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Luan G, Hu Y, Chen M, You M, Xu C, Yin D, Liu J, Yao H. Associations Between Air Temperature and Daily Varicella Cases - Jinan City, Shandong Province, China, 2019-2021. China CDC Wkly 2024; 6:36-39. [PMID: 38250698 PMCID: PMC10797300 DOI: 10.46234/ccdcw2024.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 01/05/2024] [Indexed: 01/23/2024] Open
Abstract
What is already known about this topic? The impact of air temperature on varicella has been studied, but there is limited research exploring its effect on varicella by gender and age group. What is added by this report? We conducted a time series analysis to examine the differential effects of air temperature on varicella infection across different demographic groups. Our findings indicate that lower temperatures have a more pronounced influence on varicella incidence among males and children compared to females and adults. What are the implications for public health practice? These findings can assist in identifying populations that are vulnerable to temperature-related varicella and in guiding the implementation of effective measures for varicella control.
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Affiliation(s)
- Guijie Luan
- Chinese Center for Disease Control and Prevention, Beijing, China
- Institute for Immunization management, Shandong Center for Disease Control and Prevention, Jinan City, Shandong Province, China
| | - Yuehua Hu
- Chinese Center for Disease Control and Prevention, Beijing, China
| | - Meng Chen
- Institute for Immunization management, Shandong Center for Disease Control and Prevention, Jinan City, Shandong Province, China
| | - Meiying You
- Chinese Center for Disease Control and Prevention, Beijing, China
| | - Chengdong Xu
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Dapeng Yin
- Hainan Provincial Center for Disease Control and Prevention, Haikou City, Hainan Province, China
| | - Jianjun Liu
- Chinese Center for Disease Control and Prevention, Beijing, China
| | - Hongyan Yao
- Chinese Center for Disease Control and Prevention, Beijing, China
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Parikh K, Shepley BR, Tymko MM, Hijmans JG, Hoiland RL, Desouza CA, Sekhon MS, Ainslie PN, Bain AR. Cerebral uptake of microvesicles occurs in normocapnic but not hypocapnic passive hyperthermia in young healthy male adults. J Physiol 2023; 601:5601-5616. [PMID: 37975212 DOI: 10.1113/jp285265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 11/01/2023] [Indexed: 11/19/2023] Open
Abstract
Passive hyperthermia causes cerebral hypoperfusion primarily from heat-induced respiratory alkalosis. However, despite the cerebral hypoperfusion, it is possible that the mild alkalosis might help to attenuate cerebral inflammation. In this study, the cerebral exchange of extracellular vesicles (microvesicles), which are known to elicit pro-inflammatory responses when released in conditions of stress, were examined in hyperthermia with and without respiratory alkalosis. Ten healthy male adults were heated passively, using a warm water-perfused suit, up to core temperature + 2°C. Blood samples were taken from the radial artery and internal jugular bulb. Microvesicle concentrations were determined in platelet-poor plasma via cells expressing CD62E (activated endothelial cells), CD31+ /CD42b- (apoptotic endothelial cells), CD14 (monocytes) and CD45 (pan-leucocytes). Cerebral blood flow was measured via duplex ultrasound of the internal carotid and vertebral arteries to determine cerebral exchange kinetics. From baseline to poikilocapnic (alkalotic) hyperthermia, there was no change in microvesicle concentration from any cell origin measured (P-values all >0.05). However, when blood CO2 tension was normalized to baseline levels in hyperthermia, there was a marked increase in cerebral uptake of microvesicles expressing CD62E (P = 0.028), CD31+ /CD42b- (P = 0.003) and CD14 (P = 0.031) compared with baseline, corresponding to large increases in arterial but not jugular venous concentrations. In a subset of seven participants who underwent hypercapnia and hypocapnia in the absence of heating, there was no change in microvesicle concentrations or cerebral exchange, suggesting that hyperthermia potentiated the CO2 /pH-mediated cerebral uptake of microvesicles. These data provide insight into a potential beneficial role of respiratory alkalosis in heat stress. KEY POINTS: The hyperthermia-induced hyperventilatory response is observed in most humans, despite causing potentially harmful reductions in cerebral blood flow. We tested the hypothesis that the respiratory-induced alkalosis is associated with lower circulating microvesicle concentrations, specifically in the brain, despite the reductions in blood flow. At core temperature + 2°C with respiratory alkalosis, microvesicles derived from endothelial cells, monocytes and leucocytes were at concentrations similar to baseline in the arterial and cerebral venous circulation, with no changes in cross-brain microvesicle kinetics. However, when core temperature was increased by 2°C with CO2 /pH normalized to resting levels, there was a marked cerebral uptake of microvesicles derived from endothelial cells and monocytes. The CO2 /pH-mediated alteration in cerebral microvesicle uptake occurred only in hyperthermia. These new findings suggest that the heat-induced hyperventilatory response might serve a beneficial role by preventing potentially inflammatory microvesicle uptake in the brain.
