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Singh B, Huang D. The Role of Circadian Rhythms in Stroke: A Narrative Review. Neurochem Res 2024; 49:290-305. [PMID: 37838637 DOI: 10.1007/s11064-023-04040-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 09/12/2023] [Accepted: 09/24/2023] [Indexed: 10/16/2023]
Abstract
Stroke, a debilitating condition often leading to long-term disability, poses a substantial global concern and formidable challenge. The increasing incidence of stroke has drawn the attention of medical researchers and neurologists worldwide. Circadian rhythms have emerged as pivotal factors influencing stroke's onset, pathogenesis, treatment, and outcomes. To gain deeper insights into stroke, it is imperative to explore the intricate connection between circadian rhythms and stroke, spanning from molecular mechanisms to pathophysiological processes. Despite existing studies linking circadian rhythm to stroke onset, there remains a paucity of comprehensive reviews exploring its role in pathogenesis, treatment, and prognosis. This review undertakes a narrative analysis of studies investigating the relationship between circadian variation and stroke onset. It delves into the roles of various physiological factors, including blood pressure, coagulation profiles, blood cells, catecholamines, cortisol, and the timing of antihypertensive medication, which contribute to variations in circadian-related stroke risk. At a molecular level, the review elucidates the involvement of melatonin, circadian genes, and glial cells in the pathophysiology. Furthermore, it provides insights into the diverse factors influencing stroke treatment and outcomes within the context of circadian variation. The review underscores the importance of considering circadian rhythms when determining the timing of stroke interventions, emphasizing the necessity for personalized stroke management strategies that incorporate circadian rhythms. It offers valuable insights into potential molecular targets and highlights areas that require further exploration to enhance our understanding of the underlying pathophysiology. In comparison to the published literature, this manuscript distinguishes itself through its coverage of circadian rhythms' impact on stroke across the entire clinical spectrum. It presents a unique synthesis of epidemiological, clinical, molecular, and cellular evidence, underscoring their collective significance.
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Affiliation(s)
- Bivek Singh
- Department of Neurology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China.
- Department of Medicine, National Cardiac Centre, Basundhara, Kathmandu, , Bagmati Province, Nepal.
| | - Dongya Huang
- Department of Neurology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
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Palmeira NGF, Bianco HT, Bombig MTN, Povoa FF, Fonseca FAH, Izar MC, Thalenberg JM, Luna B, Marui F, Fischer SM, Amodeo C, de Souza DDSM, Povoa R. Association between Morning Surge and Left Ventricular Hypertrophy in Obese Hypertensive Patients. Arq Bras Cardiol 2023; 120:e20230050. [PMID: 37820172 PMCID: PMC10519347 DOI: 10.36660/abc.20230050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 06/12/2023] [Accepted: 07/17/2023] [Indexed: 10/13/2023] Open
Abstract
BACKGROUND Weight gain can trigger mechanisms that increase blood pressure. Nevertheless, obesity causes structural changes in the myocardium, including increased ventricular mass, atrial dilatation, and diastolic and systolic dysfunction. Additionally, blood pressure variations, like morning surge (MS) in obese hypertensive patients may have clinical relevance in cardiovascular events. Although morning blood pressure surge is a physiological phenomenon, excess MS can be considered an independent risk factor for cardiovascular events. OBJECTIVE To evaluate MS values and their association with left ventricular hypertrophy (LVH) and nocturnal dipping (ND) in obese and non-obese hypertensive patients. METHODS A cross-sectional study that evaluated BP measurements by ambulatory blood pressure monitoring (ABPM) and the presence of LVH by echocardiography in 203 hypertensive outpatients, divided into two groups: 109 non-obese and 94 obese hypertensives patients. The significance level was set at 0.05 in two-tailed tests. RESULTS A MS above 20 mmHg by ABPM was detected in 59.2% of patients in the non-obese group and 40.6% in the obese group. LVH was found in 18.1% and 39.3% of patients in the non-obese and obese groups, respectively, p<0.001. In the "obese group", it was observed that a MS>16 mmHg was associated with LVH, [prevalence ratio: 2.80; 95%CI (1.12-6.98), p=0.03]. For the non-obese group, the cut-off point of MS for this association was >22 mmHg. CONCLUSION High MS was positively associated with LVH, with a particular behavior in the hypertensive obese group.
