Circadian rhythm in hypertension: Bibliometrics and knowledge mapping from 1990 to 2022

Recently, research on the circadian rhythm of hypertension has gained popularity. However, few bibliometric analyses have been conducted in this field. In this study, CiteSpace 6.1. R6, VOSviewer 1.6.18, R language (version 4.2.3), R package Bibliometrix (4.1.2), and Microsoft Excel 365 were used to conduct the data mining and knowledge visualization analysis. A total of 1,560 papers from 1,825 institutions in 77 countries were included. Research on the role of circadian rhythms in hypertension is increasing annually. Overall, Chronobiology International published the most literature and Hypertension received the most citations. Ramon Hermida from the Universidade de Vigo in Spain published the most papers and had the most citations. The United States of America and Japan have been the most productive countries. The University of Ferrara, Universidade de Vigo, and the University of California system produced the most publications. Amongst authors, Hermida had the most and longest literature bursts. Keywords such as "chronic kidney disease," "oxidative stress," and "gene expression" have been breakout keywords since 2014. This study revealed the dynamic evolution of research on circadian rhythms in hypertension and provides a knowledge base for researchers.

The contribution of circadian clock to the biological processes

All organisms have various circadian, behavioral, and physiological 24-h periodic rhythms, which are controlled by the circadian clock. The circadian clock controls various behavioral and physiological rhythms. In mammals, the primary circadian clock is present in the suprachiasmatic nucleus of the hypothalamus. The rhythm of the circadian clock is controlled by the interaction between negative and positive feedback loops, consisting of crucial clock regulators (including Bmal1 and Clock), three cycles (mPer1, mPer2, and mPer3), and two cryptochromes (Cry1 and Cry2). The development of early mammalian embryos is an ordered and complex biological process that includes stages from fertilized eggs to blastocysts and undergoes important morphological changes, such as blastocyst formation, cell multiplication, and compaction. The circadian clock affects the onset and timing of embryonic development. The circadian clock affects many biological processes, including eating time, immune function, sleep, energy metabolism, and endocrinology, therefore, it is also crucial for overall health, growth and development after birth. This review summarized the effects of the circadian clock in the body's physiological activities. A new strategy is proposed for the prevention of malformations or diseases by regulating the circadian clock or changing circadian rhythms.

Association between time-of-day for eating, exercise, and sleep with blood pressure in adults with elevated blood pressure or hypertension: a systematic review

The purpose of this review is to synthesize results from studies examining the association between time-of-day for eating, exercise, and sleep with blood pressure (BP) in adults with elevated BP or hypertension. Six databases were searched for relevant publications from which 789 were identified. Ten studies met inclusion criteria. Four studies examined time-of-day for eating, five examined time-of-day for exercise, and one examined time-of-day for sleep and their associations with BP. Results suggested that later time-of-day for eating ( n  = 2/4) and later sleep mid-point ( n  = 1/1) were significantly related to higher BP in multivariable models, whereas morning ( n  = 3/5) and evening ( n  = 4/5) exercise were associated with significantly lower BP. Although this small body of work is limited by a lack of prospective, randomized controlled study designs and underutilization of 24 h ambulatory BP assessment, these results provide preliminary, hypothesis-generating support for the independent role of time-of-day for eating, exercise, and sleep with lower BP.

Effect of timed dosing of usual antihypertensives according to patient chronotype on cardiovascular outcomes: the Chronotype sub-study cohort of the Treatment in Morning versus Evening (TIME) study

Background

Timing drug administration to endogenous circadian rhythms may enhance treatment efficacy. In the Chronotype sub-study of the Treatment in Morning versus Evening (TIME) clinical trial we examined whether timing of usual antihypertensive medications according to patient chronotype (a behavioural marker of personal circadian rhythm) may influence clinical cardiovascular outcomes.

Methods

This was a cohort sub-study of TIME, a prospective, randomised, open-label, blinded-endpoint, UK clinical trial of morning versus evening dosing of usual antihypertensive medications and cardiovascular outcomes. On August 3rd, 2020, all active TIME participants were invited to complete a validated chronotype questionnaire. Chronotype was quantitatively assessed as the mid sleep time on free days corrected for sleep debt on workdays (MSFsc). We analysed associations between chronotype and antihypertensive dosing time and explored their combined effect on cardiovascular outcomes (a composite endpoint of hospitalisation for non-fatal myocardial infarction (MI) or non-fatal stroke, and single components) using proportional hazard time-to-event models adjusted for baseline covariates. These were used to specifically test for interactions between dosing time and chronotype.

Findings

Between August 3, 2020, and March 31, 2021, 5358 TIME participants completed the online questionnaire. 2778 were previously randomised to morning dosing and 2580 to evening dosing of their usual antihypertensives. Chronotype was symmetrically distributed around a median MSFsc of 3:07 am. The composite endpoint increased for later MSFsc (later chronotype) dosed in the morning but not in those dosed in the evening (hazard ratios 1.46 [95% CI 1.14-1.86] and 0.96 [95% CI 0.70-1.30] per hour of MSFsc, respectively; interaction p = 0.036). Later chronotype was associated with increased risk of hospitalisation for non-fatal MI in the morning dosing group, and reduced risk in the evening dosing group (hazard ratios 1.62 [95% CI 1.18-2.22] and 0.66 [95% CI 0.44-1.00] per hour of MSFsc, respectively; interaction p < 0.001). No interaction between chronotype and antihypertensive dosing time was observed for stroke events.

Interpretation

Alignment of dosing time of usual antihypertensives with personal chronotype could lower the incidence of non-fatal MI compared to a 'misaligned' dosing time regimen. Future studies are warranted to establish whether synchronizing administration time of antihypertensive therapy with individual chronotype reduces risk of MI.

Funding

The TIME study was funded by the British Heart Foundation (CS/14/1/30659) with support from the British and Irish Hypertension Society.

The circadian rhythm: A new target of natural products that can protect against diseases of the metabolic system, cardiovascular system, and nervous system

BACKGROUND

The treatment of metabolic system, cardiovascular system, and nervous system diseases remains to be explored. In the internal environment of organisms, the metabolism of substances such as carbohydrates, lipids and proteins (including biohormones and enzymes) exhibit a certain circadian rhythm to maintain the energy supply and material cycle needed for the normal activities of organisms. As a key factor for the health of organisms, the circadian rhythm can be disrupted by pathological conditions, and this disruption accelerates the progression of diseases and results in a vicious cycle. The current treatments targeting the circadian rhythm for the treatment of metabolic system, cardiovascular system, and nervous system diseases have certain limitations, and the identification of safer and more effective circadian rhythm regulators is needed.

AIM OF THE REVIEW

To systematically assess the possibility of using the biological clock as a natural product target for disease intervention, this work reviews a range of evidence on the potential effectiveness of natural products targeting the circadian rhythm to protect against diseases of the metabolic system, cardiovascular system, and nervous system. This manuscript focuses on how natural products restore normal function by affecting the amplitude of the expression of circadian factors, sleep/wake cycles and the structure of the gut microbiota.

KEY SCIENTIFIC CONCEPTS OF THE REVIEW

This work proposes that the circadian rhythm, which is regulated by the amplitude of the expression of circadian rhythm-related factors and the sleep/wake cycle, is crucial for diseases of the metabolic system, cardiovascular system and nervous system and is a new target for slowing the progression of diseases through the use of natural products. This manuscript provides a reference for the molecular modeling of natural products that target the circadian rhythm and provides a new perspective for the time-targeted action of drugs.