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Affiliation(s)
- Khushali Parikh
- Faculty of Human Kinetics, Department of Kinesiology, University of Windsor, Windsor, ON, Canada
| | - Brooke R Shepley
- Faculty of Human Kinetics, Department of Kinesiology, University of Windsor, Windsor, ON, Canada
| | - Michael M Tymko
- Centre for Heart, Lung and Vascular Health, University of British Columbia, Kelowna, BC, Canada
- Department of Human Health and Nutritional Sciences, College of Biological Science, University of Guelph, Guelph, ON, Canada
| | - Jamie G Hijmans
- Department of Integrative Biology, University of Colorado Boulder, Boulder, CO, USA
| | - Ryan L Hoiland
- Centre for Heart, Lung and Vascular Health, University of British Columbia, Kelowna, BC, Canada
- Division of Critical Care Medicine, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Collaborative Entity for Researching Brain Ischemia, University of British Columbia, Vancouver, BC, Canada
| | | | - Mypinder S Sekhon
- Division of Critical Care Medicine, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Collaborative Entity for Researching Brain Ischemia, University of British Columbia, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, University of British Columbia, Kelowna, BC, Canada
| | - Anthony R Bain
- Faculty of Human Kinetics, Department of Kinesiology, University of Windsor, Windsor, ON, Canada
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Ravanelli N, Barry H, Bain AR, Vachon L, Martel C, Gagnon D. Impact of passive heat stress and passive heat acclimation on circulating extracellular vesicles: An exploratory analysis. Exp Physiol 2023; 108:344-352. [PMID: 36621798 PMCID: PMC10103847 DOI: 10.1113/ep090823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 12/13/2022] [Indexed: 01/10/2023]
Abstract
NEW FINDINGS What is the central question of this study? How does passive heat stress and subsequent heat acclimation affect the circulating concentration of extracellular vesicles? What is the main finding and its importance? Passive heat stress increased the circulating concentration of total and platelet extracellular vesicles. Seven days of hot water immersion did not modify the change in circulating concentrations of extracellular vesicles during passive heat stress. ABSTRACT This retrospective exploratory analysis aimed to improve our understanding of the effect of passive heat stress and subsequent heat acclimation on the circulating concentration of extracellular vesicles (EVs). Healthy young adults (four females and six males, 25 ± 4 years of age, 1.72 ± 0.08 m in height and weighing 71.6 ± 9.0 kg) were heated with a water-perfused suit before and after seven consecutive days of hot water immersion. Pre-acclimation, participants were heated until oesophageal temperature increased to ∼1.4°C above baseline values. Post-acclimation, participants were heated until oesophageal temperature reached the same absolute value as the pre-acclimation visit (∼38.2°C). Venous blood samples were obtained before and at the end of passive heating to quantify plasma concentrations of EVs from all cell types (CSFE+ ), all cell types except erythrocytes (CSFE+ MHCI+ ), platelets (CSFE+ MHCI+ CD41+ ), endothelial cells (CSFE+ MHCI+ CD62e+ ), red blood cells (CSFE+ CD235a+ ) and leucocytes (CSFE+ MHCI+ CD45+ ) via flow cytometry. Passive heat stress increased the concentration of CFSE+ EVs (46,150,000/ml [3,620,784, 88,679,216], P = 0.036), CFSE+ MHCI+ EVs (28,787,500/ml [9,851,127, 47,723,873], P = 0.021) and CSFE+ MHCI+ CD41+ EVs (28,343,500/ml [9,637,432, 47,049,568], P = 0.008). The concentration of CSFE+ MHCI+ CD62e+ EVs (94,230/ml [-55,099, 243,559], P = 0.187), CSFE+ CD235a+ EVs (-1,414/ml [-15,709, 12,882], P = 0.403) or CSFE+ MHCI+ CD45+ EVs (-192,915/ml [-690,166, 304,336], P = 0.828) did not differ during heat stress. The change in circulating EVs during passive heat stress did not differ after heat acclimation (thermal state × acclimation interactions, all P ≥ 0.180). These results demonstrate that passive heat stress increases the circulating concentration of total and platelet EVs and that passive heat acclimation does not alter this increase.
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Affiliation(s)
| | - Hadiatou Barry
- Montreal Heart InstituteMontrealQuebecCanada
- Department of Pharmacology and PhysiologyUniversité de MontréalMontrealQuebecCanada
| | - Anthony R. Bain
- Department of KinesiologyUniversity of WindsorWindsorOntarioCanada
| | - Laurent Vachon
- Montreal Heart InstituteMontrealQuebecCanada
- Department of MedicineUniversité de MontréalMontrealQuebecCanada
| | - Catherine Martel
- Montreal Heart InstituteMontrealQuebecCanada
- Department of MedicineUniversité de MontréalMontrealQuebecCanada
| | - Daniel Gagnon
- Montreal Heart InstituteMontrealQuebecCanada
- Department of Pharmacology and PhysiologyUniversité de MontréalMontrealQuebecCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontrealQuebecCanada
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Li F, Deng J, He Q, Zhong Y. ZBP1 and heatstroke. Front Immunol 2023; 14:1091766. [PMID: 36845119 PMCID: PMC9950778 DOI: 10.3389/fimmu.2023.1091766] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 01/19/2023] [Indexed: 02/12/2023] Open
Abstract
Heatstroke, which is associated with circulatory failure and multiple organ dysfunction, is a heat stress-induced life-threatening condition characterized by a raised core body temperature and central nervous system dysfunction. As global warming continues to worsen, heatstroke is expected to become the leading cause of death globally. Despite the severity of this condition, the detailed mechanisms that underlie the pathogenesis of heatstroke still remain largely unknown. Z-DNA-binding protein 1 (ZBP1), also referred to as DNA-dependent activator of IFN-regulatory factors (DAI) and DLM-1, was initially identified as a tumor-associated and interferon (IFN)-inducible protein, but has recently been reported to be a Z-nucleic acid sensor that regulates cell death and inflammation; however, its biological function is not yet fully understood. In the present study, a brief review of the main regulators is presented, in which the Z-nucleic acid sensor ZBP1 was identified to be a significant factor in regulating the pathological characteristics of heatstroke through ZBP1-dependent signaling. Thus, the lethal mechanism of heatstroke is revealed, in addition to a second function of ZBP1 other than as a nucleic acid sensor.
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Affiliation(s)
- Fanglin Li
- Critical Care Medicine, The Second Xiangya Hospital, Central South University, Changsha, China,Department of Critical Care Medicine and Hematology, The 3rd Xiangya Hospital, Central South University, Changsha, China
| | - Jiayi Deng
- Critical Care Medicine, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Qiuli He
- Department of Nephrology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, China,*Correspondence: Qiuli He, ; Yanjun Zhong,
| | - Yanjun Zhong
- Critical Care Medicine, The Second Xiangya Hospital, Central South University, Changsha, China,*Correspondence: Qiuli He, ; Yanjun Zhong,
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He L, Lin Q, Zhong L, Zeng Q, Song J. Thromboelastography maximum amplitude as an early predictor of disseminated intravascular coagulation in patients with heatstroke. Int J Hyperthermia 2022; 39:605-610. [PMID: 35465816 DOI: 10.1080/02656736.2022.2066206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
OBJECTIVES The aim of this study was to investigate the ability of TEG to predict DIC associated with heatstroke. METHODS We carried out a retrospective, single-center study of 67 patients with heatstroke admitted to an intensive care unit (ICU) at a comprehensive hospital between July 2016 and August 2021. Conventional coagulation tests (CCTs) and TEG were performed within 2 h of admission in ICU. Patients were diagnosed with DIC based on International Society of Thrombosis and Hemostasis criteria, and those with or without DIC were compared in terms of CCTs and TEG findings. The ability of individual parameters to predict DIC was assessed based on logistic regression and the area under receiver operating characteristic curves (AUC). RESULTS Of the 67 patients, 19 (28.4%) were diagnosed with DIC. Compared to patients without DIC, those with DIC had significantly longer reaction time [14.5(10.6-26.0) vs. 6.2(5.1-10.1)min](p < 0.001) and kinetic time [10.9(5.9-25.0) vs. 2.7(2.2-4.7) min](p < 0.001). Conversely, those with DIC had significantly lower alpha angle [22(9.1-43.3) vs. 55.0(44.8-61.7)°](p < 0.001), maximum amplitude (MA) [(26.9(17.7-41.4) vs. 52.2(45.8-58.1) mm)] (p < 0.001) and coagulation index [-17.3(-39 to -7.9)vs. -2.4(-6.2to-0.6)](p < 0.001). MA at a cutoff value of 45.4 mm gave an AUC of 0.9 for predicting DIC, with sensitivity of 77.1%, specificity of 89.5%, positive predictive value of 10.5% and negative predictive value of 22.9%. Multifactorial logistic regression identified MA < 45.4 mm as an independent predictor of DIC (odds ratio 9, 95% confidence interval 1.2-69.2, p = 0.035). MA decreased significantly as DIC score increased and was significantly lower in the non-survivors on admission. CONCLUSIONS MA < 45.4 mm in patients with heatstroke may predict elevated risk of DIC. HighlightsPatients with heatstroke-induced disseminated intravascular coagulation (DIC) has high mortality.A retrospective, single-center study was performed to investigate the ability of thromboelastography (TEG) to predict DIC associated with heatstroke.The maximum amplitude (MA) value of TEG decreased significantly with the increase of DIC score.MA < 45.4 mm was firstly demonstrated to an independent predictor of heatstroke-induced DIC.
