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Muscle Lipid Oxidation Is Not Affected by Obstructive Sleep Apnea in Diabetes and Healthy Subjects. Int J Mol Sci 2023; 24:ijms24065308. [PMID: 36982383 PMCID: PMC10048979 DOI: 10.3390/ijms24065308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 03/05/2023] [Accepted: 03/07/2023] [Indexed: 03/12/2023] Open
Abstract
The molecular mechanisms linking obstructive sleep apnea (OSA) with type 2 diabetes mellitus (T2DM) remain unclear. This study investigated the effect of OSA on skeletal muscle lipid oxidation in nondiabetic controls and in type 2 diabetes (T2DM) patients. Forty-four participants matched for age and adiposity were enrolled: nondiabetic controls (control, n = 14), nondiabetic patients with severe OSA (OSA, n = 9), T2DM patients with no OSA (T2DM, n = 10), and T2DM patients with severe OSA (T2DM + OSA, n = 11). A skeletal muscle biopsy was performed; gene and protein expressions were determined and lipid oxidation was analyzed. An intravenous glucose tolerance test was performed to investigate glucose homeostasis. No differences in lipid oxidation (178.2 ± 57.1, 161.7 ± 22.4, 169.3 ± 50.9, and 140.0 ± 24.1 pmol/min/mg for control, OSA, T2DM, and T2DM+OSA, respectively; p > 0.05) or gene and protein expressions were observed between the groups. The disposition index, acute insulin response to glucose, insulin resistance, plasma insulin, glucose, and HBA1C progressively worsened in the following order: control, OSA, T2DM, and T2DM + OSA (p for trend <0.05). No association was observed between the muscle lipid oxidation and the glucose metabolism variables. We conclude that severe OSA is not associated with reduced muscle lipid oxidation and that metabolic derangements in OSA are not mediated through impaired muscle lipid oxidation.
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Behrendt T, Altorjay AC, Bielitzki R, Behrens M, Glazachev OS, Schega L. Influence of acute and chronic intermittent hypoxic-hyperoxic exposure prior to aerobic exercise on cardiovascular risk factors in geriatric patients-a randomized controlled trial. Front Physiol 2022; 13:1043536. [PMID: 36388103 PMCID: PMC9650443 DOI: 10.3389/fphys.2022.1043536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 10/11/2022] [Indexed: 04/08/2024] Open
Abstract
Background: Intermittent hypoxic-hyperoxic exposure (IHHE) and aerobic training have been proposed as non-pharmacological interventions to reduce age-related risk factors. However, no study has yet examined the effects of IHHE before aerobic exercise on cardiovascular risk factors in the elderly. Therefore, the aim of this study was to investigate the acute and chronic effects of IHHE prior to aerobic cycling exercise on blood lipid and lipoprotein concentrations as well as blood pressure in geriatric patients. Methods: In a randomized, controlled, and single-blinded trial, thirty geriatric patients (72-94 years) were assigned to two groups: intervention (IG; n = 16) and sham control group (CG; n = 14). Both groups completed 6 weeks of aerobic cycling training, 3 times a week for 20 min per day. The IG and CG were additionally exposed to IHHE or sham IHHE (i.e., normoxia) for 30 min prior to aerobic cycling. Blood samples were taken on three occasions: immediately before the first, ∼10 min after the first, and immediately before the last session. Blood samples were analyzed for total (tCh), high-density (HDL-C), and low-density lipoprotein cholesterol (LDL-C), and triglyceride (Tgl) serum concentration. Resting systolic (SBP) and diastolic blood pressure (DBP) was assessed within 1 week before, during (i.e., at week two and four), and after the interventions. Results: The baseline-adjusted ANCOVA revealed a higher LDL-C concentration in the IG compared to the CG after the first intervention session (ηp 2 = 0.12). For tCh, HDL-C, Tgl, and tCh/HDL-C ratio there were no differences in acute changes between the IG and the CG (ηp 2 ≤ 0.01). With regard to the chronic effects on lipids and lipoproteins, data analysis indicated no differences between groups (ηp 2 ≤ 0.03). The repeated measures ANOVA revealed an interaction effect for SBP (ηp 2 = 0.06) but not for DBP (ηp 2 ≤ 0.01). Within-group post-hoc analysis for the IG indicated a reduction in SBP at post-test (d = 0.05). Conclusion: Applying IHHE prior to aerobic cycling seems to be effective to reduce SBP in geriatric patients after 6 weeks of training. The present study suggests that IHHE prior to aerobic cycling can influence the acute exercise-related responses in LDL-C concentration but did not induce chronic changes in basal lipid or lipoprotein concentrations.
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Affiliation(s)
- Tom Behrendt
- Department for Sport Science, Chair for Health and Physical Activity, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Ann-Christin Altorjay
- Department of Internal Medicine, Division of Cardiology and Angiology, University Hospital Magdeburg, Magdeburg, Germany
| | - Robert Bielitzki
- Department for Sport Science, Chair for Health and Physical Activity, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Martin Behrens
- Department for Sport Science, Chair for Health and Physical Activity, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
- Department of Orthopedics, University Medicine Rostock, Rostock, Germany
| | - Oleg S. Glazachev
- Departement Human Physiology, Institute of Clinical Medicine, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Lutz Schega
- Department for Sport Science, Chair for Health and Physical Activity, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
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Thanaviratananich S, Cheng H, Chirakalwasan N, Reutrakul S. Association between nocturnal hypoxemic burden and glucose metabolism. Sleep Breath 2021; 26:1465-1470. [PMID: 34390444 DOI: 10.1007/s11325-021-02464-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 07/12/2021] [Accepted: 08/02/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE To evaluate the association between a novel integrated event-based and hypoxemia-based parameter of polysomnography (PSG), hypoxemic load or HL100, and fasting blood glucose (FBG) and hemoglobin A1c (HbA1c) levels. METHODS Adult patients, who underwent an in-lab PSG at the University of Iowa Hospitals and Clinics with FBG or HbA1c levels, were included. Event-based parameter and hypoxemia-based parameter data were derived. HL100, defined as the integrated area of desaturation between the 100% oxygen saturation and the measured saturation levels during sleep divided by the total sleep time, was calculated by Python software. Demographic data and glycemic parameters within 1 year prior to PSG (FBG and HbA1c) were retrieved from chart review. Spearman correlation analysis and stepwise backward regression analysis were performed to determine independent predictors of FBG and HbA1c levels. RESULTS Of the 467 patients who underwent an in-lab PSG, 218 had FBG levels, 84 had HbA1c levels, and 118 had both values. All event-based and hypoxemia-based parameters, including HL100, were significantly correlated to FBG and HbA1c levels. Stepwise backward regression analyses, adjusted for age, sex, body mass index, and diabetes status, revealed that log HL100 was significantly related to FBG (B = 23.9, p = 0.010), but none of log event-based or hypoxemia-based parameters were found to be significantly related HbA1c levels. CONCLUSIONS HL100 was shown to be an independent predictor of FBG in this cohort, implying that any degree of desaturation below 100% could adversely affect glucose metabolism. HL100 may be useful for interpretation of sleep studies, risk stratification, and patient management purposes in the future.
