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Kämpf S, Fenk S, Van Cromvoirt A, Bogdanov N, Hartnack S, Stirn M, Hofmann-Lehmann R, Reichler IM, Bogdanova A. Differences in selected blood parameters between brachycephalic and non-brachycephalic dogs. Front Vet Sci 2023; 10:1166032. [PMID: 37649563 PMCID: PMC10464621 DOI: 10.3389/fvets.2023.1166032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 07/11/2023] [Indexed: 09/01/2023] Open
Abstract
Introduction Cranial and upper-airway anatomy of short-nosed, flat-faced brachycephalic dogs predisposes them to brachycephalic obstructive airway syndrome (BOAS). Periodic apnoea increased inspiratory resistance, and an inability to thermoregulate effectively are characteristic of BOAS, but internationally accepted objective markers of BOAS severity are missing. The objective of this study was to compare the selected blood parameters between non-brachycephalic (NC) and brachycephalic (BC) dogs, exploring the possibility of developing a blood test for BOAS severity grading in the future. Methods We evaluated blood biochemistry, complete blood cell counts, red blood cell (RBC) indices, reticulocyte counts, a blood-born marker of intermittent hypoxia (glutathione, NO production), RBC hydration, deformability, and blood markers of metabolic changes and stress between BC (n = 18) and NC (meso- and dolichocephalic, n = 22) dogs. Results Reticulocyte counts and the abundance of middle-fluorescence immature reticulocytes were significantly (p < 0.05) higher in BC dogs compared to NC dogs. BC dogs had significantly more NO-derived NO2 - /NO3 - in plasma than NC dogs. RBCs of BC dogs were shedding significantly more membrane, as follows from the intensity of eosin maleimide staining, and had a significantly higher mean corpuscular hemoglobin concentration than NC dogs. Intracellular reduced glutathione content in RBCs of BC dogs was significantly lower, while plasma lactate was significantly higher in BC dogs compared to NC dogs. Plasma cholesterol and triglycerides were significantly lower, and cortisol was significantly higher in BC dogs compared to NC dogs. Eosinophil counts were significantly lower and the neutrophil-to-lymphocyte ratio was higher in BC dogs compared to NC dogs. Discussion Taken together, our findings suggest that the brachycephalic phenotype in dogs is associated with alterations at the level of blood cells and, systemically, with oxidation and metabolic changes. The parameters identified within this study should be further investigated for their potential as objective indicators for BOAS.
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Affiliation(s)
- Sandra Kämpf
- Red Blood Cell Research Group, Institute of Veterinary Physiology, Faculty of Vetsuisse, University of Zurich, Zürich, Switzerland
- Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Simone Fenk
- Red Blood Cell Research Group, Institute of Veterinary Physiology, Faculty of Vetsuisse, University of Zurich, Zürich, Switzerland
- Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Ankie Van Cromvoirt
- Red Blood Cell Research Group, Institute of Veterinary Physiology, Faculty of Vetsuisse, University of Zurich, Zürich, Switzerland
- Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Nikolay Bogdanov
- Red Blood Cell Research Group, Institute of Veterinary Physiology, Faculty of Vetsuisse, University of Zurich, Zürich, Switzerland
- Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Sonja Hartnack
- Section of Epidemiology, Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Martina Stirn
- Clinical Laboratory, Department for Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Regina Hofmann-Lehmann
- Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
- Clinical Laboratory, Department for Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Iris Margaret Reichler
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Anna Bogdanova
- Red Blood Cell Research Group, Institute of Veterinary Physiology, Faculty of Vetsuisse, University of Zurich, Zürich, Switzerland
- Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
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2
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Association of lipoprotein levels with sleep apnea: role of autonomic dysfunction. Endocr Regul 2021; 55:22-29. [PMID: 33600665 DOI: 10.2478/enr-2021-0004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Objectives. Although multiple mechanisms, including autonomic dysfunction, seem to link sleep-disordered breathing (SDB) with dyslipidemia in animal studies, the data in clinical studies are limited. The aim of this study was to explore the association of lipoprotein levels with SDB measures in healthy habitual snorers. We supposed that autonomic dysfunction is the linking mechanism.Methods. We enrolled 110 previously healthy subjects with complaints of habitual snoring. To assess SDB, polysomnography was performed. Blood samples for the analysis of total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein cholesterol (LDL), and triglycerides (TG) were obtained in a fasting condition after the polysomnography. Baroreflex sensitivity (BRS) was used to assess the autonomic dysfunction.Results. In stepwise multiple linear regression analysis, minimal nocturnal blood oxygen saturation (beta=-0.240, p=0.020) and neck circumference (beta=0.224, p=0.03) were the only significant contributors in model predicting TG. SDB measures were not identified as significant contributors in models predicting TC, LDL, and HDL. We failed to find any significant difference in BRS in SDB subjects when compared according to the presence or absence of hypercholesterolemia/ hypertriglyceridemia. In SDB subjects, the area under the curve in a receiver operating curve to predict hypercholesterolemia and hypertriglyceridemia by BRS was 0.468 (95% CI: 0.328-0.608) and 0.425 (95% CI: 0.304-0.546), respectively.Conclusions. Our results suggest that minimal nocturnal blood oxygen saturation is significant contributor in model predicting TG. No significant decrease in BRS was found in SDB subjects with hypercholesterolemia and hypertriglyceridemia. In SDB subjects, the role of autonomic dys-function in the development of dyslipidemia remains controversial.