Association between nocturnal blood pressure phenotype and adverse cardiovascular prognosis in patients with coronary heart disease and hypertension

Nocturnal blood pressure and nighttime dipping patterns are associated with the occurrence of cardiovascular events. However, there is few research on whether riser pattern is associated with the poor prognosis of patients with coronary heart disease (CHD) and hypertension independent of nighttime systolic blood pressure (SBP). This prospective and observational clinical study included 568 hospitalized patients with CHD and hypertension. All patients underwent 24-h ambulatory blood pressure (BP) monitoring during their hospitalization. Multivariate adjusted Cox proportional hazard models were utilized to examine the associations of nocturnal blood pressure and dipping status with primary endpoint events. Additionally, Harrell's C-statistics were employed to compare the discriminative ability of each model. During the 1-year follow-up period, 64 (11.3%) primary endpoint events were recorded, including 55 (9.7%) atherosclerotic cardiovascular disease (ASCVD) events. After adjusting for demographic and clinical risk variables, nighttime SBP was significantly related to the risk of incident primary endpoint events [per 20 mm Hg increase: hazard ratio (HR) = 1.775, 95% confidence interval (CI) 1.256-2.507]. The riser pattern group exhibited a significantly higher risk for primary endpoint events compared to the dipper pattern group, even after adjusting for office SBP (HR: 2.687, 95% CI: 1.015-7.110, p = .047). Furthermore, the addition of nighttime SBP or dipping status to the base model yielded statistically significant increments in C-statistic values (p = .036 and p = .007). However, adding both nighttime SBP and dipping status did not significantly enhance the model's performance in predicting the risk of primary endpoint events and ASCVD events according to the C-index (p = .053 and p = .054), which meant that the riser pattern group did not exhibit a significantly higher risk for primary endpoint events compared to the dipper pattern group after adjusting for nighttime SBP. In conclusion, nocturnal SBP and riser pattern demonstrated an association with adverse prognosis in patients with CHD and hypertension. Notably, nocturnal SBP proved to be a more reliable predictor than dipping status.

Female mice display sex-specific differences in cerebrovascular function and subarachnoid haemorrhage-induced injury

BACKGROUND

In male mice, a circadian rhythm in myogenic reactivity influences the extent of brain injury following subarachnoid haemorrhage (SAH). We hypothesized that female mice have a different cerebrovascular phenotype and consequently, a distinct SAH-induced injury phenotype.

METHODS

SAH was modelled by pre-chiasmatic blood injection. Olfactory cerebral resistance arteries were functionally assessed by pressure myography; these functional assessments were related to brain histology and neurobehavioral assessments. Cystic fibrosis transmembrane conductance regulator (CFTR) expression was assessed by PCR and Western blot. We compared non-ovariectomized and ovariectomized mice.

FINDINGS

Cerebrovascular myogenic reactivity is not rhythmic in females and no diurnal differences in SAH-induced injury are observed; ovariectomy does not unmask a rhythmic phenotype for any endpoint. CFTR expression is rhythmic, with similar expression levels compared to male mice. CFTR inhibition studies, however, indicate that CFTR activity is lower in female arteries. Pharmacologically increasing CFTR expression in vivo (3 mg/kg lumacaftor for 2 days) reduces myogenic tone at Zeitgeber time 11, but not Zeitgeber time 23. Myogenic tone is not markedly augmented following SAH in female mice and lumacaftor loses its ability to reduce myogenic tone; nevertheless, lumacaftor confers at least some injury benefit in females with SAH.

INTERPRETATION

Female mice possess a distinct cerebrovascular phenotype compared to males, putatively due to functional differences in CFTR regulation. This sex difference eliminates the CFTR-dependent cerebrovascular effects of SAH and may alter the therapeutic efficacy of lumacaftor compared to males.

FUNDING

Brain Aneurysm Foundation, Heart and Stroke Foundation and Ted Rogers Centre for Heart Research.

H-type Hypertension Status and Influencing Factors of the Elderly People Over 80 Years Old Based on Random Forest Model

Hypertension is a common chronic disease in elderly people over 80 years old. Clinically, H-type hypertension occurs when hypertension coexists with hyperhomocysteinemia level of ≥ 10 umol/L. Effective identification of risk factors for H-type hypertension in the elderly can greatly improve patient prognosis.Consecutively, 494 patients with hypertension admitted to the Fourth Affiliated Hospital of Harbin Medical University from January 2019 to December 2021 were selected as the study population. They were divided into H-type hypertension (n = 197) and non-H-type hypertension groups (n = 297). Patient data were collected, including basic information, history, and clinical data. The random forest model and LASSO analysis were used to screen the influencing factors for H-type hypertension. Multiple stepwise regression analysis was used to analyze the selected variables.A total of 197 elderly people over 80 years old suffered from H-type hypertension, with an incidence rate of 39.88%. The random forest model and LASSO analysis results showed that the top 8 independent variables in importance ranking were ejection fraction (EF), fibrinogen, glycated hemoglobin (HbA1c), B-type natriuretic peptide, creatinine, fasting blood glucose, uric acid, and serum triiodothyronine levels. The results of multivariate analysis showed that EF was the protective factor, while fibrinogen, HbA1c, and creatinine were the risk factors for H-type hypertension in elderly people over 80 years old (P < 0.05).Healthcare professionals can indirectly assess the prevalence of H-type hypertension by focusing on EF, fibrinogen, creatinine, and HbA1c in elderly hypertensive patients. This provided proactive intervention and medical services to improve prognosis outcomes.

The Option of Chronotherapy of Hypertension

The aim of the present paper is to explore the option of chronotherapy of hypertension and its effectiveness in blood pressure (BP) lowering compared with its standard daily treatment. The treatment of BP has gone through many different schemes over the years. From no treatment in the early 1930s, to step care, to multiple drug combinations, or to single daily drug combinations with 2-3 drugs, still BP is not well controlled in a significant number of patients. Recently, the role of the circadian rhythm in the treatment of hypertension has been tested by several studies comparing the evening versus the morning drug administration with no clear evidence of superiority of either mode of drug administration. However, in cases of morning surge of BP, nocturnal hypertension, and renal disease, the evening drug administration has been more effective than the morning drug administration, and thus, more preferable. In order to get a better perspective on this approach of hypertension treatment, a Medline search of the English literature was contacted between 2010 and 2023 using the terms BP control, circadian rhythm, morning drug administration, evening drug administration, and 38 pertinent papers were selected for analysis. Careful review of the selected papers showed that chronotherapy of hypertension is effective. However, the overall effectiveness of evening drug administration compared with the morning administration is not significantly more effective compared to the morning administration and more work is needed in this field.

Circadian and Diurnal Regulation of Cerebral Blood Flow

Circadian and diurnal variation in cerebral blood flow directly contributes to the diurnal variation in the risk of stroke, either through factors that trigger stroke or due to impaired compensatory mechanisms. Cerebral blood flow results from the integration of systemic hemodynamics, including heart rate, cardiac output, and blood pressure, with cerebrovascular regulatory mechanisms, including cerebrovascular reactivity, autoregulation, and neurovascular coupling. We review the evidence for the circadian and diurnal variation in each of these mechanisms and their integration, from the detailed evidence for mechanisms underlying the nocturnal nadir and morning surge in blood pressure to identifying limited available evidence for circadian and diurnal variation in cerebrovascular compensatory mechanisms. We, thus, identify key systemic hemodynamic factors related to the diurnal variation in the risk of stroke but particularly identify the need for further research focused on cerebrovascular regulatory mechanisms.

Pioneering new frontiers in circadian medicine chronotherapies for cardiovascular health

Cardiovascular disease (CVD) is a global health concern. Circadian medicine improves cardiovascular care by aligning treatments with our body's daily rhythms and their underlying cellular circadian mechanisms. Time-based therapies, or chronotherapies, show special promise in clinical cardiology. They optimize treatment schedules for better outcomes with fewer side effects by recognizing the profound influence of rhythmic body cycles. In this review, we focus on three chronotherapy areas (medication, light, and meal timing) with potential to enhance cardiovascular care. We also highlight pioneering research in the new field of rest, the gut microbiome, novel chronotherapies for hypertension, pain management, and small molecules that targeting the circadian mechanism.

Nighttime administration of antihypertensive medication: a review of chronotherapy in hypertension

Hypertension remains a global health concern because of suboptimal blood pressure control despite advancements in antihypertensive treatments. Chronotherapy, defined as evening or bedtime administration of medication based on biological rhythms, is emerging as a potential strategy to improve blood pressure control and treatment outcomes. Clinical trials have investigated the potential effects of nighttime administration of antihypertensive medication in the improvement of 24 hours blood pressure control and reduction of cardiovascular risk. Implementing chronotherapy in clinical practice could have significant implications in enhancing blood pressure control and improving clinical outcomes in patients with hypertension, particularly those with resistant hypertension. However, recent trials have reported contradictory results, causing confusion in real-world practice. Herein we review, analyze, and critique the current evidence and propose suggestions regarding the clinical application and future directions of chronotherapy.

