Morning Blood Pressure Surge and Nighttime Blood Pressure in Relation to Nocturnal Sleep Pattern and Arterial Stiffness

The impact of forced awakening on morning blood pressure surge

BACKGROUND

Poor sleep quality can cause an increase in morning blood pressure surge (MBPS), an independent risk factor of cardiovascular disease (CVD) events. Awakening induced by external factors such as alarm clocks, may also contribute to increased MBPS.

OBJECTIVES

To (1) compare the MBPS and sleep quality parameters between natural and forced awakenings and (2) examine the potential impact of forced awakening on MBPS, independent of sleep quality.

METHODS

Thirty-two healthy adults participated in this pilot study, which included one night of natural awakening and one night of forced awakening (i.e., sleep was interrupted by an alarm after five hours). Objective and self-reported sleep quality parameters were measured using a multisensory wristband and sleep diaries, respectively, and beat-to-beat blood pressure variability was assessed using a continuous blood pressure monitor. Analyses included a paired t-test (objective 1) and linear mixed models (objective 2).

RESULTS

Participants predominantly consisted of young, healthy, and highly educated Asian adults. During the night of sleep with forced awakening, significantly higher MBPS, lower objective wakefulness after sleep onset, and lower self-reported sleep latency were observed, compared to the night with natural awakening. Forced awakening was significantly associated with increased MBPS after controlling for age, sex, mean arterial pressure, and sleep quality.

CONCLUSIONS

Forced awakening may significantly increase MBPS, consequently heightening the risk of CVD events. Study findings should be validated in a larger sample. Further research is also warranted to examine the impact of forced awakening on MBPS in individuals with CVD.

Morning blood pressure surge and intracranial atherosclerotic plaque characteristics: a high-resolution magnetic resonance vessel wall imaging study

OBJECTIVE

To investigate the relationship between morning blood pressure surge (MBPS) and intracranial atherosclerotic plaque burden and vulnerability.

METHODS

A total of 267 ischaemic stroke patients were retrospectively analysed. Sleep-trough and prewaking MBPS were calculated from ambulatory blood pressure monitoring (ABPM). Plaque characteristics, including intraplaque haemorrhage (IPH), maximum wall thickness (max WT), and stenosis degree, were obtained from high-resolution MR vessel wall imaging (HR-vwMRI). Linear and logistic regression were used to detect the association.

RESULTS

Subjects with the top tertile of sleep-trough MBPS (≥15.1 mmHg) had a lower prevalence (9.1% vs. 19.6%, P = .029) of severe stenosis (≥70%) than others. Subjects within the top tertile of prewaking MBPS (≥7.6 mmHg) had a lower percentage of IPH (27.3% vs. 40.4%, P = .035) than others. After adjusting for stroke risk factors (age, sex, diabetes, hyperlipidaemia, hyperhomocysteinaemia, smoking, and family stroke history) and 24-h mean systolic blood pressure, 10 mmHg sleep-trough MBPS increment was associated with 0.07mm max WT reduction, and the top tertile MBPS group was associated with a lower chance of severe stenosis (odd ratio = 0.407, 95% CI, 0.175-0.950). Additionally, an increased prewaking MBPS is associated with a lower incidence of IPH, with OR = 0.531 (95% CI, 0.296-0.952). Subgroup analysis demonstrated that the positive findings could only be seen in non-diabetic subjects.

CONCLUSION

Increment of MBPS is negatively associated with intracranial atherosclerotic plaque burden and vulnerability, and this relationship remains significant in the non-diabetic subgroup.

ADVANCES IN KNOWLEDGE

This study provided evidence that MBPS was associated with the intracranial atherosclerotic plaque burden and vulnerability on HR-vwMRI.

Sex-Dependent Association Between Early Morning Ambulatory Blood Pressure Variations and Acute Mountain Sickness

Background

Acute high altitude (HA) exposure elicits blood pressure (BP) responses in most subjects, and some of them suffer from acute mountain sickness (AMS). However, a 24-h ambulatory BP (ABP) change and the correlation with the occurrence of AMS in different sexes are still unclear.

Objectives

This prospective study aimed to investigate HA induced BP responses in males and females and the relationship between AMS and 24-h ABP.

Methods

Forty-six subjects were matched according to demographic parameters by propensity score matching with a ratio of 1:1. All the subjects were monitored by a 24-h ABP device; the measurement was one period of 24 h BP. 2018 Lake Louise questionnaire was used to evaluate AMS.

Results

Both the incidence of AMS (14 [60.9%] vs. 5 [21.7%], P = 0.007) and headache (18 [78.3%] vs. 8 [34.8%], P = 0.003) were higher in females than in males. All subjects showed an elevated BP in the early morning [morning systolic BP (SBP), 114.72 ± 13.57 vs. 120.67 ± 11.10, P = 0.013]. The elevation of morning SBP variation was more significant in females than in males (11.95 ± 13.19 vs. −0.05 ± 14.49, P = 0.005), and a higher morning BP surge increase (4.69 ± 18.09 vs. −9.66 ± 16.96, P = 0.005) was observed after acute HA exposure in the female group. The increase of morning SBP was associated with AMS occurrence (R = 0.662, P < 0.001) and AMS score (R = 0.664, P = 0.001). Among the AMS symptoms, we further revealed that the incidence (R = 0.786, P < 0.001) and the severity of headache (R = 0.864, P < 0.001) are closely correlated to morning SBP.

Conclusions

Our study demonstrates that females are more likely to suffer from AMS than males. AMS is closely associated with elevated BP in the early morning period, which may be correlated to higher headache incidence in subjects with higher morning SBP.