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Affiliation(s)
- Natascha Gonçalves Francisco Palmeira
- Escola Paulista de MedicinaUniversidade Federal de São PauloSão PauloSPBrasilEscola Paulista de Medicina da Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, SP – Brasil
| | - Henrique Tria Bianco
- Escola Paulista de MedicinaUniversidade Federal de São PauloSão PauloSPBrasilEscola Paulista de Medicina da Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, SP – Brasil
| | | | - Fernando Focaccia Povoa
- Escola Paulista de MedicinaUniversidade Federal de São PauloSão PauloSPBrasilEscola Paulista de Medicina da Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, SP – Brasil
| | - Francisco A. H. Fonseca
- Escola Paulista de MedicinaUniversidade Federal de São PauloSão PauloSPBrasilEscola Paulista de Medicina da Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, SP – Brasil
| | - Maria Cristina Izar
- Universidade Federal de São PauloSão PauloSPBrasilUniversidade Federal de São Paulo, São Paulo, SP – Brasil
| | - José Marcos Thalenberg
- Escola Paulista de MedicinaUniversidade Federal de São PauloSão PauloSPBrasilEscola Paulista de Medicina da Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, SP – Brasil
| | - Braulio Luna
- Universidade Federal de São PauloSão PauloSPBrasilUniversidade Federal de São Paulo, São Paulo, SP – Brasil
| | - Fabiane Marui
- Universidade Federal de São PauloSão PauloSPBrasilUniversidade Federal de São Paulo, São Paulo, SP – Brasil
| | - Simone Matheus Fischer
- Universidade Federal de São PauloSão PauloSPBrasilUniversidade Federal de São Paulo, São Paulo, SP – Brasil
| | - Celso Amodeo
- Universidade Federal de São PauloSão PauloSPBrasilUniversidade Federal de São Paulo, São Paulo, SP – Brasil
| | | | - Rui Povoa
- Universidade Federal de São PauloSão PauloSPBrasilUniversidade Federal de São Paulo, São Paulo, SP – Brasil
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Midday Nap Duration and Hypertension among Middle-Aged and Older Chinese Adults: A Nationwide Retrospective Cohort Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18073680. [PMID: 33916042 PMCID: PMC8037516 DOI: 10.3390/ijerph18073680] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/30/2021] [Accepted: 03/31/2021] [Indexed: 12/11/2022]
Abstract
The goal of this study was to investigate the associations of midday nap duration and change in midday nap duration with hypertension in a retrospective cohort using a nationwide representative sample of middle-aged and older Chinese adults. Data were obtained from the China Health and Retirement Longitudinal Study (CHARLS) database during 2011–2015. Information on midday nap duration was collected via a self-reported questionnaire and blood pressure was objectively measured. Hazard ratios (HR) with 95% confidence interval (CI) were estimated using Cox proportional hazards regression models to quantify the associations. A sample of 5729 Chinese adults (≥45 years old) were included in the longitudinal analysis. Relative to non-nappers, participants who napping for ≥90 min/day was associated with significantly larger HR for hypertension at four-year follow-up (HR = 1.18, 95% CI = 1.01–1.40, p = 0.048). Compared with people who napped ≥90 min/day both at baseline (2011) and follow-up (2013), hypertension risk at four-year follow-up declined in individuals whose midday nap durations decreased in the 2-year study period from ≥ 90 min/day to 1–59 min/day (HR = 0.59, 95% CI = 0.36–0.97, p = 0.037) and 60–89 min/day (HR = 0.68, 95% CI = 0.47–0.99, p = 0.044). Among middle-aged and older Chinese adults, relative to non-nappers, people who had longer midday nap duration (≥90 min/day) were associated with significantly larger HR for hypertension and decreased napping duration may confer benefit for hypertension prevention.