Circadian Regulation of Endocrine Fibroblast Growth Factors on Systemic Energy Metabolism

The circadian clock is an endogenous biochemical timing system that coordinates the physiology and behavior of organisms to earth's ∼24-hour circadian day/night cycle. The central circadian clock synchronized by environmental cues hierarchically entrains peripheral clocks throughout the body. The circadian system modulates a wide variety of metabolic signaling pathways to maintain whole-body metabolic homeostasis in mammals under changing environmental conditions. Endocrine fibroblast growth factors (FGFs), namely FGF15/19, FGF21, and FGF23, play an important role in regulating systemic metabolism of bile acids, lipids, glucose, proteins, and minerals. Recent evidence indicates that endocrine FGFs function as nutrient sensors that mediate multifactorial interactions between peripheral clocks and energy homeostasis by regulating the expression of metabolic enzymes and hormones. Circadian disruption induced by environmental stressors or genetic ablation is associated with metabolic dysfunction and diurnal disturbances in FGF signaling pathways that contribute to the pathogenesis of metabolic diseases. Time-restricted feeding strengthens the circadian pattern of metabolic signals to improve metabolic health and prevent against metabolic diseases. Chronotherapy, the strategic timing of medication administration to maximize beneficial effects and minimize toxic effects, can provide novel insights into linking biologic rhythms to drug metabolism and toxicity within the therapeutical regimens of diseases. Here we review the circadian regulation of endocrine FGF signaling in whole-body metabolism and the potential effect of circadian dysfunction on the pathogenesis and development of metabolic diseases. We also discuss the potential of chrononutrition and chronotherapy for informing the development of timing interventions with endocrine FGFs to optimize whole-body metabolism in humans. SIGNIFICANCE STATEMENT: The circadian timing system governs physiological, metabolic, and behavioral functions in living organisms. The endocrine fibroblast growth factor (FGF) family (FGF15/19, FGF21, and FGF23) plays an important role in regulating energy and mineral metabolism. Endocrine FGFs function as nutrient sensors that mediate multifactorial interactions between circadian clocks and metabolic homeostasis. Chronic disruption of circadian rhythms increases the risk of metabolic diseases. Chronological interventions such as chrononutrition and chronotherapy provide insights into linking biological rhythms to disease prevention and treatment.

Evening versus morning dosing regimen drug therapy for hypertension

BACKGROUND

Variation in blood pressure levels display circadian rhythms. Complete 24-hour blood pressure control is the primary goal of antihypertensive treatment and reducing adverse cardiovascular outcomes is the ultimate aim. This is an update of the review first published in 2011.

OBJECTIVES

To evaluate the effectiveness of administration-time-related effects of once-daily evening versus conventional morning dosing antihypertensive drug therapy regimens on all-cause mortality, cardiovascular mortality and morbidity, total adverse events, withdrawals from treatment due to adverse effects, and reduction of systolic and diastolic blood pressure in people with primary hypertension.

SEARCH METHODS

We searched the Cochrane Hypertension Specialised Register via Cochrane Register of Studies (17 June 2022), Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 6, 2022); MEDLINE, MEDLINE In-Process and MEDLINE Epub Ahead of Print (1 June 2022); Embase (1 June 2022); ClinicalTrials.gov (2 June 2022); Chinese Biomedical Literature Database (CBLD) (1978 to 2009); Chinese VIP (2009 to 7 August 2022); Chinese WANFANG DATA (2009 to 4 August 2022); China Academic Journal Network Publishing Database (CAJD) (2009 to 6 August 2022); Epistemonikos (3 September 2022) and the reference lists of relevant articles. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing the administration-time-related effects of evening with morning dosing monotherapy regimens in people with primary hypertension. We excluded people with known secondary hypertension, shift workers or people with white coat hypertension.

DATA COLLECTION AND ANALYSIS

Two to four review authors independently extracted data and assessed trial quality. We resolved disagreements by discussion or with another review author. We performed data synthesis and analyses using Review Manager Web for all-cause mortality, cardiovascular mortality and morbidity, serious adverse events, overall adverse events, withdrawals due to adverse events, change in 24-hour blood pressure and change in morning blood pressure. We assessed the certainty of the evidence using GRADE. We conducted random-effects meta-analysis, fixed-effect meta-analysis, subgroup analysis and sensitivity analysis.

MAIN RESULTS

We included 27 RCTs in this updated review, of which two RCTs were excluded from the meta-analyses for lack of data and number of groups not reported. The quantitative analysis included 25 RCTs with 3016 participants with primary hypertension. RCTs used angiotensin-converting enzyme inhibitors (six trials), calcium channel blockers (nine trials), angiotensin II receptor blockers (seven trials), diuretics (two trials), α-blockers (one trial), and β-blockers (one trial). Fifteen trials were parallel designed, and 10 trials were cross-over designed. Most participants were white, and only two RCTs were conducted in Asia (China) and one in Africa (South Africa). All trials excluded people with risk factors of myocardial infarction and strokes. Most trials had high risk or unclear risk of bias in at least two of several key criteria, which was most prominent in allocation concealment (selection bias) and selective reporting (reporting bias). Meta-analysis showed significant heterogeneity across trials. No RCTs reported on cardiovascular mortality and cardiovascular morbidity. There may be little to no differences in all-cause mortality (after 26 weeks of active treatment: RR 0.49, 95% CI 0.04 to 5.42; RD 0, 95% CI -0.01 to 0.01; very low-certainty evidence), serious adverse events (after 8 to 26 weeks of active treatment: RR 1.17, 95% CI 0.53 to 2.57; RD 0, 95% CI -0.02 to 0.03; very low-certainty evidence), overall adverse events (after 6 to 26 weeks of active treatment: RR 0.89, 95% CI 0.67 to 1.20; I² = 37%; RD -0.02, 95% CI -0.07 to 0.02; I² = 38%; very low-certainty evidence) and withdrawals due to adverse events (after 6 to 26 weeks active treatment: RR 0.76, 95% CI 0.47 to 1.23; I² = 0%; RD -0.01, 95% CI -0.03 to 0; I² = 0%; very low-certainty evidence), but the evidence was very uncertain.

AUTHORS' CONCLUSIONS

Due to the very limited data and the defects of the trials' designs, this systematic review did not find adequate evidence to determine which time dosing drug therapy regimen has more beneficial effects on cardiovascular outcomes or adverse events. We have very little confidence in the evidence showing that evening dosing of antihypertensive drugs is no more or less effective than morning administration to lower 24-hour blood pressure. The conclusions should not be assumed to apply to people receiving multiple antihypertensive drug regimens.

Effect of aspirin on blood pressure in hypertensive patients: a systematic review and meta-analysis

INTRODUCTION

Aspirin is widely used for secondary prevention in patients with hypertension. However, previous studies mainly focused on the preventive effects of aspirin, and there has been a lack of reliable evidence on whether taking aspirin affects blood pressure This study aimed to investigate whether aspirin would affect the blood pressure in patients with hypertension.

METHODS

PubMed, Cochrane database, Embase, Scopus and Medline databases were searched until September 2023. For continuous variables (e.g., blood pressure reduction), the mean difference (MD) was selected as the effect magnitude indices. We used the Cochrane Collaboration's Risk of Bias tool to assess the risk of bias.

RESULT

A total of five studies were included, comprising 20,312 patients. We found that aspirin did not affect SBP (MD = -0.78, 95% CI: - 2.41, 0.84). A similar result was found for DBP (MD = -0.86, 95% CI: - 2.14, 0.42).

CONCLUSION

This study showed no significant difference in blood pressure between the aspirin and control groups, suggesting that aspirin does not affect blood pressure.

