Cardiovascular and metabolic responses to passive hypoxic conditioning in overweight and mildly obese individuals

2020 ◽  
Vol 319 (2) ◽  
pp. R211-R222
Author(s):  
Samarmar Chacaroun ◽  
Anna Borowik ◽  
Stephane Doutreleau ◽  
Elise Belaidi ◽  
Bernard Wuyam ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Blood Glucose ◽  
Lipid Profile ◽  
Vascular Function ◽  
Arterial Oxygen ◽  
Nitric Oxide Metabolites

Although severe intermittent hypoxia (IH) is well known to induce deleterious cardiometabolic consequences, moderate IH may induce positive effects in obese individuals. The present study aimed to evaluate the effect of two hypoxic conditioning programs on cardiovascular and metabolic health status of overweight or obese individuals. In this randomized single-blind controlled study, 35 subjects (54 ± 9.3 yr, 31.7 ± 3.5 kg/m2) were randomized into three 8-wk interventions (three 1-h sessions per week): sustained hypoxia (SH), arterial oxygen saturation ([Formula: see text]) = 75%; IH, 5 min [Formula: see text] = 75% – 3 min normoxia; normoxia. Ventilation, heart rate, blood pressure, and tissue oxygenation were measured during the first and last hypoxic conditioning sessions. Vascular function, blood glucose and insulin, lipid profile, nitric oxide metabolites, and oxidative stress were evaluated before and after the interventions. Both SH and IH increased ventilation in hypoxia (+1.8 ± 2.1 and +2.3 ± 3.6 L/min, respectively; P < 0.05) and reduced normoxic diastolic blood pressure (−12 ± 15 and −13 ± 10 mmHg, respectively; P < 0.05), whereas changes in normoxic systolic blood pressure were not significant (+3 ± 9 and −6 ± 13 mmHg, respectively; P > 0.05). IH only reduced heart rate variability (e.g., root-mean-square difference of successive normal R-R intervals in normoxia −21 ± 35%; P < 0.05). Both SH and IH induced no significant change in body mass index, vascular function, blood glucose, insulin and lipid profile, nitric oxide metabolites, or oxidative stress, except for an increase in superoxide dismutase activity following SH. This study indicates that passive hypoxic conditioning in obese individuals induces some positive cardiovascular and respiratory improvements despite no change in anthropometric data and even a reduction in heart rate variability during IH exposure.

scholarly journals Impact of ACE I/D gene polymorphism on blood pressure, heart rate variability and nitric oxide responses to the aerobic exercise in hypertensive elderly

2018 ◽  
Vol 11 (2) ◽  
pp. 57-62
Author(s):  
S.R. Moreira ◽  
O.T. Nóbrega ◽  
H.A.P. Santana ◽  
M.M. Sales ◽  
P.T.V. Farinatti ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Gene Polymorphism ◽  
Aerobic Exercise

scholarly journals Chemical Sympathectomy Restores Baroreceptor-Heart Rate Reflex and Heart Rate Variability in Rats With Chronic Nitric Oxide Deficiency

2015 ◽  
pp. 459-466 ◽  
Author(s):  
M. CHASWAL ◽  
S. DAS ◽  
J. PRASAD ◽  
A. KATYAL ◽  
M. FAHIM
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Frequency Domain ◽  
Autonomic Dysfunction ◽  
Sympathetic Innervation ◽  
Chemical Sympathectomy ◽  
Principal Mechanism ◽  
Cardiac Autonomic Dysfunction

Nitric oxide (NO) plays a crucial role not only in regulation of blood pressure but also in maintenance of cardiac autonomic tone and its deficiency induced hypertension is accompanied by cardiac autonomic dysfunction. However, underlying mechanisms are not clearly defined. We hypothesized that sympathetic activation mediates hemodynamic and cardiac autonomic changes consequent to deficient NO synthesis. We used chemical sympathectomy by 6-hydroxydopamine to examine the influence of sympathetic innervation on baroreflex sensitivity (BRS) and heart rate variability (HRV) of chronic NG-nitro-L-arginine methyl ester (L-NAME) treated adult Wistar rats. BRS was determined from heart rate responses to changes in systolic arterial pressure achieved by intravenous administration of phenylephrine and sodium nitroprusside. Time and frequency domain measures of HRV were calculated from 5-min electrocardiogram recordings. Chronic L-NAME administration (50 mg/kg per day for 7 days orally through gavage) in control rats produced significant elevation of blood pressure, tachycardia, attenuation of BRS for bradycardia and tachycardia reflex and fall in time as well as frequency domain parameters of HRV. Sympathectomy completely abolished the pressor as well as tachycardic effect of chronic L-NAME. In addition, BRS and HRV improved after removal of sympathetic influence in chronic L-NAME treated rats. These results support the concept that an exaggerated sympathetic activity is the principal mechanism of chronic L NAME hypertension and associated autonomic dysfunction.

