1
|
Liu W, Zhang S, Li Q, Wu Y, Jia X, Feng W, Li Z, Shi Y, Hou Q, Ma J, Liu Y, Gao P, Ganz T, Liu S. Lactate modulates iron metabolism by binding soluble adenylyl cyclase. Cell Metab 2023; 35:1597-1612.e6. [PMID: 37480842 DOI: 10.1016/j.cmet.2023.06.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 04/18/2023] [Accepted: 06/27/2023] [Indexed: 07/24/2023]
Abstract
Overproduction of lactate (LA) can occur during exercise and in many diseases such as cancers. Individuals with hyperlactatemia often display anemia, decreased serum iron, and elevated hepcidin, a key regulator of iron metabolism. However, it is unknown whether and how LA regulates hepcidin expression. Here, we show LA binds to soluble adenylyl cyclase (sAC) in normal hepatocytes and affects systemic iron homeostasis in mice by increasing hepcidin expression. Comprehensive in vitro, in vivo, and in silico experiments show that the LA-sAC interaction raises cyclic adenosine monophosphate (cAMP) levels, which activates the PKA-Smad1/5/8 signaling pathway to increase hepcidin transcription. We verified this regulatory axis in wild-type mice and in mice with disordered iron homeostasis. LA also regulates hepcidin in humans at rest and subjected to extensive exercise that produce elevated LA. Our study links hyperlactatemia to iron deficiency, offering a mechanistic explanation for anemias seen in athletes and patients with lactic acidosis.
Collapse
Affiliation(s)
- Wei Liu
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250117, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Shuping Zhang
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250117, China
| | - Quanjin Li
- University of Chinese Academy of Sciences, Beijing 100049, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yue Wu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuan Jia
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenya Feng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaolong Li
- University of Chinese Academy of Sciences, Beijing 100049, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yali Shi
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingzhi Hou
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250117, China
| | - Juan Ma
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yajun Liu
- National Center for Orthopaedics, Beijing Jishuitan Hospital, Beijing 100035, China; Beijing Research Institute of Traumatology and Orthopaedics, Beijing 100035, China
| | - Pu Gao
- University of Chinese Academy of Sciences, Beijing 100049, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Tomas Ganz
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Sijin Liu
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250117, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
2
|
Corbett J, Tipton MJ, Perissiou M, James T, Young JS, Newman A, Cummings M, Montgomery H, Grocott MPW, Shepherd AI. Effect of different levels of acute hypoxia on subsequent oral glucose tolerance in males with overweight: A balanced cross-over pilot feasibility study. Physiol Rep 2023; 11:e15623. [PMID: 37144546 PMCID: PMC10161207 DOI: 10.14814/phy2.15623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 05/06/2023] Open
Abstract
Previous research has shown that ≤60 min hypoxic exposure improves subsequent glycaemic control, but the optimal level of hypoxia is unknown and data are lacking from individuals with overweight. We undertook a cross-over pilot feasibility study investigating the effect of 60-min prior resting exposure to different inspired oxygen fractions (CON FI O2 = 0.209; HIGH FI O2 = 0.155; VHIGH FI O2 = 0.125) on glycaemic control, insulin sensitivity, and oxidative stress during a subsequent oral glucose tolerance test (OGTT) in males with overweight (mean (SD) BMI = 27.6 (1.3) kg/m2 ; n = 12). Feasibility was defined by exceeding predefined withdrawal criteria for peripheral blood oxygen saturation (SpO2 ), partial pressure of end-tidal oxygen or carbon dioxide and acute mountain sickness (AMS), and dyspnoea symptomology. Hypoxia reduced SpO2 in a stepwise manner (CON = 97(1)%; HIGH = 91(1)%; VHIGH = 81(3)%, p < 0.001), but did not affect peak plasma glucose concentration (CON = 7.5(1.8) mmol∙L-1 ; HIGH = 7.7(1.1) mmol∙L-1 ; VHIGH = 7.7(1.1) mmol∙L-1 ; p = 0.777; η2 = 0.013), plasma glucose area under the curve, insulin sensitivity, or metabolic clearance rate of glucose (p > 0.05). We observed no between-conditions differences in oxidative stress (p > 0.05), but dyspnoea and AMS symptoms increased in VHIGH (p < 0.05), with one participant meeting the withdrawal criteria. Acute HIGH or VHIGH exposure prior to an OGTT does not influence glucose homeostasis in males with overweight, but VHIGH is associated with adverse symptomology and reduced feasibility.
Collapse
Affiliation(s)
- Jo Corbett
- Extreme Environments Laboratory, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, UK
| | - Michael J Tipton
- Extreme Environments Laboratory, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, UK
| | - Maria Perissiou
- Clinical, Health and Rehabilitation Team, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, UK
| | - Thomas James
- Extreme Environments Laboratory, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, UK
- Clinical, Health and Rehabilitation Team, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, UK
| | - John S Young
- National Horizons Centre, Teesside University, Middlesbrough, UK
- School of Health and Life Sciences, Teesside University, Middlesbrough, UK
| | - Alexander Newman
- National Horizons Centre, Teesside University, Middlesbrough, UK
| | - Michael Cummings
- Diabetes and Endocrinology Department, Portsmouth Hospitals University NHS Trust, Portsmouth, UK
| | - Hugh Montgomery
- Centre for Sport Exercise and Health, Dept Medicine, University College London, London, UK
| | - Michael P W Grocott
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton/University of Southampton, Southampton, UK
| | - Anthony I Shepherd
- Clinical, Health and Rehabilitation Team, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, UK
- Diabetes and Endocrinology Department, Portsmouth Hospitals University NHS Trust, Portsmouth, UK
| |
Collapse
|
3
|
The role of exercise and hypoxia on glucose transport and regulation. Eur J Appl Physiol 2023; 123:1147-1165. [PMID: 36690907 DOI: 10.1007/s00421-023-05135-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 01/06/2023] [Indexed: 01/25/2023]
Abstract
Muscle glucose transport activity increases with an acute bout of exercise, a process that is accomplished by the translocation of glucose transporters to the plasma membrane. This process remains intact in the skeletal muscle of individuals with insulin resistance and type 2 diabetes mellitus (T2DM). Exercise training is, therefore, an important cornerstone in the management of individuals with T2DM. However, the acute systemic glucose responses to carbohydrate ingestion are often augmented during the early recovery period from exercise, despite increased glucose uptake into skeletal muscle. Accordingly, the first aim of this review is to summarize the knowledge associated with insulin action and glucose uptake in skeletal muscle and apply these to explain the disparate responses between systemic and localized glucose responses post-exercise. Herein, the importance of muscle glycogen depletion and the key glucoregulatory hormones will be discussed. Glucose uptake can also be stimulated independently by hypoxia; therefore, hypoxic training presents as an emerging method for enhancing the effects of exercise on glucose regulation. Thus, the second aim of this review is to discuss the potential for systemic hypoxia to enhance the effects of exercise on glucose regulation.
Collapse
|
4
|
Cheng J, Luo Y, Yang L, Li Y, Zhang F, Zhang X, Zhou X, Ji L. The association between living altitude and serum leptin concentrations in native women. Front Endocrinol (Lausanne) 2023; 14:1107932. [PMID: 36909317 PMCID: PMC9992867 DOI: 10.3389/fendo.2023.1107932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 02/08/2023] [Indexed: 02/24/2023] Open
Abstract
BACKGROUND Lower diabetes prevalence and cardiovascular mortality have been observed in residents at a higher altitude. Leptin is associated with incident diabetes and adverse cardiovascular outcomes, and our aim was to investigate the association of living altitude with serum leptin concentrations. METHODS Two cross-sectional surveys were used in this study, including native populations living at Tibet (high altitude) and Beijing (low altitude). A propensity score was conducted for matching age and body mass index (BMI) between native women at high and low altitude. Pearson's correlation analysis was performed to evaluate the correlation of leptin with other variables. RESULTS A total of 1414 native women were included in this study, including 594 at high altitude and 820 at low altitude. The serum leptin concentrations of native women living at high altitude were 13.74 ± 11.03 ng/ml, which was significantly lower than that of native women living at low altitude (20.90 ± 12.91 ng/ml). After matching age and BMI, women living at the high altitude still had lower serum leptin concentrations. After adjusting for the potential confounding factors, the correlation coefficient between Ln (leptin) and BMI of women at high altitude was significantly lower than that of women at low altitude (0.228 versus 0.559; P <0.0001). The serum leptin concentrations of each BMI subgroup (<18.5, 18.5 to <25, 25 to <30, ≥ 30 kg/m2) in women at high altitude were lower than that in women at low altitude. CONCLUSIONS Serum leptin concentrations were significantly decreased in native women living at high altitude, and living altitude may alter the correlation of BMI and leptin. The findings of our study support that residents at high altitude have a protective effect with regards to improving cardiovascular and metabolic outcomes.
Collapse
Affiliation(s)
- Jiayu Cheng
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing, China
| | - Yingying Luo
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing, China
| | - Lihui Yang
- Department of Endocrinology and Metabolism, Tibet Autonomous Region People’s Hospital, Lasah, China
| | - Yufeng Li
- Department of Endocrinology and Metabolism, Capital Medical University Pinggu Teaching Hospital, Beijing, China
| | - Fang Zhang
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing, China
| | - Xiuying Zhang
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing, China
| | - Xianghai Zhou
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing, China
- *Correspondence: Xianghai Zhou, ; Linong Ji,
| | - Linong Ji
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing, China
- *Correspondence: Xianghai Zhou, ; Linong Ji,
| |
Collapse
|
5
|
Tee CCL, Cooke MB, Chong MC, Yeo WK, Camera DM. Mechanisms for Combined Hypoxic Conditioning and Divergent Exercise Modes to Regulate Inflammation, Body Composition, Appetite, and Blood Glucose Homeostasis in Overweight and Obese Adults: A Narrative Review. Sports Med 2023; 53:327-348. [PMID: 36441492 PMCID: PMC9877079 DOI: 10.1007/s40279-022-01782-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/09/2022] [Indexed: 11/29/2022]
Abstract
Obesity is a major global health issue and a primary risk factor for metabolic-related disorders. While physical inactivity is one of the main contributors to obesity, it is a modifiable risk factor with exercise training as an established non-pharmacological treatment to prevent the onset of metabolic-related disorders, including obesity. Exposure to hypoxia via normobaric hypoxia (simulated altitude via reduced inspired oxygen fraction), termed hypoxic conditioning, in combination with exercise has been increasingly shown in the last decade to enhance blood glucose regulation and decrease the body mass index, providing a feasible strategy to treat obesity. However, there is no current consensus in the literature regarding the optimal combination of exercise variables such as the mode, duration, and intensity of exercise, as well as the level of hypoxia to maximize fat loss and overall body compositional changes with hypoxic conditioning. In this narrative review, we discuss the effects of such diverse exercise and hypoxic variables on the systematic and myocellular mechanisms, along with physiological responses, implicated in the development of obesity. These include markers of appetite regulation and inflammation, body conformational changes, and blood glucose regulation. As such, we consolidate findings from human studies to provide greater clarity for implementing hypoxic conditioning with exercise as a safe, practical, and effective treatment strategy for obesity.
Collapse
Affiliation(s)
- Chris Chow Li Tee
- Division of Research and Innovation, National Sports Institute of Malaysia, Kuala Lumpur, Malaysia
- Sport and Exercise Medicine Group, Swinburne University, Room SPW224, Mail H21, PO Box 218, Hawthorn, VIC, 3122, Australia
| | - Matthew B Cooke
- Sport and Exercise Medicine Group, Swinburne University, Room SPW224, Mail H21, PO Box 218, Hawthorn, VIC, 3122, Australia
| | - Mee Chee Chong
- Sport and Exercise Medicine Group, Swinburne University, Room SPW224, Mail H21, PO Box 218, Hawthorn, VIC, 3122, Australia
| | - Wee Kian Yeo
- Division of Research and Innovation, National Sports Institute of Malaysia, Kuala Lumpur, Malaysia
| | - Donny M Camera
- Sport and Exercise Medicine Group, Swinburne University, Room SPW224, Mail H21, PO Box 218, Hawthorn, VIC, 3122, Australia.
| |
Collapse
|
6
|
Sprint Interval Exercise Improves Cognitive Performance Unrelated to Postprandial Glucose Fluctuations at Different Levels of Normobaric Hypoxia. J Clin Med 2022; 11:jcm11113159. [PMID: 35683546 PMCID: PMC9181000 DOI: 10.3390/jcm11113159] [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: 03/31/2022] [Revised: 05/30/2022] [Accepted: 05/30/2022] [Indexed: 12/10/2022] Open
Abstract
Objective: The aim of our study was to examine cognition response to sprint interval exercise (SIE) against different levels of hypoxia. Research design and methods: 26 recreational active males performed SIE (20 × 6 s of all-out cycling bouts, 15 s of passive recovery) under normoxia (FIO2: 0.209), moderate hypoxia (FIO2: 0.154), and severe hypoxia (FIO2: 0.112) in a single-blinded crossover design. Cognitive function and blood glucose were assessed before and after 0, 10, 30, and 60 min of the SIE. Heart rate (HR), peripheral oxygen saturation (SpO2), and ratings of perceived exertion (RPE, the Borg 6−20-point scale) during each SIE trial were recorded before and immediately after every five cycling bouts, and after 0, 10, 30, and 60 min of the SIE. Results: All the three SIE trials had a significantly faster overall reaction time in the Stroop test at 10 min after exercise as compared to that of the baseline value (p = 0.003, ƞ2 = 0.606), and returned to normal after 60 min. The congruent RT at 10 min after SIE was significantly shorter than that of the baseline (p < 0.05, ƞ2 = 0.633), while the incongruent RT at both 10 min and 30 min were significantly shorter than that measured at baseline (p < 0.05, ƞ2 = 0.633). No significant differences in terms of accuracy were found across the three trials at any time points (p = 0.446, ƞ2 = 0.415). Blood glucose was significantly reduced at 10 min and was sustained for at least 60 min after SIE when compared to pre-exercise in all trials (p < 0.05). Conclusions: Acute SIE improved cognitive function regardless of oxygen conditions, and the sustained improvement following SIE could last for at least 10−30 min and was unaffected by the altered blood glucose level.