Clinical Significance of Nocturnal Hypertension and Nighttime Blood Pressure Dipping in Hypertension

PURPOSE OF REVIEW

This narrative review article aims to discuss more recent evidence, current challenges, and future perspectives regarding the clinical importance of nocturnal hypertension and nighttime blood pressure dipping, with particular reference to diagnosis, prognostic value, and therapeutic approach.

RECENT FINDINGS

The importance of nighttime blood pressure and nighttime blood pressure dipping has been demonstrated in decades. Increased nighttime blood pressure has been acknowledged as an unfavorable clinical trait. However, more recent evidence suggests that the abolishment of normal circadian blood pressure rhythm is not always a solid predictor of adverse cardiovascular events and needs to be interpreted in the light of each patients' individual characteristics. Physicians treating hypertensive patients with adverse nighttime blood pressure profiles often face the dilemma of chronotherapy. This has been a blurred field for years, yet very recent evidence from appropriately designed studies attempts to shed light on this puzzling question. As 24-h ambulatory blood pressure monitoring is being increasingly recommended and applied in real-world practice for the diagnosis and monitoring of hypertension, information on nighttime blood pressure and nocturnal dipping profile is collected but is not always easy to interpret.

Circadian neurogenetics and its implications in neurophysiology, behavior, and chronomedicine

The circadian rhythm affects multiple physiological processes, and disruption of the circadian system can be involved in a range of disease-related pathways. The genetic underpinnings of the circadian rhythm have been well-studied in model organisms. Significant progress has been made in understanding how clock genes affect the physiological functions of the nervous system. In addition, circadian timing is becoming a key factor in improving drug efficacy and reducing drug toxicity. The circadian biology of the target cell determines how the organ responds to the drug at a specific time of day, thus regulating pharmacodynamics. The current review brings together recent advances that have begun to unravel the molecular mechanisms of how the circadian clock affects neurophysiological and behavioral processes associated with human brain diseases. We start with a brief description of how the ubiquitous circadian rhythms are regulated at the genetic, cellular, and neural circuit levels, based on knowledge derived from extensive research on model organisms. We then summarize the latest findings from genetic studies of human brain disorders, focusing on the role of human clock gene variants in these diseases. Lastly, we discuss the impact of common dietary factors and medications on human circadian rhythms and advocate for a broader application of the concept of chronomedicine.

Demonstrating the Benefits of Antihypertensive Nighttime Dosing and Indapamide Usage in Hypertension Management

Background: Uncontrolled hypertension, specifically nocturnal hypertension, increases the risk for significant clinical outcomes. Evidence on the use of nighttime antihypertensives is scant and conflicting. In addition, hydrochlorothiazide continues to be the primary thiazide used despite being the least potent. Objective: The primary purpose of this study was to evaluate instituting nighttime dosing to control hypertension and compare the short-term effectiveness of blood pressure control with indapamide versus hydrochlorothiazide. Methods: This was a retrospective, observational study. Participant inclusion criteria consisted of patients 18 years of age or older, a current diagnosis of hypertension, and hypertension that required medical therapy. The investigator documented whether a patient was taking at least one antihypertensive at night versus all morning medications, as well as the use of indapamide versus hydrochlorothiazide. The patient's baseline and first follow-up blood pressure readings were documented. The primary outcome was to determine whether including nighttime dosing in antihypertensive regimens is more effective than all morning antihypertensive regimens. The secondary outcome was to determine whether indapamide was more effective than hydrochlorothiazide. Results: A total of 64 patients were included in the study. Twenty-eight patients were taking >1 nighttime antihypertensives versus 32 patients on all morning medications. Patients on at least one nighttime medication demonstrated greater systolic blood pressure reduction. There was no difference in blood pressure reduction between indapamide and hydrochlorothiazide. Conclusion: The study findings support the use of nighttime dosing to improve blood pressure management. The results on the effectiveness of indapamide versus hydrochlorothiazide conflict with previous research.

Impact of timing of antihypertensive treatment on mortality: an observational study from the Spanish Ambulatory Blood Pressure Monitoring Registry

BACKGROUND AND AIMS

Whether bedtime versus morning administration of antihypertensive therapy is beneficial on outcomes is controversial. We evaluated the risk of total and cardiovascular mortality in a very large observational cohort of treated hypertensive patients, according to the timing of their usual treatment administration (morning versus evening).

METHODS

Vital status and cause of death were obtained from death certificates of 28 406 treated hypertensive patients (mean age 62 years, 53% male individuals), enrolled in the Spanish Ambulatory Blood Pressure Monitoring (ABPM) Registry between 2004 and 2014. Among the 28 406 patients, most (86%) received their medication exclusively in the morning; whilst 13% were treated exclusively in the evening or at bedtime. Follow-up was for a median of 9.7 years and 4345 deaths occurred, of which 1478 were cardiovascular deaths.

RESULTS

Using Cox-models adjusted for clinical confounders and 24-h SBP, and compared with patients treated in the morning (reference group), all-cause mortality [hazard ratio 1.01; 95% CI 0.93-1.09) and cardiovascular mortality (hazard ratio 1.04; 95% CI 0.91-1.19) was not significantly different in those receiving evening medication dosing. The results were consistent in all the subgroups of patients analysed.

CONCLUSION

In this very large observational study, morning versus bedtime dosing of antihypertensive medication made no difference to the subsequent risk of all-cause or cardiovascular mortality. These findings are in accordance with results from a recent randomized controlled trial and do not support the hypothesis of a specific beneficial effect of night-time antihypertensive treatment dosing on risk of all-cause or cardiovascular death.

Circadian Regulation of Drug Responses: Toward Sex-Specific and Personalized Chronotherapy

Today's challenge for precision medicine involves the integration of the impact of molecular clocks on drug pharmacokinetics, toxicity, and efficacy toward personalized chronotherapy. Meaningful improvements of tolerability and/or efficacy of medications through proper administration timing have been confirmed over the past decade for immunotherapy and chemotherapy against cancer, as well as for commonly used pharmacological agents in cardiovascular, metabolic, inflammatory, and neurological conditions. Experimental and human studies have recently revealed sexually dimorphic circadian drug responses. Dedicated randomized clinical trials should now aim to issue personalized circadian timing recommendations for daily medical practice, integrating innovative technologies for remote longitudinal monitoring of circadian metrics, statistical prediction of molecular clock function from single-timepoint biopsies, and multiscale biorhythmic mathematical modelling. Importantly, chronofit patients with a robust circadian function, who would benefit most from personalized chronotherapy, need to be identified. Conversely, nonchronofit patients could benefit from the emerging pharmacological class of chronobiotics targeting the circadian clock.

Clinical trial design for assessing hypertension medications: are critical circadian chronopharmacological principles being taking into account?

INTRODUCTION

Clinical hypertension trials typically rely on homeostatic principles, including single time-of-day office blood pressure (BP) measurements (OBPM), rather than circadian chronopharmacological principles, including ambulatory monitoring (ABPM) done around-the-clock to derive the asleep systolic BP (SBP) mean and sleep-time relative SBP decline - jointly the strongest prognosticators of cardiovascular disease (CVD) risk and true definition of hypertension - to qualify participants and assess outcomes.

AREAS COVERED

Eight chronopharmacological elements are indispensable for design and conduct of hypertension medication trials, mainly those on ingestion-time differences in effects, and also a means of rating quality of investigations. Accordingly, we highlight the findings and shortcomings of: (i) 155 such ingestion-time trials, 83.9% finding at-bedtime/evening treatment more beneficial than conventional upon-awakening/morning treatment; (ii) HOPE and ONTARGET CVD outcomes investigations assessing in the former add-on ramipril at-bedtime and in the latter telmisartan, ramipril, or both in combination in the morning; and (iii) pragmatic TIME CVD outcomes trial.

EXPERT OPINION

Failure to incorporate chronopharmacological principals - including ABPM to derive asleep SBP and SBP dipping to qualify subjects as hypertensive and assess CVD risk - results in deficient study design, dubious findings, and unnecessary medical controversy at the expense of advances in patient care.

