Circadian Rhythms in Hypertension

1981 ◽  
Vol 26 (4) ◽  
pp. 309-314 ◽  
Author(s):  
M. W. Millar-Craig ◽  
S. Mann ◽  
V. Balasubramanian ◽  
D. G. Altman ◽  
E. B. Raftery
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Circadian Variation ◽  
Early Morning ◽  
Outpatient Basis ◽  
Night Time ◽  
Arterial Blood ◽  
Chronic Therapy ◽  
Hourly Data ◽  
Daytime Blood Pressure

Continuous intra-arterial blood pressure recordings have been performed in 37 untreated ambulatory hypertensive subjects, who were investigated on an outpatient basis. Hourly data analysis demonstrated a circadian variation of both blood pressure and heart rate which were highest during the morning and fell during the late afternoon to reach a nadir during sleep. Prior to waking there was an increase in blood pressure, but not heart rate; however both blood pressure and heart rate increased briskly shortly after waking. Chronic therapy with oxprenolol (in 10patients) reduced daytime blood pressure, but had little effect during the night-time or early morning.

Physical Activity and the Circadian Rhythm of Blood Pressure

1979 ◽  
Vol 57 (s5) ◽  
pp. 291s-294s ◽  
Author(s):  
S. Mann ◽  
M. W. Millar Craig ◽  
D. I. Melville ◽  
V. Balasubramanian ◽  
E. B. Raftery
Keyword(s):  
Physical Activity ◽  
Blood Pressure ◽  
Heart Rate ◽  
Circadian Rhythm ◽  
Ambulatory Blood Pressure ◽  
Blood Pressure Monitoring ◽  
Circadian Variation ◽  
Bed Rest ◽  
Pressure Monitoring ◽  
Night Time

1. Ambulatory blood pressure monitoring was carried out in 10 subjects for a period of 48 h, the first or second 24 h part of which was selected randomly to be a period of complete bed rest. 2. Heart rate was significantly lower throughout the period of bed rest except for the period 04.00–08.00 hours, when there was little difference. 3. The circadian variation of blood pressure was reduced during the day of bed rest but this was mainly due to higher night-time pressures.

Circadian periodicity of cerebral blood flow revealed by laser-Doppler flowmetry in awake rats: relation to blood pressure and activity

2005 ◽  
Vol 289 (4) ◽  
pp. H1662-H1668 ◽  
Author(s):  
C. A. Wauschkuhn ◽  
K. Witte ◽  
S. Gorbey ◽  
B. Lemmer ◽  
L. Schilling
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Locomotor Activity ◽  
Cerebral Perfusion ◽  
Circadian Variation ◽  
Laser Doppler ◽  
Doppler Flowmetry ◽  
Circadian Periodicity ◽  
Arterial Blood

Cardiovascular parameters such as arterial blood pressure (ABP) and heart rate display pronounced circadian variation. The present study was performed to detect whether there is a circadian periodicity in the regulation of cerebral perfusion. Normotensive Sprague-Dawley rats (SDR, ∼15 wk old) and hypertensive (mREN2)27 transgenic rats (TGR, ∼12 wk old) were instrumented in the abdominal aorta with a blood pressure sensor coupled to a telemetry system for continuous recording of ABP, heart rate, and locomotor activity. After 5–12 days, a laser-Doppler flow (LDF) probe was attached to the skull by means of a guiding device to measure changes in brain cortical blood flow (CBF). After the animals recovered from anesthesia, measurements were taken for 3–4 days. The time series were analyzed with respect to the midline estimating statistic of rhythm (i.e., mean value of a periodic event after fit to a cosine function), amplitude, and acrophase (i.e., phase angle that corresponds to the peak of a given period) of the 24-h period. The LDF signal displayed a significant circadian rhythm, with the peak occurring at around midnight in SDR and TGR, despite inverse periodicity of ABP in TGR. This finding suggests independence of LDF periodicity from ABP regulation. Furthermore, the acrophase of the LDF was consistently found before the acrophase of the activity. From the present data, it is concluded that there is a circadian periodicity in the regulation of cerebral perfusion that is independent of circadian changes in ABP and probably is also independent of locomotor activity. The presence of a circadian periodicity in CBF may have implications for the occurrence of diurnal alterations in cerebrovascular events in humans.

scholarly journals SAT-719 Prenatal Exposure to Bisphenol A, S and F Increases Blood Pressure in Female Rats