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3
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Barros D, García-Río F. Obstructive sleep apnea and dyslipidemia: from animal models to clinical evidence. Sleep 2020; 42:5204276. [PMID: 30476296 DOI: 10.1093/sleep/zsy236] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 10/02/2018] [Accepted: 11/22/2018] [Indexed: 01/11/2023] Open
Abstract
Lipid metabolism deregulation constitutes the pathogenic basis for the development of atherosclerosis and justifies a high incidence of cardiovascular-related morbidity and mortality. Some data suggest that dyslipidemia may be associated with sleep-disordered breathing, mainly obstructive sleep apnea (OSA), due to alterations in fundamental biochemical processes, such as intermittent hypoxia (IH). The aim of this systematic review was to identify and critically evaluate the current evidence supporting the existence of a possible relationship between OSA and alterations in lipid metabolism. Much evidence shows that, during the fasting state, OSA and IH increase lipid delivery from the adipose tissue to the liver through an up-regulation of the sterol regulatory element-binding protein-1 and stearoyl-CoA desaturase-1, increasing the synthesis of cholesterol esters and triglycerides. In the postprandial state, lipoprotein clearance is delayed due to lower lipoprotein lipase activity, probably secondary to IH-up-regulation of angiopoietin-like protein 4 and decreased activity of the peroxisome proliferator-activated receptor alpha. Moreover, oxidative stress can generate dysfunctional oxidized lipids and reduce the capacity of high-density lipoproteins (HDL) to prevent low-density lipoprotein (LDL) oxidation. In the clinical field, several observational studies and a meta-regression analysis support the existence of a link between OSA and dyslipidemia. Although there is evidence of improved lipid profile after apnea-hypopnea suppression with continuous positive airway pressure (CPAP), the majority of the data come from observational studies. In contrast, randomized controlled trials evaluating the effects of CPAP on lipid metabolism present inconclusive results and two meta-analyses provide contradictory evidence.
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Affiliation(s)
- David Barros
- Servicio de Neumología, Hospital Montecelo, Pontevedra, Spain
| | - Francisco García-Río
- Servicio de Neumología, Hospital Universitario La Paz-IdiPAZ, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain.,Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
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4
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Baum DM, Morales Rodriguez B, Attali V, Cauhapé M, Arnulf I, Cardot P, Bodineau L, Fiamma MN. New Zealand Obese Mice as a Translational Model of Obesity-related Obstructive Sleep Apnea Syndrome. Am J Respir Crit Care Med 2019; 198:1336-1339. [PMID: 30019912 DOI: 10.1164/rccm.201801-0162le] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
| | | | - Valérie Attali
- 1 Sorbonne Université/Inserm UMR_S1158 Paris, France and.,2 Groupe Hospitalier Pitié-Salpêtrière Charles Foix Paris, France
| | | | - Isabelle Arnulf
- 2 Groupe Hospitalier Pitié-Salpêtrière Charles Foix Paris, France
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5
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Gonçalves IS, Agostinho JR, Silva G, Guimarães T, Bernardes A, Santos I, Pinto P, Bárbara C, de Sousa J, Pinto FJ, Marques P. Accuracy and utility of a pacemaker respiratory monitoring algorithm for the detection of obstructive sleep apnea in patients with atrial fibrillation. Sleep Med 2019; 61:88-94. [DOI: 10.1016/j.sleep.2019.01.051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 01/19/2019] [Accepted: 01/21/2019] [Indexed: 12/11/2022]
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6
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Gianella P, Caccamo R, Bellino C, Bottero E, Fietta F, Roncone S, Ostanello F, Pietra M, Buracco P. Evaluation of metabolic profile and C-reactive protein concentrations in brachycephalic dogs with upper airway obstructive syndrome. J Vet Intern Med 2019; 33:2183-2192. [PMID: 31454107 PMCID: PMC6766536 DOI: 10.1111/jvim.15575] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 07/11/2019] [Indexed: 02/06/2023] Open
Abstract
Background Brachycephalic dogs have abnormal breathing patterns similar to those in humans with obstructive sleep apnea syndrome. Obstructive sleep apnea syndrome is associated with dyslipidemia, hyperglycemia, and insulin resistance. Despite the fact that anatomic and functional alterations are well described in brachycephalic dogs, little is known about the consequences of upper airway obstruction on systemic inflammatory response and metabolic profile. Objectives To describe history, clinical presentation, and anatomic abnormalities; to evaluate systemic inflammatory response and metabolic profile; and to identify possible associations among clinical signs, anatomic abnormalities, inflammatory response, and metabolic profile in brachycephalic dogs with airway obstruction. Animals Thirty purebred brachycephalic dogs with brachycephalic airway obstructive syndrome (BAOS). Methods Prospective study. The following information was recorded and studied: respiratory and digestive signs, airway and digestive endoscopic anomalies, presence or absence of tracheal hypoplasia, histologic evaluation of gastrointestinal tract biopsy specimens, serum concentrations of C‐reactive protein (CRP), fructosamine, insulin, glucose, triglyceride, cholesterol, and plasma concentrations of lipoprotein classes. Results A high proportion of dogs (76.7%) had gastrointestinal signs. Esophageal deviation, atony of the cardia of the stomach, and distal esophagitis were the most common endoscopic anomalies detected. Twenty‐six (86.6%) dogs had different degrees of laryngeal collapse. Gastrointestinal histologic evaluation identified mostly chronic inflammation. Glucose, fructosamine, triglycerides, cholesterol, CRP, pre‐beta, beta lipoproteins, and chylomicrons were increased to a variable extent. Significant associations among clinical signs, anatomic abnormalities, CRP, and metabolic profile were not found. Conclusion and Clinical Importance Despite the presence of inflammation and some mild metabolic derangements, the clinicopathological variables evaluated did not offer valuable information in dogs with BAOS.
