.401-3.570) for the DMCKD3-4 group compared with the CKD2-only group. The risk of ND was high for stage 3-4 CKD: 1.581 (95% CI: 1.180-2.120) for non-diabetics and 1.842 (95% CI: 1.348-2.601) for diabetics. Diabetics showed higher rates of morning HTN, ND and uncontrolled sustained HTN compared with non-diabetics with CKD of the same stages.

Both Low and High 24-Hour Diastolic Blood Pressure Are Associated With Worse Cognitive Performance in Type 2 Diabetes: The Maastricht Study

OBJECTIVE

Hypertension and diabetes are both risk factors for cognitive decline, and individuals with both might have an especially high risk. We therefore examined linear and nonlinear (quadratic) associations of 24-h blood pressure (BP) with cognitive performance in participants with and without type 2 diabetes. We also tested the association of nocturnal dipping status with cognitive performance.

RESEARCH DESIGN AND METHODS

This study was performed as part of the Maastricht Study, an ongoing population-based cohort study. Cross-sectional associations of 24-h BP (n = 713, of whom 201 had type 2 diabetes) and nocturnal dipping status (n = 686, of whom 196 had type 2 diabetes) with performance on tests for global cognitive functioning, information processing speed, verbal memory (immediate and delayed word recall), and response inhibition were tested using linear regression analysis and adjusted for demographics, vascular risk factors, cardiovascular disease, depression, and lipid-modifying and antihypertensive medication use.

RESULTS

After full adjustment, we found quadratic (inverted U-shaped) associations of 24-h diastolic blood pressure (DBP) with information processing speed (b for quadratic term = -0.0267, P < 0.01) and memory (immediate word recall: b = -0.0180, P < 0.05; delayed word recall: b = -0.0076, P < 0.01) in participants with diabetes, but not in those without. No clear pattern was found for dipping status.

CONCLUSIONS

This study shows that both low and high 24-h DBP are associated with poorer performance on tests of information processing speed and memory in individuals with type 2 diabetes.

The 24 h pattern of arterial pressure in mice is determined mainly by heart rate-driven variation in cardiac output

Few studies have systematically investigated whether daily patterns of arterial blood pressure over 24 h are mediated by changes in cardiac output, peripheral resistance, or both. Understanding the hemodynamic mechanisms that determine the 24 h patterns of blood pressure may lead to a better understanding of how such patterns become disturbed in hypertension and influence risk for cardiovascular events. In conscious, unrestrained C57BL/6J mice, we investigated whether the 24 h pattern of arterial blood pressure is determined by variation in cardiac output, systemic vascular resistance, or both and also whether variations in cardiac output are mediated by variations in heart rate and or stroke volume. As expected, arterial pressure and locomotor activity were significantly (P < 0.05) higher during the nighttime period compared with the daytime period when mice are typically sleeping (+12.5 ± 1.0 mmHg, [13%] and +7.7 ± 1.3 activity counts, [254%], respectively). The higher arterial pressure during the nighttime period was mediated by higher cardiac output (+2.6 ± 0.3 mL/min, [26%], P < 0.05) in association with lower peripheral resistance (-1.5 ± 0.3 mmHg/mL/min, [-13%] P < 0.05). The increased cardiac output during the nighttime was mainly mediated by increased heart rate (+80.0 ± 16.5 beats/min, [18%] P < 0.05), as stroke volume increased minimally at night (+1.6 ± 0.5 μL per beat, [6%] P < 0.05). These results indicate that in C57BL/6J mice, the 24 h pattern of blood pressure is hemodynamically mediated primarily by the 24 h pattern of cardiac output which is almost entirely determined by the 24 h pattern of heart rate. These findings suggest that the differences in blood pressure between nighttime and daytime are mainly driven by differences in heart rate which are strongly correlated with differences in locomotor activity.