Collapse
|
7
|
Luo Y, Chen Q, Zou J, Fan J, Li Y, Luo Z. Chronic Intermittent Hypoxia Exposure Alternative to Exercise Alleviates High-Fat-Diet-Induced Obesity and Fatty Liver. Int J Mol Sci 2022; 23:ijms23095209. [PMID: 35563600 PMCID: PMC9104027 DOI: 10.3390/ijms23095209] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/01/2022] [Accepted: 05/04/2022] [Indexed: 01/27/2023] Open
Abstract
Obesity often concurs with nonalcoholic fatty liver disease (NAFLD), both of which are detrimental to human health. Thus far, exercise appears to be an effective treatment approach. However, its effects cannot last long and, moreover, it is difficult to achieve for many obese people. Thus, it is necessary to look into alternative remedies. The present study explored a noninvasive, easy, tolerable physical alternative. In our experiment, C57BL/6 mice were fed with a high-fat diet (HFD) to induce overweight/obesity and were exposed to 10% oxygen for one hour every day. We found that hypoxia exerted protective effects. First, it offset HFD-induced bodyweight gain and insulin resistance. Secondly, hypoxia reversed the HFD-induced enlargement of white and brown adipocytes and fatty liver, and protected liver function. Thirdly, HFD downregulated the expression of genes required for lipolysis and thermogenesis, such as UCP1, ADR3(beta3-adrenergic receptor), CPT1A, ATGL, PPARα, and PGC1α, M2 macrophage markers arginase and CD206 in the liver, and UCP1 and PPARγ in brown fat, while these molecules were upregulated by hypoxia. Furthermore, hypoxia induced the activation of AMPK, an energy sensing enzyme. Fourthly, our results showed that hypoxia increased serum levels of epinephrine. Indeed, the effects of hypoxia on bodyweight, fatty liver, and associated changes in gene expression ever tested were reproduced by injection of epinephrine and prevented by propranolol at varying degrees. Altogether, our data suggest that hypoxia triggers stress responses where epinephrine plays important roles. Therefore, our study sheds light on the hope to use hypoxia to treat the daunting disorders, obesity and NAFLD.
Collapse
Affiliation(s)
- Yunfei Luo
- Jiangxi Provincial Key Laboratory of Tumor Pathogens and Molecular Pathology, Department of Pathophysiology, Schools of Basic Sciences, Nanchang University, Nanchang 330031, China; (Y.L.); (Q.C.); (J.Z.); (J.F.); (Y.L.)
| | - Qiongfeng Chen
- Jiangxi Provincial Key Laboratory of Tumor Pathogens and Molecular Pathology, Department of Pathophysiology, Schools of Basic Sciences, Nanchang University, Nanchang 330031, China; (Y.L.); (Q.C.); (J.Z.); (J.F.); (Y.L.)
| | - Junrong Zou
- Jiangxi Provincial Key Laboratory of Tumor Pathogens and Molecular Pathology, Department of Pathophysiology, Schools of Basic Sciences, Nanchang University, Nanchang 330031, China; (Y.L.); (Q.C.); (J.Z.); (J.F.); (Y.L.)
| | - Jingjing Fan
- Jiangxi Provincial Key Laboratory of Tumor Pathogens and Molecular Pathology, Department of Pathophysiology, Schools of Basic Sciences, Nanchang University, Nanchang 330031, China; (Y.L.); (Q.C.); (J.Z.); (J.F.); (Y.L.)
| | - Yuanjun Li
- Jiangxi Provincial Key Laboratory of Tumor Pathogens and Molecular Pathology, Department of Pathophysiology, Schools of Basic Sciences, Nanchang University, Nanchang 330031, China; (Y.L.); (Q.C.); (J.Z.); (J.F.); (Y.L.)
| | - Zhijun Luo
- Jiangxi Provincial Key Laboratory of Tumor Pathogens and Molecular Pathology, Department of Pathophysiology, Schools of Basic Sciences, Nanchang University, Nanchang 330031, China; (Y.L.); (Q.C.); (J.Z.); (J.F.); (Y.L.)
- Queen Mary School, Nanchang University, Nanchang 330031, China
- Correspondence: ; Tel.: +86-158-7917-7010
| |
Collapse
|
8
|
Variations in HIF-1α Contributed to High Altitude Hypoxia Adaptation via Affected Oxygen Metabolism in Tibetan Sheep. Animals (Basel) 2021; 12:ani12010058. [PMID: 35011164 PMCID: PMC8749702 DOI: 10.3390/ani12010058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 12/24/2021] [Accepted: 12/27/2021] [Indexed: 01/19/2023] Open
Abstract
Simple Summary Hypoxia-inducible factors (HIFs) play an important role in the adaptation of animals to high-altitude hypoxia. In high-altitude indigenous species, variation in the hypoxia-inducible factor-1 alpha (HIF-1α) gene has been reported in Tibetans, yaks and Tibetan horses, but has not been investigated in Tibetan sheep, and is not known if it might affect high-altitude hypoxia adaptation in these sheep. In this study, Kompetitive Allele-Specific PCR (KASP) was used for genotyping of ovine HIF-1α and investigated the effect of variation in HIF-1α on the high-altitude hypoxia adaptation of Tibetan sheep. The results suggest that ovine HIF-1α variants may promote the ability of oxygen utilization in Tibetan sheep and it may serve as a genetic marker for improving high-altitude hypoxia adaptability. Abstract The Tibetan sheep is an indigenous species of the Tibetan plateau and has been well adapted to high-altitude hypoxia. In comparison to lowland sheep breeds, the blood gas indicators have changed and the HIFs signaling pathway is activated in Tibetan sheep. These phenotypic and genetic alterations in Tibetan sheep are thought to be an important basis for adaptation to high-altitude hypoxia and variation in genes encoding the subunits that make up HIFs, such as HIF-1α can affect blood gas indicators. In this study, exons 9, 10, 12 of the HIF-1α gene were sequenced to find variations and 3 SNPs were detected, and these 3 SNPs were genotyped by KASP in 341 Hu sheep and 391 Tibetan sheep. In addition, 197 Hu sheep, 160 Tibetan sheep and 12 Gansu alpine merino sheep were used for blood gas indicators analysis. The results showed significant differences between the blood gas indicators of high-altitude breeds (Tibetan sheep and Gansu alpine merino sheep) and low-altitude breeds (Hu sheep), implying that the differences in blood gas indicators are mainly caused by differences in altitude. The haplotype combinations H2H3 and H1H3 were more frequent in the Tibetan sheep population, H2H3 increases O2 carrying capacity by increasing hematocrit and hemoglobin concentrations; H1H3 makes O2 dissociate more readily from oxyhemoglobin by decreasing partial pressure of oxygen and oxygen saturation. These results suggest that variants at the HIF-1α promote the ability of oxygen utilization in Tibetan sheep, which may underpin the survival and reproduction of Tibetan sheep on the Tibetan plateau.
Collapse
|
9
|
Chan JS, Chiew AE, Rimke AN, Chan G, Rampuri ZH, Kozak MD, Boulé NG, Steinback CD, Davenport MH, Day TA. Blood glucose concentration is unchanged during exposure to acute normobaric hypoxia in healthy humans. Physiol Rep 2021; 9:e14932. [PMID: 34337893 PMCID: PMC8327160 DOI: 10.14814/phy2.14932] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 11/24/2022] Open
Abstract
Normal blood [glucose] regulation is critical to support metabolism, particularly in contexts of metabolic stressors (e.g., exercise, high altitude hypoxia). Data regarding blood [glucose] regulation in hypoxia are inconclusive. We aimed to characterize blood [glucose] over 80 min following glucose ingestion during both normoxia and acute normobaric hypoxia. In a randomized cross-over design, on two separate days, 28 healthy participants (16 females; 21.8 ± 1.6 years; BMI 22.8 ± 2.5 kg/m2 ) were randomly exposed to either NX (room air; fraction of inspired [FI ]O2 ~0.21) or HX (FI O2 ~0.148) in a normobaric hypoxia chamber. Measured FI O2 and peripheral oxygen saturation were both lower at baseline in hypoxia (p < 0.001), which was maintained over 80 min, confirming the hypoxic intervention. Following a 10-min baseline (BL) under both conditions, participants consumed a standardized glucose beverage (75 g, 296 ml) and blood [glucose] and physiological variables were measured at BL intermittently over 80 min. Blood [glucose] was measured from finger capillary samples via glucometer. Initial fasted blood [glucose] was not different between trials (NX:4.8 ± 0.4 vs. HX:4.9 ± 0.4 mmol/L; p = 0.47). Blood [glucose] was sampled every 10 min (absolute, delta, and percent change) following glucose ingestion over 80 min, and was not different between conditions (p > 0.77). In addition, mean, peak, and time-to-peak responses during the 80 min were not different between conditions (p > 0.14). There were also no sex differences in these blood [glucose] responses in hypoxia. We conclude that glucose regulation is unchanged in young, healthy participants with exposure to acute steady-state normobaric hypoxia, likely due to counterbalancing mechanisms underlying blood [glucose] regulation in hypoxia.
Collapse
Affiliation(s)
- Jason S. Chan
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Alexandra E. Chiew
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Alexander N. Rimke
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Garrick Chan
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Zahrah H. Rampuri
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Mackenzie D. Kozak
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Normand G. Boulé
- Alberta Diabetes InstituteFaculty of Kinesiology, Sport, and RecreationUniversity of AlbertaEdmontonABCanada
| | - Craig D. Steinback
- Alberta Diabetes InstituteFaculty of Kinesiology, Sport, and RecreationUniversity of AlbertaEdmontonABCanada
| | - Margie H. Davenport
- Alberta Diabetes InstituteFaculty of Kinesiology, Sport, and RecreationUniversity of AlbertaEdmontonABCanada
| | - Trevor A. Day
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| |
Collapse
|
10
|
Kim SW, Jung WS, Chung S, Park HY. Exercise intervention under hypoxic condition as a new therapeutic paradigm for type 2 diabetes mellitus: A narrative review. World J Diabetes 2021; 12:331-343. [PMID: 33889283 PMCID: PMC8040082 DOI: 10.4239/wjd.v12.i4.331] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 01/25/2021] [Accepted: 03/08/2021] [Indexed: 02/06/2023] Open
Abstract
This review aims to summarize the health benefits of exposure to hypoxic conditions during exercise in patients with type 2 diabetes mellitus (T2DM). Exposure to hypoxic conditions during exercise training positively changes the physiological response in healthy subjects. Exposure to hypoxic conditions during exercise could markedly increase skeletal muscle glucose uptake compared to that in normoxic conditions. Furthermore, post-exercise insulin sensitivity of T2DM patients increases more when exercising under hypoxic than under normoxic conditions. Regular exercise under short-term hypoxic conditions can improve blood glucose control at lower workloads than in normoxic conditions. Additionally, exercise training under short-term hypoxic conditions can maximize weight loss in overweight and obese patients. Previous studies on healthy subjects have reported that regular exercise under hypoxic conditions had a more positive effect on vascular health than exercising under normoxic conditions. However, currently, evidence indicating that exposure to hypoxic conditions could positively affect T2DM patients in the long-term is lacking. Therefore, further evaluations of the beneficial effects of exercise under hypoxic conditions on the human body, considering different cycle lengths, duration of exposures, sessions per day, and the number of days, are necessary. In this review, we conclude that there is evidence that exercise under hypoxic conditions can yield health benefits, which is potentially valuable in terms of clinical care as a new intervention for T2DM patients.
Collapse
Affiliation(s)
- Sung-Woo Kim
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul 05029, South Korea
| | - Won-Sang Jung
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul 05029, South Korea
| | - Sochung Chung
- Department of Pediatrics, Konkuk University Medical Center, Research Institute of Medical Science, Konkuk University, School of Medicine, Seoul 05029, South Korea
| | - Hun-Young Park
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul 05029, South Korea
- Department of Sports Science and Medicine, Konkuk University, Seoul 05029, South Korea
| |
Collapse
|
11
|
Inconvenience of Living Place Affects Individual HbA1c Level in a Rural Area in Japan: Shimane CoHRE Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18031147. [PMID: 33525428 PMCID: PMC7908499 DOI: 10.3390/ijerph18031147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/17/2021] [Accepted: 01/26/2021] [Indexed: 12/13/2022]
Abstract
Background: It has been shown that the socio-geographical environment of residential areas, such as altitude, affects the health status and health-maintenance behavior of residents. Here, we examined a hypothesis that altitude of residence would influence glycemic control in a general elderly population living in a rural area. Methods: A thousand and sixteen participants living in a mountainous region in Japan were recruited at health examinations. Hemoglobin A1c (HbA1c) was measured in serum as a parameter of glycemic control. The altitude of residence, distance to grocery stores and to medical facilities were estimated using a geographic information system. Results: Linear regression analysis confirmed a significant effect of the altitude on log HbA1c even after adjustment of other demographic and biochemical factors. When the distance to grocery stores or medical facilities were used instead of the altitude in a linear regression analysis, distance to secondary medical facilities alone showed a significant effect on HbA1c. Conclusions: We found a positive correlation between HbA1c level and residential altitude in a rural area of Japan. The altitude seemed to be a parameter substituting the inconvenicence of residential areas. Socio-geographical factors of living place, such as inconvenience, may influence glycemic control of the residents.