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Affiliation(s)
- Paola Gianella
- Department of Veterinary Sciences, University of Turin, Torino, Italy
| | - Roberta Caccamo
- Department of Veterinary Sciences, University of Turin, Torino, Italy
| | - Claudio Bellino
- Department of Veterinary Sciences, University of Turin, Torino, Italy
| | | | - Federica Fietta
- Department of Veterinary Sciences, University of Turin, Torino, Italy
| | - Silvia Roncone
- Department of Veterinary Sciences, University of Turin, Torino, Italy
| | - Fabio Ostanello
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Marco Pietra
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Paolo Buracco
- Department of Veterinary Sciences, University of Turin, Torino, Italy
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7
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Kopke MA, Wightman P, Ruaux CG. Obstructive sleep apnea in a Chihuahua successfully managed with ondansetron. Clin Case Rep 2019; 7:872-876. [PMID: 31110706 PMCID: PMC6510004 DOI: 10.1002/ccr3.2110] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 03/02/2019] [Indexed: 12/19/2022] Open
Abstract
While the persistence of clinical signs related to brachycephalic obstructive airway syndrome, particularly sleep-disordered breathing patterns following appropriate surgical management is likely to be relatively rare, this potential sequela needs to be considered, along with being aware of possible medical management options such as serotonin antagonists.
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Affiliation(s)
- Matthew A. Kopke
- School of Veterinary ScienceMassey University Veterinary Teaching HospitalPalmerston NorthNew Zealand
| | - Paul Wightman
- School of Veterinary ScienceMassey University Veterinary Teaching HospitalPalmerston NorthNew Zealand
| | - Craig G. Ruaux
- School of Veterinary ScienceMassey University Veterinary Teaching HospitalPalmerston NorthNew Zealand
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8
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9
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Alzoubi MR, Aldomi Al-Domi H. Could omega-3 fatty acids a therapeutic treatment of the immune-metabolic consequence of intermittent hypoxia in obstructive sleep apnea? Diabetes Metab Syndr 2017; 11:297-304. [PMID: 27389079 DOI: 10.1016/j.dsx.2016.06.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 06/19/2016] [Indexed: 02/07/2023]
Abstract
Obesity and Obstructive sleep Apnea (OSA) seems to bi-directional; obesity itself increases the risk of OSA, but on the other hand, OSA may also predispose the individuals to weight gain, both obesity and OSA share a common immune-metabolic link state which have a synergistic effect on the activation of inflammation, insulin resistance and dyslipidemia, and cardiovascular disease. The Immune-metabolic role of omega-3 fatty acids Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA), which capable of modulating both metabolic and immune process, which may decrease pro-inflammatory cytokines, insulin resistance, and dyslipidemia. To date, no study in humans suffering from OSA and omega-3 fatty acids has been performed. Hence, the objective of this review aimed to discussing the link between immune-metabolic consequences related to intermittent hypoxia and does Omega-3 fatty acids a therapeutic treatment for co-morbidity associated with obstructive sleep apnea.
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Affiliation(s)
- Mohammed R Alzoubi
- Department of Nutrition and Food Technology, Faculty of Agriculture, The University of Jordan, 11942 Amman, Jordan.
| | - Hayder Aldomi Al-Domi
- Department of Nutrition and Food Technology, Faculty of Agriculture, The University of Jordan, 11942 Amman, Jordan.
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10
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Chami HA, Gottlieb DJ, Redline S, Punjabi NM. Association between Glucose Metabolism and Sleep-disordered Breathing during REM Sleep. Am J Respir Crit Care Med 2016. [PMID: 26200994 DOI: 10.1164/rccm.201501-0046oc] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
RATIONALE Sleep-disordered breathing (SDB) has been associated with impaired glucose metabolism. It is possible that the association between SDB and glucose metabolism is distinct for non-REM versus REM sleep because of differences in sleep-state-dependent sympathetic activation and/or degree of hypoxemia. OBJECTIVES To characterize the association between REM-related SDB, glucose intolerance, and insulin resistance in a community-based sample. METHODS A cross-sectional analysis that included 3,310 participants from the Sleep Heart Health Study was undertaken (53% female; mean age, 66.1 yr). Full montage home-polysomnography and fasting glucose were available on all participants. SDB severity during REM and non-REM sleep was quantified using the apnea-hypopnea index in REM (AHIREM) and non-REM sleep (AHINREM), respectively. Fasting and 2-hour post-challenge glucose levels were assessed during a glucose tolerance test (n = 2,264). The homeostatic model assessment index for insulin resistance (HOMA-IR) was calculated (n = 1,543). Linear regression was used to assess the associations of AHIREM and AHINREM with fasting and post-prandial glucose levels and HOMA-IR. MEASUREMENTS AND MAIN RESULTS AHIREM and AHINREM were associated with fasting glycemia, post-prandial glucose levels, and HOMA-IR in models that adjusted for age, sex, race, and site. However, with additional adjustment for body mass index, waist circumference, and sleep duration, AHIREM was only associated with HOMA-IR (β = 0.04; 95% CI, 0.1-0.07; P = 0.01), whereas AHINREM was only associated with fasting (β = 0.93; 95% CI, 0.14-1.72; P = 0.02) and post-prandial glucose levels (β = 3.0; 95% CI, 0.5-5.5; P = 0.02). CONCLUSIONS AHIREM is associated with insulin resistance but not with fasting glycemia or glucose intolerance.