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Abstract
BACKGROUND The morning period which is recognized as the highest risk for cardiovascular events is associated with a surge in blood pressure (BP). However, it is unclear what aspect of this rise is important. AIM To determine whether the rate of rise (RoR), the magnitude (day night difference) or the product [BP power (BPPower)] is associated with increased cardiovascular risk. METHODS We developed a logistic equation method to fit individual 24-h patterns of BP to determine RoR, amplitude and BPPower using the ambulatory recordings from the Ohasama study including 564 men and 971 women (16.6 years follow-up). RESULTS Men had a higher risk of cardiovascular events than women (24, 16%, P < 0.001). Age and night BP were strong linear risk predictors. In men sorting risk by quintiles of BPPower (adjusted for age, night BP, smoking status) revealed no clear linear or nonlinear pattern. However, in women BPPower had a U-shaped relationship with the lowest risk being the 2-3rd quintile for all cardiovascular events (Pquadratic = 0.01) including cardiovascular death (Pquadratic = 0.03) and nonfatal stroke (Pquadratic = 0.02). A similar but less clear trend was observed with the RoR but only stroke (infarct) reached significance (Pquadratic = 0.03) while sorting by range showed a U shaped pattern for combined cardiovascular events (Pquadratic = 0.04). CONCLUSION These findings suggest that the morning BPPower is an important independent risk factor for predicting cardiovascular events and stroke but only in women with median levels having the lowest risk.
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Shin J. Clock time-based hourly blood pressure surge around 6 am: Blood pressure dynamics specific to awakening or endogenous circadian rhythm? J Clin Hypertens (Greenwich) 2019; 21:587-588. [PMID: 30868733 DOI: 10.1111/jch.13497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 01/23/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Jinho Shin
- Division of Cardiology, Department of Internal Medicine, Hanyang University College of Medicine, Seoul, South Korea
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A polymorphism in the noradrenaline transporter gene is associated with increased blood pressure in patients with resistant hypertension. J Hypertens 2018; 36:1571-1577. [DOI: 10.1097/hjh.0000000000001736] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Papademetriou V, Tsioufis CP, Sinhal A, Chew DP, Meredith IT, Malaiapan Y, Worthley MI, Worthley SG. Catheter-Based Renal Denervation for Resistant Hypertension. Hypertension 2014; 64:565-72. [DOI: 10.1161/hypertensionaha.114.03605] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Renal denervation has emerged as a novel approach for the treatment of patients with drug-resistant hypertension. To date, only limited data have been published using multielectrode radiofrequency ablation systems. In this article, we present the 12-month data of EnligHTN I, a first-in-human study using a multielectrode ablation catheter. EnligHTN I enrolled 46 patients (average age, 60±10 years; on average 4.7±1.0 medications) with drug-resistant hypertension. Eligible patients were on ≥3 antihypertensive medications and had a systolic blood pressure (BP) ≥160 mm Hg (≥150 mm Hg for diabetics). Bilateral renal artery ablation was performed using a percutaneous femoral approach and standardized techniques. The average baseline office BP was 176/96 mm Hg, average 24-hour ambulatory BP was 150/83 mm Hg, and average home BP was 158/90 mm Hg. The average reductions (mm Hg) at 1, 3, 6, and 12 months were as follows: office: −28/−10, −27/−10, −26/−10, and −27/−11 mm Hg (
P
<0.001 for all); 24-hour ambulatory: −10/−5, −10/−5, −10/−6 (
P
<0.001 for all), and −7/−4 for 12 months (
P
<0.0094). Reductions in home measurements (based on 2-week average) were −9/−4, −8/−5,−10/−7, and −11/−6 mm Hg (
P
<0.001 at 12 months). At 12 months, there were no signals of worsening renal function and no new serious or life-threatening adverse events. One patient with baseline nonocclusive renal artery stenosis progressed to 75% diameter stenosis, requiring renal artery stenting. The 12-month data continue to demonstrate safety and efficacy of the EnligHTN ablation system in patients with drug-resistant hypertension. Home BP measurements parallel measurements obtained with 24-hour ambulatory monitoring.