Collapse
|
12
|
Rebello CJ, Kirwan JP, Greenway FL. Obesity, the most common comorbidity in SARS-CoV-2: is leptin the link? Int J Obes (Lond) 2020; 44:1810-1817. [PMID: 32647360 PMCID: PMC7347260 DOI: 10.1038/s41366-020-0640-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/29/2020] [Accepted: 07/03/2020] [Indexed: 12/13/2022]
Abstract
Overweight and obesity are major risk factors for diabetes, cardiovascular disease, and lung disease. These diseases are the most commonly reported health conditions that predispose individuals with SARS-CoV-2 infection to require hospitalization including intensive care unit admissions. The innate immune response is the host’s first line of defense against a human coronavirus infection. However, most coronaviruses are armed with one strategy or another to overcome host antiviral defense, and the pathogenicity of the virus is related to its capacity to suppress host immunity. The multifaceted nature of obesity including its effects on immunity can fundamentally alter the pathogenesis of acute respiratory distress syndrome and pneumonia, which are the major causes of death due to SARS-CoV-2 infection. Elevated circulating leptin concentrations are a hallmark of obesity, which is associated with a leptin-resistant state. Leptin is secreted by adipocytes in proportion to body fat and regulates appetite and metabolism through signaling in the hypothalamus. However, leptin also signals through the Jak/STAT and Akt pathways, among others, to modulate T cell number and function. Thus, leptin connects metabolism with the immune response. Therefore, it seems appropriate that its dysregulation would have serious consequences during an infection. We propose that leptin may be the link between obesity and its high prevalence as a comorbidity of the SARS-CoV-2 infection. In this article, we present a synthesis of the mechanisms underpinning susceptibility to respiratory viral infections and the contribution of the immunomodulatory effects of obesity to the outcome.
Collapse
Affiliation(s)
- Candida J Rebello
- Pennington Biomedical Research Center, 6400, Perkins Road, Baton Rouge, LA 70808, USA
| | - John P Kirwan
- Pennington Biomedical Research Center, 6400, Perkins Road, Baton Rouge, LA 70808, USA
| | - Frank L Greenway
- Pennington Biomedical Research Center, 6400, Perkins Road, Baton Rouge, LA 70808, USA.
| |
Collapse
|
13
|
Hara Y, Watanabe N. Changes in expression of genes related to glucose metabolism in liver and skeletal muscle of rats exposed to acute hypoxia. Heliyon 2020; 6:e04334. [PMID: 32642586 PMCID: PMC7334421 DOI: 10.1016/j.heliyon.2020.e04334] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 02/01/2019] [Accepted: 06/24/2020] [Indexed: 02/08/2023] Open
Abstract
The aim of this study was to determine changes in gene expression associated with glucose metabolism in the liver and soleus muscles of rats exposed to hypoxia to improve work capacity under high altitude conditions. Rats were divided into normobaric normoxia (control) and normobaric hypoxia (hypoxia) groups (n = 7 each), and the hypoxia group was exposed to 10.5% oxygen for 90 min. Glucose metabolism-related gene expression was examined by real-time polymerase chain reaction. In the liver, the expression levels of the glucose utilization-related genes solute carrier family 2 member 1, glucokinase, and liver-type phosphofructokinase and the gluconeogenesis-related gene phosphoenolpyruvate carboxykinase 1 (Pck1) were significantly increased upon hypoxic exposure. In contrast, gene expression in the soleus was unchanged, with the exception of Pck1. The results suggest that under hypoxia, both glucose utilization and gluconeogenesis are accelerated in the liver, and liver glycogen is degraded to maintain blood glucose level.
Collapse
Affiliation(s)
- Yurie Hara
- Department of Nutritional Science, Tokyo Kasei University, 1-18-1 Kaga, Itabashi, Tokyo, 173-8602, Japan
| | - Nakamichi Watanabe
- Department of Health Science, Showa Women's University, 1-7-57 Taishido, Setagaya, Tokyo, 154-8533, Japan
| |
Collapse
|
14
|
Liu X, Liu S, Xu C. Effects of leptin on HPG axis and reproductive function in male rat in simulated altitude of 5500 m hypoxia environment. Biochem Biophys Res Commun 2020; 529:104-111. [PMID: 32560810 DOI: 10.1016/j.bbrc.2020.05.194] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 05/25/2020] [Indexed: 11/27/2022]
Abstract
High altitude hypobaric hypoxia environment impairs male's reproductive function. Leptin is an adipose tissue-derived hormone which regulates body weight homeostasis. Its receptor (LepR) has been found in all levels of male reproductive axis, indicating that it can affect male reproductive system in a direct or (and) indirect way. However, the role of leptin signaling in hypobaric hypoxia induced male reproductive dysfunction remains to be elucidated. In this study, we investigated the changes of leptin levels in male SD rats in stimulated altitude of 5500 m hypobaric hypoxia environment and their effects on the hypothalamus-pituitary-gonad axis (HPG axis). A hypoxia animal model was established using a hypobaric hypoxia chamber. Rats were divided randomly into 1, 7, 14, 28-day hypoxia group, recovery group (14 days hypoxia+14 days normoxia) and their control groups. Hypoxia groups displayed obvious changes of testicular and epididymis index compared to control groups. The total number of sperm and sperm motility rate decreased dramatically, while sperm deformity rate increased in hypoxia groups. The flow cytometry analysis showed that the percentage of haploid in 1-day, 7-day and 28-day hypoxia groups increased while the proportion of diploid decreased in 14-day and 28-day hypoxia group. TUNEL staining showed that the testis cells apoptosis index (AI) of hypoxia groups increased significantly, and the apoptosis of cells mainly focus on spermatogonia and spermatocytes. The expression of GnRH in hypothalamus decreased dramatically under hypoxia condition, accompanied with the reduction of serum testosterone (T) level in 1-day and 28-day hypoxia groups and free-testosterone level (FT) in 1-day and 14-day hypoxia groups. Importantly, ELISA analysis showed that serum leptin level decreased in 7-day hypoxia groups and acylated-ghrelin, gastrin also changed, accompanying with reduction of LepR in hypothalamus in hypoxia groups. Immunohistochemical staining exhibited increased leptin and LepR in testis under hypobaric hypoxia conditions. Our results suggested that simulated high altitude hypobaric hypoxia environment decreased male reproductive function, depressed HPG axis activity and altered the serum concentration of hormones related to food intake in adult male rats. Additionally, hypobaric hypoxia induced the leptin-LepR expression in adult male rats' testis, suggesting leptin-LepR signaling may mediate hypoxia-induced impairment in male rats' reproductive system.
Collapse
Affiliation(s)
- Xinyuan Liu
- Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, 100005, China.
| | - Shiying Liu
- Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, 100005, China.
| | - Chengli Xu
- Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, 100005, China; Center of Environmental and Health Sciences, Chinese Academy of Medical Sciences, Beijing, China.
| |
Collapse
|
15
|
Evans AM, Hardie DG. AMPK and the Need to Breathe and Feed: What's the Matter with Oxygen? Int J Mol Sci 2020; 21:ijms21103518. [PMID: 32429235 PMCID: PMC7279029 DOI: 10.3390/ijms21103518] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/12/2022] Open
Abstract
We live and to do so we must breathe and eat, so are we a combination of what we eat and breathe? Here, we will consider this question, and the role in this respect of the AMP-activated protein kinase (AMPK). Emerging evidence suggests that AMPK facilitates central and peripheral reflexes that coordinate breathing and oxygen supply, and contributes to the central regulation of feeding and food choice. We propose, therefore, that oxygen supply to the body is aligned with not only the quantity we eat, but also nutrient-based diet selection, and that the cell-specific expression pattern of AMPK subunit isoforms is critical to appropriate system alignment in this respect. Currently available information on how oxygen supply may be aligned with feeding and food choice, or vice versa, through our motivation to breathe and select particular nutrients is sparse, fragmented and lacks any integrated understanding. By addressing this, we aim to provide the foundations for a clinical perspective that reveals untapped potential, by highlighting how aberrant cell-specific changes in the expression of AMPK subunit isoforms could give rise, in part, to known associations between metabolic disease, such as obesity and type 2 diabetes, sleep-disordered breathing, pulmonary hypertension and acute respiratory distress syndrome.
Collapse
Affiliation(s)
- A. Mark Evans
- Centre for Discovery Brain Sciences and Cardiovascular Science, Edinburgh Medical School, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK
- Correspondence:
| | - D. Grahame Hardie
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK;
| |
Collapse
|
16
|
Bottura RM, Lima GHO, Hipolide DC, Pesquero JB. Association between ACTN3 and acute mountain sickness. Genes Environ 2019; 41:18. [PMID: 31867082 PMCID: PMC6902444 DOI: 10.1186/s41021-019-0133-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/10/2019] [Indexed: 12/17/2022] Open
Abstract
Background During the process of acclimatization, when our organism needs to adjust several metabolic processes in the attempt of establishing a better oxygenation, it is normal that individuals present some symptoms that can lead to the disease of the mountain. However, not everyone presents such symptoms and individuals native of high altitudes regions present genetic differences compared to natives of low altitudes which can generate a better acute adaptation. One of these differences is the higher proportion of type I muscle fibers, which may originate from the R577X polymorphism of the ACTN3 gene. The aim of this study was to compare the response of individuals with different ACTN3 genotypes at simulated 4500 m altitude on the presence of Acute Mountain Sickness (AMS) symptoms. Twenty-three volunteers (RR = 7, RX = 8, XX = 8) spent 4 hours exposed to a simulated altitude of 4500 m inside a normobaric hypoxia chamber. Lactate and glucose concentrations, SpO2, heart rate and the symptoms of AMS were analyzed immediately before entering the chamber and at each hour of exposure. Statistical analysis was performed using IBM SPSS Statistics 21 software. Results Our results point to an association between AMS symptoms and the presence of R allele from R577X polymorphism. Conclusion We conclude that individuals with at least one R allele of the R577X polymorphism seems to be more susceptible to the effects of hypoxia during the acclimatization process and may develop AMS symptoms.
Collapse
Affiliation(s)
- Ricardo Muller Bottura
- 1Department of Psychobiology, UNIFESP, Botucatu Street, 862, First Floor, Vila Clementino, SP, ZIP, São Paulo, 04023062 Brazil
| | | | - Debora Cristina Hipolide
- 1Department of Psychobiology, UNIFESP, Botucatu Street, 862, First Floor, Vila Clementino, SP, ZIP, São Paulo, 04023062 Brazil
| | | |
Collapse
|
17
|
Rood K, Lopez V, La Frano MR, Fiehn O, Zhang L, Blood AB, Wilson SM. Gestational Hypoxia and Programing of Lung Metabolism. Front Physiol 2019; 10:1453. [PMID: 31849704 PMCID: PMC6895135 DOI: 10.3389/fphys.2019.01453] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 11/11/2019] [Indexed: 12/12/2022] Open
Abstract
Gestational hypoxia is a risk factor in the development of pulmonary hypertension in the newborn and other sequela, however, the mechanisms associated with the disease remain poorly understood. This review highlights disruption of metabolism by antenatal high altitude hypoxia and the impact this has on pulmonary hypertension in the newborn with discussion of model organisms and human populations. There is particular emphasis on modifications in glucose and lipid metabolism along with alterations in mitochondrial function. Additional focus is placed on increases in oxidative stress and the progression of pulmonary vascular disease in the newborn and on the need for further exploration using a combination of contemporary and classical approaches.
Collapse
Affiliation(s)
- Kristiana Rood
- Lawrence D. Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Vanessa Lopez
- Lawrence D. Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Michael R La Frano
- Department of Food Science and Nutrition, Center for Health Research, California Polytechnic State University, San Luis Obispo, CA, United States.,Center for Health Research, California Polytechnic State University, San Luis Obispo, CA, United States
| | - Oliver Fiehn
- NIH West Coast Metabolomics Center, University of California, Davis, Davis, CA, United States.,Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, United States
| | - Lubo Zhang
- Lawrence D. Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Arlin B Blood
- Lawrence D. Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Sean M Wilson
- Lawrence D. Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| |
Collapse
|
18
|
PARK HY, JUNG WS, KIM J, HWANG H, LIM K. Changes in the Paradigm of Traditional Exercise in Obesity Therapy and Application of a New Exercise Modality: A Narrative Review Article. IRANIAN JOURNAL OF PUBLIC HEALTH 2019; 48:1395-1404. [PMID: 32292722 PMCID: PMC7145908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Obesity is recognized as an important global health problem that increases the risk of all-cause death. It is a major risk factor for various cardiovascular and metabolic diseases. METHODS We conducted this review through searching the related literature plus internet links. RESULTS Recently, many researchers have been applying various efficient alternative exercise paradigms for treating obesity, such as high-intensity interval training, whole-body vibration training, and hypoxic therapy. Compared with moderate-intensity continuous training, high-intensity interval training involves a shorter exercise time but higher energy expenditure and excess post-exercise oxygen consumption via a higher exercise intensity and is effective for treating obesity. Whole-body vibration training effectively reduces the rate of fat production and accumulation through passive vibration of the whole body and improving the body composition, muscle function, and cardiovascular function of the obese population. Hypoxic therapy has been reported to improve obesity and obesity-related diseases through appetite loss, reduced dietary intake, increased energy consumption, improved glycogen storage and fatty acid oxidation, angiogenesis and left ventricle remodeling, decreased mechanical load, and reduced sarcopenia progression due to aging. CONCLUSION The new therapeutic exercise modalities, namely, high-intensity interval training, whole-body vibration training, and hypoxic therapy, are practical, useful, and effective for improving obesity and various metabolic and cardiovascular diseases induced by obesity.