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Affiliation(s)
- Hassan A Chami
- 1 Department of Medicine, American University of Beirut, Beirut, Lebanon.,2 Department of Medicine, Boston University School of Medicine, Boston, Massachusetts
| | - Daniel J Gottlieb
- 3 VA Boston Healthcare System, Boston, Massachusetts.,4 Department of Medicine, Brigham and Women's Hospital and Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts; and
| | - Susan Redline
- 4 Department of Medicine, Brigham and Women's Hospital and Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts; and
| | - Naresh M Punjabi
- 5 Johns Hopkins University School of Medicine, Baltimore, Maryland
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11
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Circulating Endocannabinoids and Insulin Resistance in Patients with Obstructive Sleep Apnea. BIOMED RESEARCH INTERNATIONAL 2016; 2016:9782031. [PMID: 26904688 PMCID: PMC4745295 DOI: 10.1155/2016/9782031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/23/2015] [Accepted: 12/28/2015] [Indexed: 12/15/2022]
Abstract
Objectives. The purpose of this study is to investigate the relationship between plasma endocannabinoids and insulin resistance (IR) in patients with obstructive sleep apnea (OSA). Methods. A population of 64 with OSA and 24 control subjects was recruited. Body mass index (BMI), waist circumference, lipids, blood glucose and insulin, homeostasis model of assessment for insulin resistance index (HOMA-IR), anandamide (AEA), 1/2-arachidonoylglycerol (1/2-AG), and apnea-hypopnea index (AHI) were analyzed. Results. Fasting blood insulin (22.9 ± 7.8 mIU/L versus 18.5 ± 7.2 mIU/L, P < 0.05), HOMA-IR (2.9 ± 1.0 versus 2.4 ± 0.9, P < 0.01), AEA (3.2 ± 0.7 nmol/L versus 2.5 ± 0.6 nmol/L, P < 0.01), and 1/2-AG (40.8 ± 5.7 nmol/L versus 34.3 ± 7.7 nmol/L, P < 0.01) were higher in OSA group than those in control group. In OSA group, AEA, 1/2-AG, and HOMA-IR increase with the OSA severity. The correlation analysis showed significant positive correlation between HOMA-IR and AHI (r = 0.44, P < 0.01), AEA and AHI (r = 0.52, P < 0.01), AEA and HOMA-IR (r = 0.62, P < 0.01), and 1/2-AG and HOMA-IR (r = 0.33, P < 0.01). Further analysis showed that only AEA was significantly correlated with AHI and HOMA-IR after adjusting for confounding factors. Conclusions. The present study indicated that plasma endocannabinoids levels, especially AEA, were associated with IR and AHI in patients with OSA.
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12
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Abstract
Obstructive sleep apnea (OSA) is a common disorder associated with cardiovascular disease (CVD). One theory to explain this relationship proposes that OSA can induce systemic inflammation, thereby inducing CVD. This theory is based on the premise that obesity is a pro-inflammatory state, and that physiological derangements during sleep in subjects with OSA further aggravate inflammation. In support of this theory, some clinical studies have shown elevated inflammatory biomarkers in OSA subjects, or improvement in these markers following treatment of OSA. However, the data are inconsistent and often confounded by the effects of comorbid obesity. Animal models of OSA have been developed, which involve exposure of rodents or cells to intermittent hypoxia, a hallmark feature of OSA. Several of these experiments demonstrate that intermittent hypoxia can stimulate inflammatory pathways and lead to cardiovascular or metabolic pathology. In this review, we review relationships between OSA and inflammation, with particular attention to studies published within the last year.
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Affiliation(s)
- Dileep Unnikrishnan
- Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, 5501 Hopkins Bayview Circle, Rm 5B.81, Baltimore, MD, 21224, USA
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13
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Jun JC, Shin MK, Devera R, Yao Q, Mesarwi O, Bevans-Fonti S, Polotsky VY. Intermittent hypoxia-induced glucose intolerance is abolished by α-adrenergic blockade or adrenal medullectomy. Am J Physiol Endocrinol Metab 2014; 307:E1073-83. [PMID: 25315697 PMCID: PMC4254988 DOI: 10.1152/ajpendo.00373.2014] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 10/09/2014] [Indexed: 12/21/2022]
Abstract
Obstructive sleep apnea causes intermittent hypoxia (IH) during sleep and is associated with dysregulation of glucose metabolism. We developed a novel model of clinically realistic IH in mice to test the hypothesis that IH causes hyperglycemia, glucose intolerance, and insulin resistance via activation of the sympathetic nervous system. Mice were exposed to acute hypoxia of graded severity (21, 14, 10, and 7% O2) or to IH of graded frequency [oxygen desaturation index (ODI) of 0, 15, 30, or 60, SpO2 nadir 80%] for 30 min to measure levels of glucose fatty acids, glycerol, insulin, and lactate. Glucose tolerance tests and insulin tolerance tests were then performed under each hypoxia condition. Next, we examined these outcomes in mice that were administered phentolamine (α-adrenergic blockade) or propranolol (β-adrenergic blockade) or that underwent adrenal medullectomy before IH exposure. In all experiments, mice were maintained in a thermoneutral environment. Sustained and IH induced hyperglycemia, glucose intolerance, and insulin resistance in a dose-dependent fashion. Only severe hypoxia (7% O2) increased lactate, and only frequent IH (ODI 60) increased plasma fatty acids. Phentolamine or adrenal medullectomy both prevented IH-induced hyperglycemia and glucose intolerance. IH inhibited glucose-stimulated insulin secretion, and phentolamine prevented the inhibition. Propranolol had no effect on glucose metabolism but abolished IH-induced lipolysis. IH-induced insulin resistance was not affected by any intervention. Acutely hypoxia causes hyperglycemia, glucose intolerance, and insulin resistance in a dose-dependent manner. During IH, circulating catecholamines act upon α-adrenoreceptors to cause hyperglycemia and glucose intolerance.