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Affiliation(s)
- Sikawat Thanaviratananich
- Department of Neurology, Carver College of Medicine, University of Iowa, 200 Hawkins Dr, Iowa City, IA, 52242, USA.
| | - Hao Cheng
- Miami VA Healthcare System, Miami, FL, USA
| | - Naricha Chirakalwasan
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Excellence Center for Sleep Disorders, King Chulalongkorn Memorial Hospital/Thai Red Cross Society, Bangkok, Thailand
| | - Sirimon Reutrakul
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois At Chicago, Chicago, IL, USA
- Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
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Acute intermittent hypoxia evokes ventilatory long-term facilitation and active expiration in unanesthetized rats. Respir Physiol Neurobiol 2021; 294:103768. [PMID: 34343692 DOI: 10.1016/j.resp.2021.103768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 07/23/2021] [Accepted: 07/29/2021] [Indexed: 11/23/2022]
Abstract
Acute intermittent hypoxia (AIH) modifies the functioning of the respiratory network, causing respiratory motor facilitation in anesthetized animals and a compensatory increase in pulmonary ventilation in freely behaving animals. However, it is still unclear whether the ventilatory facilitation induced by AIH in unanesthetized animals is associated with changes in the respiratory pattern. We found that Holtzman male rats (80-150 g) exposed to AIH (10 × 6% O2 for 30-40 s every 5 min, n = 9) exhibited a prolonged (30 min) increase in baseline minute ventilation (P < 0.05) compared to control animals (n = 13), combined with the occurrence of late expiratory peak flow events, suggesting the presence of active expiration. The increase in ventilation after AIH was also accompanied by reductions in arterial CO2 and body temperature (n = 5-6, P < 0.05). The systemic treatment with ketanserin (a 5-HT2 receptor antagonist) before AIH prevented the changes in ventilation and active expiration (n = 11) but potentiated the hypothermic response (n = 5, P < 0.05) when compared to appropriate control rats (n = 13). Our findings indicate that the ventilatory long-term facilitation elicited by AIH exposure in unanesthetized rats is linked to the generation of active expiration by mechanisms that may depend on the activation of serotonin receptors. In contrast, the decrease in body temperature induced by AIH may not require 5-HT2 receptor activation.
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Vacelet L, Hupin D, Pichot V, Celle S, Court-Fortune I, Thomas T, Garcin A, Barthélémy JC, Gozal D, Roche F. Insulin Resistance and Type 2 Diabetes in Asymptomatic Obstructive Sleep Apnea: Results of the PROOF Cohort Study After 7 Years of Follow-Up. Front Physiol 2021; 12:650758. [PMID: 34393806 PMCID: PMC8355896 DOI: 10.3389/fphys.2021.650758] [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: 01/07/2021] [Accepted: 07/05/2021] [Indexed: 11/25/2022] Open
Abstract
The aim of the study was to assess potential associations between obstructive sleep apnea (OSA) and the occurrence of diabetes mellitus and insulin resistance in the elderly. Nondiabetic volunteers (n = 549) with undiagnosed or untreated asymptomatic OSA (66.2+/−1 years at the inclusion) were evaluated as an ancillary study of the PROOF cohort study (n = 1,011). After 7 years follow-up, 494 subjects underwent assessment of fasting insulin and glucose levels. OSA was defined by an apnea-hypopnea index (AHI) of ≥15/h using polygraphy. Diabetes mellitus was defined by a fasting glucose ≥ 1.26 g/L and/or when requiring pharmacological treatment, while insulin resistance corresponded to HOMA-IR ≥ 2. Asymptomatic OSA subjects (men or women) did not display increased risk of incident diabetes (2.8 vs. 3.9%, p = 0.51). However, there was a greater frequency of insulin resistance in subjects with severe OSA (AHI > 30) [OR 2.21; 95% CI (1.22–4.02); p = 0.009]. Furthermore, multiple logistic regression showed that triglycerides levels [OR 1.61; 95% CI (1.10–2.36); p = 0.01] and fasting glycaemia [OR 4.69; 95% CI (1.12–192.78); p = 0.04], but not AHI or oxyhemoglobin desaturation index were independently associated with higher rate of insulin resistance. The deleterious metabolic effect of asymptomatic OSA in the population may be indirectly mediated via perturbations in lipids, and is particularly likely to become manifest in severe apneic subjects with higher glycemic levels.