Management of nocturnal hypertension: An expert consensus document from Chinese Hypertension League

Nocturnal hypertension is highly prevalent among Chinese and Asian populations, which is mainly attributed to high salt intake and high salt sensitivity. Nocturnal hypertension increases the risk of cardiovascular and all-cause mortality, independent of daytime blood pressure (BP). However, it can usually be detected by 24-h ambulatory BP monitoring, rather than routine office or home BP measurement, thus is often underdiagnosed in clinical practice. Currently, no specific guidance is available for the management of nocturnal hypertension in China or worldwide. Experts from the Chinese Hypertension League summarized the epidemiologic and pathophysiologic characteristics and clinical phenotype of nocturnal hypertension and provided consensus recommendations on optimal management of nocturnal hypertension, with the goal of maximally reducing the cardiovascular disease risks. In this consensus document, 24-h ABPM is recommended for screening and diagnosis of nocturnal hypertension, especially in the elderly, patients with diabetes, chronic kidney diseases, obstructive sleep apnea and other conditions prone to high nocturnal BP. Lifestyle modifications including salt intake restriction, exercise, weight loss, sleep improvement, and mental stress relief are recommended. Long-acting antihypertensive medications are preferred for nocturnal and 24-h BP control. Some newly developed agents, renal denervation, and other device-based therapy on nocturnal BP reduction are evaluated.

Non-Dipping Blood Pressure or Nocturnal Hypertension: Does One Matter More?

PURPOSE OF REVIEW

Nocturnal hypertension and non-dipping are both associated with increased cardiovascular risk; however, debate remains over which is a better prognosticator of cardiovascular outcomes. This review explores current literature on nocturnal hypertension and non-dipping to assess their relationship to cardiovascular disease and implications for clinical practice.

RECENT FINDINGS

While current data remain inconclusive, some suggest that nocturnal hypertension is a more reliable and clinically significant marker of cardiovascular risk than non-dipping status. Importantly, reducing nocturnal HTN and non-dipping through chronotherapy, specifically evening dosing of antihypertensives, has not been conclusively shown to provide long-term cardiovascular benefits. Recent data suggests that non-dipping, compared to nocturnal hypertension, may be falling out of favor as a prognostic indicator for adverse cardiovascular outcomes. However, additional information is needed to understand how aberrant nighttime blood pressure patterns modulate cardiovascular risk to guide clinical management.

Circadian Disruption and the Molecular Clock in Atherosclerosis and Hypertension

Circadian rhythms are crucial for maintaining vascular function and disruption of these rhythms are associated with negative health outcomes including cardiovascular disease and hypertension. Circadian rhythms are regulated by the central clock within the suprachiasmatic nucleus of the hypothalamus and peripheral clocks located in nearly every cell type in the body, including cells within the heart and vasculature. In this review, we summarize the most recent preclinical and clinical research linking circadian disruption, with a focus on molecular circadian clock mechanisms, in atherosclerosis and hypertension. Furthermore, we provide insight into potential future chronotherapeutics for hypertension and vascular disease. A better understanding of the influence of daily rhythms in behaviour, such as sleep/wake cycles, feeding, and physical activity, as well as the endogenous circadian system on cardiovascular risk will help pave the way for targeted approaches in atherosclerosis and hypertension treatment/prevention.

The effects of Olmesartan/amlodipine administered in the Morning or At Night on nocturnal blood pressure reduction in Chinese patients with mild-moderate essential hypertension (OMAN Trial): study protocol for a prospective, multicenter, randomized, open-label clinical trial {1}

INTRODUCTION

Hypertension increases the risk of cardiovascular disease. Uncontrolled nocturnal blood pressure is prevalent in patients taking antihypertensive medication, with an incidence rate of 30-60%. Although chronotherapy with antihypertensive agents may provide a new direction for effective control of nocturnal blood pressure, the clinical evidence base remains controversial. This research is presently underway to compare the effects of morning and bedtime administration of antihypertensive medication on nocturnal reduction and circadian rhythm of blood pressure in patients with hypertension.

METHODS AND ANALYSIS

This study is being performed as a randomized, multicenter, open-label, parallel-group, clinical trial in which 720 participants are to undergo 24-h ambulatory blood pressure measurement (ABPM) and office blood pressure measurement (OBPM) at baseline before being randomly assigned to a morning (6-10 am) or a bedtime (6-10 pm) administration group. Each participant receives one 20/5-mg tablet of olmesartan/amlodipine (OA) daily for 4 weeks and is then followed up at 4-week intervals for a total of 12 weeks. During follow-up, the OA dosage is adjusted according to the ABPM and OBPM results. Patients with uncontrolled hypertension at the first follow-up visit will receive an increase in OA dosage to 1.5 tablets/day. For patients with blood pressure that is still uncontrolled after a further 4 weeks, the dosage of OA can be increased to 2 tablets/day. The primary objective is the reduction in mean nocturnal systolic blood pressure between baseline and week 12. The secondary objectives are the reduction in ambulatory blood pressure at weeks 4 and 12 and the blood pressure control rate at weeks 4, 8, and 12.

DISCUSSION

Antihypertensive chronotherapy remains controversial. A superiority test hypothesis design has been adopted for this trial, in which all participants will be taking the same antihypertensive medication. We anticipate that our findings will determine if nocturnal blood pressure control in Chinese patients with essential hypertension varies according to whether antihypertensive medication is taken in the morning or at bedtime. This study may provide scientific evidence for the application of chronotherapy in clinical practice.

TRIAL REGISTRATION

ChiCTR2200059719. Registered on 10 May 2022 ( http://www.chictr.org.cn/edit.aspx?pid=169782&htm=4 ) {2a,2b}.

A systematic review, meta-analysis, and meta regression of the sham controlled renal denervation randomized controlled trials

Renal denervation (RD) has been investigated as a novel blood pressure (BP) lowering treatment for hypertension. The primary objective of this meta-analysis was to assess the efficacy of RD and factors that may associate with treatment effect heterogeneity. The primary outcomes were raw mean differences (RMD) in 24-hour ambulatory, daytime ambulatory, nighttime, and office systolic BP (SBP) and diastolic BP (DBP) between sham control and RD. A prespecified subgroup analysis was performed comparing studies with follow-up less than versus greater than 4 months. If inter-study heterogeneity was found for any of the above outcomes, additional analyses were performed to assess potential moderator variables. Ten sham-controlled randomized trials were identified and included 1,544 participants, followed for a mean of 4.20 months. RD was associated with a statistically significant reduction in all SBP and DBP measures except for nighttime SBP (-2.64 mmHg; 95% confidence interval (CI) -5.84 to 0.56, p = 0.11) and nighttime DBP (- 1.21 mmHg; 95% CI -3.17 to 0.75, p = 0.23). Mild to moderate inter-study heterogeneity was identified for three outcomes (office SBP and nighttime SBP and DBP). Studies that followed patients for longer than 4 months had numerically lower reductions in most BP outcomes; however, there were no statistically significant interactions between subgroups. Compared to a sham procedure, RD was associated with statistically significant reductions in most measures of SBP and DBP that were within bounds of what would be expected from standard blood pressure lowering medications.

The effect of bedtime versus morning dosing of antihypertensive drugs on the cardiovascular outcomes: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Antihypertensive drugs are one of the most effective strategies to prevent disability and mortality; however, there have been contradictory findings about the best dosing time for antihypertensive drugs. Therefore, we aim to evaluate the effect of bedtime versus morning dosing of antihypertensive drugs on cardiovascular outcomes.

METHODS

We synthesized randomized controlled studies (RCTs) from the Web of Science, SCOPUS, EMBASE, PubMed, and CENTRAL until 13 October 2022. The risk ratio (RR) for dichotomous outcomes with the corresponding 95% confidence interval (CI) was used. The study protocol was registered in PROSPERO with ID: CRD42022368612.