Quantifying sleep architecture dynamics and individual differences using big data and Bayesian networks

The pattern of sleep stages across a night (sleep architecture) is influenced by biological, behavioral, and clinical variables. However, traditional measures of sleep architecture such as stage proportions, fail to capture sleep dynamics. Here we quantify the impact of individual differences on the dynamics of sleep architecture and determine which factors or set of factors best predict the next sleep stage from current stage information. We investigated the influence of age, sex, body mass index, time of day, and sleep time on static (e.g. minutes in stage, sleep efficiency) and dynamic measures of sleep architecture (e.g. transition probabilities and stage duration distributions) using a large dataset of 3202 nights from a non-clinical population. Multi-level regressions show that sex effects duration of all Non-Rapid Eye Movement (NREM) stages, and age has a curvilinear relationship for Wake After Sleep Onset (WASO) and slow wave sleep (SWS) minutes. Bayesian network modeling reveals sleep architecture depends on time of day, total sleep time, age and sex, but not BMI. Older adults, and particularly males, have shorter bouts (more fragmentation) of Stage 2, SWS, and they transition less frequently to these stages. Additionally, we showed that the next sleep stage and its duration can be optimally predicted by the prior 2 stages and age. Our results demonstrate the potential benefit of big data and Bayesian network approaches in quantifying static and dynamic architecture of normal sleep.

Differences in Dynamic Diurnal Blood Pressure Variability Between Japanese and American Treatment-Resistant Hypertensive Populations

BACKGROUND

Dynamic diurnal changes in 24-h ambulatory systolic blood pressure (SBP) are associated with increased cardiovascular risk. We compared ambulatory BP dynamics in Japanese and American black and white populations with treatment-resistant hypertension.Methods and Results:Both HTN-Japan (n=41) and SYMPLICITY HTN-3 (n=384 white and n=140 black patients) enrolled patients with office SBP ≥160 mmHg and 24-h ambulatory SBP ≥135 mmHg while on ≥3 antihypertensive medications. Indices of circadian variation in ambulatory BP, including morning and nighttime dynamic surges, were retrospectively compared. All 3 cohorts had similar baseline office SBP. The Japanese cohort had significantly lower body mass index, less obstructive sleep apnea, and less hypercholesterolemia than the black and white cohorts, but significantly greater morning SBP levels, including moving peak morning SBP (183 vs. 169 vs. 169 mmHg, P<0.001), morning dynamic surge (37.9 vs. 28.6 vs. 24.2 mmHg, P<0.001) and nighttime dynamic surge (24.9 vs. 8.3 vs. 7.7 mmHg, P<0.001). These racial differences in SBP surge parameters persisted despite adjustment for baseline demographic population differences through multivariate regression.

CONCLUSIONS

Greater diurnal BP variability, including dynamic surges, in Japanese compared with black and white patients may indicate ethnic differences in the underlying BP regulatory mechanism of resistant hypertension. These differences may be important to take into consideration for more specific drug and device-based therapy strategies based on ethnicity.

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.

Racial impact of diurnal variations in blood pressure on cardiovascular events in chronic kidney disease

Ambulatory blood pressure parameters, nocturnal dipping and morning surge, are associated with cardiovascular outcomes in several populations. While significant variation exists between racial groups in ambulatory blood pressure measurements and the incidence of cardiovascular disease, the effect of race on the associations of dipping and morning surge with cardiovascular outcomes is unknown. In a prospective analysis of 197 African American and 197 Japanese individuals with non-diabetic chronic kidney disease matched by age and renal function, we analyzed the associations of dipping and morning surge with cardiovascular events for both races and assessed whether these relations differed by race. Higher sleep-trough morning surge was independently associated with cardiovascular events in Japanese (hazard ratio, 1.93 per 10 mm Hg; 95% confidence interval, 1.20-3.10) but not in African American participants, with race an effect modifier (P-value <.01). Dipping was not associated with cardiovascular events in either racial group. In individuals with chronic kidney disease, the association between morning surge and cardiovascular events appears to be dependent upon race, with higher morning surge a risk factors in Japanese but not in African Americans.

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.

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.

The relationship between central hemodynamics, morning blood pressure surge, glycemic control and sodium intake in patients with type 2 diabetes and essential hypertension

AIMS

The current study aimed to investigate the relationship between morning blood pressure surge (MBPS), hemodynamic parameters, glycemic control and 24-h urinary sodium excretion (USE) in patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

MBPS and central hemodynamic parameters were assessed from ambulatory blood pressure measurements. In addition to routine biochemistry, 24h urine collection was performed to measure protein, albumin and sodium excretion.

RESULTS

There were 146 (38%) patients with T2DM and 238 (72%) patients without T2DM (control group). Patients with T2DM had statistically higher MBPS compared with patients without T2DM (P<0.0001). In patients with T2DM, MBPS was correlated with HbA1c (rho=0.311, P<0.0001), 24h urinary sodium excretion (USE) (rho=0.292, P=0.004) and various hemodynamic parameters. Additionally, regression analysis showed that being male (P=0.006), the presence of coronary artery disease (P=0.023), HbA1c (P=0.012), and 24h USE (P=0.001) were independently related with log MBPS in T2DM patients.

CONCLUSION

This study demonstrated that T2DM was an independent risk factor for increased MBPS and MBPS was associated with central hemodynamic parameters. Additionally poor glycemic control and sodium intake were associated with worse MBPS in T2DM.