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Affiliation(s)
- Laurine Vacelet
- Service de Physiologie Clinique et de l'Exercice, CHU Saint Etienne, Saint Etienne Cedex, France.,Sainbiose DVH U1059 Inserm, Faculté de Médecine J Lisfranc, Université Jean Monnet, Saint Etienne Cedex, France
| | - David Hupin
- Service de Physiologie Clinique et de l'Exercice, CHU Saint Etienne, Saint Etienne Cedex, France.,Service de Pneumologie, CHU Saint Etienne, Saint Etienne Cedex, France
| | - Vincent Pichot
- Service de Physiologie Clinique et de l'Exercice, CHU Saint Etienne, Saint Etienne Cedex, France.,Service de Pneumologie, CHU Saint Etienne, Saint Etienne Cedex, France
| | - Sébastien Celle
- Service de Physiologie Clinique et de l'Exercice, CHU Saint Etienne, Saint Etienne Cedex, France.,Service de Pneumologie, CHU Saint Etienne, Saint Etienne Cedex, France
| | - Isabelle Court-Fortune
- Sainbiose DVH U1059 Inserm, Faculté de Médecine J Lisfranc, Université Jean Monnet, Saint Etienne Cedex, France
| | - Thierry Thomas
- Service de Pneumologie, CHU Saint Etienne, Saint Etienne Cedex, France.,Service de Rhumatologie, CHU Saint Etienne, Saint Etienne Cedex, France
| | - Arnauld Garcin
- Service de Pneumologie, CHU Saint Etienne, Saint Etienne Cedex, France.,URCIP, CHU Saint Etienne, Saint Etienne Cedex, France
| | - Jean-Claude Barthélémy
- Service de Physiologie Clinique et de l'Exercice, CHU Saint Etienne, Saint Etienne Cedex, France.,Service de Pneumologie, CHU Saint Etienne, Saint Etienne Cedex, France
| | - David Gozal
- Department of Child Health, MU Women's and Children's Hospital, Columbia, MO, United States
| | - Frédéric Roche
- Service de Physiologie Clinique et de l'Exercice, CHU Saint Etienne, Saint Etienne Cedex, France.,Service de Pneumologie, CHU Saint Etienne, Saint Etienne Cedex, France
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Nedoboy PE, Houlahan CB, Farnham MMJ. Pentobarbital Anesthesia Suppresses the Glucose Response to Acute Intermittent Hypoxia in Rat. Front Physiol 2021; 12:645392. [PMID: 33746780 PMCID: PMC7973217 DOI: 10.3389/fphys.2021.645392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/17/2021] [Indexed: 11/17/2022] Open
Abstract
A key feature of sleep disordered breathing syndromes, such as obstructive sleep apnea is intermittent hypoxia. Intermittent hypoxia is well accepted to drive the sympathoexcitation that is frequently associated with hypertension and diabetes, with measurable effects after just 1 h. The aim of this study was to directly measure the glucose response to 1 h of acute intermittent hypoxia in pentobarbital anesthetized rats, compared to conscious rats. However, we found that while a glucose response is measurable in conscious rats exposed to intermittent hypoxia, it is suppressed in anesthetized rats. Intermittent hypoxia for 1, 2, or 8 h increased blood glucose by 0.7 ± 0.1 mmol/L in conscious rats but had no effect in anesthetized rats (−0.1 ± 0.2 mmol/L). These results were independent of the frequency of the hypoxia challenges, fasting state, vagotomy, or paralytic agents. A supraphysiological challenge of 3 min of hypoxia was able to induce a glycemic response indicating that the reflex response is not abolished under pentobarbital anesthesia. We conclude that pentobarbital anesthesia is unsuitable for investigations into glycemic response pathways in response to intermittent hypoxia in rats.
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Affiliation(s)
- Polina E Nedoboy
- Cardiovascular Neuroscience Unit, Heart Research Institute, Newtown, NSW, Australia.,Department of Physiology, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
| | - Callum B Houlahan
- Cardiovascular Neuroscience Unit, Heart Research Institute, Newtown, NSW, Australia.,Department of Physiology, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
| | - Melissa M J Farnham
- Cardiovascular Neuroscience Unit, Heart Research Institute, Newtown, NSW, Australia.,Department of Physiology, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
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Brognara F, Felippe ISA, Salgado HC, Paton JFR. Autonomic innervation of the carotid body as a determinant of its sensitivity: implications for cardiovascular physiology and pathology. Cardiovasc Res 2020; 117:1015-1032. [PMID: 32832979 DOI: 10.1093/cvr/cvaa250] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 07/01/2020] [Accepted: 08/18/2020] [Indexed: 12/14/2022] Open
Abstract
The motivation for this review comes from the emerging complexity of the autonomic innervation of the carotid body (CB) and its putative role in regulating chemoreceptor sensitivity. With the carotid bodies as a potential therapeutic target for numerous cardiorespiratory and metabolic diseases, an understanding of the neural control of its circulation is most relevant. Since nerve fibres track blood vessels and receive autonomic innervation, we initiate our review by describing the origins of arterial feed to the CB and its unique vascular architecture and blood flow. Arterial feed(s) vary amongst species and, unequivocally, the arterial blood supply is relatively high to this organ. The vasculature appears to form separate circuits inside the CB with one having arterial venous anastomoses. Both sympathetic and parasympathetic nerves are present with postganglionic neurons located within the CB or close to it in the form of paraganglia. Their role in arterial vascular resistance control is described as is how CB blood flow relates to carotid sinus afferent activity. We discuss non-vascular targets of autonomic nerves, their possible role in controlling glomus cell activity, and how certain transmitters may relate to function. We propose that the autonomic nerves sub-serving the CB provide a rapid mechanism to tune the gain of peripheral chemoreflex sensitivity based on alterations in blood flow and oxygen delivery, and might provide future therapeutic targets. However, there remain a number of unknowns regarding these mechanisms that require further research that is discussed.
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Affiliation(s)
- Fernanda Brognara
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton Auckland 1023, New Zealand.,Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Igor S A Felippe
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton Auckland 1023, New Zealand
| | - Helio C Salgado
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Julian F R Paton
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton Auckland 1023, New Zealand
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Post-weaning exposure to high-sucrose diet induces early non-alcoholic fatty liver disease onset and progression in male mice: role of dysfunctional white adipose tissue. J Dev Orig Health Dis 2020; 11:509-520. [PMID: 32594969 DOI: 10.1017/s2040174420000598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome, ranging from simple steatosis to non-alcoholic steatohepatitis (NASH) particularly among chronic consumers of added sugar-rich diets. However, the impact of early consumption of such diets on NAFLD onset and progression is unclear. Thus, this study sought to characterise metabolic factors involved in NAFLD progression in young mice fed with a high-sucrose diet (HSD). Male Swiss mice were fed HSD or regular chow (CTR) from weaning for up to 60 or 90 days. Obesity development, glucose homeostasis and serum biochemical parameters were determined at each time-point. At day 90, mice were euthanised and white adipose tissue (WAT) collected for lipolytic function assessment and liver for histology, gene expression and cytokines quantification. At day 60, HSD mice presented increased body mass, hypertriglyceridemia, peripheral insulin resistance (IR) and simple steatosis. Upon 90 days on diet, WAT from HSD mice displayed impaired insulin sensitivity, which coincided with increased fasting levels of glucose and free fatty acids (FFA), as well as NAFLD progression to NASH. Transcriptional levels of lipogenic genes, particularly stearoyl-CoA desaturase-1, were consistently increased, leading to hepatic leukocyte infiltration and pro-inflammatory cytokines spillover. Therefore, our dataset supports IR triggering in the WAT as a major factor for dysfunctional release of FFA towards portal circulation and consequent upregulation of lipogenic genes and hepatic inflammatory onset, which decisively concurred for NAFLD-to-NASH progression in young HSD-fed mice. Notwithstanding, this study forewarns against the early introduction of dietary sugars in infant diet, particularly following breastfeeding cessation.
