1
|
Jun JC. Senolytic Therapy in Sleep Apnea: Murky Waters or Fountain of Youth? Am J Respir Crit Care Med 2024; 209:907-908. [PMID: 38301230 DOI: 10.1164/rccm.202312-2280ed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 02/01/2024] [Indexed: 02/03/2024] Open
Affiliation(s)
- Jonathan C Jun
- Division of Pulmonary and Critical Care Medicine Johns Hopkins University Baltimore, Maryland
| |
Collapse
|
2
|
Osman A, Gu C, Kim DE, Duan D, Barron B, Pham LV, Polotsky VY, Jun JC. Ketogenic diet acutely improves gas exchange and sleep apnoea in obesity hypoventilation syndrome: A non-randomized crossover study. Respirology 2023; 28:784-793. [PMID: 37246156 DOI: 10.1111/resp.14526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 05/17/2023] [Indexed: 05/30/2023]
Abstract
BACKGROUND AND OBJECTIVE Obesity hypoventilation syndrome (OHS) causes hypercapnia which is often refractory to current therapies. We examine whether hypercapnia in OHS can be improved by a ketogenic dietary intervention. METHODS We conducted a single-arm crossover clinical trial to examine the impact of a ketogenic diet on CO2 levels in patients with OHS. Patients were instructed to adhere to 1 week of regular diet, 2 weeks of ketogenic diet, followed by 1 week of regular diet in an ambulatory setting. Adherence was assessed with capillary ketone levels and continuous glucose monitors. At weekly visits, we measured blood gases, calorimetry, body composition, metabolic profiles, and sleep studies. Outcomes were assessed with linear mixed models. RESULTS A total of 20 subjects completed the study. Blood ketones increased from 0.14 ± 0.08 during regular diet to 1.99 ± 1.11 mmol/L (p < 0.001) after 2 weeks of ketogenic diet. Ketogenic diet decreased venous CO2 by 3.0 mm Hg (p = 0.008), bicarbonate by 1.8 mmol/L (p = 0.001), and weight by 3.4 kg (p < 0.001). Sleep apnoea severity and nocturnal oxygen levels significantly improved. Ketogenic diet lowered respiratory quotient, fat mass, body water, glucose, insulin, triglycerides, leptin, and insulin-like growth factor 1. Rebound hypercapnia was observed after resuming regular diet. CO2 lowering was dependent on baseline hypercapnia, and associated with circulating ketone levels and respiratory quotient. The ketogenic diet was well tolerated. CONCLUSION This study demonstrates for the first time that a ketogenic diet may be useful for control of hypercapnia and sleep apnoea in patients with obesity hypoventilation syndrome.
Collapse
Affiliation(s)
- Adam Osman
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Chenjuan Gu
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - David E Kim
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Daisy Duan
- Division of Endocrinology, Diabetes, and Metabolism, Johns Hopkins University, Baltimore, Maryland, USA
| | - Bobbie Barron
- Institute for Clinical and Translational Research, Johns Hopkins University, Baltimore, Maryland, USA
| | - Luu V Pham
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jonathan C Jun
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| |
Collapse
|
3
|
Jun JC, Taylor SL. Could Sleep Apnea Be Suffocating Your Gut Microbiome? Chest 2023; 164:290-291. [PMID: 37558324 DOI: 10.1016/j.chest.2023.04.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 04/25/2023] [Indexed: 08/11/2023] Open
Affiliation(s)
- Jonathan C Jun
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD.