scholarly journals Evaluation of heart rate variability, blood pressure and lipid profile alterations from dual transceiver mobile phone radiation exposure

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jamil Dauda Usman ◽  
Mikail Umar Isyaku ◽  
Adesoji Adedipe Fasanmade
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Electromagnetic Field ◽  
Treatment Group ◽  
Mobile Phone ◽  
Lipid Profile ◽  
Wistar Rats ◽  
Recovery Period ◽  
High Density Lipoproteins

AbstractObjectivesElectromagnetic fields have been reported to alter electrical activities in the brain and heart. However, there is paucity of information on the potential functional alterations that magnetic fields from mobile phone could cause to the heart. This study investigated heart rate variability (HRV), blood pressure (BP) and lipid profile in Wistar rats exposed to electromagnetic field radiation from a dual transceiver mobile phone (DTrMP).MethodsTwenty-one male albino Wistar rats (140–180 g) were randomly assigned to two major groups positioned 5 m apart as follows: control: no phone (n=7) and treatment group (n=14) continuously exposed to electromagnetic field from Tecno T312 DTrMP 900/1800 MHz set in silence mode. Experimental treatment consisted in 10 min calls/day, directed to this device for a period of six weeks. Seven animals from the treatment group were allowed to recover for a period of two weeks after exposure. HRV, systolic, diastolic and mean arterial BP were noninvasively investigated, while serum lipid profile and heart tissue nitric oxide (NO) activities were determined using standard procedures.ResultsThere was significant (p<0.05) increase in systolic, diastolic, mean arterial BP and a decrease in HRV. Serum high density lipoproteins decreased, while total cholesterol, atherogenic indices, and heart NO levels increased significantly in the radiation exposed animals. The alterations observed in exposed animals remained unchanged even after the recovery period.ConclusionsThese results suggest that exposure to electromagnetic radiation from dual transceiver mobile phones could be a risk factor to increase in blood pressure.

scholarly journals Impact of Ramadan Intermittent Fasting on the Heart Rate Variability and Cardiovascular Parameters of Patients with Controlled Hypertension

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Sabah Hammoud ◽  
Iman Saad ◽  
Rita Karam ◽  
Fayez Abou Jaoude ◽  
Bart J. F. van den Bemt ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Blood Glucose ◽  
Intermittent Fasting ◽  
Ramadan Fasting ◽  
Hypertensive Patients ◽  
Cardiac Stress ◽  
Lipid Panel ◽  
The Impact

Background. Conflicting results are reported on the effect of Ramadan fasting on the cardiovascular health of patients with hypertension, a highly prevalent cardiovascular disease risk factor. This research aimed to evaluate the impact of fasting on cardiac health and heart rate variability (as a measure of cardiac stress) of hypertensive patients. Methods. Patients with controlled hypertension were followed in a prospective cohort during and after Ramadan. Lipid panel and blood glucose were measured at the end of each phase. Blood pressure and heart rate variability were monitored in the morning, afternoon, and evening of each follow-up day. Results. The study included 58 subjects (mean age: 54 ± 11.5 years, 52% male). Fasting did not affect body composition, lipid panel parameters, and blood pressure of hypertensive subjects; males only presented lower body weight and hip circumference during Ramadan. Blood glucose was significantly higher during Ramadan. Fasting significantly increased HRV during the afternoon period. Conclusions. Ramadan intermittent fasting reduces cardiac stress among hypertensive patients controlled by and adherent to hypertensive medication, without affecting their hypertensive state.

scholarly journals Black Soybean Improves Vascular Function and Blood Pressure: A Randomized, Placebo Controlled, Crossover Trial in Humans

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2755
Author(s):  
Yoko Yamashita ◽  
Asuka Nakamura ◽  
Fumio Nanba ◽  
Shizuka Saito ◽  
Toshiya Toda ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Blood Pressure ◽  
Antioxidant Activity ◽  
Vascular Function ◽  
Crossover Trial ◽  
Black Soybean ◽  
Dietary Polyphenols ◽  
Healthy Humans ◽  
Nitric Oxide Level