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Johns EC, Denison FC, Reynolds RM. Sleep disordered breathing in pregnancy: A review of the pathophysiology of adverse pregnancy outcomes. Acta Physiol (Oxf) 2020; 229:e13458. [PMID: 32087033 DOI: 10.1111/apha.13458] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/19/2020] [Accepted: 02/19/2020] [Indexed: 12/11/2022]
Abstract
Sleep disordered breathing (SDB) is a common obesity-related co-morbidity with strong associations to cardiometabolic disease. The risk of SDB is increased during pregnancy, particularly among obese pregnant women. Accumulating evidence suggests that an association exists between maternal SDB and the development of adverse pregnancy outcomes, particularly gestational diabetes and hypertensive disorders of pregnancy. Intermittent hypoxia, a central characteristic of SDB, has been shown in animal and clinical studies to dysregulate several biological pathways. This includes the promotion of oxidative stress, increased inflammation, activation of the hypothalamic-pituitary-adrenal axis, increased sympathetic activity and impaired glucose and insulin metabolism. This review considers how, during pregnancy, these pathophysiological processes are plausible mechanisms through which SDB may contribute to an increased risk of adverse outcomes, for the mother and perhaps also the offspring. However, a lack of robust evidence specific to the pregnant population, including limited evaluation of the placental function in affected pregnancies, limits our ability to draw definite conclusions on mechanisms contributing to adverse pregnancy outcomes and, indeed, the strength of association between SDB and certain pregnancy complications.
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Affiliation(s)
- Emma C. Johns
- Tommy's Centre for Maternal and Fetal Health, MRC Centre for Reproductive Health University of Edinburgh, Queen's Medical Research Institute Edinburgh United Kingdom
| | - Fiona C. Denison
- Tommy's Centre for Maternal and Fetal Health, MRC Centre for Reproductive Health University of Edinburgh, Queen's Medical Research Institute Edinburgh United Kingdom
| | - Rebecca M. Reynolds
- Tommy's Centre for Maternal and Fetal Health, MRC Centre for Reproductive Health University of Edinburgh, Queen's Medical Research Institute Edinburgh United Kingdom
- BHF/University Centre for Cardiovascular Science University of Edinburgh, Queen's Medical Research Institute Edinburgh United Kingdom
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10
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Rogers RC, Hasser EM, Hermann GE. Thrombin action on astrocytes in the hindbrain of the rat disrupts glycemic and respiratory control. Am J Physiol Regul Integr Comp Physiol 2020; 318:R1068-R1077. [PMID: 32320636 PMCID: PMC7311679 DOI: 10.1152/ajpregu.00033.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/30/2020] [Accepted: 04/21/2020] [Indexed: 02/06/2023]
Abstract
Severe trauma can produce a postinjury "metabolic self-destruction" characterized by catabolic metabolism and hyperglycemia. The severity of the hyperglycemia is highly correlated with posttrauma morbidity and mortality. Although no mechanism has been posited to connect severe trauma with a loss of autonomic control over metabolism, traumatic injury causes other failures of autonomic function, notably, gastric stasis and ulceration ("Cushing's ulcer"), which has been connected with the generation of thrombin. Our previous studies established that proteinase-activated receptors (PAR1; "thrombin receptors") located on astrocytes in the autonomically critical nucleus of the solitary tract (NST) can modulate gastric control circuit neurons to cause gastric stasis. Hindbrain astrocytes have also been implicated as important detectors of low glucose or glucose utilization. When activated, these astrocytes communicate with hindbrain catecholamine neurons that, in turn, trigger counterregulatory responses (CRR). There may be a convergence between the effects of thrombin to derange hindbrain gastrointestinal control and the hindbrain circuitry that initiates CRR to increase glycemia in reaction to critical hypoglycemia. Our results suggest that thrombin acts within the NST to increase glycemia through an astrocyte-dependent mechanism. Blockade of purinergic gliotransmission pathways interrupted the effect of thrombin to increase glycemia. Our studies also revealed that thrombin, acting in the NST, produced a rapid, dramatic, and potentially lethal suppression of respiratory rhythm that was also a function of purinergic gliotransmission. These results suggest that the critical connection between traumatic injury and a general collapse of autonomic regulation involves thrombin action on astrocytes.
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Affiliation(s)
- Richard C Rogers
- Autonomic Neurosciences Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Eileen M Hasser
- Biomedical Sciences, Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Gerlinda E Hermann
- Autonomic Neurosciences Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
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Borghi F, Morais CL, Silva C, da Silva PC, Ishizu LY, Costa GT, Grassi-Kassisse DM. A new perspective of lactatogenesis by isolated adipocytes. Mol Cell Endocrinol 2019; 498:110560. [PMID: 31442545 DOI: 10.1016/j.mce.2019.110560] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/02/2019] [Accepted: 08/19/2019] [Indexed: 11/24/2022]
Abstract
Increased adipose tissue mass exhibited greater capacity of glucose transformation in lactate, highlighting lactatogenesis as a crucial factor in body size. Classically, lactate produced by isolated adipocytes are expressed per million of cells and were never correlated with their size. Spontaneously hypertensive rats (SHR) have a lower body weight and smaller adipocytes when compared to Wistar-Kyoto. We evaluated basal lactate by epididymal 15-weeks-old isolated adipocytes of SHR, Wistar-Kyoto and Wistar. Basal lactate was similar when expressed by one million cells. However, SHR adipocytes were smaller, so we adjusted the results by cell volume and SHR showed higher basal lactate production which was directly endorsed by hyperlactatemia in the presented conditions. Thereby, we suggest a new perspective on lactatogenesis analysis by adipocytes, which could be linked to the receptors density and associate enzymes. Moreover, we showed that the thin and hypertensive rats can be hyperlactemic in fasting conditions.