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Affiliation(s)
- Vasilios Papademetriou
- From the Veterans Affairs and Georgetown University Medical Centers, Washington, DC (V.P.); The First Cardiology Clinic, University of Athens, Ippokration Hospital, Athens, Greece (V.P., C.P.T.); Department of Cardiology, Flinders University, Bedford Park, Australia (A.S., D.P.C.); Monash Heart and Monash University, Melbourne, Australia (I.T.M., Y.M.); Royal Adelaide Hospital, Adelaide, Australia (M.I.W.); and University of Adelaide, Adelaide, Australia (S.G.W.)
| | - Costas P. Tsioufis
- From the Veterans Affairs and Georgetown University Medical Centers, Washington, DC (V.P.); The First Cardiology Clinic, University of Athens, Ippokration Hospital, Athens, Greece (V.P., C.P.T.); Department of Cardiology, Flinders University, Bedford Park, Australia (A.S., D.P.C.); Monash Heart and Monash University, Melbourne, Australia (I.T.M., Y.M.); Royal Adelaide Hospital, Adelaide, Australia (M.I.W.); and University of Adelaide, Adelaide, Australia (S.G.W.)
| | - Ajay Sinhal
- From the Veterans Affairs and Georgetown University Medical Centers, Washington, DC (V.P.); The First Cardiology Clinic, University of Athens, Ippokration Hospital, Athens, Greece (V.P., C.P.T.); Department of Cardiology, Flinders University, Bedford Park, Australia (A.S., D.P.C.); Monash Heart and Monash University, Melbourne, Australia (I.T.M., Y.M.); Royal Adelaide Hospital, Adelaide, Australia (M.I.W.); and University of Adelaide, Adelaide, Australia (S.G.W.)
| | - Derek P. Chew
- From the Veterans Affairs and Georgetown University Medical Centers, Washington, DC (V.P.); The First Cardiology Clinic, University of Athens, Ippokration Hospital, Athens, Greece (V.P., C.P.T.); Department of Cardiology, Flinders University, Bedford Park, Australia (A.S., D.P.C.); Monash Heart and Monash University, Melbourne, Australia (I.T.M., Y.M.); Royal Adelaide Hospital, Adelaide, Australia (M.I.W.); and University of Adelaide, Adelaide, Australia (S.G.W.)
| | - Ian T. Meredith
- From the Veterans Affairs and Georgetown University Medical Centers, Washington, DC (V.P.); The First Cardiology Clinic, University of Athens, Ippokration Hospital, Athens, Greece (V.P., C.P.T.); Department of Cardiology, Flinders University, Bedford Park, Australia (A.S., D.P.C.); Monash Heart and Monash University, Melbourne, Australia (I.T.M., Y.M.); Royal Adelaide Hospital, Adelaide, Australia (M.I.W.); and University of Adelaide, Adelaide, Australia (S.G.W.)
| | - Yuvi Malaiapan
- From the Veterans Affairs and Georgetown University Medical Centers, Washington, DC (V.P.); The First Cardiology Clinic, University of Athens, Ippokration Hospital, Athens, Greece (V.P., C.P.T.); Department of Cardiology, Flinders University, Bedford Park, Australia (A.S., D.P.C.); Monash Heart and Monash University, Melbourne, Australia (I.T.M., Y.M.); Royal Adelaide Hospital, Adelaide, Australia (M.I.W.); and University of Adelaide, Adelaide, Australia (S.G.W.)