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Affiliation(s)
- Longping He
- Department of Critical Care Medicine, the 908th Hospital of Chinese Logistical Support Force, Nanchang, China
| | - Qingwei Lin
- Department of Critical Care Medicine, the 908th Hospital of Chinese Logistical Support Force, Nanchang, China
| | - Lincui Zhong
- Department of Critical Care Medicine, the 908th Hospital of Chinese Logistical Support Force, Nanchang, China
- Nanchang Key Laboratory of Thrombosis and Hemostasis, Nanchang, China
| | - Qingbo Zeng
- Nanchang Key Laboratory of Thrombosis and Hemostasis, Nanchang, China
- Intensive Care Unit, Nanchang Hongdou Hospital of TCM, Nanchang, China
| | - Jingchun Song
- Department of Critical Care Medicine, the 908th Hospital of Chinese Logistical Support Force, Nanchang, China
- Nanchang Key Laboratory of Thrombosis and Hemostasis, Nanchang, China
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Trinity JD, Drummond MJ, Fermoyle CC, McKenzie AI, Supiano MA, Richardson RS. Cardiovasomobility: an integrative understanding of how disuse impacts cardiovascular and skeletal muscle health. J Appl Physiol (1985) 2022; 132:835-861. [PMID: 35112929 PMCID: PMC8934676 DOI: 10.1152/japplphysiol.00607.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Cardiovasomobility is a novel concept that encompasses the integration of cardiovascular and skeletal muscle function in health and disease with critical modification by physical activity, or lack thereof. Compelling evidence indicates that physical activity improves health while a sedentary, or inactive, lifestyle accelerates cardiovascular and skeletal muscle dysfunction and hastens disease progression. Identifying causative factors for vascular and skeletal muscle dysfunction, especially in humans, has proven difficult due to the limitations associated with cross-sectional investigations. Therefore, experimental models of physical inactivity and disuse, which mimic hospitalization, injury, and illness, provide important insight into the mechanisms and consequences of vascular and skeletal muscle dysfunction. This review provides an overview of the experimental models of disuse and inactivity and focuses on the integrated responses of the vasculature and skeletal muscle in response to disuse/inactivity. The time course and magnitude of dysfunction evoked by various models of disuse/inactivity are discussed in detail, and evidence in support of the critical roles of mitochondrial function and oxidative stress are presented. Lastly, strategies aimed at preserving vascular and skeletal muscle dysfunction during disuse/inactivity are reviewed. Within the context of cardiovasomobility, experimental manipulation of physical activity provides valuable insight into the mechanisms responsible for vascular and skeletal muscle dysfunction that limit mobility, degrade quality of life, and hasten the onset of disease.
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Affiliation(s)
- Joel D Trinity
- Salt Lake City Veteran Affairs Medical Center Geriatric Research, Education, and Clinical Center, Salt Lake City, Utah.,Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Micah J Drummond
- Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah.,Department of Physical Therapy, University of Utah, Salt Lake City, Utah
| | - Caitlin C Fermoyle
- Salt Lake City Veteran Affairs Medical Center Geriatric Research, Education, and Clinical Center, Salt Lake City, Utah.,Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah
| | - Alec I McKenzie
- Salt Lake City Veteran Affairs Medical Center Geriatric Research, Education, and Clinical Center, Salt Lake City, Utah.,Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah
| | - Mark A Supiano
- Salt Lake City Veteran Affairs Medical Center Geriatric Research, Education, and Clinical Center, Salt Lake City, Utah.,Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah
| | - Russell S Richardson
- Salt Lake City Veteran Affairs Medical Center Geriatric Research, Education, and Clinical Center, Salt Lake City, Utah.,Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
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Ogawa T, Hoekstra SP, Kamijo YI, Goosey-Tolfrey VL, Walsh JJ, Tajima F. F, Leicht CA. Serum and plasma brain-derived neurotrophic factor concentration are elevated by systemic but not local passive heating. PLoS One 2021; 16:e0260775. [PMID: 34882699 PMCID: PMC8659342 DOI: 10.1371/journal.pone.0260775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 11/16/2021] [Indexed: 11/30/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) plays a key role in neuronal adaptations. While previous studies suggest that whole-body heating can elevate circulating BDNF concentration, this is not known for local heating protocols. This study investigated the acute effects of whole-body versus local passive heating on serum and plasma BDNF concentration. Using a water-perfused suit, ten recreationally active males underwent three 90 min experimental protocols: heating of the legs with upper-body cooling (LBH), whole-body heating (WBH) and a control condition (CON). Blood samples were collected before, immediately after and 1 h post-heating for the determination of serum and plasma BDNF concentration, platelet count as well as the BDNF release per platelet. Rectal temperature, cardiac output and femoral artery shear rate were assessed at regular intervals. Serum and plasma BDNF concentration were elevated after WBH (serum: 19.1±5.0 to 25.9±11.3 ng/ml, plasma: 2.74±0.9 to 4.58±2.0; p<0.044), but not LBH (serum: 19.1±4.7 to 22.3±4.8 ng/ml, plasma: 3.25±1.13 to 3.39±0.90 ng/ml; p>0.126), when compared with CON (serum: 18.6±6.4 to 16.8±3.4 ng/ml, plasma: 2.49±0.69 to 2.82±0.89 ng/ml); accompanied by an increase in platelet count (p<0.001). However, there was no change in BDNF content per platelet after either condition (p = 0.392). All physiological measures were elevated to a larger extent after WBH compared with LBH (p<0.001), while shear rate and rectal temperature were higher during LBH than CON (p<0.038). In conclusion, WBH but not LBH acutely elevates circulating BDNF concentration. While these findings further support the use of passive heating to elevate BDNF concentration, a larger increase in shear rate, sympathetic activity and/or rectal temperature than found after LBH appears needed to induce an acute BDNF response by passive heating.
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Affiliation(s)
- Takahiro Ogawa
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan
| | - Sven P. Hoekstra
- The Peter Harrison Centre for Disability Sport, Loughborough University, Loughborough, United Kingdom
| | - Yoshi-Ichiro Kamijo
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan
| | | | - Jeremy J. Walsh
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Fumihiro Tajima F.