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Affiliation(s)
- Filipy Borghi
- LABEEST - Laboratory of Stress Study, Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, 13083-862, Campinas, SP, Brazil
| | - Camila L Morais
- LABEEST - Laboratory of Stress Study, Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, 13083-862, Campinas, SP, Brazil
| | - Carolina Silva
- LABEEST - Laboratory of Stress Study, Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, 13083-862, Campinas, SP, Brazil
| | - Priscila C da Silva
- LABEEST - Laboratory of Stress Study, Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, 13083-862, Campinas, SP, Brazil
| | - Larissa Y Ishizu
- LABEEST - Laboratory of Stress Study, Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, 13083-862, Campinas, SP, Brazil
| | - Gustavo T Costa
- LABEEST - Laboratory of Stress Study, Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, 13083-862, Campinas, SP, Brazil
| | - Dora M Grassi-Kassisse
- LABEEST - Laboratory of Stress Study, Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, 13083-862, Campinas, SP, Brazil.
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12
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Leucine increases muscle mitochondrial respiration and attenuates glucose intolerance in diet-induced obesity in Swiss mice. J Funct Foods 2019. [DOI: 10.1016/j.jff.2019.103544] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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13
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Brunetta HS, de Paula GC, de Oliveira J, Martins EL, Dos Santos GJ, Galina A, Rafacho A, de Bem AF, Nunes EA. Decrement in resting and insulin-stimulated soleus muscle mitochondrial respiration is an early event in diet-induced obesity in mice. Exp Physiol 2019; 104:306-321. [PMID: 30578638 DOI: 10.1113/ep087317] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 12/19/2018] [Indexed: 01/08/2023]
Abstract
NEW FINDINGS What is the central question of this study? What are the temporal responses of mitochondrial respiration and mitochondrial responsivity to insulin in soleus muscle fibres from mice during the development of obesity and insulin resistance? What is the main finding and its importance? Short- and long-term feeding with a high-fat diet markedly reduced soleus mitochondrial respiration and mitochondrial responsivity to insulin before any change in glycogen synthesis. Muscle glycogen synthesis and whole-body insulin resistance were present after 14 and 28 days, respectively. Our findings highlight the plasticity of mitochondria during the development of obesity and insulin resistance. ABSTRACT Recently, significant attention has been given to the role of muscle mitochondrial function in the development of insulin resistance associated with obesity. Our aim was to investigate temporal alterations in mitochondrial respiration, H2 O2 emission and mitochondrial responsivity to insulin in permeabilized skeletal muscle fibres during the development of obesity in mice. Male Swiss mice (5-6 weeks old) were fed with a high-fat diet (60% calories from fat) or standard diet for 7, 14 or 28 days to induce obesity and insulin resistance. Diet-induced obese (DIO) mice presented with reduced glucose tolerance and hyperinsulinaemia after 7 days of high-fat diet. After 14 days, the expected increase in muscle glycogen content after systemic injection of glucose and insulin was not observed in DIO mice. At 28 days, blood glucose decay after insulin injection was significantly impaired. Complex I (pyruvate + malate) and II (succinate)-linked respiration and oxidative phosphorylation (ADP) were decreased after 7 days of high-fat diet and remained low in DIO mice after 14 and 28 days of treatment. Moreover, mitochondria from DIO mice were incapable of increasing respiratory coupling and ADP responsivity after insulin stimulation in all observed periods. Markers of mitochondrial content were reduced only after 28 days of treatment. The mitochondrial H2 O2 emission profile varied during the time course of DIO, with a reduction of H2 O2 emission in the early stages of DIO and an increased emission after 28 days of treatment. Our data demonstrate that DIO promotes transitory alterations in mitochondrial physiology during the early and late stages of insulin resistance related to obesity.
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Affiliation(s)
- Henver Simionato Brunetta
- Multicenter Graduate Program in Physiological Sciences, Federal University of Santa Catarina, Florianopólis, Santa Catrina, Brazil
| | - Gabriela Cristina de Paula
- Graduate Program in Biochemistry, Federal University of Santa Catarina, Florianopólis, Santa Catrina, Brazil
| | - Jade de Oliveira
- Graduate Program in Health Sciences, University of Extremo Sul Catarinense, Criciúma, Santa Catarina, Brazil
| | - Eduarda Lopes Martins
- Graduate Program in Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gustavo Jorge Dos Santos
- Multicenter Graduate Program in Physiological Sciences, Federal University of Santa Catarina, Florianopólis, Santa Catrina, Brazil
| | - Antonio Galina
- Graduate Program in Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Alex Rafacho
- Multicenter Graduate Program in Physiological Sciences, Federal University of Santa Catarina, Florianopólis, Santa Catrina, Brazil
| | - Andreza Fabro de Bem
- Graduate Program in Biochemistry, Federal University of Santa Catarina, Florianopólis, Santa Catrina, Brazil.,Department of Physiological Sciences, Institute of Biological Sciences, University of Brasília, Brasília, Distrito Federal, Brazil
| | - Everson Araújo Nunes
- Multicenter Graduate Program in Physiological Sciences, Federal University of Santa Catarina, Florianopólis, Santa Catrina, Brazil
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Abstract
Known primarily for its oxygen-sensing capabilities, the carotid body chemoreceptors have recently been implicated, primarily by work in animal models, in the pathophysiology of a number of metabolic conditions. The research presented in this brief review highlights translational work conducted at the Mayo Clinic between 2010 and 2017 in healthy humans and discusses key areas for future work in disease populations.
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Affiliation(s)
- Jacqueline K Limberg
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota and Department of Nutrition and Exercise Physiology, University of Missouri , Columbia, Missouri
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16
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Ferreira FBD, Dos Santos C, Bruxel MA, Nunes EA, Spiller F, Rafacho A. Glucose homeostasis in two degrees of sepsis lethality induced by caecum ligation and puncture in mice. Int J Exp Pathol 2017; 98:329-340. [PMID: 29226508 DOI: 10.1111/iep.12255] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 10/20/2017] [Indexed: 12/19/2022] Open
Abstract
Sepsis is associated with high mortality. Both critically ill humans and animal models of sepsis exhibit changes in their glucose homeostasis, that is, hypoglycaemia, with the progression of infection. However, the relationship between basal glycaemia, glucose tolerance and insulin sensitivity is not well understood. Thus, we aimed to evaluate this glucose homeostasis triad at the late stage of sepsis (24 h after surgery) in male Swiss mice subjected to lethal and sublethal sepsis by the caecal ligation and puncture (CLP) model. The percentage of survival 24 h after CLP procedure in the Lethal and Sublethal groups was around 66% and 100% respectively. Both Lethal and Sublethal groups became hypoglycaemic in fasting and fed states 24 h after surgery. The pronounced fed hypoglycaemia in the Lethal group was not due to worsening anorexic behaviour or hepatic inability to deliver glucose in relation to the Sublethal group. Reduction in insulin sensitivity in CLP mice occurred in a lethality-dependent manner and was not associated with glucose intolerance. Analysis of oral and intraperitoneal glucose tolerance tests, as well as the gastrointestinal motility data, indicated that CLP mice had reduced intestinal glucose absorption. Altogether, we suggest cessation of appetite and intestinal glucose malabsorption are key contributors to the hypoglycaemic state observed during experimental severe sepsis.