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Affiliation(s)
- Jonathan C Jun
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Mi-Kyung Shin
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ronald Devera
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Qiaoling Yao
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Omar Mesarwi
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Shannon Bevans-Fonti
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Vsevolod Y Polotsky
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
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Keenan BT, Maislin G, Sunwoo BY, Arnardottir ES, Jackson N, Olafsson I, Juliusson S, Schwab RJ, Gislason T, Benediktsdottir B, Pack AI. Obstructive sleep apnoea treatment and fasting lipids: a comparative effectiveness study. Eur Respir J 2014; 44:405-14. [PMID: 24833762 PMCID: PMC6668707 DOI: 10.1183/09031936.00043614] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Obstructive sleep apnoea (OSA) is associated with cardiovascular disease. Dyslipidaemia has been implicated as a mechanism linking OSA with atherosclerosis, but no consistent associations with lipids exist for OSA or positive airway pressure treatment. We assessed the relationships between fasting lipid levels and obesity and OSA severity, and explored the impact of positive airway pressure treatment on 2-year fasting lipid level changes. Analyses included moderate-to-severe OSA patients from the Icelandic Sleep Apnoea Cohort. Fasting morning lipids were analysed in 613 untreated participants not on lipid-lowering medications at baseline. Patients were then initiated on positive airway pressure and followed for 2 years. Sub-classification using propensity score quintiles, which aimed to replicate covariate balance associated with randomised trials and, therefore, minimise selection bias and allow causal inference, was used to design the treatment group comparisons. 199 positive airway pressure adherent patients and 118 non-users were identified. At baseline, obesity was positively correlated with triglycerides and negatively correlated with total cholesterol, and low-density and high-density lipoprotein cholesterol. A small correlation was observed between the apnoea/hypopnoea index and high-density lipoprotein cholesterol. No effect of positive airway pressure adherence on 2-year fasting lipid changes was observed. Results do not support the concept of changes in fasting lipids as a primary mechanism for the increased risk of atherosclerotic cardiovascular disease in OSA.
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Affiliation(s)
- Brendan T Keenan
- Center for Sleep and Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA, USA Joint first authors
| | - Greg Maislin
- Center for Sleep and Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA, USA Division of Sleep Medicine, Dept of Medicine, University of Pennsylvania, Philadelphia, PA, USA Joint first authors
| | - Bernie Y Sunwoo
- Center for Sleep and Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA, USA Division of Sleep Medicine, Dept of Medicine, University of Pennsylvania, Philadelphia, PA, USA Division of Pulmonary, Allergy and Critical Care, Dept of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Erna Sif Arnardottir
- Dept of Respiratory Medicine and Sleep, Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Nicholas Jackson
- Center for Sleep and Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Isleifur Olafsson
- Dept of Clinical Biochemistry, Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland
| | | | - Richard J Schwab
- Center for Sleep and Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA, USA Division of Sleep Medicine, Dept of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Thorarinn Gislason
- Dept of Respiratory Medicine and Sleep, Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Bryndis Benediktsdottir
- Dept of Respiratory Medicine and Sleep, Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland Faculty of Medicine, University of Iceland, Reykjavik, Iceland Joint senior authors
| | - Allan I Pack
- Center for Sleep and Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA, USA Division of Sleep Medicine, Dept of Medicine, University of Pennsylvania, Philadelphia, PA, USA Joint senior authors
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He Q, Yang QC, Zhou Q, Zhu H, Niu WY, Feng J, Wang Y, Cao J, Chen BY. Effects of varying degrees of intermittent hypoxia on proinflammatory cytokines and adipokines in rats and 3T3-L1 adipocytes. PLoS One 2014; 9:e86326. [PMID: 24466027 PMCID: PMC3897671 DOI: 10.1371/journal.pone.0086326] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Accepted: 12/09/2013] [Indexed: 01/16/2023] Open
Abstract
Objectives Intermittent hypoxia (IH), resulted from recurring episodes of upper airway obstruction, is the hallmark feature and the most important pathophysiologic pathway of obstructive sleep apnea (OSA). IH is believed to be the most important factor causing systemic inflammation. Studies suggest that insulin resistance (IR) is positively associated with OSA. In this study, we hypothesized that the recurrence of IH might result in cellular and systemic inflammation, which was manifested through the levels of proinflammatory cytokines and adipokines after IH exposure, and because IR is linked with inflammation tightly, this inflammatory situation may implicate an IR status. Methods We developed an IH 3T3-L1 adipocyte and rat model respectively, recapitulating the nocturnal oxygen profile in OSA. In IH cells, nuclear factor kappa B (NF-κB) DNA binding reactions, hypoxia-inducible factor-1α (HIF-1α), glucose transporter-1 (Glut-1), necrosis factor alpha (TNF-α), interleukin (IL) -6, leptin, adiponectin mRNA transcriptional activities and protein expressions were measured. In IH rats, blood glucose, insulin, TNF-α, IL-6, leptin and adiponectin levels were analyzed. Results The insulin and blood glucose levels in rats and NF-κB DNA binding activities in cells had significantly statistical results described as severe IH>moderate IH>mild IH>sustained hypoxia>control. The mRNA and protein levels of HIF-1α and Glut-1 in severe IH group were the highest. In cellular and animal models, both the mRNA and protein levels of TNF-α, IL-6 and leptin were the highest in severe IH group, when the lowest in severe IH group for adiponectin. Conclusions Oxidative stress and the release of pro-inflammatory cytokines/adipokines, which are the systemic inflammatory markers, are associated with IH closely and are proportional to the severity of IH. Because IR and glucose intolerance are linked with inflammation tightly, our results may implicate the clinical relationships between OSA and IR.