Collapse
Affiliation(s)
- Hun-Young PARK
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Republic of Korea
| | - Won-Sang JUNG
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Republic of Korea
| | - Jisu KIM
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Republic of Korea
| | - Hyejung HWANG
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Republic of Korea
| | - Kiwon LIM
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Republic of Korea,Department of Physical Education, Konkuk University, Seoul, Republic of Korea,Corresponding Author:
| |
Collapse
|
19
|
Serebrovska TV, Portnychenko AG, Portnichenko VI, Xi L, Egorov E, Antoniuk-Shcheglova I, Naskalova S, Shatylo VB. Effects of intermittent hypoxia training on leukocyte pyruvate dehydrogenase kinase 1 (PDK-1) mRNA expression and blood insulin level in prediabetes patients. Eur J Appl Physiol 2019; 119:813-823. [PMID: 30701312 DOI: 10.1007/s00421-019-04072-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 01/04/2019] [Indexed: 02/08/2023]
Abstract
PURPOSE Intermittent hypoxia training/treatment (IHT) is an emerging therapeutic approach to alleviate chronic diseases, such as diabetes. The present study investigated the effects of IHT on blood leucocyte pyruvate dehydrogenase kinase 1 (PDK-1) mRNA expression and its relationship with the changes in blood insulin level. METHODS Seven adult healthy volunteers and 11 prediabetic patients participated in this study. A 3-week course of IHT consisted of a 40-min session of 4 cycles of 5-min 12% O2 and 5-min room air breathing per day, 3 sessions per week for 3 weeks (i.e., total 9 sessions of IHT). Plasma insulin levels and leukocyte PDK-1 mRNA expression were determined at various time points either under fasting condition or following oral glucose tolerance test (OGTT). Correlation between the IHT-induced changes in PDK-1 mRNA and insulin or glucose levels in the same serological samples was analyzed. RESULTS At pre-IHT baseline, PDK-1 mRNA expression was two times higher in prediabetes than control subjects. IHT resulted in significant augmentation in PDK-1 mRNA expression (> twofold) in prediabetes at the end of 3-week IHT and remained elevated 1 month after IHT, which was correlated with a significantly reduced insulin release and lower blood glucose after glucose loading with OGTT. CONCLUSION IHT can trigger beneficial effects in normalizing blood insulin levels in prediabetic patients under oral glucose load, which were closely correlated with an enhanced mRNA expression of PDK-1 in leukocytes. Further clinical trials are warranted to validate the utility of IHT as a non-invasive complementary therapy against diabetes-associated pathologies.
Collapse
Affiliation(s)
| | - Alla G Portnychenko
- Bogomoletz Institute of Physiology, Kiev, 01024, Ukraine
- ICAMER, National Academy of Sciences of Ukraine, Kiev, 03680, Ukraine
| | - Vladimir I Portnichenko
- Bogomoletz Institute of Physiology, Kiev, 01024, Ukraine
- ICAMER, National Academy of Sciences of Ukraine, Kiev, 03680, Ukraine
| | - Lei Xi
- Pauley Heart Center, Department of Internal Medicine, Virginia Commonwealth University, 1101 East Marshall Street, Room 7-020C, Richmond, VA, 23298, USA.
- School of Sports Medicine and Health, Chengdu Sport University, Chengdu, 610041, China.
| | - Egor Egorov
- CELLGYM Technologies GmbH, 10623, Berlin, Germany
| | | | | | - Valeriy B Shatylo
- D.F. Chebotarev State Institute of Gerontology, Kiev, 04114, Ukraine
| |
Collapse
|
20
|
Park HY, Kim J, Park MY, Chung N, Hwang H, Nam SS, Lim K. Exposure and Exercise Training in Hypoxic Conditions as a New Obesity Therapeutic Modality: A Mini Review. J Obes Metab Syndr 2018; 27:93-101. [PMID: 31089548 PMCID: PMC6489458 DOI: 10.7570/jomes.2018.27.2.93] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/08/2018] [Accepted: 05/16/2018] [Indexed: 01/15/2023] Open
Abstract
Obesity is an important health problem caused by positive energy balance. Generally, low calorie dietary intake combined with regular exercise is the most common modality to lose bodily fat in obese people. Although this is the first modality of choice for obesity treatment, it needs to be applied to obese patients for at least 12 weeks or more and it does not provide consistent results because it is difficult to suppress increased appetite due to exercise. Recently, many researchers have been applying hypoxic conditions for the treatment of obesity, as many studies show that people residing in high altitudes have a lower percentage of body fat and fewer obesity-related illnesses than people living at sea level. Hypoxic therapy treatment, including hypoxic exposure or hypoxic exercise training, is recommended as a way to treat and prevent obesity by suppression of appetite, increasing basal metabolic rate and fat oxidation, and minimizing side effects. Hypoxic therapy inhibits energy intake and appetite-related hormones, and enhances various cardiovascular and metabolic function parameters. These observations indicate that hypoxic therapy is a new treatment modality for inducing fat reduction and promoting metabolic and cardiovascular health, which may be an important and necessary strategy for the treatment of obesity. As such, hypoxic therapy is now used as a general medical practice for obesity treatment in many developed countries. Therefore, hypoxic therapy could be a new, practical, and useful therapeutic modality for obesity and obesity-related comorbidities.
Collapse
Affiliation(s)
- Hun-Young Park
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Korea
| | - Jisu Kim
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Korea
| | - Mi-Young Park
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Korea
| | - Nana Chung
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Korea
| | - Hyejung Hwang
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Korea
| | - Sang-Seok Nam
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Korea
| | - Kiwon Lim
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Korea.,Laboratory of Exercise Nutrition, Department of Physical Education, Konkuk University, Seoul, Korea
| |
Collapse
|
21
|
Siques P, Brito J, Flores K, Ordenes S, Arriaza K, Pena E, León-Velarde F, López de Pablo ÁL, Gonzalez MC, Arribas S. Long-Term Chronic Intermittent Hypobaric Hypoxia Induces Glucose Transporter (GLUT4) Translocation Through AMP-Activated Protein Kinase (AMPK) in the Soleus Muscle in Lean Rats. Front Physiol 2018; 9:799. [PMID: 30002630 PMCID: PMC6031730 DOI: 10.3389/fphys.2018.00799] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 06/07/2018] [Indexed: 11/20/2022] Open
Abstract
Background: In chronic hypoxia (CH) and short-term chronic intermittent hypoxia (CIH) exposure, glycemia and insulin levels decrease and insulin sensitivity increases, which can be explained by changes in glucose transport at skeletal muscles involving GLUT1, GLUT4, Akt, and AMPK, as well as GLUT4 translocation to cell membranes. However, during long-term CIH, there is no information regarding whether these changes occur similarly or differently than in other types of hypoxia exposure. This study evaluated the levels of AMPK and Akt and the location of GLUT4 in the soleus muscles of lean rats exposed to long-term CIH, CH, and normoxia (NX) and compared the findings. Methods: Thirty male adult rats were randomly assigned to three groups: a NX (760 Torr) group (n = 10), a CIH group (2 days hypoxia/2 days NX; n = 10) and a CH group (n = 10). Rats were exposed to hypoxia for 30 days in a hypobaric chamber set at 428 Torr (4,600 m). Feeding (10 g daily) and fasting times were accurately controlled. Measurements included food intake (every 4 days), weight, hematocrit, hemoglobin, glycemia, serum insulin (by ELISA), and insulin sensitivity at days 0 and 30. GLUT1, GLUT4, AMPK levels and Akt activation in rat soleus muscles were determined by western blot. GLUT4 translocation was measured with confocal microscopy at day 30. Results: (1) Weight loss and increases in hematocrit and hemoglobin were found in both hypoxic groups (p < 0.05). (2) A moderate decrease in glycemia and plasma insulin was found. (3) Insulin sensitivity was greater in the CIH group (p < 0.05). (4) There were no changes in GLUT1, GLUT4 levels or in Akt activation. (5) The level of activated AMPK was increased only in the CIH group (p < 0.05). (6) Increased GLUT4 translocation to the plasma membrane of soleus muscle cells was observed in the CIH group (p < 0.05). Conclusion: In lean rats experiencing long-term CIH, glycemia and insulin levels decrease and insulin sensitivity increases. Interestingly, there is no increase of GLUT1 or GLUT4 levels or in Akt activation. Therefore, cellular regulation of glucose seems to primarily involve GLUT4 translocation to the cell membrane in response to hypoxia-mediated AMPK activation.
Collapse
Affiliation(s)
- Patricia Siques
- Institute of Health Studies, University Arturo Prat, Iquique, Chile
| | - Julio Brito
- Institute of Health Studies, University Arturo Prat, Iquique, Chile
| | - Karen Flores
- Institute of Health Studies, University Arturo Prat, Iquique, Chile
| | - Stefany Ordenes
- Institute of Health Studies, University Arturo Prat, Iquique, Chile
| | - Karem Arriaza
- Institute of Health Studies, University Arturo Prat, Iquique, Chile
| | - Eduardo Pena
- Institute of Health Studies, University Arturo Prat, Iquique, Chile
| | - Fabiola León-Velarde
- Department of Biological and Physiological Sciences, Facultad de Ciencias y Filosofía/IIA, Cayetano Heredia University, Lima, Peru
| | - Ángel L López de Pablo
- Department of Physiology, Faculty of Medicine, University Autonoma of Madrid, Madrid, Spain
| | - M C Gonzalez
- Department of Physiology, Faculty of Medicine, University Autonoma of Madrid, Madrid, Spain
| | - Silvia Arribas
- Department of Physiology, Faculty of Medicine, University Autonoma of Madrid, Madrid, Spain
| |
Collapse
|
22
|
Abnormal Glucose Metabolism and High-Energy Expenditure in Idiopathic Pulmonary Arterial Hypertension. Ann Am Thorac Soc 2018; 14:190-199. [PMID: 27922752 DOI: 10.1513/annalsats.201608-605oc] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
RATIONALE Insulin resistance has emerged as a potential mechanism related to the pathogenesis of idiopathic pulmonary arterial hypertension (IPAH). However, direct measurements of insulin and glucose metabolism have not been performed in patients with IPAH to date. OBJECTIVES To perform comprehensive metabolic phenotyping of humans with IPAH. METHODS We assessed plasma insulin and glucose, using an oral glucose tolerance test and estimated insulin resistance, and β-cell function in 14 patients with IPAH and 14 control subjects matched for age, sex, blood pressure, and body mass index. Body composition (dual-energy X-ray absorptiometry), inflammation (CXC chemokine ligand 10, endothelin-1), physical fitness (6-min walk test), and energy expenditure (indirect calorimetry) were also assessed. MEASUREMENTS AND MAIN RESULTS Patients with IPAH had a higher rate of impaired glucose tolerance (57 vs. 14%; P < 0.05) and reduced glucose-stimulated insulin secretion compared with matched control subjects (IPAH: 1.31 ± 0.76 μU/ml⋅mg/dl vs. control subjects: 2.21 ± 1.27 μU/ml⋅mg/dl; P < 0.05). Pancreatic β-cell function was associated with circulating endothelin-1 (r = -0.71, P < 0.01) and CXC chemokine ligand 10 (r = -0.56, P < 0.05). Resting energy expenditure was elevated in IPAH (IPAH: 32 ± 3.4 vs. control subjects: 28.8 ± 2.9 kcal/d/kg fat-free mass; P < 0.05) and correlated with the plasma glucose response (r = 0.51, P < 0.01). Greater insulin resistance was associated with reduced 6-minute walk distance (r = 0.55, P < 0.05). CONCLUSIONS Independent of age, sex, blood pressure, and body mass index, patients with IPAH have glucose intolerance, decreased insulin secretion in response to glucose, and elevated resting energy expenditure. These abnormalities are associated with circulating markers of inflammation and vascular dysfunction.
Collapse
|
23
|
Brinkmann C, Bloch W, Brixius K. Exercise during short-term exposure to hypoxia or hyperoxia - novel treatment strategies for type 2 diabetic patients?! Scand J Med Sci Sports 2017. [PMID: 28649714 DOI: 10.1111/sms.12937] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Both hypoxia (decreased oxygen availability) and hyperoxia (increased oxygen availability) have been shown to alter exercise adaptations in healthy subjects. This review aims to clarify the possible benefits of exercise during short-term exposure to hypoxia or hyperoxia for patients with type 2 diabetes mellitus (T2DM). There is evidence that exercise during short-term exposure to hypoxia can acutely increase skeletal muscle glucose uptake more than exercise in normoxia, and that post-exercise insulin sensitivity in T2DM patients is more increased when exercise is performed under hypoxic conditions. Furthermore, interventional studies show that glycemic control can be improved through regular physical exercise in short-term hypoxia at a lower workload than in normoxia, and that exercise training in short-term hypoxia can contribute to increased weight loss in overweight/obese (insulin-resistant) subjects. While numerous studies involving healthy subjects report that regular exercise in hypoxia can increase vascular health (skeletal muscle capillarization and vascular dilator function) to a higher extent than exercise training in normoxia, there is no convincing evidence yet that hypoxia has such additive effects in T2DM patients in the long term. Some studies indicate that the use of hyperoxia during exercise can decrease lactate concentrations and subjective ratings of perceived exertion. Thus, there are interesting starting points for future studies to further evaluate possible beneficial effects of exercise in short-term hypoxia or hyperoxia at different oxygen concentrations and exposure durations. In general, exposure to hypoxia/hyperoxia should be considered with caution. Possible health risks-especially for T2DM patients-are also analyzed in this review.