RESULTS

Five RCTs with 59 200 participants were included. Bedtime dosing was significantly associated with less incidence of myocardial infarction (MI) [RR: 0.80 with 95% CI (0.70-0.91), P = 0.0007] compared with morning dosing; however, there was no statistically significant difference between bedtime and morning dosing, regarding all-cause mortality [RR: 0.77 with 95% CI (0.51-1.16), P = 0.21], cardiovascular mortality [RR: 0.65 with 95% CI (0.35-1.21), P = 0.17], major adverse cardiac events (MACE) [RR: 0.79 with 95% CI (0.56-1.10), P = 0.16], heart failure [RR: 0.68 with 95% CI (0.42-1.09), P = 0.11], cerebrovascular accidents [RR: 0.80 with 95% CI (0.53-1.22), P = 0.30], coronary revascularization [RR: 0.79 with 95% CI (0.50-1.24), P = 0.30}, and angina [RR: 0.91 with 95% CI (0.55-1.50), P = 0.70].

CONCLUSION

Evidence about the comparative efficacy of bedtime versus morning dosing of antihypertensives is still uncertain. However, bedtime dosing significantly reduced MI, which warrants more robust RCTs to validate.

Should Antihypertensive Medications Be Routinely Administered in the Nighttime Instead of Daytime?

The optimal timing for administering antihypertensive medications remains a topic of debate. This review examines the effectiveness of nighttime vs daytime administration of antihypertensive medications in controlling blood pressure (BP). The MAPEC and Hygia trials suggest that nighttime dosing achieves better BP control and significantly lowers cardiovascular events. However, concerns about methodology and generalizability have been raised. In contrast, the HARMONY and TIME trials found no significant difference in BP control nor cardiovascular outcomes between daytime and nighttime dosing. Current research suggests that the timing of antihypertensive medication administration may not be a crucial factor. Therefore, the decision about the timing of antihypertensive medications administration should be individualized, taking into account patient preference and clinical context, in order to promote consistent compliance.

Effects of exercise timing on metabolic health

The increasing prevalence of metabolic syndrome is associated with major health and socioeconomic consequences. Currently, physical exercise, together with dietary interventions, is the mainstay of the treatment of obesity and related metabolic complications. Although exercise training includes different modalities, with variable intensity, duration, volume, or frequency, which may have a distinct impact on several characteristics related to metabolic syndrome, the potential effects of exercise timing on metabolic health are yet to be fully elucidated. Remarkably, promising results with regard to this topic have been reported in the last few years. Similar to other time-based interventions, including nutritional therapy or drug administration, time-of-day-based exercise may become a useful approach for the management of metabolic disorders. In this article, we review the role of exercise timing in metabolic health and discuss the potential mechanisms that could drive the metabolic-related benefits of physical exercise performed in a time-dependent manner.

New insights into the mechanisms of diabetic kidney disease: Role of circadian rhythm and Bmal1

It is common for diabetic kidney disease (DKD) to be complicated by abnormal blood glucose, blood lipids, and blood pressure rhythms. Thus, it is essential to examine diagnostic and treatment plans from the perspective of circadian disruption. This brief review discusses the clinical relevance of circadian rhythms in DKD and how the core clock gene encoding brain and muscle arnt-like protein 1 (BMAL1) functions owing to the importance of circadian rhythm disruption processes, including the excretion of urinary protein and irregular blood pressure, which occur in DKD. Exploring Bmal1 and its potential mechanisms and signaling pathways in DKD following contact with Sirt1 and NF-κB is novel and important. Finally, potential pharmacological and behavioral intervention strategies for DKD circadian rhythm disturbance are outlined. This review aids in unveiling novel, potential molecular targets for DKD based on circadian rhythms.

Statement on chronotherapy for the treatment of hypertension: consensus document from the Korean society of hypertension

Nocturnal blood pressure (BP) has been shown to have a significant predictive value for cardiovascular disease. In some cases, it has a superior predictive value for future cardiovascular outcomes than daytime BP. As efficacy of BP medications wanes during nighttime and early morning, control of nocturnal hypertension and morning hypertension can be difficult. As such, chronotherapy, the dosing of BP medication in the evening, has been an ongoing topic of interest in the field of hypertension. Some studies have shown that chronotherapy is effective in reducing nocturnal BP, improving non dipping and rising patterns to dipping patterns, and improving cardiovascular prognosis. However, criticism and concerns have been raised regarding the design of these studies, such as the Hygia study, and the implausible clinical benefits in cardiovascular outcomes considering the degree of BP lowering from bedtime dosing. Studies have shown that there is no consistent evidence to suggest that routine administration of antihypertensive medications at bedtime can improve nocturnal BP and early morning BP control. However, in some cases of uncontrolled nocturnal hypertension and morning hypertension, such as in those with diabetes mellitus, chronic kidney disease, and obstructive sleep apnea, bedtime dosing has shown efficacy in reducing evening and early morning BP. The recently published the Treatment in Morning versus Evening (TIME) study failed to demonstrate benefit of bedtime dosing in reducing cardiovascular outcomes in patients with hypertension. With issues of the Hygia study and negative results from the TIME study, it is unclear at this time whether routine bedtime dosing is beneficial for reducing cardiovascular outcomes.

An update on the role and potential mechanisms of clock genes regulating spermatogenesis: A systematic review of human and animal experimental studies

Circadian clocks can be traced in nearly all life kingdoms, with the male reproductive system no exception. However, our understanding of the circadian clock in spermatogenesis seems to fall behind other scenarios. The present review aims to summarize the current knowledge about the role and especially the potential mechanisms of clock genes in spermatogenesis regulation. Accumulating studies have revealed rhythmic oscillation in semen parameters and some physiological events of spermatogenesis. Disturbing the clock gene expression by genetic mutations or environmental changes will also notably damage spermatogenesis. On the other hand, the mechanisms of spermatogenetic regulation by clock genes remain largely unclear. Some recent studies, although not revealing the entire mechanisms, indeed attempted to shed light on this issue. Emerging clues hinted that gonadal hormones, retinoic acid signaling, homologous recombination, and the chromatoid body might be involved in the regulation of spermatogenesis by clock genes. Then we highlight the challenges and the promising directions for future studies so as to stimulate attention to this critical field which has not gained adequate concern.

Critical appraisal of recent translational chronopharmacology and chronotherapeutic reviews, meta-analyses, and pragmatic patient trials discloses significant deficiencies of design and conduct and suspect findings

The conduct of molecular and laboratory animal circadian rhythm research has increased exponentially in the past few decades, such that today investigations are being performed by scientists of many diverse disciplines. Knowledge gained from past works is now being explored for translational applications to clinical medicine, often termed "circadian medicine," through the implementation of patient trials. However, these trials are being led, more often than not, by investigators who have little or no formal training and in-depth expertise in the methods of human circadian rhythm research, causing them to be deficient in design and produce dubious findings that have already led to unnecessary medical controversy at the expense of advances in patient care. Evidence of the very significant shortcomings of today's translational circadian medicine research is exemplified in two recent publications in well-read reputable medical journals concerning the chronotherapy of blood pressure (BP) medications: one a review and meta-analysis by Maqsood et al. published in the journal Hypertension in 2023 that pertains to ingestion-time differences in the extent of BP reduction exerted by hypertensive medications and the other a report by Mackenzie et al. in the journal Lancet in 2022 that details the results of the pragmatic TIME study that assessed ingestion-time differences in cardiovascular disease outcomes. Herein, we appraise the inaccurate trial selection, lack of quality assessment, and the numerous other shortcomings that culminated in suspect findings and faulty conclusions of the former, as well as the deficiencies in design and conduct of the latter using as reference the eight items identified in 2021 by a working committee of the International Society for Chronobiology and American Association for Medical Chronobiology and Chronotherapeutics as being necessary for high-quality research of circadian rhythm-dependencies of the therapeutic effects of BP-lowering medications. The TIME study when rated for its quality according to the extent to which its investigational methods satisfy all of the eight recommended items attains a very low overall score of + 1 out of a possible range of -1 to + 7. Moreover, our review of the methods of the currently ongoing pragmatic BedMed trial discloses major deficiencies of the same sort rending a poor quality score of + 0.5. Although the focus of this article is the appraisal of the quality of contemporary circadian medicine hypertension chronotherapy research, it additionally exposes the inadequacies and dubious quality of the critique of such manuscripts submitted for publication to influential journals, in that some peer reviewers might also be deficient in the knowledge required to properly rate their merit.