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Affiliation(s)
- Qing He
- Department of Endocrinology, Tianjin Medical University General Hospital, Tianjin, China
| | - Qing-chan Yang
- Respiratory Department of Tianjin Medical University General Hospital, Tianjin, China
| | - Qin Zhou
- Department of Endocrinology, Tianjin Medical University General Hospital, Tianjin, China
| | - Hui Zhu
- Department of Endocrinology, Tianjin Medical University General Hospital, Tianjin, China
| | - Wen-yan Niu
- Immunology Department, Tianjin Medical University, Tianjin, China
| | - Jing Feng
- Respiratory Department of Tianjin Medical University General Hospital, Tianjin, China
- * E-mail:
| | - Yan Wang
- Respiratory Department of Tianjin Medical University General Hospital, Tianjin, China
| | - Jie Cao
- Respiratory Department of Tianjin Medical University General Hospital, Tianjin, China
| | - Bao-yuan Chen
- Respiratory Department of Tianjin Medical University General Hospital, Tianjin, China
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Rafacho A, Gonçalves-Neto LM, Ferreira FBD, Protzek AOP, Boschero AC, Nunes EA, Zoccal DB. Glucose homoeostasis in rats exposed to acute intermittent hypoxia. Acta Physiol (Oxf) 2013; 209:77-89. [PMID: 23692825 DOI: 10.1111/apha.12118] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2012] [Revised: 01/15/2013] [Accepted: 05/15/2013] [Indexed: 11/29/2022]
Abstract
AIM Chronic exposure to intermittent hypoxia commonly induces the activation of sympathetic tonus and the disruption of glucose homoeostasis. However, the effects of exposure to acute intermittent hypoxia (AIH) on glucose homoeostasis are not yet fully elucidated. Herein, we evaluated parameters related to glucose metabolism in rats exposed to AIH. METHODS Male adult rats were submitted to 10 episodes of hypoxia (6% O2 , for 45 s) interspersed with 5-min intervals of normoxia (21%), while the control (CTL) group was kept in normoxia. RESULTS Acute intermittent hypoxia rats presented higher fasting glycaemia, normal insulinaemia, increased lactataemia and similar serum lipid levels, compared to controls (n = 10, P < 0.05). Additionally, AIH rats exhibited increased glucose tolerance (GT) (n = 10, P < 0.05) and augmented insulin sensitivity (IS) (n = 10, P < 0.05). The p-Akt/Akt protein ratio was increased in the muscle, but not in the liver and adipose tissue of AIH rats (n = 6, P < 0.05). The elevated glycaemia in AIH rats was associated with a reduction in the hepatic glycogen content (n = 10, P < 0.05). Moreover, the AIH-induced increase in blood glucose concentration, as well as reduced hepatic glycogen content, was prevented by prior systemic administration of the β-adrenergic antagonist (P < 0.05). The effects of AIH on glycaemia and Akt phosphorylation were transient and not observed after 60 min. CONCLUSIONS We suggest that AIH induces an increase in blood glucose concentration as a result of hepatic glycogenolysis recruitment through sympathetic activation. The augmentation of GT and IS might be attributed, at least in part, to increased β-adrenergic sympathetic stimulation and Akt protein activation in skeletal muscles, leading to a higher glucose availability and utilization.
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Affiliation(s)
- A. Rafacho
- Department of Physiological Sciences; Centre of Biological Sciences; UFSC - Federal University of de Santa Catarina; Florianópolis; Santa Catarina; Brazil
| | - L. M. Gonçalves-Neto
- Department of Physiological Sciences; Centre of Biological Sciences; UFSC - Federal University of de Santa Catarina; Florianópolis; Santa Catarina; Brazil
| | - F. B. D. Ferreira
- Department of Physiological Sciences; Centre of Biological Sciences; UFSC - Federal University of de Santa Catarina; Florianópolis; Santa Catarina; Brazil
| | - A. O. P. Protzek
- Department of Structural and Functional Biology; Institute of Biology; UNICAMP - State University of Campinas; Campinas; São Paulo; Brazil
| | - A. C. Boschero
- Department of Structural and Functional Biology; Institute of Biology; UNICAMP - State University of Campinas; Campinas; São Paulo; Brazil
| | - E. A. Nunes
- Department of Physiological Sciences; Centre of Biological Sciences; UFSC - Federal University of de Santa Catarina; Florianópolis; Santa Catarina; Brazil
| | - D. B. Zoccal
- Department of Physiological Sciences; Centre of Biological Sciences; UFSC - Federal University of de Santa Catarina; Florianópolis; Santa Catarina; Brazil
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Togeiro SM, Carneiro G, Ribeiro Filho FF, Zanella MT, Santos-Silva R, Taddei JA, Bittencourt LRA, Tufik S. Consequences of obstructive sleep apnea on metabolic profile: a Population-Based Survey. Obesity (Silver Spring) 2013; 21:847-51. [PMID: 23712988 DOI: 10.1002/oby.20288] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 05/14/2012] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Epidemiologic studies that control for potential confounders are needed to assess the independent associations of obstructive sleep apnea (OSA) with metabolic abnormalities. The aim of our study was to evaluate the associations of OSA with metabolic abnormalities among the adult population of Sao Paulo, Brazil. DESIGN AND METHODS Questionnaires were applied face-to-face, full night polysomnography (PSG) was performed, and blood samples were collected in a population-based survey in Sao Paulo, Brazil, adopting a probabilistic three-stage cluster sample method. The metabolic profile included fasting glucose, insulin, and lipid levels. The hepatic insulin resistance index was assessed by the homeostasis model assessment-estimated insulin resistance (HOMAIR ). RESULTS A total of 1,042 volunteers underwent PSG. Mild OSA and moderate to severe OSA comprised 21.2% and 16.7% of the population, respectively. Subjects with severe to moderate OSA were older, more obese, had higher fasting glucose, HOMAIR , and triglycerides (TG) levels than did the mild and non-OSA group (P < 0.001). Multivariate regression analyses showed that an apnea-hypopnea index (AHI) ≥ 15 and a time of oxy-hemoglobin saturation <90% were independently associated with impaired fasting glucose, elevated TG, and HOMAIR . CONCLUSIONS The results of this large cross-sectional epidemiological study showed that the associations of OSA and metabolic abnormalities were independent of other risk factors.