Collapse
Affiliation(s)
- C Brinkmann
- Institute of Cardiovascular Research and Sport Medicine, Department of Molecular and Cellular Sport Medicine, German Sport University Cologne, Cologne, Germany.,Institute of Cardiovascular Research and Sport Medicine, Department of Preventive and Rehabilitative Sport Medicine, German Sport University Cologne, Cologne, Germany
| | - W Bloch
- Institute of Cardiovascular Research and Sport Medicine, Department of Molecular and Cellular Sport Medicine, German Sport University Cologne, Cologne, Germany
| | - K Brixius
- Institute of Cardiovascular Research and Sport Medicine, Department of Molecular and Cellular Sport Medicine, German Sport University Cologne, Cologne, Germany
| |
Collapse
|
24
|
Hobbins L, Hunter S, Gaoua N, Girard O. Normobaric hypoxic conditioning to maximize weight loss and ameliorate cardio-metabolic health in obese populations: a systematic review. Am J Physiol Regul Integr Comp Physiol 2017; 313:R251-R264. [PMID: 28679682 DOI: 10.1152/ajpregu.00160.2017] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/23/2017] [Accepted: 07/04/2017] [Indexed: 02/07/2023]
Abstract
Normobaric hypoxic conditioning (HC) is defined as exposure to systemic and/or local hypoxia at rest (passive) or combined with exercise training (active). HC has been previously used by healthy and athletic populations to enhance their physical capacity and improve performance in the lead up to competition. Recently, HC has also been applied acutely (single exposure) and chronically (repeated exposure over several weeks) to overweight and obese populations with the intention of managing and potentially increasing cardio-metabolic health and weight loss. At present, it is unclear what the cardio-metabolic health and weight loss responses of obese populations are in response to passive and active HC. Exploration of potential benefits of exposure to both passive and active HC may provide pivotal findings for improving health and well being in these individuals. A systematic literature search for articles published between 2000 and 2017 was carried out. Studies investigating the effects of normobaric HC as a novel therapeutic approach to elicit improvements in the cardio-metabolic health and weight loss of obese populations were included. Studies investigated passive (n = 7; 5 animals, 2 humans), active (n = 4; all humans) and a combination of passive and active (n = 4; 3 animals, 1 human) HC to an inspired oxygen fraction ([Formula: see text]) between 4.8 and 15.0%, ranging between a single session and daily sessions per week, lasting from 5 days up to 8 mo. Passive HC led to reduced insulin concentrations (-37 to -22%) in obese animals and increased energy expenditure (+12 to +16%) in obese humans, whereas active HC lead to reductions in body weight (-4 to -2%) in obese animals and humans, and blood pressure (-8 to -3%) in obese humans compared with a matched workload in normoxic conditions. Inconclusive findings, however, exist in determining the impact of acute and chronic HC on markers such as triglycerides, cholesterol levels, and fitness capacity. Importantly, most of the studies that included animal models involved exposure to severe levels of hypoxia ([Formula: see text] = 5.0%; simulated altitude >10,000 m) that are not suitable for human populations. Overall, normobaric HC demonstrated observable positive findings in relation to insulin and energy expenditure (passive), and body weight and blood pressure (active), which may improve the cardio-metabolic health and body weight management of obese populations. However, further evidence on responses of circulating biomarkers to both passive and active HC in humans is warranted.
Collapse
Affiliation(s)
- L Hobbins
- Sport and Exercise Science Research Centre, London South Bank University, London, United Kingdom;
| | - S Hunter
- Sport and Exercise Science Research Centre, London South Bank University, London, United Kingdom
| | - N Gaoua
- Sport and Exercise Science Research Centre, London South Bank University, London, United Kingdom
| | - O Girard
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar; and.,Institute of Sport Sciences, University of Lausanne, Switzerland
| |
Collapse
|
25
|
Nüsken E, Wohlfarth M, Lippach G, Rauh M, Schneider H, Dötsch J, Nüsken KD. Reduced Perinatal Leptin Availability May Contribute to Adverse Metabolic Programming in a Rat Model of Uteroplacental Insufficiency. Endocrinology 2016; 157:1813-25. [PMID: 27007072 DOI: 10.1210/en.2015-1898] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Leptin availability in perinatal life critically affects metabolic programming. We tested the hypothesis that uteroplacental insufficiency and intrauterine stress affect perinatal leptin availability in rat offspring. Pregnant rats underwent bilateral uterine vessel ligation (LIG; n = 14), sham operation (SOP; n = 12), or no operation (controls, n = 14). Fetal livers (n = 180), placentas (n = 180), and maternal blood were obtained 4 hours (gestational day [E] 19), 24 hours (E20), and 72 hours (E22) after surgery. In the offspring, we took blood samples on E22 (n = 44), postnatal day (P) 1 (n = 29), P2 (n = 16), P7 (n = 30), and P12 (n = 30). Circulating leptin (ELISA) was significantly reduced in LIG (E22, P1, P2) and SOP offspring (E22). Postnatal leptin surge was delayed in LIG but was accelerated in SOP offspring. Placental leptin gene expression (quantitative RT-PCR) was reduced in LIG (E19, E20, E22) and SOP (E20, E22). Hepatic leptin receptor (Lepr-a, mediating leptin degradation) gene expression was increased in LIG fetuses (E20, E22) only. Surprisingly, hypoxia-inducible factors (Hif; Western blot) were unaltered in placentas and were reduced in the livers of LIG (Hif1a, E20; Hif2a, E19, E22) and SOP (Hif2a, E19) fetuses. Gene expression of prolyl hydroxylase 3, a factor expressed under hypoxic conditions contributing to Hif degradation, was increased in livers of LIG (E19, E20, E22) and SOP (E19) fetuses and in placentas of LIG and SOP (E19). In summary, reduced placental leptin production, increased fetal leptin degradation, and persistent perinatal hypoleptinemia are present in intrauterine growth restriction offspring, especially after uteroplacental insufficiency, and may contribute to perinatal programming of leptin resistance and adiposity in later life.
Collapse
Affiliation(s)
- Eva Nüsken
- Department of Pediatrics (E.N., M.W., G.L., J.D., K.-D.N.), Medical Faculty, University of Cologne, 50937 Cologne, Germany; and Department of Pediatrics (M.R., H.S.), University of Erlangen-Nuremberg, 91054 Erlangen, Germany
| | - Maria Wohlfarth
- Department of Pediatrics (E.N., M.W., G.L., J.D., K.-D.N.), Medical Faculty, University of Cologne, 50937 Cologne, Germany; and Department of Pediatrics (M.R., H.S.), University of Erlangen-Nuremberg, 91054 Erlangen, Germany
| | - Gregor Lippach
- Department of Pediatrics (E.N., M.W., G.L., J.D., K.-D.N.), Medical Faculty, University of Cologne, 50937 Cologne, Germany; and Department of Pediatrics (M.R., H.S.), University of Erlangen-Nuremberg, 91054 Erlangen, Germany
| | - Manfred Rauh
- Department of Pediatrics (E.N., M.W., G.L., J.D., K.-D.N.), Medical Faculty, University of Cologne, 50937 Cologne, Germany; and Department of Pediatrics (M.R., H.S.), University of Erlangen-Nuremberg, 91054 Erlangen, Germany
| | - Holm Schneider
- Department of Pediatrics (E.N., M.W., G.L., J.D., K.-D.N.), Medical Faculty, University of Cologne, 50937 Cologne, Germany; and Department of Pediatrics (M.R., H.S.), University of Erlangen-Nuremberg, 91054 Erlangen, Germany
| | - Jörg Dötsch
- Department of Pediatrics (E.N., M.W., G.L., J.D., K.-D.N.), Medical Faculty, University of Cologne, 50937 Cologne, Germany; and Department of Pediatrics (M.R., H.S.), University of Erlangen-Nuremberg, 91054 Erlangen, Germany
| | - Kai-Dietrich Nüsken
- Department of Pediatrics (E.N., M.W., G.L., J.D., K.-D.N.), Medical Faculty, University of Cologne, 50937 Cologne, Germany; and Department of Pediatrics (M.R., H.S.), University of Erlangen-Nuremberg, 91054 Erlangen, Germany
| |
Collapse
|
26
|
Ge RL, Simonson TS, Gordeuk V, Prchal JT, McClain DA. Metabolic aspects of high-altitude adaptation in Tibetans. Exp Physiol 2015; 100:1247-55. [PMID: 26053282 PMCID: PMC10905973 DOI: 10.1113/ep085292] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 06/02/2015] [Indexed: 12/15/2022]
Abstract
NEW FINDINGS What is the topic of this review? The topic of this review is how Tibetans have adapted genetically to high altitude, particularly with reference to altitude-induced changes in metabolism. What advances does it highlight? It highlights recent work on metabolic phenotyping in Tibetans and demonstrates that selected genetic haplotypes influence their metabolism of fats and glucose. Recent studies have identified genes involved in high-altitude adaptation in Tibetans. Three of these genes (EPAS1, EGLN1 and PPARA) are associated with decreased haemoglobin levels compared with non-Tibetans living at altitude. Consistent with the phenotype, EGLN1 in Tibetans has a gain-of-function mutation that confers a higher affinity for oxygen, hence less sensitivity to hypoxia. Considering the demands imposed upon metabolism in meeting energy demands despite limitations on fuel oxidation, we hypothesized that other selected genes might alter metabolism to allow adaptation to altitude despite the desensitization of the upstream hypoxia sensing caused by the EGLN1 mutation that results in the failure to sense hypoxia. A shift in fuel preference to glucose oxidation and glycolysis at the expense of fatty acid oxidation would provide adaptation to decreased oxygen availability. Measurements of serum metabolites from Tibetans living at high altitude are consistent with this hypothesis; the EPAS1 haplotype is significantly associated with increased lactate levels (suggesting increased anaerobic metabolism), and the PPARA haplotype and serum free fatty acids are positively related (suggesting decreased fat oxidation). These data suggest that the high-altitude adaptations may offer protection from diabetes at high altitude but increase the risk of diabetes at lower elevations and/or with adoption of a non-traditional diet. It should also be considered in future work in the field that because iron is a cofactor for EGLN1, there may be significant associations of phenotypes with the significant degrees of variation seen in tissue iron among human populations.
Collapse
Affiliation(s)
- Ri-Li Ge
- Research Center for High-Altitude Medicine, Qinghai University Medical School, Xining, Qinghai, People's Republic of China
| | - Tatum S Simonson
- Department of Human Genetics and the Divisions of Endocrinology, Metabolism, and Diabetes and Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Victor Gordeuk
- Section of Hematology and Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Josef T Prchal
- Department of Human Genetics and the Divisions of Endocrinology, Metabolism, and Diabetes and Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Donald A McClain
- Department of Human Genetics and the Divisions of Endocrinology, Metabolism, and Diabetes and Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT, USA
| |
Collapse
|
27
|
Mohajeri S, Perkins BA, Brubaker PL, Riddell MC. Diabetes, trekking and high altitude: recognizing and preparing for the risks. Diabet Med 2015; 32:1425-37. [PMID: 25962798 DOI: 10.1111/dme.12795] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/07/2015] [Indexed: 12/25/2022]
Abstract
Although regular physical activity is encouraged for individuals with diabetes, exercise at high altitude increases risk for a number of potential complications. This review highlights our current understanding of the key physiological and clinical issues that accompany high-altitude travel and proposes basic clinical strategies to help overcome obstacles faced by trekkers with Type 1 or Type 2 diabetes. Although individuals with diabetes have adaptations to the hypoxia of high altitude (increased ventilation, heart rate, blood pressure and hormonal responses), elevated counter-regulatory hormones can impair glycaemic control, particularly if mountain sickness occurs. Moreover, high-altitude-induced anorexia and increased energy expenditure can predispose individuals to dysglycaemia unless careful adjustments in medication are performed. Frequent blood glucose monitoring is imperative, and results must be interpreted with caution because capillary blood glucose meter results may be less accurate at high elevations and low temperatures. It is also important to undergo pre-travel screening to rule out possible contraindications owing to chronic diabetes complications and make well-informed decisions about risks. Despite the risks, healthy, physically fit and well-prepared individuals with Type 1 or Type 2 diabetes who are capable of advanced self-management can be encouraged to participate in these activities and attain their summit goals. Moreover, trekking at high altitude can serve as an effective means to engage in physical activity and to increase confidence with fundamental diabetes self-management skills.
Collapse
Affiliation(s)
- S Mohajeri
- School of Kinesiology and Health Science, Muscle Health Research Centre and Physical Activity and Chronic Disease Unit, York University, Toronto
| | - B A Perkins
- Division of Endocrinology and Department of Medicine, University of Toronto
| | - P L Brubaker
- Department of Physiology and Department of Medicine, University of Toronto, Toronto, Canada
| | - M C Riddell
- School of Kinesiology and Health Science, Muscle Health Research Centre and Physical Activity and Chronic Disease Unit, York University, Toronto
| |
Collapse
|
28
|
Kilimanjaro Abruzzo expedition: effects of high-altitude trekking on anthropometric, cardiovascular and blood biochemical parameters. SPORT SCIENCES FOR HEALTH 2015; 11:271-278. [PMID: 26613007 PMCID: PMC4648976 DOI: 10.1007/s11332-015-0235-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 08/03/2015] [Indexed: 01/03/2023]
Abstract
The effect of the combination of trekking and balanced appropriated diet were studied in mountaineers who spent 6 days at an altitude ranging from 900 to 5895 m above sea level (a.s.l.), during the Kilimanjaro Abruzzo Expedition. This study explored whether anthropometric, cardiovascular and blood biochemical parameters were significantly changed by a regular trekking performed at high altitude, with reduced oxygen levels, together with a macronutrient-containing balanced diet (total daily caloric intake: 3000–3500 Kcals). In consideration of the short period of high-altitude exposure, high-altitude exercise appeared to provide beneficial and rapid effects on the lipid profile and to modulate cardiovascular functions. These effects rely on both high-altitude hypoxia and physical activity. The most interesting observation is that even just a few days of high-altitude exercise, along with a balanced diet, was able to improve plasma lipid profiles.