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Affiliation(s)
- Francielle B D Ferreira
- Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Cristiane Dos Santos
- Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Maciel A Bruxel
- Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Everson A Nunes
- Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Fernando Spiller
- Department of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Alex Rafacho
- Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, Brazil
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Thomas A, Belaidi E, Moulin S, Horman S, van der Zon GC, Viollet B, Levy P, Bertrand L, Pepin JL, Godin-Ribuot D, Guigas B. Chronic Intermittent Hypoxia Impairs Insulin Sensitivity but Improves Whole-Body Glucose Tolerance by Activating Skeletal Muscle AMPK. Diabetes 2017; 66:2942-2951. [PMID: 28882901 DOI: 10.2337/db17-0186] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 08/30/2017] [Indexed: 11/13/2022]
Abstract
Obstructive sleep apnea syndrome is a highly prevalent disease resulting in transient respiratory arrest and chronic intermittent hypoxia (cIH). cIH is associated with insulin resistance and impaired metabolic homeostasis in rodents and humans, but the exact underlying mechanisms remain unclear. In the current study, we investigated the effects of 2 weeks of cIH (1-min cycle, fraction of inspired oxygen 21-5%, 8 h/day) on whole-body insulin sensitivity and glucose tolerance in lean mice. Although food intake and body weight were reduced compared with normoxia, cIH induced systemic insulin resistance in a hypoxia-inducible factor 1-independent manner and impaired insulin signaling in liver, white adipose tissue, and skeletal muscle. Unexpectedly, cIH improved whole-body glucose tolerance independently of changes in body weight and glucose-induced insulin response. This effect was associated with elevated phosphorylation of Thr172-AMPK and Ser237-TBC1 domain family member 1 (TBC1D1) in skeletal muscle, suggesting a tissue-specific AMPK-dependent increase in TBC1D1-driven glucose uptake. Remarkably, although food intake, body weight, and systemic insulin sensitivity were still affected, the improvement in glucose tolerance by cIH was abolished in muscle-specific AMPKα1α2-deficient mice. We conclude that cIH impairs insulin sensitivity while improving whole-body glucose tolerance by promoting specific activation of the skeletal muscle AMPK pathway.
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Affiliation(s)
- Amandine Thomas
- Laboratoire HP2, Université Grenoble Alpes, Grenoble, France
- INSERM U1042, Grenoble, France
| | - Elise Belaidi
- Laboratoire HP2, Université Grenoble Alpes, Grenoble, France
- INSERM U1042, Grenoble, France
| | - Sophie Moulin
- Laboratoire HP2, Université Grenoble Alpes, Grenoble, France
- INSERM U1042, Grenoble, France
| | - Sandrine Horman
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Gerard C van der Zon
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Benoit Viollet
- Institut Cochin, INSERM U1016, Paris, France
- CNRS UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Patrick Levy
- Laboratoire HP2, Université Grenoble Alpes, Grenoble, France
- INSERM U1042, Grenoble, France
| | - Luc Bertrand
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Jean-Louis Pepin
- Laboratoire HP2, Université Grenoble Alpes, Grenoble, France
- INSERM U1042, Grenoble, France
| | - Diane Godin-Ribuot
- Laboratoire HP2, Université Grenoble Alpes, Grenoble, France
- INSERM U1042, Grenoble, France
| | - Bruno Guigas
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, the Netherlands
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
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Newhouse LP, Joyner MJ, Curry TB, Laurenti MC, Man CD, Cobelli C, Vella A, Limberg JK. Three hours of intermittent hypoxia increases circulating glucose levels in healthy adults. Physiol Rep 2017; 5:5/1/e13106. [PMID: 28087818 PMCID: PMC5256164 DOI: 10.14814/phy2.13106] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 12/08/2016] [Accepted: 12/08/2016] [Indexed: 01/10/2023] Open
Abstract
An independent association exists between sleep apnea and diabetes. Animal models suggest exposure to intermittent hypoxia, a consequence of sleep apnea, results in altered glucose metabolism and fasting hyperglycemia. However, it is unknown if acute exposure to intermittent hypoxia increases glucose concentrations in nondiabetic humans. We hypothesized plasma glucose would be increased from baseline following 3 h of intermittent hypoxia in healthy humans independent of any effect on insulin sensitivity. Eight (7M/1F, 21–34 years) healthy subjects completed two study visits randomized to 3 h of intermittent hypoxia or continuous normoxia, followed by an oral glucose tolerance test. Intermittent hypoxia consisted of 25 hypoxic events per hour where oxygen saturation (SpO2) was significantly reduced (Normoxia: 97 ± 1%, Hypoxia: 90 ± 2%, P < 0.01). Venous plasma glucose concentrations were measured on both visits before and after the 3 h protocol. No changes in plasma glucose were observed from baseline after 3 h of continuous normoxia (5.1 ± 0.2 vs. 5.1 ± 0.1 mmol/L, P > 0.05). In contrast, circulating glucose concentrations were increased after 3 h of intermittent hypoxia when compared to baseline (5.0 ± 0.2 vs. 5.3 ± 0.2 mmol/L, P = 0.01). There were no detectable changes in insulin sensitivity following intermittent hypoxia when compared to continuous normoxia, as assessed by the oral glucose tolerance test (P > 0.05). Circulating glucose is increased after 3 h of intermittent hypoxia in healthy humans, independent of any lasting changes in insulin sensitivity. These novel findings could explain, in part, the high prevalence of diabetes in patients with sleep apnea and warrant future studies to identify underlying mechanisms.