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan
- The Peter Harrison Centre for Disability Sport, Loughborough University, Loughborough, United Kingdom
| | - Christof A. Leicht
- The Peter Harrison Centre for Disability Sport, Loughborough University, Loughborough, United Kingdom
- * E-mail:
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The Effects of Repeated Thermal Stress on the Physiological Parameters of Young Physically Active Men Who Regularly Use the Sauna: A Multifactorial Assessment. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182111503. [PMID: 34770018 PMCID: PMC8583525 DOI: 10.3390/ijerph182111503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/27/2021] [Accepted: 10/29/2021] [Indexed: 11/20/2022]
Abstract
The aim of this study was to determine the effects of thermal stress (TS) on changes in blood biochemical parameters and fluid electrolyte levels in young adult men with moderate and high levels of physical activity. Thirty men (22.67 ± 2.02 years) were exposed to four 12-min sauna sessions (temperature: 90–91 °C; relative humidity: 14–16%) with four 6-min cool-down breaks. The evaluated variables were anthropometric, physiological, and hematological characteristics. The mean values of HRavg (102.5 bpm) were within the easy effort range, whereas HRpeak (143.3 bpm) values were within the very difficult effort range. A significant increase was noted in pO2 (p < 0.001), total cholesterol (p < 0.008), HDL (p < 0.006) and LDL cholesterol (p < 0.007). Significant decreases were observed in the SBP (by 9.7 mmHg), DBP (by 6.9 mmHg) (p < 0.001), pH (p < 0.001), aHCO3- (p < 0.005), sHCO3- (p < 0.003), BE (ecf) (p < 0.022), BE (B), ctCO2 (for both p < 0.005), glucose (p < 0.001), and LA (p < 0.036). High 72-min TS did not induce significant changes in the physiological parameters of young and physically active men who regularly use the sauna, excluding significant loss of body mass. We can assume that relatively long sauna sessions do not disturb homeostasis and are safe for the health of properly prepared males.
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Brunt VE, Minson CT. Heat therapy: mechanistic underpinnings and applications to cardiovascular health. J Appl Physiol (1985) 2021; 130:1684-1704. [PMID: 33792402 DOI: 10.1152/japplphysiol.00141.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cardiovascular diseases (CVD) are the leading cause of death worldwide, and novel therapies are drastically needed to prevent or delay the onset of CVD to reduce the societal and healthcare burdens associated with these chronic diseases. One such therapy is "heat therapy," or chronic, repeated use of hot baths or saunas. Although using heat exposure to improve health is not a new concept, it has received renewed attention in recent years as a growing number of studies have demonstrated robust and widespread beneficial effects of heat therapy on cardiovascular health. Here, we review the existing literature, with particular focus on the molecular mechanisms that underscore the cardiovascular benefits of this practice.
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Affiliation(s)
- Vienna E Brunt
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado.,Department of Human Physiology, University of Oregon, Eugene, Oregon
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10
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Shepley BR, Ainslie PN, Hoiland RL, Donnelly J, Sekhon MS, Zetterberg H, Blennow K, Bain AR. Negligible influence of moderate to severe hyperthermia on blood-brain barrier permeability and neuronal parenchymal integrity in healthy men. J Appl Physiol (1985) 2021; 130:792-800. [PMID: 33444119 DOI: 10.1152/japplphysiol.00645.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
With growing use for hyperthermia as a cardiovascular therapeutic, there is surprisingly little information regarding the acute effects it may have on the integrity of the neurovascular unit (NVU). Indeed, relying on animal data would suggest hyperthermia comparable to levels attained in thermal therapy will disrupt the blood-brain barrier (BBB) and damage the cerebral parenchymal cells. We sought to address the hypothesis that controlled passive hyperthermia is not sufficient to damage the NVU in healthy humans. Young men (n = 11) underwent acute passive heating until +2°C or absolute esophageal temperature of 39.5°C. The presence of BBB opening was determined by trans-cerebral exchange kinetics (radial-arterial and jugular venous cannulation) of S100B. Neuronal parenchymal damage was determined by the trans-cerebral exchange of tau protein, neuron-specific enolase (NSE), and neurofilament-light protein (NF-L). Cerebral blood flow to calculate exchange kinetics was measured by duplex ultrasound of the right internal carotid and left vertebral artery. Passive heating was performed via a warm-water perfused suit. In hyperthermia, there was no increase in the cerebral exchange of S100B (P = 0.327), tau protein (P = 0.626), NF-L (P = 0.447), or NSE (P = 0.908) suggesting the +2°C core temperature is not sufficient to acutely stress the NVU in healthy men. However, there was a significant condition effect (P = 0.028) of NSE, corresponding to a significant increase in arterial (P = 0.023) but not venous (P = 0.173) concentrations in hyperthermia, potentially indicating extra-cerebral release of NSE. Collectively, results from the present study support the notion that in young men there is little concern for NVU damage with acute hyperthermia of +2 °C.NEW & NOTEWORTHY The acute effects of passive whole-body hyperthermia on the integrity of the neurovascular unit (NVU) in humans have remained unclear. We demonstrate that passive heating for ∼1 h until an increase of +2°C esophageal temperature in healthy men does not increase the cerebral release of neuronal parenchymal stress biomarkers, suggesting the NVU integrity is maintained. This preliminary study indicates passive heating is safe for the brain, at least in young healthy men.