Vascular dysfunction and injurious stimuli such as oxidative stress are closely related to the risk of cardiovascular diseases (CVD). Dietary polyphenols are reported to exert beneficial effects in reducing the risk of CVD. Black soybean has been used as a nutritionally rich food and contains abundant polyphenols in its seed coat and grain. Black soybean has many beneficial physiological activities, and its prevention effects on CVD risk were reported mainly in animal experiments. In this study, we performed a randomized, single blind, placebo controlled, crossover trial to investigate the effect of black soybean consumption on the vascular function in healthy humans. Twenty-two healthy adults aged from 30 to 60 completed the four week trial with daily consumption of about a 40 g test material cookie containing 20 g roasted black soybean powder. Body composition, vascular function, biomarkers for oxidative stress, and polyphenol contents in the urine and the plasma were measured. After ingestion of the black soybean cookie, vascular function, which was evaluated by plethysmogram using a Pulse Analyzer®, was improved and systolic blood pressure was decreased. Moreover, nitric oxide levels in plasma and urine were increased, while an oxidative stress biomarker, 8-hydroxy-2′-deoxyguanosine level, in the plasma was decreased accompanied by an increase in the concentration of polyphenols derived from black soybean in plasma and urine. These results suggest that the antioxidant activity of black soybean polyphenols and an increase in the nitric oxide level may contribute to the improvement of vascular function. Thus, black soybean is an attractive food material for improvement of vascular function through decreasing oxidative stress by its potent antioxidant activity and increasing the nitric oxide level in healthy humans.

scholarly journals Bredemolic Acid Improves Cardiovascular Function and Attenuates Endothelial Dysfunction in Diet-Induced Prediabetes: Effects on Selected Markers

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Akinjide Moses Akinnuga ◽  
Angezwa Siboto ◽  
Bongiwe Khumalo ◽  
Ntethelelo Hopewell Sibiya ◽  
Phikelelani Ngubane ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Lipid Peroxidation ◽  
Heart Rate ◽  
Endothelial Dysfunction ◽  
Endothelial Function ◽  
Lipid Profile ◽  
Cardiovascular Function ◽  
Male Rats ◽  
Cardiovascular Dysfunction

Prediabetes is an intermediate hyperglycaemic state which has been associated with cardiovascular dysfunction. However, cardiovascular dysfunction is not only caused by intermediate hyperglycaemia but also endothelial dysfunction, inflammation, and oxidative stress associated with prediabetes. Bredemolic acid (BA), an isomer of maslinic acid, has been reported to ameliorate the intermediate hyperglycaemia found in prediabetes; however, the effects of this triterpene on cardiovascular function have not yet been determined. Therefore, this study investigated the effects of BA on cardiovascular function in diet-induced prediabetic rats. Thirty-six male rats that weighed 150–180 g were divided into two groups, the non-prediabetic (n = 6) and the prediabetic groups (n = 30), which were fed normal diet (ND) and HFHC diet, respectively. The prediabetic rats were further subdivided into five groups (n = 6) and treated with either BA (80 mg/kg) or metformin (MET, 500 mg/kg) every third day for 12 weeks. After 12 weeks, blood samples and the heart were collected for biochemical analysis. The untreated prediabetic rats showed a significant increase in body mass index (BMI), waist circumference (WC), blood pressure, heart rate, lipid profile, lipid peroxidation, and inflammatory markers with significant decrease in endothelial function and antioxidant biomarkers by comparison with the non-prediabetic animals. The administration of BA significantly improved cardiovascular functions such as blood pressure, heart rate, and endothelial function. There was also a significant decrease in BMI, WC, lipid profile, lipid peroxidation, and inflammation with a concomitant increase in antioxidant capacity. BA administration improved cardiovascular function by attenuation of oxidative stress, inflammatory, and endothelial dysfunction markers.

scholarly journals The Effects of Acute Aerobic Exercise on Blood Pressure, Arterial Function, and Heart Rate Variability in Men Living With HIV

2021 ◽  
Vol 12 ◽  
Author(s):  
Juliana Pereira Barros ◽  
Tainah de Paula ◽  
Mauro Felippe Felix Mediano ◽  
Marcus Vinicius dos Santos Rangel ◽  
Walace Monteiro ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Oxygen Uptake ◽  
Vascular Function ◽  
Augmentation Index ◽  
Exercise Session ◽  
Healthy Controls ◽  
Arterial Function ◽  
Living With Hiv