Nondipping blood pressure pattern predicts cardiovascular events and mortality in patients with atherosclerotic peripheral vascular disease

BACKGROUND

Patients with peripheral vascular disease (PVD) are often underdiagnosed and undertreated. Nocturnal nondipping blood pressure (BP) pattern, as diagnosed by ambulatory BP monitoring (ABPM), is associated with increased cardiovascular risk, but has not been studied in patients with PVD. We aimed to investigate if a nondipping BP pattern predicts cardiovascular events or all-cause death in outpatients with PVD.

METHODS

Consecutive outpatients with carotid or lower-extremity PVD were examined with 24-hour ABPM (n = 396). Nondipping was defined as a < 10% fall in systolic BP level during night-time. We used Cox regression models adjusting for potential confounders. We also evaluated the incremental prognostic value of dipping status in the COPART risk score. Our primary composite outcome was cardiovascular events or all-cause death.

RESULTS

In the cohort (mean age 70; 40% women), 137 events occurred during a 5.1-year median follow-up; incident rate of 7.35 events per 100 person-years. Nondipping was significantly associated with outcome (hazard ratio 1.55, 95% CI 1.07-2.26, p = 0.021) in a fully adjusted model. When adding nondipping to the risk markers in the COPART risk score, the model fit significantly improved (χ2 7.91, p < 0.005) and the C-statistic increased from 0.65 to 0.67.

CONCLUSION

In a cohort of outpatients with PVD, nondipping was an independent risk factor for future cardiovascular events or mortality and seemed to be a strong predictor in patients with carotid artery disease but not in lower-extremity PVD. Additional studies are needed to evaluate the clinical utility of ABPM for improved prevention in these high-risk patients. (ClinicalTrials.gov Identifier: NCT01452165).

Bedtime versus morning use of antihypertensives in frail continuing care residents (BedMed-Frail): protocol for a prospective, randomised, open-label, blinded end-point pragmatic trial

INTRODUCTION

BedMed-Frail explores risks and benefits of switching antihypertensives from morning to bedtime in a frail population at greater risk of hypotensive adverse effects.

METHODS AND ANALYSIS

Design: Prospective parallel randomised, open-label, blinded end-point trial.Participants: Hypertensive continuing care residents, in either long-term care or supportive living, who are free from glaucoma, and using ≥1 once daily antihypertensive.Setting: 16 volunteer continuing care facilities in Alberta, Canada, with eligible residents identified using electronic health claims data.Intervention: All non-opted out eligible residents are randomised centrally by the provincial health data steward to bedtime versus usual care (typically morning) administration of once daily antihypertensives. Timing changes are made (maximum one change per week) by usual care facility pharmacists.Follow-up: Via linked governmental healthcare databases tracking hospital, continuing care and community medical services.Primary outcome: Composite of all-cause death, or hospitalisation for myocardial infarction/acute-coronary syndrome, stroke, or congestive heart failure.Secondary outcomes: Each primary outcome element on its own, all-cause unplanned hospitalisation or emergency department visit, non-vertebral fracture and, as assessed roughly 135 days postrandomisation, fall in the last 30 days, deteriorated cognition, urinary incontinence, decubitus skin ulceration, inappropriate or disruptive behaviour a minimum of 4 days per week, and receipt of antipsychotic medication or physical restraints in the last 7 days.Process outcome: Proportion of blood pressure medication doses taken at bedtime (broken down monthly).Primary outcome analysis: Cox-Proportional Hazards Survival Analysis.Sample size: The trial will continue until a projected 368 primary outcome events have occurred.Current status: Enrolment is ongoing with 642 randomisations to date (75% female, mean age 88 years).

ETHICS AND DISSEMINATION

BedMed-Frail has ethical approval from the University of Alberta Health Ethics Review Board (Pro00086129) and will publish results in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04054648.

Pers reverse angiotensin II -induced vascular smooth muscle cell proliferation by targeting cyclin E expression via inhibition of the MAPK signaling pathway

The circadian rhythm of blood pressure (BP) is believed to be regulated by the clock system, which is closely linked to levels of angiotensin II (Ang II). This study aimed to investigate whether Ang II mediates the proliferation of vascular smooth muscle cells (VSMCs) through the interaction between the clock system and the mitogen-activated protein kinase (MAPK) signaling pathway. Primary rat aortic VSMCs were treated with Ang II, with or without MAPK inhibitors. VSMC proliferation, expression of clock genes, CYCLIN E, and MAPK pathways were assessed. Ang II treatment resulted in increased VSMC proliferation and rapid upregulation of clock gene Periods (Pers) expression. Compared to the non-diseased control (NC) group, VSMCs incubated with Ang II displayed a noticeable delay in the G1/S phase transition and downregulation of CYCLIN E upon silencing of Per1 and Per2 genes. Importantly, silencing Per1 or Per2 in VSMCs led to decreased expression of key MAPK pathway proteins, including RAS, phosphorylated mitogen-activated protein kinase (P-MEK), and phosphorylated extracellular signal-regulated protein kinase (P-ERK). Moreover, the MEK and ERK inhibitors, U0126 and SCH772986, significantly attenuated the Ang II-induced proliferation of VSMCs, as evidenced by an increased G1/S phase transition and decreased CYCLIN E expression. The MAPK pathway plays a critical role in regulating VSMC proliferation in response to Ang II stimulation. This regulation is controlled by the expression of circadian clock genes involved in the cell cycle. These findings provide novel insights for further research on diseases associated with abnormal VSMC proliferation.

Understanding the role of chronopharmacology for drug optimization: what do we know?

INTRODUCTION

Circadian rhythm influences the pharmacokinetics and pharmacodynamics of a number of drugs and affects their therapeutic efficacy and toxicity depending on the time of day they are administered. Chronopharmacology is a method for incorporating knowledge about circadian rhythm into pharmacotherapy. Chronotherapy, which is the clinical application of chronopharmacology, is particularly relevant when the risk and/or severity of symptoms of a disease change in a predictable manner over time. Chronotherapy has potential benefits in the treatment of many diseases.

AREAS COVERED

Although a considerable amount of knowledge about chronopharmacology and chronotherapy has been accumulated, its therapeutic application in clinical practice remains limited in terms of therapy optimization. Resolution of these issues will improve our ability to deliver adequate drug treatment.

EXPERT OPINION

We propose four approaches for promoting chronotherapy-based drug treatment in clinical practice: targeting drug development and regulatory authorities; education about chronotherapy; drug information for both health professionals and consumers; and a chronotherapy network.

Ultrathin Niobium Carbide MXenzyme for Remedying Hypertension by Antioxidative and Neuroprotective Actions

Hypertension, as a leading risk factor for cardiovascular diseases, is associated with oxidative stress and impairment of endogenous antioxidant mechanisms, but there is still a tremendous knowledge gap between hypertension treatment and nanomedicines. Herein, we report a specific nanozyme based on ultrathin two-dimensional (2D) niobium carbide (Nb2 C) MXene, termed Nb2 C MXenzyme, to fight against hypertension by achieving highly efficient reactive oxygen species elimination and inflammatory factors inhibition. The biocompatible Nb2 C MXenzyme displays multiple enzyme-mimicking activities, involving superoxide dismutase, catalase, glutathione peroxidase, and peroxidase, inducing cytoprotective effects by resisting oxidative stress, thereby alleviating inflammatory response and reducing blood pressure, which is systematically demonstrated in a stress-induced hypertension rat model. This strategy not only opens new opportunities for nanozymes to treat hypertension but also expands the potential biomedical applications of 2D MXene nanosystems.

Circadian rhythm in cardiovascular diseases: a bibliometric analysis of the past, present, and future

BACKGROUND

One of the most prominent features of living organisms is their circadian rhythm, which governs a wide range of physiological processes and plays a critical role in maintaining optimal health and function in response to daily environmental changes. This work applied bibliometric analysis to explore quantitative and qualitative trends in circadian rhythm in cardiovascular diseases (CVD). It also aims to identify research hotspots and provide fresh suggestions for future research.