Collapse
|
29
|
Woolcott OO, Ader M, Bergman RN. Glucose homeostasis during short-term and prolonged exposure to high altitudes. Endocr Rev 2015; 36:149-73. [PMID: 25675133 PMCID: PMC4399271 DOI: 10.1210/er.2014-1063] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Most of the literature related to high altitude medicine is devoted to the short-term effects of high-altitude exposure on human physiology. However, long-term effects of living at high altitudes may be more important in relation to human disease because more than 400 million people worldwide reside above 1500 m. Interestingly, individuals living at higher altitudes have a lower fasting glycemia and better glucose tolerance compared with those who live near sea level. There is also emerging evidence of the lower prevalence of both obesity and diabetes at higher altitudes. The mechanisms underlying improved glucose control at higher altitudes remain unclear. In this review, we present the most current evidence about glucose homeostasis in residents living above 1500 m and discuss possible mechanisms that could explain the lower fasting glycemia and lower prevalence of obesity and diabetes in this population. Understanding the mechanisms that regulate and maintain the lower fasting glycemia in individuals who live at higher altitudes could lead to new therapeutics for impaired glucose homeostasis.
Collapse
Affiliation(s)
- Orison O Woolcott
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048
| | | | | |
Collapse
|
30
|
Bailey DP, Smith LR, Chrismas BC, Taylor L, Stensel DJ, Deighton K, Douglas JA, Kerr CJ. Appetite and gut hormone responses to moderate-intensity continuous exercise versus high-intensity interval exercise, in normoxic and hypoxic conditions. Appetite 2015; 89:237-45. [PMID: 25700630 DOI: 10.1016/j.appet.2015.02.019] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 02/04/2015] [Accepted: 02/13/2015] [Indexed: 02/04/2023]
Abstract
This study investigated the effects of continuous moderate-intensity exercise (MIE) and high-intensity interval exercise (HIIE) in combination with short exposure to hypoxia on appetite and plasma concentrations of acylated ghrelin, peptide YY (PYY), and glucagon-like peptide-1 (GLP-1). Twelve healthy males completed four, 2.6 h trials in a random order: (1) MIE-normoxia, (2) MIE-hypoxia, (3) HIIE-normoxia, and (4) HIIE-hypoxia. Exercise took place in an environmental chamber. During MIE, participants ran for 50 min at 70% of altitude-specific maximal oxygen uptake (V˙O2max) and during HIIE performed 6 × 3 min running at 90% V˙O2max interspersed with 6 × 3 min active recovery at 50% V˙O2max with a 7 min warm-up and cool-down at 70% V˙O2max (50 min total). In hypoxic trials, exercise was performed at a simulated altitude of 2980 m (14.5% O2). Exercise was completed after a standardised breakfast. A second meal standardised to 30% of participants' daily energy requirements was provided 45 min after exercise. Appetite was suppressed more in hypoxia than normoxia during exercise, post-exercise, and for the full 2.6 h trial period (linear mixed modelling, p <0.05). Plasma acylated ghrelin concentrations were lower in hypoxia than normoxia post-exercise and for the full 2.6 h trial period (p <0.05). PYY concentrations were higher in HIIE than MIE under hypoxic conditions during exercise (p = 0.042). No differences in GLP-1 were observed between conditions (p > 0.05). These findings demonstrate that short exposure to hypoxia causes suppressions in appetite and plasma acylated ghrelin concentrations. Furthermore, appetite responses to exercise do not appear to be influenced by exercise modality.
Collapse
Affiliation(s)
- Daniel P Bailey
- Institute for Sport and Physical Activity Research, Department of Sport Science and Physical Activity, University of Bedfordshire, Polhill Avenue, Bedford, Bedfordshire MK41 9EA, UK.
| | - Lindsey R Smith
- Institute for Sport and Physical Activity Research, Department of Sport Science and Physical Activity, University of Bedfordshire, Polhill Avenue, Bedford, Bedfordshire MK41 9EA, UK
| | - Bryna C Chrismas
- Institute for Sport and Physical Activity Research, Department of Sport Science and Physical Activity, University of Bedfordshire, Polhill Avenue, Bedford, Bedfordshire MK41 9EA, UK
| | - Lee Taylor
- Institute for Sport and Physical Activity Research, Department of Sport Science and Physical Activity, University of Bedfordshire, Polhill Avenue, Bedford, Bedfordshire MK41 9EA, UK
| | - David J Stensel
- School of Sport, Exercise and Health Sciences, Loughborough University, Ashby Road, Loughborough, Leicestershire LE11 3TU, UK
| | - Kevin Deighton
- School of Sport, Exercise and Health Sciences, Loughborough University, Ashby Road, Loughborough, Leicestershire LE11 3TU, UK
| | - Jessica A Douglas
- School of Sport, Exercise and Health Sciences, Loughborough University, Ashby Road, Loughborough, Leicestershire LE11 3TU, UK
| | - Catherine J Kerr
- Department of Sport and Health Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK
| |
Collapse
|
31
|
Tesler N, Latshang TD, Lo Cascio CM, Stadelmann K, Stoewhas AC, Kohler M, Bloch KE, Achermann P, Huber R. Ascent to moderate altitude impairs overnight memory improvements. Physiol Behav 2015; 139:121-6. [DOI: 10.1016/j.physbeh.2014.11.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 11/08/2014] [Accepted: 11/10/2014] [Indexed: 11/15/2022]
|
32
|
D’Hulst G, Sylow L, Hespel P, Deldicque L. Acute systemic insulin intolerance does not alter the response of the Akt/GSK-3 pathway to environmental hypoxia in human skeletal muscle. Eur J Appl Physiol 2015; 115:1219-31. [DOI: 10.1007/s00421-015-3103-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 01/05/2015] [Indexed: 01/15/2023]
|
33
|
Wee J, Climstein M. Hypoxic training: Clinical benefits on cardiometabolic risk factors. J Sci Med Sport 2015; 18:56-61. [DOI: 10.1016/j.jsams.2013.10.247] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 08/29/2013] [Accepted: 10/13/2013] [Indexed: 01/13/2023]
|
34
|
Goto K, Morishima T, Kurobe K, Huang Z, Ogita F. Augmented Carbohydrate Oxidation under Moderate Hypobaric Hypoxia Equivalent to Simulated Altitude of 2500 m. TOHOKU J EXP MED 2015; 236:163-8. [DOI: 10.1620/tjem.236.163] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Kazushige Goto
- Faculty of Sport and Health Science, Ritsumeikan University
| | | | - Kazumichi Kurobe
- Faculty of Business, Sports Management Course, Hannan University
| | - Zhong Huang
- Department of Sports Sciences, Japan Institute of Sports Sciences
| | - Futoshi Ogita
- Department of Sports and Life Science, National Institute of Fitness and Sports in Kanoya
| |
Collapse
|
35
|
Morishima T, Mori A, Sasaki H, Goto K. Impact of exercise and moderate hypoxia on glycemic regulation and substrate oxidation pattern. PLoS One 2014; 9:e108629. [PMID: 25329405 PMCID: PMC4199615 DOI: 10.1371/journal.pone.0108629] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 08/15/2014] [Indexed: 01/06/2023] Open
Abstract
Objective We examined metabolic and endocrine responses during rest and exercise in moderate hypoxia over a 7.5 h time courses during daytime. Methods Eight sedentary, overweight men (28.6±0.8 kg/m2) completed four experimental trials: a rest trial in normoxia (FiO2 = 20.9%, NOR-Rest), an exercise trial in normoxia (NOR-Ex), a rest trial in hypoxia (FiO2 = 15.0%, HYP-Rest), and an exercise trial in hypoxia (HYP-Ex). Experimental trials were performed from 8:00 to 15:30 in an environmental chamber. Blood and respiratory gas samples were collected over 7.5 h. In the exercise trials, subjects performed 30 min of pedaling exercise at 60% of VO2max at 8:00, 10:30, and 13:00, and rested during the remaining period in each environment. Standard meals were provided at 8:30, 11:00, and 13:30. Results The areas under the curves for blood glucose and serum insulin concentrations over 7.5 h did not differ among the four trials. At baseline, %carbohydrate contribution was significantly higher in the hypoxic trials than in the normoxic trials (P<0.05). Although exercise promoted carbohydrate oxidation in the NOR-Ex and HYP-Ex trials, %carbohydrate contribution during each exercise and post-exercise period were significantly higher in the HYP-Ex trial than in the NOR-Ex trial (P<0.05). Conclusion Three sessions of 30 min exercise (60% of VO2max) in moderate hypoxia over 7.5 h did not attenuate postprandial glucose and insulin responses in young, overweight men. However, carbohydrate oxidation was significantly enhanced when the exercise was conducted in moderate hypoxia.
Collapse
Affiliation(s)
- Takuma Morishima
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Ayaka Mori
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Hiroto Sasaki
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Kazushige Goto
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
- * E-mail:
| |
Collapse
|
36
|
Successive exposure to moderate hypoxia does not affect glucose metabolism and substrate oxidation in young healthy men. SPRINGERPLUS 2014; 3:370. [PMID: 25089253 PMCID: PMC4117865 DOI: 10.1186/2193-1801-3-370] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 07/03/2014] [Indexed: 12/03/2022]
Abstract
Introduction Exposure to hypoxia has been suggested to acutely alter glucose regulation. However, the effects of successive exposure to moderate hypoxia on postprandial glucose regulation and substrate oxidation pattern after multiple meals have not been elucidated. Purpose We examined the effects of successive exposure to moderate hypoxia on metabolic responses and substrate oxidation pattern. Methods Eight healthy men (21.0 ± 0.6 yrs, 173 ± 2.3 cm, 70.6 ± 5.0 kg, 23.4 ± 1.1 kg/m2) completed two experimental trials on separate days: a rest trial under normoxic conditions (FiO2 = 20.9%) and a rest trial under hypoxic conditions (FiO2 = 15.0%). Experimental trials were performed over 7 h in an environmental chamber. Blood and respiratory gas samples were collected over 7 h. Standard meals were provided 1 h (745 kcal) and 4 h (731 kcal) after entering the chamber. Results Although each meal significantly increased blood glucose and serum insulin concentrations (P < 0.05), these responses did not differ significantly between the trials. There were no significant differences in areas under the curves for glucose or insulin concentrations over 7 h between the trials. No significant differences were observed in blood lactate, serum cortisol, free fatty acid, or glycerol concentrations over 7 h between the trials. The oxygen consumption (
) and carbon dioxide production (
) 3 h after entering the chamber were significantly higher in the hypoxic trial than in the normoxic trial (P < 0.05). However, the differences did not affect respiratory exchange ratio (RER). The average values of
,
, and RER did not differ between the trials. Conclusion Seven hours of moderate hypoxia did not alter postprandial glucose responses or substrate oxidation in young healthy men.
Collapse
|
37
|
Duivenvoorde LPM, van Schothorst EM, Derous D, van der Stelt I, Masania J, Rabbani N, Thornalley PJ, Keijer J. Oxygen restriction as challenge test reveals early high-fat-diet-induced changes in glucose and lipid metabolism. Pflugers Arch 2014; 467:1179-93. [PMID: 24974902 DOI: 10.1007/s00424-014-1553-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 05/06/2014] [Accepted: 06/09/2014] [Indexed: 01/17/2023]
Abstract
Challenge tests stress homeostasis and may reveal deviations in health that remain masked under unchallenged conditions. Ideally, challenge tests are non-invasive and applicable in an early phase of an animal experiment. Oxygen restriction (OxR; based on ambient, mild normobaric hypoxia) is a non-invasive challenge test that measures the flexibility to adapt metabolism. Metabolic inflexibility is one of the hallmarks of the metabolic syndrome. To test whether OxR can be used to reveal early diet-induced health effects, we exposed mice to a low-fat (LF) or high-fat (HF) diet for only 5 days. The response to OxR was assessed by calorimetric measurements, followed by analysis of gene expression in liver and epididymal white adipose tissue (eWAT) and serum markers for e.g. protein glycation and oxidation. Although HF feeding increased body weight, HF and LF mice did not differ in indirect calorimetric values under normoxic conditions and in a fasting state. Exposure to OxR; however, increased oxygen consumption and lipid oxidation in HF mice versus LF mice. Furthermore, OxR induced gluconeogenesis and an antioxidant response in the liver of HF mice, whereas it induced de novo lipogenesis and an antioxidant response in eWAT of LF mice, indicating that HF and LF mice differed in their adaptation to OxR. OxR also increased serum markers of protein glycation and oxidation in HF mice, whereas these changes were absent in LF mice. Cumulatively, OxR is a promising new method to test food products on potential beneficial effects for human health.