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Affiliation(s)
| | | | - Timothy B Curry
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota
| | | | - Chiara Dalla Man
- Department of Information Engineering, University of Padua, Padua, Italy
| | - Claudio Cobelli
- Department of Information Engineering, University of Padua, Padua, Italy
| | - Adrian Vella
- Department of Endocrinology, Mayo Clinic, Rochester, Minnesota
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Lemes EV, Aiko S, Orbem CB, Formentin C, Bassi M, Colombari E, Zoccal DB. Long-term facilitation of expiratory and sympathetic activities following acute intermittent hypoxia in rats. Acta Physiol (Oxf) 2016; 217:254-66. [PMID: 26910756 DOI: 10.1111/apha.12661] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 01/14/2016] [Accepted: 02/15/2016] [Indexed: 12/20/2022]
Abstract
AIM Acute intermittent hypoxia (AIH) promotes persistent increases in ventilation and sympathetic activity, referred as long-term facilitation (LTF). Augmented inspiratory activity is suggested as a major component of respiratory LTF. In this study, we hypothesized that AIH also elicits a sustained increase in expiratory motor activity. We also investigated whether the expiratory LTF contributes to the development of sympathetic LTF after AIH. METHODS Rats were exposed to AIH (10 × 6-7% O2 for 45 s, every 5 min), and the cardiorespiratory parameters were evaluated during 60 min using in vivo and in situ approaches. RESULTS In unanesthetized conditions (n = 9), AIH elicited a modest but sustained increase in baseline mean arterial pressure (MAP, 104 ± 2 vs. 111 ± 3 mmHg, P < 0.05) associated with enhanced sympathetic and respiratory-related variabilities. In the in situ preparations (n = 9), AIH evoked LTF in phrenic (33 ± 12%), thoracic sympathetic (75 ± 25%) and abdominal nerve activities (69 ± 14%). The sympathetic overactivity after AIH was phase-locked with the emergence of bursts in abdominal activity during the late-expiratory phase. In anesthetized vagus-intact animals, AIH increased baseline MAP (113 ± 3 vs. 122 ± 2 mmHg, P < 0.05) and abdominal muscle activity (535 ± 94%), which were eliminated after pharmacological inhibition of the retrotrapezoid nucleus/parafacial respiratory group (RTN/pFRG). CONCLUSION These findings indicate that increased expiratory activity is also an important component of AIH-elicited respiratory LTF. Moreover, the development of sympathetic LTF after AIH is linked to the emergence of active expiratory pattern and depends on the integrity of the neurones of the RTN/pFRG.
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Affiliation(s)
- E. V. Lemes
- Department of Physiology and Pathology; School of Dentistry of Araraquara; São Paulo State University (UNESP); Araraquara SP Brazil
| | - S. Aiko
- Department of Physiological Sciences; Centre of Biological Sciences; Federal University of Santa Catarina (UFSC); Florianópolis SC Brazil
| | - C. B. Orbem
- Department of Physiological Sciences; Centre of Biological Sciences; Federal University of Santa Catarina (UFSC); Florianópolis SC Brazil
| | - C. Formentin
- Department of Physiological Sciences; Centre of Biological Sciences; Federal University of Santa Catarina (UFSC); Florianópolis SC Brazil
| | - M. Bassi
- Department of Physiology and Pathology; School of Dentistry of Araraquara; São Paulo State University (UNESP); Araraquara SP Brazil
| | - E. Colombari
- Department of Physiology and Pathology; School of Dentistry of Araraquara; São Paulo State University (UNESP); Araraquara SP Brazil
| | - D. B. Zoccal
- Department of Physiology and Pathology; School of Dentistry of Araraquara; São Paulo State University (UNESP); Araraquara SP Brazil
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Chen X, Zhao T, Huang X, Wu L, Wu K, Fan M, Zhu L. Intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats. Cell Stress Chaperones 2016; 21:515-22. [PMID: 26902078 PMCID: PMC4837188 DOI: 10.1007/s12192-016-0679-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Revised: 02/07/2016] [Accepted: 02/08/2016] [Indexed: 12/21/2022] Open
Abstract
Increasing studies have shown protective effects of intermittent hypoxia on brain injury and heart ischemia. However, the effect of intermittent hypoxia on blood glucose metabolism, especially in diabetic conditions, is rarely observed. The aim of this study was to investigate whether intermittent hypoxia influences blood glucose metabolism in type 1 diabetic rats. Streptozotocin-induced diabetic adult rats and age-matched control rats were treated with intermittent hypoxia (at an altitude of 3 km, 4 h per day for 3 weeks) or normoxia as control. Fasting blood glucose, body weight, plasma fructosamine, plasma insulin, homeostasis model assessment of insulin resistance (HOMA-IR), pancreas β-cell mass, and hepatic and soleus glycogen were measured. Compared with diabetic rats before treatment, the level of fasting blood glucose in diabetic rats after normoxic treatment was increased (19.88 ± 5.69 mmol/L vs. 14.79 ± 5.84 mmol/L, p < 0.05), while it was not different in diabetic rats after hypoxic treatment (13.14 ± 5.77 mmol/L vs. 14.79 ± 5.84 mmol/L, p > 0.05). Meanwhile, fasting blood glucose in diabetic rats after hypoxic treatment was also lower than that in diabetic rats after normoxic treatment (13.14 ± 5.77 mmol/L vs. 19.88 ± 5.69 mmol/L, p<0.05). Plasma fructosamine in diabetic rats receiving intermittent hypoxia was significantly lower than that in diabetic rats receiving normoxia (1.28 ± 0.11 vs. 1.39 ± 0.11, p < 0.05), while there were no significant changes in body weight, plasma insulin and β-cell mass. HOMA-IR in diabetic rats after hypoxic treatment was also lower compared with diabetic rats after normoxic treatment (3.48 ± 0.48 vs. 3.86 ± 0.42, p < 0.05). Moreover, intermittent hypoxia showed effect on the increase of soleus glycogen but not hepatic glycogen. We conclude that intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats and its regulation on muscular glycogenesis may play a role in the underlying mechanism.
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Affiliation(s)
- Xiaofei Chen
- Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China
- Department of Ophthalmology, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China
| | - Tong Zhao
- Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China
| | - Xin Huang
- Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China
| | - Liying Wu
- Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China
| | - Kuiwu Wu
- Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China
| | - Ming Fan
- Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China.
| | - Lingling Zhu
- Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China.