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Affiliation(s)
- Brooke R Shepley
- University of Windsor, Faculty of Human Kinetics, Department of Kinesiology, Windsor, ON, Canada
| | - Philip N Ainslie
- University of British Columbia, Kelowna, Centre for Heart Lung and Vascular Health, Vancouver, BC, Canada
| | - Ryan L Hoiland
- University of British Columbia, Kelowna, Centre for Heart Lung and Vascular Health, Vancouver, BC, Canada.,Department of Anesthesiology, Pharmacology, and Therapeutics, Vancouver General Hospital, Vancouver, BC, Canada
| | - Joseph Donnelly
- Brain Physics Laboratory, Division of Academic Neurosurgery, Department of Clinical Neurosciences, Addenbrookes Hospital, University of Cambridge, Cambridge, UK
| | - Mypinder S Sekhon
- University of British Columbia, Kelowna, Centre for Heart Lung and Vascular Health, Vancouver, BC, Canada.,Division of Critical Care Medicine and Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.,Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.,Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK.,UK Dementia Research Institute at UCL, London, UK
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.,Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Anthony R Bain
- University of Windsor, Faculty of Human Kinetics, Department of Kinesiology, Windsor, ON, Canada
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11
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Bain AR, Hoiland RL, Donnelly J, Nowak-Flück D, Sekhon M, Tymko MM, Greiner JJ, DeSouza CA, Ainslie PN. Cerebral metabolism, oxidation and inflammation in severe passive hyperthermia with and without respiratory alkalosis. J Physiol 2020; 598:943-954. [PMID: 31900940 DOI: 10.1113/jp278889] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/20/2019] [Indexed: 12/20/2022] Open
Abstract
KEY POINTS It was unknown whether respiratory alkalosis impacts the global cerebral metabolic response as well as the cerebral pro-oxidation and inflammatory response in passive hyperthermia. This study demonstrated that the cerebral metabolic rate was increased by ∼20% with passive hyperthermia of up to +2°C oesophageal temperature, and this response was unaffected by respiratory alkalosis. Additionally, the increase in cerebral metabolism did not significantly impact the net cerebral release of oxidative and inflammatory markers. These data indicate that passive heating of up to +2°C core temperature in healthy young men is not enough to confer a major oxidative and inflammatory burden on the brain, but it does markedly increase the cerebral metabolic rate, independently of P aC O 2 . ABSTRACT There is limited information concerning the impact of arterial P C O 2 /pH on heat-induced alteration in cerebral metabolism, as well as on the cerebral oxidative/inflammatory burden of hyperthermia. Accordingly, we sought to address two hypotheses: (1) passive hyperthermia will increase the cerebral metabolic rate of oxygen (CMRO2 ) consistent with a combined influence of Q10 and respiratory alkalosis; and (2) the net cerebral release of pro-oxidative and pro-inflammatory markers will be elevated in hyperthermia, particularly in poikilocapnic hyperthermia. Healthy young men (n = 6) underwent passive heating until an oesophageal temperature of 2°C above resting was reached. At 0.5°C increments in core temperature, CMRO2 was calculated from the product of cerebral blood flow (ultrasound) and the radial artery-jugular venous oxygen content difference (cannulation). Net cerebral glucose/lactate exchange, and biomarkers of oxidative and inflammatory stress were also measured. At +2.0°C oesophageal temperature, arterial P C O 2 was restored to normothermic values using end-tidal forcing. The primary findings were: (1) while CMRO2 was increased (P < 0.05) by ∼20% with hyperthermia of +1.5-2.0°C, this was not influenced by respiratory alkalosis, and (2) although biomarkers of pro-oxidation and pro-inflammation were systemically elevated in hyperthermia (P < 0.05), there were no differences in the trans-cerebral exchange kinetics. These novel data indicate that passive heating of up to +2°C core temperature in healthy young men is not enough to confer a major oxidative and inflammatory burden on the brain, despite it markedly increasing CMRO2 , irrespective of arterial pH.
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Affiliation(s)
- Anthony R Bain
- Faculty of Human Kinetics, University of Windsor, Windsor, Ontario, Canada
| | - Ryan L Hoiland
- Faculty of Health and Social Development, Center for Heart Lung and Vascular Health University of British Columbia, Kelowna, British Columbia, Canada
| | - Joseph Donnelly
- Brain Physics Laboratory, Division of Academic Neurosurgery, Department of Clinical Neurosciences, Addenbrookes Hospital, University of Cambridge, Cambridge, UK
| | - Daniela Nowak-Flück
- Faculty of Health and Social Development, Center for Heart Lung and Vascular Health University of British Columbia, Kelowna, British Columbia, Canada
| | - Mypinder Sekhon
- Faculty of Health and Social Development, Center for Heart Lung and Vascular Health University of British Columbia, Kelowna, British Columbia, Canada.,Division of Critical Care Medicine and Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Michael M Tymko
- Faculty of Health and Social Development, Center for Heart Lung and Vascular Health University of British Columbia, Kelowna, British Columbia, Canada
| | - Jared J Greiner
- Department of Integrative Physiology, Integrative Vascular Biology Laboratory, University of Colorado, Boulder, CO, USA
| | - Christopher A DeSouza
- Department of Integrative Physiology, Integrative Vascular Biology Laboratory, University of Colorado, Boulder, CO, USA
| | - Philip N Ainslie
- Faculty of Health and Social Development, Center for Heart Lung and Vascular Health University of British Columbia, Kelowna, British Columbia, Canada
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12
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McVey MJ, Maishan M, Blokland KEC, Bartlett N, Kuebler WM. Extracellular vesicles in lung health, disease, and therapy. Am J Physiol Lung Cell Mol Physiol 2019; 316:L977-L989. [PMID: 30892076 DOI: 10.1152/ajplung.00546.2018] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Both physiological homeostasis and pathological disease processes in the lung typically result from complex, yet coordinated multicellular responses that are synchronized via paracrine and endocrine intercellular communication pathways. Of late, extracellular vesicles have emerged as important information shuttles that can coordinate and disseminate homeostatic and disease signals. In parallel, extracellular vesicles in biological fluids such as sputum, mucus, epithelial lining fluid, edema fluid, the pulmonary circulation, pleural fluid, and lymphatics have emerged as promising candidate biomarkers for diagnosis and prognosis in lung disease. Extracellular vesicles are small, subcellular, membrane-bound vesicles containing cargos from parent cells such as lipids, proteins, genetic information, or entire organelles. These cargos endow extracellular vesicles with biologically active information or functions by which they can reprogram their respective target cells. Recent studies show that extracellular vesicles found in lung-associated biological fluids play key roles as biomarkers and effectors of disease. Conversely, administration of naïve or engineered extracellular vesicles with homeostatic or reparative effects may provide a promising novel protective and regenerative strategy to treat lung disease. To highlight this rapidly developing field, the American Journal of Physiology-Lung Cellular and Molecular Physiology is now launching a special Call for Papers on extracellular vesicles in lung health, disease, and therapy. This review aims to set the stage for this call by introducing extracellular vesicles and their emerging roles in lung physiology and pathobiology.
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Affiliation(s)
- Mark J McVey
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital , Toronto, Ontario , Canada.,Department of Physiology, University of Toronto , Toronto, Ontario , Canada.,Department of Anesthesia, University of Toronto , Toronto, Ontario , Canada.,SickKids Department of Anesthesia and Pain Medicine , Toronto, Ontario , Canada
| | - Mazharul Maishan
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital , Toronto, Ontario , Canada
| | - Kaj E C Blokland
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales , Australia.,National Health and Medical Research Council Centre of Research Excellence in Pulmonary Fibrosis , Sydney, New South Wales , Australia.,Department of Pathology and Medical Biology, Groningen Research Institute for Asthma and COPD, University of Groningen, University Medical Center Groningen , Groningen , The Netherlands
| | - Nathan Bartlett
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales , Australia
| | - Wolfgang M Kuebler
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital , Toronto, Ontario , Canada.,Department of Physiology, University of Toronto , Toronto, Ontario , Canada.,Department of Surgery, University of Toronto , Toronto, Ontario , Canada.,Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin , Germany
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13
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Abstract
In addition to its role as an environmental stressor, scientists have recently demonstrated the potential for heat to be a therapy for improving or mitigating declines in arterial health. Many studies at both ends of the scientific controls spectrum (tightly controlled, experimental vs. practical) have demonstrated the beneficial effects of heating on microvascular function (e.g., reactive hyperemia, cutaneous vascular conductance); endothelial function (e.g., flow-mediated dilation); and arterial stiffness (e.g., pulse-wave velocity, compliance, β-stiffness index). It is important to note that findings of beneficial effects are not unanimous, likely owing to the varied methodology in both heating protocols and assessments of outcome measures. Mechanisms of action for the effects of both acute and chronic heating are also understudied. Heat science is a very promising area of human physiology research, as it has the potential to contribute to approaches addressing the global cardiovascular disease burden, particularly in aging and at risk populations, and those for whom exercise is not feasible or recommended.