A numerical study of the effect of varied blood pressure on the stability of carotid atherosclerotic plaque

Background

Blood pressure (BP) is associated with early atherosclerosis and plaque rupture because the BP variability can significantly affect the blood flow velocity and shear stress over the plaque. However, the mechanical response of BP variability to the plaque remains unclear. Therefore, we investigated the correlation between different maximum systolic blood pressure (SBP) and the stress distribution on plaque, as well as the stress over the plaque and blood velocity around the plaque using different BP variations, which are the BP variability in different phases during one cardiac cycle and beat-to-beat BP variability.

Method

We established a two-dimensional artery model with stenosis at the degree of 62.5%. Eight combinations of pulsatile pressure gradients between the inflow and outflow were implemented at the model. Three levels of fibrous cap thickness were taken into consideration to investigate the additional effect on the BP variability. Wall shear stress and stress/strain distribution over the plaque were derived as well as the oscillation shear index (OSI) to analyze the impact of the changing rate of BP.

Result

The stresses at diastole were 2.5% ± 1.8% lower than that at systole under the same pressure drop during one cycle. It was also found that elevated SBP might cause the immediate increment of stress in the present cycle (292% ± 72.3%), but slight reduction in the successive cycle (0.48% ± 0.4%).

Conclusion

The stress/strain distribution over the plaque is sensitive to the BP variability during one cardiac cycle, and the beat-to-beat BP variability could cause considerable impact on the progression of atherosclerosis in long-term.

Morning blood pressure surge is associated with serum gamma-glutamyltransferase activity in essential hypertensive patients

The phenomenon that blood pressure rises sharply in the morning is called 'Morning Blood Pressure Surge' (MBPS). Serum gamma-glutamyltransferase (GGT) is a proinflammatory marker involved in the pathogenesis of cardiovascular diseases. Although both are novel cardiovascular risk factors associated with inflammation and atherosclerosis, the specific relationship between MBPS and serum GGT is unknown. This study investigates the relationship between MBPS and serum GGT activity in essential hypertensive patients. Totally, 320 hypertensive patients were recruited. Mean MBPS was 17.0 ± 12.9 mm Hg. MBPS was positively correlated with age (r = +0.222, P < 0.0001), body mass index (r = +0.132, P = 0.018), GGT (r = +0.271, P < 0.0001), daytime augmentation index adjusted for heart rate (AIx@75) (r = +0.140, P=0.014), 24-h pulse wave velocity (PWV) (r = +0.143, P = 0.014) and daytime PWV (r = +0.158, P = 0.007). From the 25th to 75th quartile of serum GGT, MBPS increased significantly (Ptrend < 0.0001). In multivariate linear regression analysis, MBPS was independently associated with age (P = 0.002), dipping status (P < 0.0001) and logGGT (P < 0.0001). In conclusion, MBPS is independently associated serum GGT activity in essential hypertensive patients. This is the first study in the literature to demonstrate an independent and a dose-response relationship between the two novel cardiovascular risk factors, MBPS and serum GGT, in this patient population.

Therapeutic effects of melatonin receptor agonists on sleep and comorbid disorders

Several melatonin receptors agonists (ramelteon, prolonged-release melatonin, agomelatine and tasimelteon) have recently become available for the treatment of insomnia, depression and circadian rhythms sleep-wake disorders. The efficacy and safety profiles of these compounds in the treatment of the indicated disorders are reviewed. Accumulating evidence indicates that sleep-wake disorders and co-existing medical conditions are mutually exacerbating. This understanding has now been incorporated into the new Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5). Therefore, when evaluating the risk/benefit ratio of sleep drugs, it is pertinent to also evaluate their effects on wake and comorbid condition. Beneficial effects of melatonin receptor agonists on comorbid neurological, psychiatric, cardiovascular and metabolic symptomatology beyond sleep regulation are also described. The review underlines the beneficial value of enhancing physiological sleep in comorbid conditions.