| | - Matthew I. Worthley
- From the Veterans Affairs and Georgetown University Medical Centers, Washington, DC (V.P.); The First Cardiology Clinic, University of Athens, Ippokration Hospital, Athens, Greece (V.P., C.P.T.); Department of Cardiology, Flinders University, Bedford Park, Australia (A.S., D.P.C.); Monash Heart and Monash University, Melbourne, Australia (I.T.M., Y.M.); Royal Adelaide Hospital, Adelaide, Australia (M.I.W.); and University of Adelaide, Adelaide, Australia (S.G.W.)
| | - Stephen G. Worthley
- From the Veterans Affairs and Georgetown University Medical Centers, Washington, DC (V.P.); The First Cardiology Clinic, University of Athens, Ippokration Hospital, Athens, Greece (V.P., C.P.T.); Department of Cardiology, Flinders University, Bedford Park, Australia (A.S., D.P.C.); Monash Heart and Monash University, Melbourne, Australia (I.T.M., Y.M.); Royal Adelaide Hospital, Adelaide, Australia (M.I.W.); and University of Adelaide, Adelaide, Australia (S.G.W.)
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Head GA, Andrianopoulos N, McGrath BP, Martin CA, Carrington MJ, Lukoshkova EV, Davern PJ, Jennings GL, Reid CM. Predictors of mean arterial pressure morning rate of rise and power function in subjects undergoing ambulatory blood pressure recording. PLoS One 2014; 9:e93186. [PMID: 24667944 PMCID: PMC3965554 DOI: 10.1371/journal.pone.0093186] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Accepted: 03/03/2014] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND We determined clinical predictors of the rate of rise (RoR) in blood pressure in the morning as well as a novel measure of the power of the BP surge (BP(power)) derived from ambulatory blood pressure recordings. METHODS BP(power) and RoR were calculated from 409 ambulatory blood pressure (ABP) recordings from subjects attending a cardiovascular risk clinic. Anthropometric data, blood biochemistry, and history were recorded. The 409 subjects were 20-82 years old (average 57, SD = 13), 46% male, 9% with hypertension but not on medication and 34% on antihypertensive medication. RESULTS Average RoR was 11.1 mmHg/hour (SD = 8) and BP(power) was 273 mmHg(2)/hour (SD = 235). Only cholesterol, low density lipoprotein and body mass index (BMI) were associated with higher BP(power) and RoR (P<0.05) from 25 variables assessed. BP(power) was lower in those taking beta-blockers or diuretics. Multivariate analysis identified that only BMI was associated with RoR (4.2% increase/unit BMI, P = 0.020) while cholesterol was the only remaining associated variable with BP(power) (17.5% increase/mmol/L cholesterol, P = 0.047). A follow up of 213 subjects with repeated ABP after an average 1.8 years identified that baseline cholesterol was the only predictor for an increasing RoR and BP(power) (P<0.05). 37 patients who commenced statin subsequently had lower BP(power) whereas 90 age and weight matched controls had similar BP(power) on follow-up. CONCLUSIONS Cholesterol is an independent predictor of a greater and more rapid rise in morning BP as well as of further increases over several years. Reduction of cholesterol with statin therapy is very effective in reducing the morning blood pressure surge.