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Affiliation(s)
- Jem L Cheng
- Department of Kinesiology, McMaster University , Hamilton, Ontario , Canada
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14
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Coombs GB, Barak OF, Phillips AA, Mijacika T, Sarafis ZK, Lee AHX, Squair JW, Bammert TD, DeSouza NM, Gagnon D, Krassioukov AV, Dujic Z, DeSouza CA, Ainslie PN. Acute heat stress reduces biomarkers of endothelial activation but not macro- or microvascular dysfunction in cervical spinal cord injury. Am J Physiol Heart Circ Physiol 2018; 316:H722-H733. [PMID: 30575438 DOI: 10.1152/ajpheart.00693.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cardiovascular diseases (CVD) are highly prevalent in spinal cord injury (SCI), and peripheral vascular dysfunction might be a contributing factor. Recent evidence demonstrates that exposure to heat stress can improve vascular function and reduce the risk of CVD in uninjured populations. We therefore aimed to examine the extent of vascular dysfunction in SCI and the acute effects of passive heating. Fifteen participants with cervical SCI and 15 uninjured control (CON) participants underwent ultrasound assessments of vascular function and venous blood sampling for biomarkers of endothelial activation (i.e., CD62e+) and apoptosis (i.e., CD31+/42b-) before and after a 60-min exposure to lower limb hot water immersion (40°C). In SCI, macrovascular endothelial function was reduced in the brachial artery [SCI: 4.8 (3.2)% vs. CON: 7.6 (3.4)%, P = 0.04] but not the femoral artery [SCI: 3.7 (2.6)% vs. CON: 4.0 (2.1)%, P = 0.70]. Microvascular function, via reactive hyperemia, was ~40% lower in SCI versus CON in both the femoral and brachial arteries ( P < 0.01). Circulating concentrations of CD62e+ were elevated in SCI versus CON [SCI: 152 (106) microparticles/µl vs. CON: 58 (24) microparticles/µl, P < 0.05]. In response to heating, macrovascular and microvascular function remained unchanged, whereas increases (+83%) and decreases (-93%) in antegrade and retrograde shear rates, respectively, were associated with heat-induced reductions of CD62e+ concentrations in SCI to levels similar to CON ( P = 0.05). These data highlight the potential of acute heating to provide a safe and practical strategy to improve vascular function in SCI. The chronic effects of controlled heating warrant long-term testing. NEW & NOTEWORTHY Individuals with cervical level spinal cord injury exhibit selectively lower flow-mediated dilation in the brachial but not femoral artery, whereas peak reactive hyperemia was lower in both arteries compared with uninjured controls. After 60 min of lower limb hot water immersion, femoral artery blood flow and shear patterns were acutely improved in both groups. Elevated biomarkers of endothelial activation in the spinal cord injury group decreased with heating, but these biomarkers remained unchanged in controls.
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Affiliation(s)
- Geoff B Coombs
- Centre for Heart, Lung and Vascular Health, University of British Columbia Okanagan , Kelowna, British Columbia , Canada
| | - Otto F Barak
- Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia
| | - Aaron A Phillips
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Hotchkiss Brain Institute, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada
| | - Tanja Mijacika
- Department of Integrative Physiology, School of Medicine, University of Split , Split , Croatia
| | - Zoe K Sarafis
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia , Vancouver, British Columbia , Canada
| | - Amanda H X Lee
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia , Vancouver, British Columbia , Canada
| | - Jordan W Squair
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia , Vancouver, British Columbia , Canada
| | - Tyler D Bammert
- Integrative Vascular Biology Laboratory, Department of Integrative Physiology, University of Colorado , Boulder, Colorado
| | - Noah M DeSouza
- Integrative Vascular Biology Laboratory, Department of Integrative Physiology, University of Colorado , Boulder, Colorado
| | - Daniel Gagnon
- Cardiovascular Prevention and Rehabilitation Centre, Montreal Heart Institute Research Centre, Département de pharmacologie et physiologie, Faculté de Médecine, Université de Montréal , Montreal, Quebec , Canada
| | - Andrei V Krassioukov
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia , Vancouver, British Columbia , Canada.,Division of Physical Medicine and Rehabilitation, Faculty of Medicine, University of British Columbia , Vancouver, British Columbia , Canada
| | - Zeljko Dujic
- Department of Integrative Physiology, School of Medicine, University of Split , Split , Croatia
| | - Christopher A DeSouza
- Integrative Vascular Biology Laboratory, Department of Integrative Physiology, University of Colorado , Boulder, Colorado
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, University of British Columbia Okanagan , Kelowna, British Columbia , Canada.,International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia , Vancouver, British Columbia , Canada
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15
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Myette-Côté É, Durrer C, Neudorf H, Bammert TD, Botezelli JD, Johnson JD, DeSouza CA, Little JP. The effect of a short-term low-carbohydrate, high-fat diet with or without postmeal walks on glycemic control and inflammation in type 2 diabetes: a randomized trial. Am J Physiol Regul Integr Comp Physiol 2018; 315:R1210-R1219. [PMID: 30303707 PMCID: PMC6734060 DOI: 10.1152/ajpregu.00240.2018] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/03/2018] [Accepted: 10/05/2018] [Indexed: 12/17/2022]
Abstract
Lowering carbohydrate consumption effectively lowers glucose, but impacts on inflammation are unclear. The objectives of this study were to: 1) determine whether reducing hyperglycemia by following a low-carbohydrate, high-fat (LC) diet could lower markers of innate immune cell activation in type 2 diabetes (T2D) and 2) examine if the combination of an LC diet with strategically timed postmeal walking was superior to an LC diet alone. Participants with T2D ( n = 11) completed a randomized crossover study involving three 4-day diet interventions: 1) low-fat low-glycemic index (GL), 2) and 3) LC with 15-min postmeal walks (LC+Ex). Four-day mean glucose was significantly lower in the LC+Ex group as compared with LC (-5%, P < 0.05), whereas both LC+Ex (-16%, P < 0.001) and LC (-12%, P < 0.001) conditions were lower than GL. A significant main effect of time was observed for peripheral blood mononuclear cells phosphorylated c-Jun N-terminal kinase ( P < 0.001), with decreases in all three conditions (GL: -32%, LC: -45%, and LC+Ex: -44%). A significant condition by time interaction was observed for monocyte microparticles ( P = 0.040) with a significant decrease in GL (-76%, P = 0.035) and a tendency for a reduction in LC (-70%, P = 0.064), whereas there was no significant change in LC+Ex (0.5%, P = 0.990). Both LC (-27%, P = 0.001) and LC+Ex (-35%, P = 0.005) also led to significant reductions in circulating proinsulin. An LC diet improved 4-day glycemic control and fasting proinsulin levels when compared with GL, with added glucose-lowering benefits when LC was combined with postmeal walking.