METHODS

The Web of Science Core Collection was used to search the data on circadian rhythm in CVD. HistCite, CiteSpace, and VOSviewer were used for bibliometric analysis and visualization. The analysis included the overall distribution of yearly outputs, top nations, active institutions and authors, core journals, co-cited references, and keywords. To assess the quality and efficacy of publications, the total global citation score (TGCS) and total local citation score (TLCS) were calculated.

RESULTS

There were 2102 papers found to be associated with the circadian rhythm in CVD, with the overall number of publications increasing year after year. The United States had the most research citations and was the most prolific country. Hermida RC, Young ME, and Ayala DE were the top three writers. The three most notable journals on the subject were Chronobiology International, Hypertension Research, and Hypertension. In the early years, the major emphasis of circadian rhythm in CVD was hormones. Inflammation, atherosclerosis, and myocardial infarction were the top developing research hotspots.

CONCLUSION

Circadian rhythm in CVD has recently received a lot of interest from the medical field. These topics, namely inflammation, atherosclerosis, and myocardial infarction, are critical areas of investigation for understanding the role of circadian rhythm in CVD. Although they may not be future research priorities, they remain of significant importance. In addition, how to implement these chronotherapy theories in clinical practice will depend on additional clinical trials to get sufficient trustworthy clinical evidence.

Dihydromyricetin Inhibits M1 Macrophage Polarization in Atherosclerosis by Modulating miR-9-Mediated SIRT1/NF-κB Signaling Pathway

Dihydromyricetin (DMY), a natural flavonoid compound extracted from the stems and leaves of Ampelopsis grossedentata, has been found as a potential therapeutic chemical for treating atherosclerosis. This study explores the underlying mechanism of DMY repressing M1 macrophage polarization in atherosclerosis. We showed that DMY treatment markedly decreased M1 macrophage markers (e.g., Tnf-α and IL-1β) and p65-positive macrophage numbers in the vessel wall of Apoe-deficient (Apoe^-/-) mice. Overexpression of miR-9 or knockdown of SIRT1 in macrophages reversed the effect of DMY on M1 macrophage polarization. The data we presented in the study indicate that the miR-9-mediated SIRT1/NF-κB pathway plays a pivotal role in M1 macrophage polarization and is one of the molecular mechanisms underlying the anti-atherosclerosis effects of DMY. We provide new solid evidence that DMY may be explored as a potential therapeutic adjuvant for treating atherosclerosis.

Gender Difference of Blood Pressure Control Rate and Clinical Prognosis in Patients With Resistant Hypertension: Real-World Observation Study

BACKGROUND

There are several differences in the clinical course of hypertension due to the biological and social differences between men and women. Resistant hypertension is an advanced disease state, and significant gender difference could be expected, but much has not been revealed yet. The purpose of this study was to compare gender differences on the current status of blood pressure (BP) control and clinical prognosis in patients with resistant hypertension.

METHODS

This is a multicenter, retrospective cohort study using common data model databases of 3 tertiary hospitals in Korea. Total 4,926 patients with resistant hypertension were selected from January 2017 to December 2018. Occurrence of dialysis, heart failure (HF) hospitalization, myocardial infarction, stroke, dementia or all-cause mortality was followed up for 3 years.

RESULTS

Male patients with resistant hypertension were younger but had a higher cardiovascular risk than female patients. Prevalence of left ventricular hypertrophy and proteinuria was higher in men than in women. On-treatment diastolic BP was lower in women than in men and target BP achievement rate was higher in women than in men. During 3 years, the incidence of dialysis and myocardial infarction was higher in men, and the incidence of stroke and dementia was higher in women. After adjustment, male sex was an independent risk factor for HF hospitalization, myocardial infarction, and all-cause death.

CONCLUSION

In resistant hypertension, men were younger than women, but end-organ damage was more common and the risk of cardiovascular event was higher. More intensive cardiovascular prevention strategies may be required in male patients with resistant hypertension.

Hypertension as Cardiovascular Risk Factor in Chronic Kidney Disease

Hypertension is the leading modifiable cause of premature death and hence one of the global targets of World Health Organization for prevention. Hypertension also affects the great majority of patients with chronic kidney disease (CKD). Both hypertension and CKD are intrinsically related, as hypertension is a strong determinant of worse renal and cardiovascular outcomes and renal function decline aggravates hypertension. This bidirectional relationship is well documented by the high prevalence of hypertension across CKD stages and the dual benefits of effective antihypertensive treatments on renal and cardiovascular risk reduction. Achieving an optimal blood pressure (BP) target is mandatory and requires several pharmacological and lifestyle measures. However, it also requires a correct diagnosis based on reliable BP measurements (eg, 24-hour ambulatory BP monitoring, home BP), especially for populations like patients with CKD where reduced or reverse dipping patterns or masked and resistant hypertension are frequent and associated with a poor cardiovascular and renal prognosis. Even after achieving BP targets, which remain debated in CKD, the residual cardiovascular risk remains high. Current antihypertensive options have been enriched with novel agents that enable to lower the existing renal and cardiovascular risks, such as SGLT2 (sodium-glucose cotransporter-2) inhibitors and novel nonsteroidal mineralocorticoid receptor antagonists. Although their beneficial effects may be driven mostly from actions beyond BP control, recent evidence underline potential improvements on abnormal 24-hour BP phenotypes such as nondipping. Other promising novelties are still to come for the management of hypertension in CKD. In the present review, we shall discuss the existing evidence of hypertension as a cardiovascular risk factor in CKD, the importance of identifying hypertension phenotypes among patients with CKD, and the traditional and novel aspects of the management of hypertensives with CKD.

Pathophysiology of the Nondipping Blood Pressure Pattern

The nondipping blood pressure (BP) pattern corresponds to a disruption in the circadian BP rhythm with an insufficient decrease in BP levels during nighttime sleep as observed using 24-hour ambulatory BP monitoring. Patients with nondipping BP pattern have poorer renal and cardiovascular outcomes, independent of their average 24-hour BP levels. The pathophysiology of nondipping BP is complex and involves numerous mechanisms: perturbations of (1) the circadian rhythm, (2) the autonomic nervous system, and (3) water and sodium regulation. This review provides an outline of the pathways potentially involved in the nondipping BP profile in different conditions. A recent hypothesis is also discussed involving the role of gut microbiota in the dipping/nondipping patterns, via the fecal diet-derived short chain fatty acids.

Current Management of Hypertension in Older Adults

Hypertension is a major global health issue and it accounts for a big proportion of disability and mortality worldwide even in adults aged 65 years and above. Moreover, advanced age per se is an independent risk factor for adverse cardiovascular events and there is abundant scientific evidence supporting the beneficial effects of blood pressure lowering, within certain limits, in this subset of hypertensive patients. The aim of this review article is to summarize the available evidence regarding the appropriate management of hypertension in this specific subgroup, in an era of a constantly increasing aging population.

Controversies in Hypertension III: Dipping, Nocturnal Hypertension, and the Morning Surge

A comprehensive approach to hypertension requires out-of-office determinations by home and/or ambulatory monitoring. The 4 phenotypes comparing office and out-of-office pressures in treated and untreated patients include normotension, hypertension, white-coat phenomena, and masked phenomena. Components of out-of-office pressure may be equally as important as mean values. Nighttime pressures are normally 10 - 20% lower than daytime (normal "dipping"). Abnormalities include dipping more than 20% (extreme dippers), less than 10 % (non-dippers), or rising above daytime (risers) and have been associated with elevated cardiovascular risk. Nighttime pressure may be elevated (nocturnal hypertension) in isolation or together with daytime hypertension. Isolated nocturnal hypertension theoretically changes white-coat hypertension to true hypertension and normotension to masked hypertension. Pressure normally peaks in the morning hours ("morning surge") when cardiovascular events are most common. Morning hypertension may result from residual nocturnal hypertension or an exaggerated surge and has been associated with enhanced cardiovascular risk, especially in Asian populations. Randomized trials are needed to determine whether altering therapy based solely on either abnormal dipping, isolated nocturnal hypertension, and/or an abnormal surge is justified.