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Affiliation(s)
- Geoffrey A. Head
- Baker IDI Heart and Diabetes Institute, Melbourne and Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Australia
- * E-mail:
| | - Nick Andrianopoulos
- NHMRC Centre for Clinical Research Excellence in Therapeutics, Monash University, Melbourne, Australia
| | - Barry P. McGrath
- Monash Health Dandenong Australia and Monash University, Melbourne, Australia
| | - Catherine A. Martin
- Monash Health Dandenong Australia and Monash University, Melbourne, Australia
- Australian Catholic University, Fitzroy, Australia
| | - Melinda J. Carrington
- Baker IDI Heart and Diabetes Institute, Melbourne and Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Australia
| | | | - Pamela J. Davern
- Baker IDI Heart and Diabetes Institute, Melbourne and Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Australia
| | - Garry L. Jennings
- Baker IDI Heart and Diabetes Institute, Melbourne and Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Australia
| | - Christopher M. Reid
- NHMRC Centre for Clinical Research Excellence in Therapeutics, Monash University, Melbourne, Australia
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Steinberg GR, Byron JK, Mahoney MM. A retrospective study of circadian and seasonal presentations of dogs with congestive heart failure: 119 cases (1997-2009). J Vet Emerg Crit Care (San Antonio) 2012; 22:341-6. [PMID: 22702440 DOI: 10.1111/j.1476-4431.2012.00748.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To test the hypothesis that there is a daily or seasonal rhythm in the presentation of congestive heart failure (CHF) in dogs. DESIGN Retrospective case series from 1997 to 2009. SETTING Small animal veterinary teaching hospital. ANIMALS One hundred and nineteen dogs with 126 acute presentations of CHF. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Medical records from a veterinary teaching hospital were searched for the occurrence of CHF. The effect of admission time, weekday, month, and season were analyzed separately using chi-square tests. CHF presentations were largely confined to Monday and Tuesday (57%) and between 9 am and 11:59 am (55%). CHF was more common during September, October, and November (37%). CONCLUSIONS Information from this study may assist veterinarians in educating clients about the timing of clinical signs, and enable veterinary hospitals to anticipate CHF cases during certain times of the day and year.
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Affiliation(s)
- Gary R Steinberg
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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Davern P, Jackson K, Nguyen-Huu T, La Greca L, Head G. Cardiovascular reactivity and neuronal activation to stress in Schlager genetically hypertensive mice. Neuroscience 2010; 170:551-8. [DOI: 10.1016/j.neuroscience.2010.07.040] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 07/16/2010] [Accepted: 07/18/2010] [Indexed: 11/17/2022]
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A novel measure of the power of the morning blood pressure surge from ambulatory blood pressure recordings. Am J Hypertens 2010; 23:1074-81. [PMID: 20559284 DOI: 10.1038/ajh.2010.126] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND We defined a new measure of the morning blood pressure (BP) surge (MBPS) that is derived by the product of the rate of morning rise (RoR) and the amplitude (day-night difference) giving an effective "Power" of the BP rise (BP(Power)). We applied this method to determine whether morning BP(Power) is different in hypertensives compared to normotensives, males compared to females or altered by antihypertensive treatment. METHODS BP(Power), RoR, and day-night amplitude were calculated using a double logistic fit of 691 ambulatory recordings. RESULTS Ambulatory recordings from untreated male and female subjects showed that upper quartile (distributed by day BP, n = 100) had a 92% greater BP(Power) (P < 0.001) than the lower quartile subjects (n = 100) due to both a faster RoR and greater amplitude. Males had a 29% greater BP(Power) than females (P = 0.003). Untreated hypertensives and white coat hypertensives showed a greater morning BP(Power) (+158% and +86%, respectively) compared to matched normotensives. Subjects taking calcium channel blockers and diuretics alone or in combination with angiotensin receptor blockers had lower morning BP(Power) than those on angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor antagonists alone. CONCLUSIONS A new measure of the MBPS, BP(Power) which is based on a mathematical estimate of the rate and amplitude of the rise, is higher in hypertensives, white coat hypertensives, and is modifiable by some specific antihypertensive therapies suggests that it may be theoretically useful to highlight those subjects at greatest risk of cardiovascular events and for determining the most benefit of antihypertensive therapy.