| | - Steven L Taylor
- Microbiome and Host Health Programme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| |
Collapse
|
4
|
Duan D, Perin J, Osman A, Sgambati F, Kim LJ, Pham LV, Polotsky VY, Jun JC. Effects of sex, age, and body mass index on serum bicarbonate. Front Sleep 2023; 2:1195823. [PMID: 37736141 PMCID: PMC10512520 DOI: 10.3389/frsle.2023.1195823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
Abstract
Rationale Obesity hypoventilation syndrome (OHS) is often underdiagnosed, with significant morbidity and mortality. Bicarbonate, as a surrogate of arterial carbon dioxide, has been proposed as a screening tool for OHS. Understanding the predictors of serum bicarbonate could provide insights into risk factors for OHS. We hypothesized that the bicarbonate levels would increase with an increase in body mass index (BMI), since the prevalence of OHS increases with obesity. Methods We used the TriNetX Research Network, an electronic health record database with de-identified clinical data from participating healthcare organizations across the United States, to identify 93,320 adults without pulmonary or advanced renal diseases who had serum bicarbonate and BMI measurements within 6 months of each other between 2017 and 2022. We used linear regression analysis to examine the associations between bicarbonate and BMI, age, and their interactions for the entire cohort and stratified by sex. We also applied a non-linear machine learning algorithm (XGBoost) to examine the relative importance of age, BMI, sex, race/ethnicity, and obstructive sleep apnea (OSA) status on bicarbonate. Results This cohort population was 56% women and 72% white and 80% non-Hispanic individuals, with an average (SD) age of 49.4 (17.9) years and a BMI of 29.1 (6.1) kg/m2. The mean bicarbonate was 24.8 (2.8) mmol/L, with higher levels in men (mean 25.2 mmol/L) than in women (mean 24.4 mmol/L). We found a small negative association between bicarbonate and BMI, with an expected change of -0.03 mmol/L in bicarbonate for each 1 kg/m2 increase in BMI (p < 0.001), in the entire cohort and both sexes. We found sex differences in the bicarbonate trajectory with age, with women exhibiting lower bicarbonate values than men until age 50, after which the bicarbonate levels were modestly higher. The non-linear machine learning algorithm similarly revealed that age and sex played larger roles in determining bicarbonate levels than the BMI or OSA status. Conclusion Contrary to our hypothesis, BMI is not associated with elevated bicarbonate levels, and age modifies the impact of sex on bicarbonate.
Collapse
Affiliation(s)
- Daisy Duan
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Jamie Perin
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Adam Osman
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Francis Sgambati
- Center for Interdisciplinary Sleep Research and Education, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Lenise J. Kim
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Luu V. Pham
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Vsevolod Y. Polotsky
- Departments of Anesthesiology and Critical Care Medicine and Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC, United States
| | - Jonathan C. Jun
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| |
Collapse
|
5
|
Duan D, Kim LJ, Jun JC, Polotsky VY. Connecting insufficient sleep and insomnia with metabolic dysfunction. Ann N Y Acad Sci 2023; 1519:94-117. [PMID: 36373239 PMCID: PMC9839511 DOI: 10.1111/nyas.14926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The global epidemic of obesity and type 2 diabetes parallels the rampant state of sleep deprivation in our society. Epidemiological studies consistently show an association between insufficient sleep and metabolic dysfunction. Mechanistically, sleep and circadian rhythm exert considerable influences on hormones involved in appetite regulation and energy metabolism. As such, data from experimental sleep deprivation in humans demonstrate that insufficient sleep induces a positive energy balance with resultant weight gain, due to increased energy intake that far exceeds the additional energy expenditure of nocturnal wakefulness, and adversely impacts glucose metabolism. Conversely, animal models have found that sleep loss-induced energy expenditure exceeds caloric intake resulting in net weight loss. However, animal models have significant limitations, which may diminish the clinical relevance of their metabolic findings. Clinically, insomnia disorder and insomnia symptoms are associated with adverse glucose outcomes, though it remains challenging to isolate the effects of insomnia on metabolic outcomes independent of comorbidities and insufficient sleep durations. Furthermore, both pharmacological and behavioral interventions for insomnia may have direct metabolic effects. The goal of this review is to establish an updated framework for the causal links between insufficient sleep and insomnia and risks for type 2 diabetes and obesity.