Collapse
Affiliation(s)
- Loes P M Duivenvoorde
- Human and Animal Physiology, Wageningen University, De Elst 1, 6708 WD, Wageningen, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Siervo M, Riley HL, Fernandez BO, Leckstrom CA, Martin DS, Mitchell K, Levett DZH, Montgomery HE, Mythen MG, Grocott MPW, Feelisch M. Effects of prolonged exposure to hypobaric hypoxia on oxidative stress, inflammation and gluco-insular regulation: the not-so-sweet price for good regulation. PLoS One 2014; 9:e94915. [PMID: 24733551 PMCID: PMC3986261 DOI: 10.1371/journal.pone.0094915] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 03/21/2014] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVES The mechanisms by which low oxygen availability are associated with the development of insulin resistance remain obscure. We thus investigated the relationship between such gluco-insular derangements in response to sustained (hypobaric) hypoxemia, and changes in biomarkers of oxidative stress, inflammation and counter-regulatory hormone responses. METHODS After baseline testing in London (75 m), 24 subjects ascended from Kathmandu (1,300 m) to Everest Base Camp (EBC;5,300 m) over 13 days. Of these, 14 ascended higher, with 8 reaching the summit (8,848 m). Assessments were conducted at baseline, during ascent to EBC, and 1, 6 and 8 week(s) thereafter. Changes in body weight and indices of gluco-insular control were measured (glucose, insulin, C-Peptide, homeostasis model assessment of insulin resistance [HOMA-IR]) along with biomarkers of oxidative stress (4-hydroxy-2-nonenal-HNE), inflammation (Interleukin-6 [IL-6]) and counter-regulatory hormones (glucagon, adrenalin, noradrenalin). In addition, peripheral oxygen saturation (SpO2) and venous blood lactate concentrations were determined. RESULTS SpO2 fell significantly from 98.0% at sea level to 82.0% on arrival at 5,300 m. Whilst glucose levels remained stable, insulin and C-Peptide concentrations increased by >200% during the last 2 weeks. Increases in fasting insulin, HOMA-IR and glucagon correlated with increases in markers of oxidative stress (4-HNE) and inflammation (IL-6). Lactate levels progressively increased during ascent and remained significantly elevated until week 8. Subjects lost on average 7.3 kg in body weight. CONCLUSIONS Sustained hypoxemia is associated with insulin resistance, whose magnitude correlates with the degree of oxidative stress and inflammation. The role of 4-HNE and IL-6 as key players in modifying the association between sustained hypoxia and insulin resistance merits further investigation.
Collapse
Affiliation(s)
- Mario Siervo
- Human Nutrition Research Centre, Institute for Ageing and Health, Newcastle University, Newcastle on Tyne, United Kingdom
| | - Heather L. Riley
- Warwick Systems Biology Centre, University of Warwick, Coventry, United Kingdom
| | - Bernadette O. Fernandez
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
- University of Southampton, Clinical & Experimental Sciences, Faculty of Medicine, Southampton General Hospital, Southampton, United Kingdom
| | - Carl A. Leckstrom
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Daniel S. Martin
- Centre for Altitude Space and Extreme Environment Medicine, Portex Unit, UCL Institute of Child Health, London, United Kingdom
- Division of Surgery and Interventional Science, University College London, Royal Free Hospital, London, United Kingdom
| | - Kay Mitchell
- Centre for Altitude Space and Extreme Environment Medicine, Portex Unit, UCL Institute of Child Health, London, United Kingdom
- University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton, United Kingdom
| | - Denny Z. H. Levett
- Centre for Altitude Space and Extreme Environment Medicine, Portex Unit, UCL Institute of Child Health, London, United Kingdom
- University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton, United Kingdom
- Southampton NIHR Respiratory Biomedical Research Unit, Southampton, United Kingdom
| | - Hugh E. Montgomery
- Centre for Altitude Space and Extreme Environment Medicine, Portex Unit, UCL Institute of Child Health, London, United Kingdom
| | - Monty G. Mythen
- Centre for Altitude Space and Extreme Environment Medicine, Portex Unit, UCL Institute of Child Health, London, United Kingdom
| | - Michael P. W. Grocott
- University of Southampton, Clinical & Experimental Sciences, Faculty of Medicine, Southampton General Hospital, Southampton, United Kingdom
- Centre for Altitude Space and Extreme Environment Medicine, Portex Unit, UCL Institute of Child Health, London, United Kingdom
- University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton, United Kingdom
- Southampton NIHR Respiratory Biomedical Research Unit, Southampton, United Kingdom
| | - Martin Feelisch
- Warwick Systems Biology Centre, University of Warwick, Coventry, United Kingdom
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
- University of Southampton, Clinical & Experimental Sciences, Faculty of Medicine, Southampton General Hospital, Southampton, United Kingdom
- Southampton NIHR Respiratory Biomedical Research Unit, Southampton, United Kingdom
| | | |
Collapse
|
39
|
Hashimoto T, Yokokawa T, Endo Y, Iwanaka N, Higashida K, Taguchi S. Modest hypoxia significantly reduces triglyceride content and lipid droplet size in 3T3-L1 adipocytes. Biochem Biophys Res Commun 2013; 440:43-9. [DOI: 10.1016/j.bbrc.2013.09.034] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 09/05/2013] [Indexed: 12/26/2022]
|
40
|
Marquez JL, Rubinstein S, Fattor JA, Shah O, Hoffman AR, Friedlander AL. Cyclic hypobaric hypoxia improves markers of glucose metabolism in middle-aged men. High Alt Med Biol 2013; 14:263-72. [PMID: 24028640 DOI: 10.1089/ham.2012.1057] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
UNLABELLED Chronic hypoxia increases dependence on glucose in men and increases insulin sensitivity in men and women. Cyclic Variations in Altitude Conditioning (CVAC) is a novel technology that provides exposure to rapidly fluctuating cyclic hypobaric hypoxia (CHH). PURPOSE To test the hypothesis that markers of glucose metabolism would change with CVAC CHH, two groups of middle-aged men were exposed to 10 weeks (40 min/day, 3 day/week) of either CHH or sham (SH) sessions. METHODS CHH subjects (age: 48 ± 6, weight: 86 ± 12 kg, BMI: 27.1 ± 3, n=11) experienced cyclic pressures simulating altitudes ranging from sea level to 3048 m (week 1) and progressing to 6096 m (by week 5 through week 10). SH subjects (age: 50 ± 4, weight: 89 ± 15 kg, BMI: 27.5 ± 3, n=10) were exposed to slowly-fluctuating pressures up to 607 m (all subjects blinded to elevation). Physical function and blood markers of glucose metabolism were measured at baseline, 3, 6, and 10 weeks. RESULTS Two CHH subjects were dropped from analysis for failure to progress past 3048 m (CHH: n=9). Weight and physical activity remained stable for both groups. There was a group-by-time interaction in fasting glucose (CHH: 96 ± 9 to 91 ± 7 mg/dL, SH: 94 ± 7 to 97 ± 9 mg/dL, p<0.05). Reduction in plasma glucose response to oral glucose tolerance test [area under the curve] was greater in CHH compared to SH after 10 weeks of exposure (p<0.03). Neither group experienced changes in fasting insulin, insulin response during the OGTT, or changes in a timed walk test. CONCLUSION Ten weeks of CVAC CHH exposure improves markers of glucose metabolism in middle-aged men at risk for metabolic syndrome.
Collapse
Affiliation(s)
- Juan L Marquez
- 1 Clinical Studies Unit, VA Palo Alto Health Care System , Palo Alto, California
| | | | | | | | | | | |
Collapse
|
41
|
Stöwhas AC, Latshang TD, Lo Cascio CM, Lautwein S, Stadelmann K, Tesler N, Ayers L, Berneis K, Gerber PA, Huber R, Achermann P, Bloch KE, Kohler M. Effects of acute exposure to moderate altitude on vascular function, metabolism and systemic inflammation. PLoS One 2013; 8:e70081. [PMID: 23936377 PMCID: PMC3731354 DOI: 10.1371/journal.pone.0070081] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Accepted: 06/13/2013] [Indexed: 11/24/2022] Open
Abstract
Background Travel to mountain areas is popular. However, the effects of acute exposure to moderate altitude on the cardiovascular system and metabolism are largely unknown. Objectives To investigate the effects of acute exposure to moderate altitude on vascular function, metabolism and systemic inflammation. Methods In 51 healthy male subjects with a mean (SD) age of 26.9 (9.3) years, oxygen saturation, blood pressure, heart rate, arterial stiffness, lipid profiles, low density lipoprotein (LDL) particle size, insulin resistance (HOMA-index), highly-sensitive C-reactive protein and pro-inflammatory cytokines were measured at 490 m (Zurich) and during two days at 2590 m, (Davos Jakobshorn, Switzerland) in randomized order. The largest differences in outcomes between the two altitudes are reported. Results Mean (SD) oxygen saturation was significantly lower at 2590 m, 91.0 (2.0)%, compared to 490 m, 96.0 (1.0)%, p<0.001. Mean blood pressure (mean difference +4.8 mmHg, p<0.001) and heart rate (mean difference +3.3 bpm, p<0.001) were significantly higher at 2590 m, compared to 490 m, but this was not associated with increased arterial stiffness. At 2590 m, lipid profiles improved (median difference triglycerides −0.14 mmol/l, p = 0.012, HDL +0.08 mmol/l, p<0.001, total cholesterol/HDL-ratio −0.25, p = 0.001), LDL particle size increased (median difference +0.45 nm, p = 0.048) and hsCRP decreased (median difference −0.18 mg/l, p = 0.024) compared to 490 m. No significant change in pro-inflammatory cytokines or insulin resistance was observed upon ascent to 2590 m. Conclusions Short-term stay at moderate altitude is associated with increased blood pressure and heart rate likely due to augmented sympathetic activity. Exposure to moderate altitude improves the lipid profile and systemic inflammation, but seems to have no significant effect on glucose metabolism. Trial Registration ClinicalTrials.gov NCT01130948
Collapse
Affiliation(s)
| | | | | | - Sina Lautwein
- Pulmonary Division, University Hospital Zurich, Zurich, Switzerland
| | - Katrin Stadelmann
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Noemi Tesler
- Child Development Centre, University Children's Hospital Zurich, Zurich, Switzerland
| | - Lisa Ayers
- Department of Clinical Immunology, Churchill Hospital, Oxford, United Kingdom
| | - Kaspar Berneis
- Department of Endocrinology, Diabetes and Nutrition, University Hospital Zurich, Zurich, Switzerland
| | - Philipp A. Gerber
- Department of Endocrinology, Diabetes and Nutrition, University Hospital Zurich, Zurich, Switzerland
| | - Reto Huber
- Child Development Centre, University Children's Hospital Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Peter Achermann
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Konrad E. Bloch
- Pulmonary Division, University Hospital Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Malcolm Kohler
- Pulmonary Division, University Hospital Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
- * E-mail:
| |
Collapse
|
42
|
Morishima T, Kurihara T, Hamaoka T, Goto K. Whole body, regional fat accumulation, and appetite-related hormonal response after hypoxic training. Clin Physiol Funct Imaging 2013; 34:90-7. [PMID: 23879294 DOI: 10.1111/cpf.12069] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 06/28/2013] [Indexed: 01/18/2023]
Abstract
The present study was conducted to determine change in regional fat accumulation and appetite-related hormonal response following hypoxic training. Twenty sedentary subjects underwent hypoxic (n = 9, HYPO, FiO(2) = 15%) or normoxic training (n = 11, NOR, FiO(2) = 20·9%) during a 4-week period (3 days per week). They performed a 4-week training at 55% of maximal oxygen uptake (V·O(2max)) for each condition. Before and after the training period, V·O(2max), whole body fat mass, abdominal fat area, intramyocellular lipid content (IMCL), fasting and postprandial appetite-related hormonal responses were determined. Both groups showed a significant increase in V·O(2max) following training (P<0·05). Whole body and segmental fat mass, abdominal fat area, IMCL did not change in either group. Fasting glucose and insulin concentrations significantly reduced in both groups (P<0·05). Although area under the curve for the postprandial blood glucose concentrations significantly decreased in both groups (P<0·05), the change was significantly greater in the HYPO group than in the NOR group (P<0·05). Changes in postprandial plasma ghrelin were similar in both groups. A significant reduction of postprandial leptin response was observed in both groups (P<0·05), while postprandial glucagon-like peptide-1 (GLP-1) concentrations increased significantly in the NOR group only (P<0·05). In conclusion, hypoxic training for 4 weeks resulted in greater improvement in glucose tolerance without loss of whole body fat mass, abdominal fat area or IMCL. However, hypoxic training did not have synergistic effect on the regulation of appetite-related hormones.