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Affiliation(s)
- Sonia M Togeiro
- Disciplina de Medicina e Biologia do Sono, Departamento de Psicobiologia, Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
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Toth LA, Bhargava P. Animal models of sleep disorders. Comp Med 2013; 63:91-104. [PMID: 23582416 PMCID: PMC3625050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 10/21/2012] [Accepted: 11/25/2012] [Indexed: 06/02/2023]
Abstract
Problems with sleep affect a large part of the general population, with more than half of all people in the United States reporting difficulties with sleep or insufficient sleep at various times and about 40 million affected chronically. Sleep is a complex physiologic process that is influenced by many internal and environmental factors, and problems with sleep are often related to specific personal circumstances or are based on subjective reports from the affected person. Although human subjects are used widely in the study of sleep and sleep disorders, the study of animals has been invaluable in developing our understanding about the physiology of sleep and the underlying mechanisms of sleep disorders. Historically, the use of animals for the study of sleep disorders has arguably been most fruitful for the condition of narcolepsy, in which studies of dogs and mice revealed previously unsuspected mechanisms for this condition. The current overview considers animal models that have been used to study 4 of the most common human sleep disorders-insomnia, narcolepsy, restless legs syndrome, and sleep apnea-and summarizes considerations relevant to the use of animals for the study of sleep and sleep disorders. Animal-based research has been vital to the elucidation of mechanisms that underlie sleep, its regulation, and its disorders and undoubtedly will remain crucial for discovering and validating sleep mechanisms and testing interventions for sleep disorders.
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Affiliation(s)
- Linda A Toth
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois, USA.
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Golbidi S, Badran M, Ayas N, Laher I. Cardiovascular consequences of sleep apnea. Lung 2011; 190:113-32. [PMID: 22048845 DOI: 10.1007/s00408-011-9340-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 10/03/2011] [Indexed: 12/25/2022]
Abstract
Sleep apnea is a common health concern that is characterized by repetitive episodes of asphyxia. This condition has been linked to serious long-term adverse effects such as hypertension, metabolic dysregulation, and cardiovascular disease. Although the mechanism for the initiation and aggravation of cardiovascular disease has not been fully elucidated, oxidative stress and subsequent endothelial dysfunction play major roles. Animal models, which have the advantage of being free of comorbidities and/or behavioral variables (that commonly occur in humans), allow invasive measurements under well-controlled experimental conditions, and as such are useful tools in the study of the pathophysiological mechanisms of sleep apnea. This review summarizes currently available information on the cardiovascular consequences of sleep apnea and briefly describes common experimental approaches useful to sleep apnea in different animal models.
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Affiliation(s)
- Saeid Golbidi
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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21
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Drager LF, Jun JC, Polotsky VY. Metabolic consequences of intermittent hypoxia: relevance to obstructive sleep apnea. Best Pract Res Clin Endocrinol Metab 2010; 24:843-51. [PMID: 21112030 PMCID: PMC3011976 DOI: 10.1016/j.beem.2010.08.011] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Obstructive sleep apnea (OSA) is recurrent obstruction of the upper airway leading to sleep fragmentation and intermittent hypoxia (IH) during sleep. There is growing evidence from animal models of OSA that IH is independently associated with metabolic dysfunction, including dyslipidemia and insulin resistance. The precise mechanisms by which IH induces metabolic disturbances are not fully understood. Over the last decade, several groups of investigators developed a rodent model of IH, which emulates the oxyhemoglobin profile in human OSA. In the mouse model, IH induces dyslipidemia, insulin resistance and pancreatic endocrine dysfunction, similar to those observed in human OSA. Recent reports provided new insights in possible mechanisms by which IH affects lipid and glucose metabolism. IH may induce dyslipidemia by up-regulating lipid biosynthesis in the liver, increasing adipose tissue lipolysis with subsequent free fatty acid flux to the liver, and inhibiting lipoprotein clearance. IH may affect glucose metabolism by inducing sympathetic activation, increasing systemic inflammation, increasing counter-regulatory hormones and fatty acids, and causing direct pancreatic beta-cell injury. IH models of OSA have improved our understanding of the metabolic impact of OSA, but further studies are needed before we can translate recent basic research findings to clinical practice.
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Affiliation(s)
- Luciano F Drager
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Johns Hopkins Asthma and Allergy Center, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA
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Abstract
Obstructive sleep apnea (OSA) and the metabolic syndrome have a strong association with each other owing to their common feature of obesity, but an association independent of obesity has been demonstrated in several studies. There is also evidence, of varying strengths, from epidemiologic and clinical studies, for the independent association between OSA and individual core components of the metabolic syndrome, including hypertension, insulin resistance and dyslipidemia. To date, the data are strongest for hypertension, while data for adverse glucose or lipid metabolism are more controversial. Obesity and other factors, such as alcohol drinking and smoking, obviously pose major confounding hurdles to the clarification of the causal or aggravational role of OSA on cardiometabolic risks. Recurrent episodes of obstructed breathing notably result in intermittent hypoxemia and sleep fragmentation, and these may in turn lead to many adverse body responses, including sympathetic activation, neurohumeral changes and inflammation, which are the seeds for cardiometabolic dysfunctions, such as atherosclerosis and diabetes mellitus. Evidence from translational studies or animal/cell work are forthcoming in the delineation of these pathogenetic mechanisms.