Relationship between elevated morning blood pressure surge, uric acid, and cardiovascular outcomes in hypertensive patients

Early morning blood pressure surge (MBPS) is a risk factor for cardiovascular events (CVEs), but the relationship with uric acid is not well understood. The authors aimed to determine the association between MBPS and increased uric acid and the effect of elevated MBPS and uric acid combination on CVEs. A total of 921 patients underwent 24-hour ambulatory blood pressure monitoring and were followed for a median of 40 months. During this period, 103 (11.2%) CVEs occurred. There was a significant relationship between increasing quartiles of serum uric acid level and increasing values of MBPS (P<.0001). Patients in the highest quartile stratified by elevated MBPS and serum uric acid level had a 3.55 odds of major CVE compared with patients in the lowest quartile. Serum uric acid is associated with MBPS and development of new CVEs.

Sleep and pregnancy-induced hypertension: a possible target for intervention?

Sleep disturbances in the general population are associated with elevated blood pressure. This may be due to several mechanisms, including sympathetic activation and hypothalamic-pituitary-adrenal (HPA) axis disturbance. Elevated blood pressure in pregnancy can have devastating effects on both maternal and fetal health and is associated with increased risk for preeclampsia and poor delivery outcomes. Preliminary evidence suggests that mechanisms linking sleep and blood pressure in the general population may also hold in the pregnant population. However, the effects of disturbed sleep on physiologic mechanisms that may directly influence blood pressure in pregnancy have not been well studied. The role that sleep disturbance plays in gestational blood pressure elevation and its subsequent consequences warrant further investigation. This review evaluates the current literature on sleep disturbance and elevated blood pressure in pregnancy and proposes possible treatment interventions.

Neighborhood problems and nocturnal blood pressure dipping

OBJECTIVE

Living in adverse neighborhood conditions has been linked with greater prevalence of cardiovascular disease (CVD). We aimed to learn whether perceived neighborhood problems are related to attenuated nocturnal blood pressure (BP) dipping, a risk factor for CVD morbidity.

METHOD

A sample of 133 adults (71 male, 62 female; 80 White, 53 Black) underwent 24-hr ambulatory blood pressure monitoring. The neighborhood problem scale (NPS) was used to assess neighborhood environmental stressors.

RESULTS

Nocturnal dipping in systolic (SBP), diastolic (DBP) and mean arterial (MAP) blood pressure was reduced in individuals with higher NPS scores (p < .05). Hierarchical regression analyses revealed that neighborhood problems explained 4%-6% of the variance in SBP, DBP, and MAP dipping (p < .05) even after adjusting for several theoretical confounders such as social status, age, gender, race, body mass index (BMI), smoking, exercise, depression and discrimination.

CONCLUSION

Neighborhood problems may contribute to attenuated BP dipping beyond the effect of known risk factors.

Influences of the circadian clock on neuronal susceptibility to excitotoxicity

Stroke is the third leading cause of death and the primary cause of morbidity in the United States, thus posing an enormous burden on the healthcare system. The factors that determine the risk of an individual toward precipitation of an ischemic event possess a strong circadian component as does the ischemic event itself. This predictability provided a window of opportunity toward the development of chronopharmaceuticals which provided much better clinical outcomes. Experiments from our lab showed for the first time that neuronal susceptibility to ischemic events follows a circadian pattern; hippocampal neurons being most susceptible to an ischemic insult occurring during peak activity in a rodent model of global cerebral ischemia. We also demonstrated that the SCN2.2 cells (like their in vivo counterpart) are resistant to excitotoxicity by glutamate and that this was dependent on activation of ERK signaling. We are currently working on elucidating the complete neuroprotective pathway that provides a barricade against glutamate toxicity in the SCN2.2 cells. Our future experiments will be engaged in hijacking the neuroprotective mechanism in the SCN2.2 cells and applying it to glutamate-susceptible entities in an effort to prevent their death in the presence of excitotoxicity. Despite the advancement in chronopharmaceuticals, optimal clinical outcome with minimal adverse events are difficult to come by at an affordable price. Superior treatment options require a better understanding of molecular mechanisms that define the disease, including the role of the circadian clock.