Collapse
Affiliation(s)
- Takuma Morishima
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
| | | | | | | |
Collapse
|
43
|
Cizza G, Piaggi P, Lucassen EA, de Jonge L, Walter M, Mattingly MS, Kalish H, Csako G, Rother KI. Obstructive sleep apnea is a predictor of abnormal glucose metabolism in chronically sleep deprived obese adults. PLoS One 2013; 8:e65400. [PMID: 23734252 PMCID: PMC3667085 DOI: 10.1371/journal.pone.0065400] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 05/01/2013] [Indexed: 12/12/2022] Open
Abstract
Context Sleep abnormalities, including obstructive sleep apnea (OSA), have been associated with insulin resistance. Objective To determine the relationship between sleep, including OSA, and glucose parameters in a prospectively assembled cohort of chronically sleep-deprived obese subjects. Design Cross-sectional evaluation of a prospective cohort study. Setting Tertiary Referral Research Clinical Center. Main Outcome Measure(s) Sleep duration and quality assessed by actigraphy, sleep diaries and questionnaires, OSA determined by a portable device; glucose metabolism assessed by oral glucose tolerance test (oGTT), and HbA1c concentrations in 96 obese individuals reporting sleeping less than 6.5 h on a regular basis. Results Sixty % of subjects had an abnormal respiratory disturbance index (RDI≥5) and 44% of these subjects had abnormal oGTT results. Severity of OSA as assessed by RDI score was associated with fasting glucose (R = 0.325, p = 0.001) and fasting insulin levels (ρ = 0.217, p = 0.033). Subjects with moderate to severe OSA (RDI>15) had higher glucose concentrations at 120 min than those without OSA (RDI<5) (p = 0.017). Subjects with OSA also had significantly higher concentrations of plasma ACTH (p = 0.009). Several pro-inflammatory cytokines were higher in subjects with OSA (p<0.050). CRP levels were elevated in this sample, suggesting increased cardiovascular risk. Conclusions OSA is associated with impaired glucose metabolism in obese, sleep deprived individuals. Since sleep apnea is common and frequently undiagnosed, health care providers should be aware of its occurrence and associated risks. Trial Registration This study was conducted under the NIDDK protocol 06-DK-0036 and is listed in ClinicalTrials.gov NCT00261898
Collapse
Affiliation(s)
- Giovanni Cizza
- Section on Neuroendocrinology of Obesity, National Institute of Diabetes, Digestive, and Kidney Disease, Bethesda, Maryland, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Laurie SS, Elliott JE, Goodman RD, Lovering AT. Catecholamine-induced opening of intrapulmonary arteriovenous anastomoses in healthy humans at rest. J Appl Physiol (1985) 2012; 113:1213-22. [PMID: 22858627 DOI: 10.1152/japplphysiol.00565.2012] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mechanism or mechanisms that cause intrapulmonary arteriovenous anastomoses (IPAVA) to either open during exercise in subjects breathing room air and at rest when breathing hypoxic gas mixtures, or to close during exercise while breathing 100% oxygen, remain unknown. During conditions when IPAVA are open, plasma epinephrine (EPI) and dopamine (DA) concentrations both increase, potentially representing a common mechanism. The purpose of this study was to determine whether EPI or DA infusions open IPAVA in resting subjects breathing room air and, subsequently, 100% oxygen. We hypothesized that these catecholamine infusions would open IPAVA. We performed saline-contrast echocardiography in nine subjects without a patent foramen ovale before and during serial EPI and DA infusions while breathing room air and then while breathing 100% oxygen. Bubble scores (0-5) were assigned based on the number and spatial distribution of bubbles in the left ventricle. Pulmonary artery systolic pressure (PASP) was estimated using Doppler ultrasound, while cardiac output (Q(C)) was measured using echocardiography. Bubble scores were significantly greater during EPI infusions of 80-320 ng·kg(-1)·min(-1) compared with baseline when subjects breathed room air; however, bubble scores did not increase when they breathed 100% oxygen. At comparable Q(C) and PASP, intravenous DA (16 μg·kg(-1)·min(-1)) and EPI (40 ng·kg(-1)·min(-1)) resulted in identical bubble scores. Subsequent studies revealed that β-blockade did not prevent hypoxia-induced opening of IPAVA. We suggest that increases in Q(C) or PASP (or both) secondary to EPI or DA infusions open IPAVA in normoxia. The closing mechanism associated with breathing 100% oxygen is independent from the opening mechanisms.
Collapse
Affiliation(s)
- Steven S Laurie
- Department of Human Physiology, University of Oregon, Eugene, OR 97403, USA
| | | | | | | |
Collapse
|
45
|
Ge RL, Simonson TS, Cooksey RC, Tanna U, Qin G, Huff CD, Witherspoon DJ, Xing J, Zhengzhong B, Prchal JT, Jorde LB, McClain DA. Metabolic insight into mechanisms of high-altitude adaptation in Tibetans. Mol Genet Metab 2012; 106:244-7. [PMID: 22503288 PMCID: PMC3437309 DOI: 10.1016/j.ymgme.2012.03.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 03/09/2012] [Accepted: 03/09/2012] [Indexed: 11/26/2022]
Abstract
Recent studies have identified genes involved in high-altitude adaptation in Tibetans. Genetic variants/haplotypes within regions containing three of these genes (EPAS1, EGLN1, and PPARA) are associated with relatively decreased hemoglobin levels observed in Tibetans at high altitude, providing corroborative evidence for genetic adaptation to this extreme environment. The mechanisms that afford adaptation to high-altitude hypoxia, however, remain unclear. Considering the strong metabolic demands imposed by hypoxia, we hypothesized that a shift in fuel preference to glucose oxidation and glycolysis at the expense of fatty acid oxidation would improve adaptation to decreased oxygen availability. Correlations between serum free fatty acid and lactate concentrations in Tibetan groups living at high altitude and putatively selected haplotypes provide insight into this hypothesis. An EPAS1 haplotype that exhibits a signal of positive selection is significantly associated with increased lactate concentration, the product of anaerobic glycolysis. Furthermore, the putatively advantageous PPARA haplotype is correlated with serum free fatty acid concentrations, suggesting a possible decrease in the activity of fatty acid oxidation. Although further studies are required to assess the molecular mechanisms underlying these patterns, these associations suggest that genetic adaptation to high altitude involves alteration in energy utilization pathways.
Collapse
Affiliation(s)
- Ri-Li Ge
- Research Center for High-Altitude Medicine, Qinghai University Medical School, Xining, Qinghai 810001, People’s Republic of China
| | - Tatum S. Simonson
- University of Utah School of Medicine, Department of Human Genetics and Divisions of Endocrinology, Metabolism, and Diabetes and Division of Hematology, Salt Lake City, UT 84112, USA
| | - Robert C. Cooksey
- University of Utah School of Medicine, Department of Human Genetics and Divisions of Endocrinology, Metabolism, and Diabetes and Division of Hematology, Salt Lake City, UT 84112, USA
| | - Uran Tanna
- Research Center for High-Altitude Medicine, Qinghai University Medical School, Xining, Qinghai 810001, People’s Republic of China
| | - Ga Qin
- Research Center for High-Altitude Medicine, Qinghai University Medical School, Xining, Qinghai 810001, People’s Republic of China
| | - Chad D. Huff
- University of Utah School of Medicine, Department of Human Genetics and Divisions of Endocrinology, Metabolism, and Diabetes and Division of Hematology, Salt Lake City, UT 84112, USA
| | - David J. Witherspoon
- University of Utah School of Medicine, Department of Human Genetics and Divisions of Endocrinology, Metabolism, and Diabetes and Division of Hematology, Salt Lake City, UT 84112, USA
| | - Jinchuan Xing
- University of Utah School of Medicine, Department of Human Genetics and Divisions of Endocrinology, Metabolism, and Diabetes and Division of Hematology, Salt Lake City, UT 84112, USA
| | - Bai Zhengzhong
- Research Center for High-Altitude Medicine, Qinghai University Medical School, Xining, Qinghai 810001, People’s Republic of China
| | - Josef T. Prchal
- University of Utah School of Medicine, Department of Human Genetics and Divisions of Endocrinology, Metabolism, and Diabetes and Division of Hematology, Salt Lake City, UT 84112, USA
| | - Lynn B. Jorde
- University of Utah School of Medicine, Department of Human Genetics and Divisions of Endocrinology, Metabolism, and Diabetes and Division of Hematology, Salt Lake City, UT 84112, USA
| | - Donald A. McClain
- University of Utah School of Medicine, Department of Human Genetics and Divisions of Endocrinology, Metabolism, and Diabetes and Division of Hematology, Salt Lake City, UT 84112, USA
- Address for correspondence: Donald McClain, Division of Endocrinology, University of Utah, 30 N. 2030 E, Salt Lake City, UT 84132, Tel.: (801) 581-7755, Fax: (801) 585-0956,
| |
Collapse
|
46
|
Urdampilleta A, González-Muniesa P, Portillo MP, Martínez JA. Usefulness of combining intermittent hypoxia and physical exercise in the treatment of obesity. J Physiol Biochem 2011; 68:289-304. [PMID: 22045452 DOI: 10.1007/s13105-011-0115-1] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Accepted: 09/01/2011] [Indexed: 12/19/2022]
Abstract
Obesity is an important public health problem worldwide and is a major risk factor for a number of chronic diseases such as type II diabetes, adverse cardiovascular events and metabolic syndrome-related features. Different treatments have been applied to tackle body fat accumulation and its associated clinical manifestations. Often, relevant weight loss is achieved during the first 6 months under different dietary treatments. From this point, a plateau is reached, and a gradual recovery of the lost weight may occur. Therefore, new research approaches are being investigated to assure weight maintenance. Pioneering investigations have reported that oxygen variations in organic systems may produce changes in body composition. Possible applications of intermittent hypoxia to promote health and in various pathophysiological states have been reported. The hypoxic stimulus in addition to diet and exercise can be an interesting approach to lose weight, by inducing higher basal noradrenalin levels and other metabolic changes whose mechanisms are still unclear. Indeed, hypoxic situations increase the diameter of arterioles, produce peripheral vasodilatation and decrease arterial blood pressure. Furthermore, hypoxic training increases the activity of glycolytic enzymes, enhancing the number of mitochondria and glucose transporter GLUT-4 levels as well as improving insulin sensitivity. Moreover, hypoxia increases blood serotonin and decreases leptin levels while appetite is suppressed. These observations allow consideration of the hypothesis that intermittent hypoxia induces fat loss and may ameliorate cardiovascular health, which might be of interest for the treatment of obesity. This new strategy may be useful and practical for clinical applications in obese patients.
Collapse
Affiliation(s)
- Aritz Urdampilleta
- Department of Pharmacy and Food Sciences, University of Basque Country, Vitoria-Gasteiz, Spain
| | | | | | | |
Collapse
|
47
|
Burtscher M, Mairer K, Wille M, Gatterer H, Ruedl G, Faulhaber M, Sumann G. Short-term exposure to hypoxia for work and leisure activities in health and disease: which level of hypoxia is safe? Sleep Breath 2011; 16:435-42. [PMID: 21499843 DOI: 10.1007/s11325-011-0521-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 03/16/2011] [Accepted: 04/05/2011] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Exposures to natural and simulated altitudes entail reduced oxygen availability and thus hypoxia. Depending on the level of hypoxia, the duration of exposure, the individual susceptibility, and preexisting diseases, health problems of variable severity may arise. Although millions of people are regularly or occasionally performing mountain sport activities, are transported by airplanes, and are more and more frequently exposed to short-term hypoxia in athletic training facilities or at their workplace, e.g., with fire control systems, there is no clear consensus on the level of hypoxia which is generally well tolerated by human beings when acutely exposed for short durations (hours to several days). CONCLUSIONS Available data from peer-reviewed literature report adaptive responses even to altitudes below 2,000 m or corresponding normobaric hypoxia (F(i)O(2) > 16.4%), but they also suggest that most of exposed subjects without severe preexisting diseases can tolerate altitudes up to 3,000 m (F(i)O(2) > 14.5%) well. However, physical activity and unusual environmental conditions may increase the risk to get sick. Large interindividual variations of responses to hypoxia have to be expected, especially in persons with preexisting diseases. Thus, the assessment of those responses by hypoxic challenge testing may be helpful whenever possible.
Collapse
Affiliation(s)
- Martin Burtscher
- Department of Sport Science, Medical Section, University of Innsbruck, Fürstenweg 185, 6020, Innsbruck, Austria.
| | | | | | | | | | | | | |
Collapse
|
48
|
The Impact of 32 Days' Exposure to Hypobaric Hypoxia on Physiological Cost of Sub-Maximal Work Performed at the Sea Level. BALTIC JOURNAL OF HEALTH AND PHYSICAL ACTIVITY 2011. [DOI: 10.2478/v10131-011-0002-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
49
|
Mackenzie R, Maxwell N, Castle P, Brickley G, Watt P. Acute hypoxia and exercise improve insulin sensitivity (S(I) (2*)) in individuals with type 2 diabetes. Diabetes Metab Res Rev 2011; 27:94-101. [PMID: 21218513 DOI: 10.1002/dmrr.1156] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND hypoxia has been shown to increase glucose uptake in skeletal muscle using the contraction-stimulated pathway, independent of the actions of insulin. Yet, the same stress has also been linked with causing insulin resistance and hyperglycaemia. The aim of this study was to examine the effects of acute hypoxia with and without exercise on insulin sensitivity (S(I)(2*) in individuals with type 2 diabetes. METHODS eight type 2 diabetic patients completed 60 min of the following: (1) normoxic rest; (2) hypoxic rest [O(2) = 14.6 (0.4)%]; (3) normoxic exercise and (4) hypoxic exercise [O(2) = 14.6 (0.4)%]. Exercise trials were set at 90% of lactate threshold. Each condition was followed by a labelled intravenous glucose tolerance test to provide estimations of insulin sensitivity (S(I)(2*) and β-cell function. RESULTS Two-compartmental analysis showed that insulin sensitivity (S(I)(2*) was higher following hypoxic rest compared with normoxic rest (p = 0.047). Insulin sensitivity (S(I)(2*) was also higher following hypoxic exercise [4.37 (0.48) × 10(-4) /min (µU/mL)] compared with normoxic exercise [3.24 (0.51) × 10(-4) /min (µU/mL)] (p = 0.048). Acute insulin response to glucose was reduced following hypoxic rest versus normoxic rest (p = 0.014). CONCLUSIONS this study demonstrated that (1) hypoxic-induced improvements in glucose tolerance in the 4 h following exposure can be attributed to improvements in peripheral insulin sensitivity (S( I)(2*) and (2) exercise and hypoxia have an additive effect on insulin sensitivity (S(I)(2*) in type 2 diabetic patients. Acute hypoxia may therefore improve short-term glycaemic control in individuals with type 2 diabetes. The application of these findings in the clinic will require further investigation.
Collapse
Affiliation(s)
- Richard Mackenzie
- School of Life Sciences, Department of Human and Health Sciences, University of Westminster, London, United Kingdom.
| | | | | | | | | |
Collapse
|