PurposeThis study aims to investigate the effects of acute cycling on blood pressure (BP), arterial function, and heart rate variability (HRV) in men living with HIV (MLHIV) using combined antiretroviral therapy (cART).MethodsTwelve MLHIV (48.7 ± 9.2 years; 25.2 ± 2.8 kg m–2) and 13 healthy controls (41.2 ± 9.9 years; 26.3 ± 2.9 kg m–2) performed a cycling bout (ES) (intensity: 50% oxygen uptake reserve; duration: time to achieve 150 kcal—MLHIV: 24.1 ± 5.5 vs. controls: 23.1 ± 3.0 min; p = 0.45), and a 20-min non-exercise session (NES).ResultsAt rest (p &lt; 0.05), MLHIV presented higher brachial systolic/diastolic BP (SBP/DBP: 123.2 ± 14.2/76.8 ± 6.3 vs. 114.3 ± 5.1/71.6 ± 2.6 mmHg) and central BP (cSBP/cDBP: 108.3 ± 9.3/76.5 ± 6.5 vs. 101.6 ± 4.9/71.3 ± 4.4 mmHg) vs. controls but lower absolute maximal oxygen uptake (2.1 ± 0.5 vs. 2.5 ± 0.3 L min–1) and HRV indices reflecting overall/vagal modulation (SDNN: 24.8 ± 7.1 vs. 42.9 ± 21.3 ms; rMSSD: 20.5 ± 8.5 vs. 38.1 ± 22.8 ms; pNN50: 3.6 ± 4.2 vs. 13.6 ± 11.3%). DBP postexercise lowered in controls vs. MLHIV (∼4 mmHg, p &lt; 0.001; ES: 0.6). Moreover, controls vs. MLHIV had greater reductions (p &lt; 0.05) in augmentation index (−13.6 ± 13.7 vs. −3.1 ± 7.2% min–1; ES: 2.4), and HRV indices up to 5 min (rMSSD: −111.8 ± 32.1 vs. −75.9 ± 22.2 ms min–1; ES: 3.8; pNN50: −76.3 ± 28.3 vs. −19.0 ± 13.7% min–1; ES: 4.4). Within-group (ES vs. NES; p &lt; 0.05) reductions occurred in controls for SBP (∼10 mmHg, 2 h), DBP (∼6 mmHg, 20, 30, and 70 min), cSBP (∼9 mmHg, 30 min), cDBP (∼7 mmHg, 30 and 70 min), augmentation index (∼10%, 30 min), and pNN50 (∼20%; up to 2 h), while in MLHIV only cSBP (∼6 mmHg, 70 min) and cDBP (∼4 mmHg, 30 min) decreased. Similar increases (up to 5 min) in heart rate (∼22 bpm) and decreases in SDNN (∼18 ms) and rMSSD (∼20 ms) occurred in both groups.ConclusionMLHIV under cART exhibited attenuated postexercise hypotension vs. healthy controls, which seemed to relate with impairments in vascular function.

scholarly journals Red Blood Cell and Endothelial eNOS Independently Regulate Circulating Nitric Oxide Metabolites and Blood Pressure

Circulation ◽  
2021 ◽  
Author(s):  
Francesca Leo ◽  
Tatsiana Suvorava ◽  
Sophia K. Heuser ◽  
Junjie Li ◽  
Anthea LoBue ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Endothelial Cells ◽  
Vascular Function ◽  
Ex Vivo ◽  
Knock Out ◽  
Catalytically Active ◽  
Nitric Oxide Metabolites ◽  
Plasma Nitrite

Background: Current paradigms suggest that nitric oxide (NO) produced by endothelial cells (ECs) via endothelial nitric oxide synthase (eNOS) in the vessel wall is the primary regulator of blood flow and blood pressure. However, red blood cells (RBCs) also carry a catalytically active eNOS, but its role is controversial and remains undefined. This study aimed to elucidate the functional significance of red cell eNOS compared to EC eNOS for vascular hemodynamics and NO metabolism. Methods: We generated tissue-specific "loss-" and "gain-of-function" models for eNOS by using cell-specific Cre-induced gene inactivation or reactivation. We created two founder lines carrying a floxed eNOS (eNOS flox/flox ) for Cre-inducible knock out (KO), as well as gene construct with an inactivated floxed/inverted exon (eNOS inv/inv ) for a Cre-inducible knock in (KI), which respectively allow targeted deletion or reactivation of eNOS in erythroid cells (RBC eNOS KO or RBC eNOS KI mice) or endothelial cells (EC eNOS KO or EC eNOS KI mice). Vascular function, hemodynamics, and NO metabolism were compared ex vivo and in vivo . Results: The EC eNOS KOs exhibited significantly impaired aortic dilatory responses to acetylcholine, loss of flow-mediated dilation (FMD), and increased systolic and diastolic blood pressure. RBC eNOS KO mice showed no alterations in acetylcholine-mediated dilation or FMD but were hypertensive. Treatment with the NOS inhibitor L-NAME further increased blood pressure in RBC eNOS KOs, demonstrating that eNOS in both ECs and RBCs contributes to blood pressure regulation. While both EC eNOS KOs and RBC eNOS KOs had lower plasma nitrite and nitrate concentrations, the levels of bound NO in RBCs were lower in RBC eNOS KOs as compared to EC eNOS KOs. Crucially, reactivation of eNOS in ECs or RBCs rescues the hypertensive phenotype of the eNOS inv/inv mice, while the levels of bound NO were restored only in RBC eNOS KI mice. Conclusions: These data reveal that eNOS in ECs and RBCs contribute independently to blood pressure homeostasis.

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