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Affiliation(s)
- Étienne Myette-Côté
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada
| | - Cody Durrer
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada
| | - Helena Neudorf
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada
| | - Tyler D Bammert
- Integrative Vascular Biology Laboratory, Department of Integrative Physiology, University of Colorado , Boulder, Colorado
| | - José Diego Botezelli
- Department of Cellular and Physiological Sciences, University of British Columbia , Vancouver, BC , Canada
| | - James D Johnson
- Department of Cellular and Physiological Sciences, University of British Columbia , Vancouver, BC , Canada
| | - Christopher A DeSouza
- Integrative Vascular Biology Laboratory, Department of Integrative Physiology, University of Colorado , Boulder, Colorado
| | - Jonathan P Little
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada
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16
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Brunt VE, Wiedenfeld-Needham K, Comrada LN, Minson CT. Passive heat therapy protects against endothelial cell hypoxia-reoxygenation via effects of elevations in temperature and circulating factors. J Physiol 2018; 596:4831-4845. [PMID: 30118148 DOI: 10.1113/jp276559] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 08/14/2018] [Indexed: 12/27/2022] Open
Abstract
KEY POINTS Accumulating evidence indicates that passive heat therapy (chronic use of hot tubs or saunas) has widespread physiological benefits, including enhanced resistance against novel stressors ('stress resistance'). Using a cell culture model to isolate the key stimuli that are likely to underlie physiological adaptation with heat therapy, we showed that both mild elevations in temperature (to 39°C) and exposure to serum from human subjects who have undergone 8 weeks of heat therapy (i.e. altered circulating factors) independently prevented oxidative and inflammatory stress associated with hypoxia-reoxygenation in cultured endothelial cells. Our results elucidate some of the mechanisms (i.e. direct effects of temperature vs. circulating factors) by which heat therapy seems to improve resistance against oxidative and inflammatory stress. Heat therapy may be a promising intervention for reducing cellular damage following ischaemic events, which has broad implications for patients with cardiovascular diseases and conditions characterized by 'chronic' ischaemia (e.g. peripheral artery disease, metabolic diseases, obesity). ABSTRACT Repeated exposure to passive heat stress ('heat therapy') has widespread physiological benefits, including cellular protection against novel stressors. Increased heat shock protein (HSP) expression and upregulation of circulating factors may impart this protection. We tested the isolated abilities of mild heat pretreatment and serum from human subjects (n = 10) who had undergone 8 weeks of heat therapy to protect against cellular stress following hypoxia-reoxygenation (H/R), a model of ischaemic cardiovascular events. Cultured human umbilical vein endothelial cells were incubated for 24 h at 37°C (control), 39°C (heat pretreatment) or 37°C with 10% serum collected before and after 8 weeks of passive heat therapy (four to five times per week to increase rectal temperature to ≥ 38.5°C for 60 min). Cells were then collected before and after incubation at 1% O2 for 16 h (hypoxia; 37°C), followed by 20% O2 for 4 h (reoxygenation; 37°C) and assessed for markers of cell stress. In control cells, H/R increased nuclear NF-κB p65 protein (i.e. activation) by 106 ± 38%, increased IL-6 release by 37 ± 8% and increased superoxide production by 272 ± 45%. Both heat pretreatment and exposure to heat therapy serum prevented H/R-induced NF-κB activation and attenuated superoxide production; by contrast, only exposure to serum attenuated IL-6 release. H/R also decreased cytoplasmic haemeoxygenase-1 (HO-1) protein (known to suppress NF-κB), in control cells (-25 ± 8%), whereas HO-1 protein increased following H/R in cells pretreated with heat or serum-exposed, providing a possible mechanism of protection against H/R. These data indicate heat therapy is capable of imparting resistance against inflammatory and oxidative stress via direct heat and humoral factors.
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Affiliation(s)
- Vienna E Brunt
- Department of Human Physiology, University of Oregon, Eugene, OR, USA
| | | | - Lindan N Comrada
- Department of Human Physiology, University of Oregon, Eugene, OR, USA
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17
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Short-term effects of Finnish sauna bathing on blood-based markers of cardiovascular function in non-naive sauna users. Heart Vessels 2018; 33:1515-1524. [PMID: 29971466 PMCID: PMC6267405 DOI: 10.1007/s00380-018-1202-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 06/15/2018] [Indexed: 12/15/2022]
Abstract
Emerging evidence suggests that sauna bathing is associated with reduced risk of cardiovascular and all-cause mortality events. However, the biochemical pathways by which sauna bathing might confer its effects on cardiovascular function are not certain. We aimed to study the acute effects of Finnish sauna bathing on various blood-based cardiovascular biomarkers. The study included 102 non-naive sauna users (54% male) with mean age of 51.9 years, who had at least one cardiovascular risk factor. Participants underwent a 30-min single sauna session (mean temperature, 73 °C). Biochemical profiling was conducted before, immediately after sauna and 30-min post-sauna. Overall median N-terminal pro-B-type natriuretic peptide (NT-proBNP) level (n = 20 participants) was 46.0 ng/L before sauna exposure, which increased to 50.5 ng/l immediately after sauna (median change, + 12.00%; p < 0.001) and remained persistent at 30-min post-sauna (median change from pre-sauna to post-30-min sauna, + 13.93%; p < 0.001). The changes were more evident in males compared with females. There were no significant changes in overall levels of high sensitivity C-reactive protein, creatine kinase, high sensitivity troponin I, and creatine kinase-MBm. However, levels of creatine kinase increased in males (median change immediately after sauna, + 2.99%; p = 0.024). Levels of NT-proBNP increased after sauna exposure. The increase in levels of creatine kinase was more evident in males. Long-term interventional studies are warranted to evaluate if these biomarkers are involved in pathways underlying the associations of sauna bathing with cardiovascular outcomes.