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Affiliation(s)
- Jamie C M Lam
- University Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, SAR, China.
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Abstract
PURPOSE OF REVIEW The aim of this review is to summarize current evidence about the impact of obstructive sleep apnea (OSA) and intermittent hypoxia on dyslipidemia and provide future perspectives in this area. RECENT FINDINGS Intermittent hypoxia, a hallmark of OSA, induces hyperlipidemia in lean mice. Hyperlipidemia of intermittent hypoxia occurs, at least in part, due to activation of the transcription factor sterol regulatory element-binding protein-1 (SREBP-1) and an important downstream enzyme of triglyceride and phospholipid biosynthesis, stearoyl-CoA desaturase-1. Furthermore, intermittent hypoxia may regulate SREBP-1 and stearoyl-CoA desaturase-1 via the transcription factor hypoxia-inducible factor 1. In contrast, key genes involved in cholesterol biosynthesis, SREBP-2 and 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase, are unaffected by intermittent hypoxia. In humans, there is no definitive evidence regarding the effect of OSA on dyslipidemia. Several cross-sectional studies suggest that OSA is independently associated with increased levels of total cholesterol, low-density lipoprotein and triglycerides, whereas others report no such relationship. Some nonrandomized and randomized studies show that OSA treatment with continuous positive airway pressure may have a beneficial effect on lipid profile. SUMMARY There is increasing evidence that intermittent hypoxia is independently associated with dyslipidemia. However, the role of OSA in causality of dyslipidemia remains to be established.
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Affiliation(s)
- Luciano F Drager
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Eastwood PR, Malhotra A, Palmer LJ, Kezirian EJ, Horner RL, Ip MS, Thurnheer R, Antic NA, Hillman DR. Obstructive Sleep Apnoea: From pathogenesis to treatment: Current controversies and future directions. Respirology 2010; 15:587-95. [PMID: 20136736 DOI: 10.1111/j.1440-1843.2009.01699.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Obstructive sleep apnoea (OSA) is a common disease, recognized as an independent risk factor for a range of clinical conditions, such as hypertension, stroke, depression and diabetes. Despite extensive research over the past two decades, the mechanistic links between OSA and other associated clinical conditions, including metabolic disorders and cardiovascular disease, remain unclear. Indeed, the pathogenesis of OSA itself remains incompletely understood. This review provides opinions from a number of leading experts on issues related to OSA and its pathogenesis, interaction with anaesthesia, metabolic consequences and comorbidities, cardiovascular disease, genetics, measurement and diagnosis, surgical treatment and pharmacotherapeutic targets.
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Affiliation(s)
- Peter R Eastwood
- West Australian Sleep Disorders Research Institute, Department of Pulmonary Physiology, Sir Charles Gairdner Hospital, Nedlands, WA 6009, Australia.
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Effect of intermittent hypoxia on atherosclerosis in apolipoprotein E-deficient mice. Atherosclerosis 2009; 209:381-6. [PMID: 19897196 DOI: 10.1016/j.atherosclerosis.2009.10.017] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 10/08/2009] [Accepted: 10/09/2009] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Obstructive sleep apnea causes intermittent hypoxia (IH) and is associated with increased cardiovascular mortality. This increased risk may be attributable to more extensive or unstable atherosclerotic plaques in subjects with OSA. We studied the effect of chronic IH in atherosclerosis-prone mice. METHODS AND RESULTS Apolipoprotein E-deficient (ApoE(-/-)) mice fed a high cholesterol diet were exposed to 4 or 12 weeks of IH and compared to intermittent air-exposed controls. At 4 weeks, IH increased plaque size in the aortic sinus and the descending aorta. At 12 weeks, atherosclerosis progressed in all groups, but more rapidly in the descending aorta of IH-exposed animals. Plaque composition was similar between IH and controls. Between 4 and 12 weeks, there were progressive increases in blood pressure, with relatively stable increases in serum lipids and arterial stiffness. CONCLUSIONS IH accelerates atherosclerotic plaque growth in ApoE(-/-) mice without affecting plaque composition. The mechanisms may include non-additive increases in serum lipids, and cumulative increases in blood pressure.
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Abstract
There is increasing evidence of a causal relationship between sleep-disordered breathing and metabolic dysfunction. Metabolic syndrome (MetS), a cluster of risk factors that promote atherosclerotic cardiovascular disease, comprises central obesity, insulin resistance, glucose intolerance, dyslipidemia, and hypertension, manifestations of altered total body energy regulation. Excess caloric intake is indisputably the key driver of MetS, but other environmental and genetic factors likely play a role; in particular, obstructive sleep apnea (OSA), characterized by intermittent hypoxia (IH), may induce or exacerbate various aspects of MetS. Clinical studies show that OSA can affect glucose metabolism, cholesterol, inflammatory markers, and nonalcoholic fatty liver disease. Animal models of OSA enable scientists to circumvent confounders such as obesity in clinical studies. In the most widely used model, which involves exposing rodents to IH during their sleep phase, the IH alters circadian glucose homeostasis, impairs muscle carbohydrate uptake, induces hyperlipidemia, and upregulates cholesterol synthesis enzymes. Complicating factors such as obesity or a high-fat diet lead to progressive insulin resistance and liver inflammation, respectively. Mechanisms for these effects are not yet fully understood, but are likely related to energy-conserving adaptations to hypoxia, which is a strong catabolic stressor. Finally, IH may contribute to the morbidity of MetS by inducing inflammation and oxidative stress. Identification of OSA as a potential causative factor in MetS would have immense clinical impact and could improve the management and understanding of both disorders.
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Affiliation(s)
- Jonathan Jun
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
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