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Davern PJ, Jackson KL, Nguyen-Huu TP, La Greca L, Head GA. Cardiovascular responses to aversive and nonaversive stressors in Schlager genetically hypertensive mice. Am J Hypertens 2010; 23:838-44. [PMID: 20379140 DOI: 10.1038/ajh.2010.69] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Schlager inbred hypertensive mice (BPH/2J) have been suggested to have high blood pressure (BP) due to an overactive sympathetic nervous system (SNS). The brain nuclei associated with the hypertension are also those involved in the integration of the cardiovascular responses to stress. Therefore, in the present study, we hypothesize that an increased contribution of the SNS in BPH/2J mice may culminate in a greater pressor response to stressful stimuli in these hypertensive mice than normotensive (BPN/3J) mice. METHODS Male hypertensive BPH/2J and normotensive BPN/3J mice were implanted with telemetry devices and exposed to a series of behavioral "stress" tests including aversive stress (shaker, clean cage switch, and restraint) and nonaversive stress (feeding). RESULTS Aversive stress caused a 67-88% greater pressor response in BPH/2J compared with BPN/3J mice. By contrast, the feeding-induced pressor response was not different between groups. All stressors induced tachycardia that was less in BPH/2J mice (feeding and restraint) and others were not different between groups (clean cage switch and shaker). CONCLUSIONS These findings indicate that hypertension in BPH/2J mice is associated with greater pressor responsiveness to aversive stress but not to appetitive arousal. Thus, BPH/2J hypertensive mice may be a particularly relevant model for human hypertensive patients that overrespond to daily stressors.
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Tanabe N, Iso H, Seki N, Suzuki H, Yatsuya H, Toyoshima H, Tamakoshi A. Daytime napping and mortality, with a special reference to cardiovascular disease: the JACC study. Int J Epidemiol 2009; 39:233-43. [DOI: 10.1093/ije/dyp327] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Davern PJ, Nguyen-Huu TP, La Greca L, Abdelkader A, Head GA. Role of the sympathetic nervous system in Schlager genetically hypertensive mice. Hypertension 2009; 54:852-9. [PMID: 19667247 DOI: 10.1161/hypertensionaha.109.136069] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Early studies indicate that the hypertension observed in the Schlager inbred mouse strain may be attributed to a neurogenic mechanism. In this study, we examined the contribution of the sympathetic nervous system in maintaining hypertension in the BPH/2J mouse and used c-Fos immunohistochemistry to elucidate whether neuronal activation in specific brain regions was associated with waking blood pressure. Male hypertensive (BPH/2J; n=14), normotensive (BPN/3J; n=18), and C57/Bl6 (n=5) mice were implanted with telemetry devices, and after 10 days of recovery, recordings of blood pressure, heart rate, and locomotor activity were measured to determine circadian variation. Mean arterial pressure was higher in BPH/2J than in BPN/3J or C57/Bl6 mice (P<0.001), and BPH/2J animals showed exaggerated day-night differences (17+/-2 versus 6+/-1 mm Hg in BPN/3J or +8+/-2 mm Hg in C57/Bl6 mice; P<0.001). Acute sympathetic blockade with pentolinium (7.5 mg/kg IP) during the active and inactive phases reduced blood pressure to comparable levels in BPH/2J and BPN/3J mice. The number of c-Fos-labeled cells was greater in the amygdala (+180%; P<0.01), paraventricular nucleus (+110%; P<0.001), and dorsomedial hypothalamus (+48%; P<0.001) in the active (hypertensive) phase in BPH/2J compared with BPN/3J mice. The level of neuronal activation was mostly similar in these regions in the inactive phase. Of all of the regions studied, neuronal activation in the medial amygdala, as detected by c-Fos, was highly correlated to mean arterial pressure (r=0.98). These findings indicate that the hypertension is largely attributable to sympathetic nervous system activity, possibly generated through greater levels of arousal regulated by neurons located in the medial amygdala.
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Affiliation(s)
- Pamela J Davern
- Neuropharmacology Laboratory, Baker IDI Heart and Diabetes Research Institute, 75 Commercial Road, Melbourne, St Kilda Road Central, Melbourne, Victoria 8008, Australia
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