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18
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Wilhelm EN, González-Alonso J, Chiesa ST, Trangmar SJ, Kalsi KK, Rakobowchuk M. Whole-body heat stress and exercise stimulate the appearance of platelet microvesicles in plasma with limited influence of vascular shear stress. Physiol Rep 2018; 5:5/21/e13496. [PMID: 29122961 PMCID: PMC5688785 DOI: 10.14814/phy2.13496] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 10/13/2017] [Indexed: 01/02/2023] Open
Abstract
Intense, large muscle mass exercise increases circulating microvesicles, but our understanding of microvesicle dynamics and mechanisms inducing their release remains limited. However, increased vascular shear stress is generally thought to be involved. Here, we manipulated exercise‐independent and exercise‐dependent shear stress using systemic heat stress with localized single‐leg cooling (low shear) followed by single‐leg knee extensor exercise with the cooled or heated leg (Study 1, n = 8) and whole‐body passive heat stress followed by cycling (Study 2, n = 8). We quantified femoral artery shear rates (SRs) and arterial and venous platelet microvesicles (PMV–CD41+) and endothelial microvesicles (EMV–CD62E+). In Study 1, mild passive heat stress while one leg remained cooled did not affect [microvesicle] (P ≥ 0.05). Single‐leg knee extensor exercise increased active leg SRs by ~12‐fold and increased arterial and venous [PMVs] by two‐ to threefold, even in the nonexercising contralateral leg (P < 0.05). In Study 2, moderate whole‐body passive heat stress increased arterial [PMV] compared with baseline (mean±SE, from 19.9 ± 1.5 to 35.5 ± 5.4 PMV.μL−1.103, P < 0.05), and cycling with heat stress increased [PMV] further in the venous circulation (from 27.5 ± 2.2 at baseline to 57.5 ± 7.2 PMV.μL−1.103 during cycling with heat stress, P < 0.05), with a tendency for increased appearance of PMV across exercising limbs. Taken together, these findings demonstrate that whole‐body heat stress may increase arterial [PMV], and intense exercise engaging either large or small muscle mass promote PMV formation locally and systemically, with no influence upon [EMV]. Local shear stress, however, does not appear to be the major stimulus modulating PMV formation in healthy humans.
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Affiliation(s)
- Eurico N Wilhelm
- Centre for Human Performance, Exercise, and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - José González-Alonso
- Centre for Human Performance, Exercise, and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom.,Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Scott T Chiesa
- Centre for Human Performance, Exercise, and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Steven J Trangmar
- Centre for Human Performance, Exercise, and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Kameljit K Kalsi
- Centre for Human Performance, Exercise, and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Mark Rakobowchuk
- Centre for Human Performance, Exercise, and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom .,Faculty of Science, Department of Biological Sciences, Thompson Rivers University, Kamloops, British Columbia, Canada
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19
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Heinonen I, Laukkanen JA. Effects of heat and cold on health, with special reference to Finnish sauna bathing. Am J Physiol Regul Integr Comp Physiol 2018; 314:R629-R638. [DOI: 10.1152/ajpregu.00115.2017] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Environmental stress such as extremely warm or cold temperature is often considered a challenge to human health and body homeostasis. However, the human body can adapt relatively well to heat and cold environments, and recent studies have also elucidated that particularly heat stress might be even highly beneficial for human health. Consequently, the aim of the present brief review is first to discuss general cardiovascular and other responses to acute heat stress, followed by a review of beneficial effects of Finnish sauna bathing on general and cardiovascular health and mortality as well as dementia and Alzheimer's disease risk. Plausible mechanisms included are improved endothelial and microvascular function, reduced blood pressure and arterial stiffness, and possibly increased angiogenesis in humans, which are likely to mediate the health benefits of sauna bathing. In addition to heat exposure with physiological adaptations, cold stress-induced physiological responses and brown fat activation on health are also discussed. This is important to take into consideration, as sauna bathing is frequently associated with cooling periods in cold(er) environments, but their combination remains poorly investigated. We finally propose, therefore, that possible additive effects of heat- and cold-stress-induced adaptations and effects on health would be worthy of further investigation.
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Affiliation(s)
- Ilkka Heinonen
- Turku PET Centre, University of Turku, Turku, Finland
- Department of Clinical Physiology and Nuclear Medicine, University of Turku, Turku, Finland
- Division of Experimental Cardiology, Thoraxcenter, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Jari A. Laukkanen
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
- Central Finland Health Care District, Jyväskylä, Finland
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
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20
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Francois ME, Myette-Cote E, Bammert TD, Durrer C, Neudorf H, DeSouza CA, Little JP. Carbohydrate restriction with postmeal walking effectively mitigates postprandial hyperglycemia and improves endothelial function in type 2 diabetes. Am J Physiol Heart Circ Physiol 2017; 314:H105-H113. [PMID: 29030343 DOI: 10.1152/ajpheart.00524.2017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Postprandial hyperglycemia has deleterious effects on endothelial function. Restricting carbohydrate intake and postmeal walking have each been shown to reduce postprandial hyperglycemia, but their combination and subsequent effects on endothelial function have not been investigated. Here, we sought to examine the effect of blunting postprandial hyperglycemia by following a low-carbohydrate diet, with or without postmeal walking exercise, on markers of vascular health in type 2 diabetes (T2D). In a randomized crossover design, individuals with T2D ( n = 11) completed three 4-day controlled diet interventions consisting of 1) low-carbohydrate diet alone (LC), 2) low-carbohydrate diet with 15-min postmeal walks (LC + Ex), and 3) low-fat control diet (CON). Fasting blood samples and brachial artery flow-mediated dilation (%FMD) were measured before and after each intervention. Total circulating microparticles (MPs), endothelial MPs, platelet MPs, monocyte-platelet aggregates, and adhesion molecules were assessed as biomarkers of vascular health. There was a significant condition × time interaction for %FMD ( P = 0.01), with post hoc tests revealing improved %FMD after LC + Ex (+0.8 ± 1.0%, P = 0.02), with no change after LC or CON. Endothelial MPs were significantly reduced with the LC diet by ~45% (from 99 ± 60 to 44 ± 31 MPs/μl, P = 0.02), with no change after LC + Ex or CON (interaction: P = 0.04). Total MPs were lower (main effect time: P = 0.02), whereas monocyte-platelet aggregates were higher (main effect time: P < 0.01) after all interventions. Plasma adhesion molecules and C-reactive protein were unaltered. Attenuating postprandial hyperglycemic excursions using a low-carbohydrate diet combined with postmeal walking appears to be an effective strategy to improve endothelial function in individuals with T2D. NEW & NOTEWORTHY Carbohydrate restriction and postmeal walking lower postprandial hyperglycemia in individuals with type 2 diabetes. Here, we show that the combination significantly improved endothelial function and that carbohydrate restriction alone reduced circulating endothelial microparticles in individuals with type 2 diabetes. Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/low-carb-diet-and-exercise-improve-endothelial-health/ .
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Affiliation(s)
- Monique E Francois
- University of British Columbia Okanagan , Kelowna, British Columbia , Canada
| | - Etienne Myette-Cote
- University of British Columbia Okanagan , Kelowna, British Columbia , Canada
| | | | - Cody Durrer
- University of British Columbia Okanagan , Kelowna, British Columbia , Canada
| | - Helena Neudorf
- University of British Columbia Okanagan , Kelowna, British Columbia , Canada
| | | | - Jonathan P Little
- University of British Columbia Okanagan , Kelowna, British Columbia , Canada
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