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Maryam H Al Mansi ◽  
YenJun Chuang ◽  
Puliyur S MohanKumar ◽  
Sheba M J MohanKumar
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Bisphenol A ◽  
Prenatal Exposure ◽  
The United States ◽  
Female Rats ◽  
Bisphenol S ◽  
Night Time ◽  
Arterial Blood ◽  
Bpa Analogs

Abstract Cardiovascular diseases are the leading causes of mortality among men and women. With the new blood pressure guidelines from the American Heart Association, almost half of the United States population has hypertension (45.6%). The reasons for this high prevalence of hypertension in our population could be several, but the effect of emerging contaminants are overlooked and understudied. Bisphenol-A (BPA) is a widely used plasticizing agent that contaminates the environment. Most humans are exposed to BPA on a daily basis and urine levels of this endocrine disrupting chemical (EDC) are positively correlated with hypertension. The FDA banned the use of BPA in baby bottles in 2012, however, it is still being used in food containers and plastics. Currently, several BPA analogs such as bisphenol-S (BPS) and bisphenol-F (BPF) are used to replace BPA in the plastic industry. But their physiological effects are not clear. In order to study the effects of these EDCs on the development of hypertension, we exposed pregnant Sprague Dawley (SD) rats to saline, 5 µg/Kg BW of BPA, BPS or 1µg/kg BW of BPF. The offspring were allowed to reach adulthood before implantation with a radiotelemeter (Data Sciences International; HD-S10) in the femoral artery for undisturbed monitoring of systolic, diastolic and mean arterial blood pressure and heart rate. Recordings were measured once a week for 11 weeks over 24 hours to establish day and night readings. Night-time systolic BP was significantly elevated in BPA, BPF and BPS exposed rats compared to control. During the day, systolic BP was significantly higher in the BPA group compared to control. Diastolic BP was elevated in the BPS and BPF groups. Heart rate was elevated the most in the BPS group. These results indicate that prenatal exposure to low levels of BPA analogs has a profound effect on hypertension.

Blood Pressure Circadian Rhythm in Essential Hypertension

1978 ◽  
Vol 55 (s4) ◽  
pp. 391s-393s ◽  
Author(s):  
Michael W. Millar Craig ◽  
Stewart Mann ◽  
V. Balasubramanian ◽  
E. B. Raftery
Keyword(s):  
Blood Pressure ◽  
Circadian Rhythm ◽  
Essential Hypertension ◽  
Diastolic Blood Pressure ◽  
Circadian Variation ◽  
Early Morning ◽  
Daytime Blood Pressure

1. Both systolic and diastolic blood pressure show a well defined circadian variation in ambulatory hypertensive subjects. 2. Blood pressure is highest in the mid-morning (10.00 hours) and lowest during sleep at 03.00 hours. 3. Treatment with oxprenolol (taken during the day) reduces daytime blood pressure but is less effective during the night and early morning.

scholarly journals Circadian Rhythm of Blood Pressure of Dipper and Non-dipper Patients With Essential Hypertension: A Mathematical Modeling Approach

2021 ◽  
Vol 11 ◽  
Author(s):  
Javiera Cortés-Ríos ◽  
Maria Rodriguez-Fernandez
Keyword(s):  
Physical Activity ◽  
Blood Pressure ◽  
Heart Rate ◽  
Circadian Rhythm ◽  
Temporal Structure ◽  
Circadian Variation ◽  
Night Time ◽  
Normalized Error ◽  
Underlying Mechanisms ◽  
Worse Prognosis

Blood pressure in humans presents a circadian variation profile with a morning increase, a small postprandial valley, and a deeper descent during night-time rest. Under certain conditions, the nocturnal decline in blood pressure can be reduced or even reversed (non-dipper), which is related to a significantly worse prognosis than a normal fall pattern (dipper). Despite several advances in recent years, our understanding of blood pressure's temporal structure, its sources and mechanisms is far from complete. In this work, we developed an ordinary differential equation-based mathematical model capable of capturing the circadian rhythm of blood pressure in dipper and non-dipper patients with arterial hypertension. The model was calibrated by means of global optimization, using 24-h data of systolic and diastolic blood pressure, physical activity, heart rate, blood glucose and norepinephrine, obtained from the literature. After fitting the model, the mean of the normalized error for each data point was <0.2%, and confidence intervals indicate that all parameters were identifiable. Sensitivity analysis allowed identifying the most relevant parameters and therefore inferring the most important blood pressure regulatory mechanisms involved in the non-dipper status, namely, increase in sympathetic over parasympathetic nervous tone, lower influence of physical activity on heart rate and greater influence of physical activity and glucose on the systemic vascular resistance. In summary, this model allows explaining the circadian rhythm of blood pressure and deepening the understanding of the underlying mechanisms and interactions integrating the results of previous works.