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Heinonen IHA, Boushel R, Kalliokoski KK. The Circulatory and Metabolic Responses to Hypoxia in Humans - With Special Reference to Adipose Tissue Physiology and Obesity. Front Endocrinol (Lausanne) 2016; 7:116. [PMID: 27621722 PMCID: PMC5002918 DOI: 10.3389/fendo.2016.00116] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 08/10/2016] [Indexed: 01/07/2023] Open
Abstract
Adipose tissue metabolism and circulation play an important role in human health. It is well-known that adipose tissue mass is increased in response to excess caloric intake leading to obesity and further to local hypoxia and inflammatory signaling. Acute exercise increases blood supply to adipose tissue and mobilization of fat stores for energy. However, acute exercise during systemic hypoxia reduces subcutaneous blood flow in healthy young subjects, but the response in overweight or obese subjects remains to be investigated. Emerging evidence also indicates that exercise training during hypoxic exposure may provide additive benefits with respect to many traditional cardiovascular risk factors as compared to exercise performed in normoxia, but unfavorable effects of hypoxia have also been documented. These topics will be covered in this brief review dealing with hypoxia and adipose tissue physiology.
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Affiliation(s)
- Ilkka H. A. Heinonen
- Turku PET Centre, University of Turku, Turku, Finland
- Department of Clinical Physiology and Nuclear Medicine, University of Turku, Turku, Finland
- Division of Experimental Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
- *Correspondence: Ilkka H. A. Heinonen,
| | - Robert Boushel
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada
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Persson PB. Insulin. Acta Physiol (Oxf) 2015; 214:427-9. [PMID: 26100001 DOI: 10.1111/apha.12543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- P B Persson
- Institute of Vegetative Physiology, Charité-Universitaetsmedizin Berlin, Berlin, Germany.
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Motta K, Barbosa AM, Bobinski F, Boschero AC, Rafacho A. JNK and IKKβ phosphorylation is reduced by glucocorticoids in adipose tissue from insulin-resistant rats. J Steroid Biochem Mol Biol 2015; 145:1-12. [PMID: 25268311 DOI: 10.1016/j.jsbmb.2014.09.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 09/15/2014] [Accepted: 09/25/2014] [Indexed: 02/06/2023]
Abstract
OBJECTIVES Peripheral insulin resistance (IR) is one of the main side effects caused by glucocorticoid (GC)-based therapies, and the molecular mechanisms of GC-induced IR are not yet fully elucidated. Thus, we aimed to investigate the effects of dexamethasone treatment on the main components of insulin and inflammatory signaling in the adipose tissue of rats. MATERIALS/METHODS Male Wistar rats received daily injections of dexamethasone (1mg/kg body weight (b.w.), intraperitoneally (i.p.)) for 5 days (DEX), whereas control rats received saline (CTL). The metabolic status was investigated, and the epididymal fat fragments were collected for lipolysis and western blot analyses. RESULTS The DEX rats became hyperglycemic, hyperinsulinemic, insulin resistant and glucose intolerant, compared with the CTL rats (P<0.05). The basal glycerol release in the fat fragments was 1.5-fold higher in the DEX rats (P<0.05). The phosphorylation of protein kinase B (PKB) at ser(473) decreased by 44%, whereas, the phosphorylation of insulin receptor substrate (IRS)-1 at ser(307) increased by 93% in the adipose tissue of the DEX rats after an oral bolus of glucose (P<0.05). The basal phosphorylation of c-jun-N-terminal kinase (JNK) and inhibitor of nuclear factor kappa-B (IKKβ) proteins was reduced by 46% and 58%, respectively, in the adipose tissue of the DEX rats (P<0.05). This was paralleled with a significant reduction (47%) in the glucocorticoid receptor (GR) protein content in the adipose tissue of the DEX rats (P<0.05). CONCLUSION The insulin-resistant status of rats induced by dexamethasone administration have PKB and IRS-1 activity attenuated in epididymal fat without increases in the phosphorylation of the proinflammatory signals JNK and IKKβ.
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Affiliation(s)
- Katia Motta
- Multicenter Graduate Program in Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina (UFSC), Florianópolis, Brazil
| | - Amanda Marreiro Barbosa
- Graduate Program in Nutrition, Center of Health Sciences, Federal University of Santa Catarina (UFSC), Florianópolis, Brazil
| | - Franciane Bobinski
- Graduate Program in Neurosciences, Center of Biological Sciences, Federal University of Santa Catarina (UFSC), Florianópolis, Brazil
| | - Antonio Carlos Boschero
- Graduate Program in Functional and Molecular Biology, Institute of Biology, Campinas State University (UNICAMP), Campinas, Brazil
| | - Alex Rafacho
- Multicenter Graduate Program in Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina (UFSC), Florianópolis, Brazil.
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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.
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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
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25
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Wang YP, Wei JY, Yang JJ, Gao WN, Wu JQ, Guo CJ. Riboflavin supplementation improves energy metabolism in mice exposed to acute hypoxia. Physiol Res 2014; 63:341-50. [PMID: 24564599 DOI: 10.33549/physiolres.932670] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
This study investigated the effects of riboflavin on energy metabolism in hypoxic mice. Kunming mice were fed diets containing riboflavin at doses of 6, 12, 24 and 48 mg/kg, respectively for 2 weeks before exposure to a simulated altitude of 6000 m for 8 h. Changes of riboflavin status and energy metabolism were assessed biochemically. Simultaneously, a (1)H nuclear magnetic resonance (NMR) based metabolomic technique was used to track the changes of plasma metabolic profiling. It was found that the content of hepatic riboflavin was decreased and erythrocyte glutathione activation coefficient was elevated significantly under hypoxic condition. Meanwhile, increased plasma pyruvate, lactate, beta-hydroxybutyrate and urea, as well as decreased plasma carnitine were observed. Riboflavin supplementation improved riboflavin status remarkably in hypoxic mice and decreased plasma levels of pyruvate, free fatty acids and beta-hydroxybutyrate significantly. Plasma carnitine was increased in response to riboflavin supplementation. Results obtained from (1)H NMR analysis were basically in line with the data from biochemical assays and remarkable changes in plasma taurine, choline and some other metabolites were also indicated. It was concluded that riboflavin requirement was increased under acute hypoxic condition and riboflavin supplementation was effective in improving energy metabolism in hypoxic mice.
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Affiliation(s)
- Y P Wang
- Institute of Health and Environmental Medicine, Tianjin, P. R. China.
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26
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Nadal A. Linking intermittent hypoxia, sympathetic response and metabolic disturbances. Acta Physiol (Oxf) 2013; 209:7-8. [PMID: 23782858 DOI: 10.1111/apha.12137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A Nadal
- Instituto de Bioingeniería, Universidad Miguel Hernández de Elche, Elche, Alicante, Spain.
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