Circadian blood pressure pattern and right ventricular and right atrial mechanics: A two- and three-dimensional echocardiographic study

The purpose of this investigation was to evaluate right ventricular (RV) and right atrial (RA) function and mechanics in untreated hypertensive patients with different blood pressure (BP) patterns by using two-dimensional (2DE) speckle tracking analyses and three-dimensional echocardiography (3DE). This cross-sectional study included 174 recently diagnosed hypertensive patients. All patients underwent a 24-hour ambulatory BP monitoring and complete 2DE and 3DE examination, including 2DE speckle tracking analysis. Our results showed that 2DE RV global longitudinal strain was significantly lower in the non-dippers. Similar results were obtained for 2DE RV systolic and early diastolic strain rate. The RA longitudinal strain, as well as RA systolic and early diastolic strain rate, was decreased in non-dippers. Our results revealed that 3DE RV end-diastolic and end-systolic volumes were increased, whereas 3DE RV ejection fraction was reduced in non-dipper hypertensive patients. Similar results were obtained for RA volumes and RA ejection fraction estimated by 2DE. Independent predictors of 3DE RV ejection fraction, 2DE RV and RA global longitudinal strain were left ventricular mass index and RV wall thickness. An additional independent predictor of the RV longitudinal strain was 3DE RV ejection fraction, and for RA longitudinal strain, an additional independent predictor was tricuspid E/é ratio. Two-DE speckle tracking evaluation and 3DE examination revealed that the RV and RA function and mechanics were more deteriorated in the non-dipper patients than in dipper untreated hypertensive patients.

Estimate of nocturnal blood pressure and detection of non-dippers based on clinical or ambulatory monitoring in the inpatient setting

BACKGROUND

Ambulatory blood pressure monitoring is regarded as the gold standard for monitoring nocturnal blood pressure (NBP) and is usually performed out of office. Currently, a novel method for monitoring NBP is indispensible in the inpatient setting. The widely used manual BP monitoring procedure has the potential to monitor NBP in the hospital setting. The feasibility and accuracy of manual sphygmomanometer to monitor NBP has not been explored widely.

METHODS

A cross-sectional study was conducted at the cardiology department of a university-affiliated hospital to study patients with mild-to-moderate essential hypertension. One hundred and fifty-five patients were recruited to compare BP derived from a manual device and ambulatory BP monitoring (ABPM). The manual BP measurement was performed six times at 22:00, 02:00, 06:00, 10:00, 14:00 and 18:00 h. The measurements at 22:00, 02:00 and 06:00 h were defined as night-time and the others as daytime. ABPM was programmed to measure at 30-min intervals between measurements.

RESULTS

All-day, daytime and night-time BP did not differ significantly from 24-h ambulatory systolic BP [all-day mean difference -0.52±4.67 mmHg, 95% confidence interval (CI) -1.26 to 0.22, P=0.168; daytime mean difference 0.24±5.45 mmHg, 95% CI -0.62 to 1.11, P=0.580; night-time mean difference 0.30±7.22 mmHg, 95% CI -0.84 to 1.45, P=0.601) rather than diastolic BP. There was a strong correlation between clinical and ambulatory BP for both systolic and diastolic BP. On the basis of ABPM, 101 (65%) patients were classified as non-dippers, compared with 106 (68%) by manual sphygmomanometer (P<0.001).

CONCLUSIONS

Traditional manual sphygmomanometer provides similar daytime and night-time systolic BP measurements in hospital. Moreover, the detection of non-dippers by manual methods is in good agreement with 24-h ABPM. Further studies are required to confirm the clinical relevance of these findings by comparing the association of NBP in the hospital ward assessed by manual monitoring with preclinical organ damage and cardiovascular and cerebrovascular outcomes.