Compression Stocking Length Effects on Arterial Blood Pressure and Heart Rate Following Head-Up Tilt in Healthy Volunteers

2014 ◽  
Vol 63 (6) ◽  
pp. 435-438 ◽  
Author(s):  
Kunihiko Tanaka ◽  
Shiori Tokumiya ◽  
Yumiko Ishihara ◽  
Yumiko Kohira ◽  
Tetsuro Katafuchi
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Healthy Volunteers ◽  
Arterial Blood Pressure ◽  
Compression Stocking ◽  
Arterial Blood ◽  
Head Up Tilt ◽  
Length Effects

Diurnal Blood Pressure Variation in Quadriplegic Chronic Spinal Cord Injury Patients

1991 ◽  
Vol 80 (3) ◽  
pp. 271-276 ◽  
Author(s):  
Henry Krum ◽  
William J. Louis ◽  
Douglas J. Brown ◽  
Graham P. Jackman ◽  
Laurence G. Howes
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Heart Rate ◽  
Spinal Cord Injury ◽  
Ambulatory Monitoring ◽  
Pressure Variation ◽  
Night Time ◽  
Cord Injury ◽  
Blood Pressure Variation ◽  
Neurologically Intact

1. Measurement of blood pressure and heart rate over a 24 h period was peformed in 10 quadriplegic spinal cord injury patients and 10 immobilized, neurologically intact orthopaedic subjects by using the Spacelabs 90207 automated ambulatory monitoring system. 2. Systolic and diastolic blood pressure fell significantly at night in orthopaedic subjects but not in quadriplegic patients, and night-time blood pressures were similar in both groups. 3. Cumulative summation of differences from a reference value (cusum analysis) confirmed a markedly diminished diurnal blood pressure variation in the quadriplegic patients. 4. These findings could not be accounted for on the basis of blood pressure variations during chronic postural change. 5. Heart rate fell significantly at night in both groups. 6. The findings suggest that the increase in blood pressure during waking hours in neurologically intact subjects is a consequence of a diurnal variation in sympathetic activity (absent in quadriplegic patients with sympathetic decentralization) which is independent of changes in physical activity.

A Comparison of the Acute Haemodynamic Effects of Propranolol and Pindolol at Rest and during Supine Exercise in Man

1980 ◽  
Vol 59 (s6) ◽  
pp. 465s-468s ◽  
Author(s):  
T. L. Svendsen ◽  
J. E. Carlsen ◽  
O. Hartling ◽  
A. McNair ◽  
J. Trap-Jensen
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Pulmonary Artery ◽  
Pulmonary Artery Pressure ◽  
Response Curves ◽  
Receptor Blocking ◽  
Artery Pressure ◽  
Arterial Blood ◽  
Β Receptor

1. Dose-response curves for heart rate, cardiac output, arterial blood pressure and pulmonary artery pressure were obtained in 16 male patients after intravenous administration of three increasing doses of pindolol, propranolol or placebo. All patients had an uncomplicated acute myocardial infarction 6–8 months earlier. 2. The dose-response curves were obtained at rest and during repeated bouts of supine bicycle exercise. The cumulative dose amounted to 0.024 mg/kg body weight for pindolol and to 0.192 mg/kg body weight for propranolol. 3. At rest propranolol significantly reduced heart rate and cardiac output by 12% and 15% respectively. Arterial mean blood pressure was reduced by 9.2 mmHg. Mean pulmonary artery pressure increased significantly by 2 mmHg. Statistically significant changes in these variables were not seen after pindolol or placebo. 4. During exercise pindolol and propranolol both reduced cardiac output, heart rate and arterial blood pressure to the same extent. After propranolol mean pulmonary artery pressure was increased significantly by 3.6 mmHg. Pindolol and placebo did not change pulmonary artery pressure significantly. 5. The study suggests that pindolol may offer haemodynamic advantages over β-receptor-blocking agents without intrinsic sympathomimetic activity during low activity of the sympathetic nervous system, and may be preferable in situations where the β-receptor-blocking effect is required only during physical or psychic stress.

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