Collapse
Affiliation(s)
- Daisy Duan
- Division of Endocrinology, Diabetes, and Metabolism; Department of Medicine; Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Lenise J. Kim
- Division of Pulmonary and Critical Care; Department of Medicine; Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jonathan C. Jun
- Division of Pulmonary and Critical Care; Department of Medicine; Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Vsevolod Y. Polotsky
- Division of Pulmonary and Critical Care; Department of Medicine; Johns Hopkins University School of Medicine, Baltimore, Maryland
| |
Collapse
|
6
|
|
7
|
Sampognaro JR, Barth AS, Jun JC, Chrispin J, Berger RD, Love CJ, Eddy C, Calkins H. Prolonged asystole during REM sleep: A case report and review of the literature. Heart Rhythm O2 2022; 3:613-619. [DOI: 10.1016/j.hroo.2022.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/07/2022] [Accepted: 07/08/2022] [Indexed: 11/25/2022] Open
|
8
|
Gu C, Loube J, Lee R, Bevans-Fonti S, Wu TD, Barmine JH, Jun JC, McCormack MC, Hansel NN, Mitzner W, Polotsky VY. Metformin Alleviates Airway Hyperresponsiveness in a Mouse Model of Diet-Induced Obesity. Front Physiol 2022; 13:883275. [PMID: 35574481 PMCID: PMC9098833 DOI: 10.3389/fphys.2022.883275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 03/14/2022] [Indexed: 12/03/2022] Open
Abstract
Obese asthma is a unique phenotype of asthma characterized by non-allergic airway hyperresponsiveness (AHR) and inflammation which responds poorly to standard asthma therapy. Metformin is an oral hypoglycemic drug with insulin-sensitizing and anti-inflammatory properties. The objective of the current study was to test the effect of metformin on AHR in a mouse model of diet-induced obesity (DIO). We fed 12-week-old C57BL/6J DIO mice with a high fat diet for 8 weeks and treated them with either placebo (control, n = 10) or metformin (n = 10) added in drinking water (300 mg/kg/day) during the last 2 weeks of the experiment. We assessed AHR, metabolic profiles, and inflammatory markers after treatments. Metformin did not affect body weight or fasting blood glucose, but significantly reduced serum insulin (p = 0.0117). Metformin reduced AHR at 30 mg/ml of methacholine challenge (p = 0.0052) without affecting baseline airway resistance. Metformin did not affect circulating white blood cell counts or lung cytokine mRNA expression, but modestly decreased circulating platelet count. We conclude that metformin alleviated AHR in DIO mice. This finding suggests metformin has the potential to become an adjuvant pharmacological therapy in obese asthma.
Collapse
Affiliation(s)
- Chenjuan Gu
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Jeff Loube
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Rachel Lee
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Shannon Bevans-Fonti
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Tianshi David Wu
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Baylor College of Medicine and the Center for Innovations in Quality, Effectiveness, and Safety, Michael E. DeBakey VA Medical Center, Houston, TX, United States
| | - Jessica H. Barmine
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Jonathan C. Jun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Meredith C. McCormack
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Nadia N. Hansel
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Wayne Mitzner
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Vsevolod Y. Polotsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- *Correspondence: Vsevolod Y. Polotsky,
| |
Collapse
|
9
|
Pho H, Berger S, Freire C, Kim LJ, Shin MK, Streeter SR, Hosamane N, Cabassa ME, Anokye-Danso F, Dergacheva O, Amorim MR, Fleury-Curado T, Jun JC, Schwartz AR, Ahima RS, Mendelowitz D, Polotsky VY. Leptin receptor expression in the dorsomedial hypothalamus stimulates breathing during NREM sleep in db/db mice. Sleep 2021; 44:6149135. [PMID: 33624805 PMCID: PMC8193564 DOI: 10.1093/sleep/zsab046] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 02/06/2021] [Indexed: 12/12/2022] Open
Abstract
STUDY OBJECTIVES Obesity leads to obstructive sleep apnea (OSA), which is recurrent upper airway obstruction during sleep, and obesity hypoventilation syndrome (OHS), hypoventilation during sleep resulting in daytime hypercapnia. Impaired leptin signaling in the brain was implicated in both conditions, but mechanisms are unknown. We have previously shown that leptin stimulates breathing and treats OSA and OHS in leptin-deficient ob/ob mice and leptin-resistant diet-induced obese mice and that leptin's respiratory effects may occur in the dorsomedial hypothalamus (DMH). We hypothesized that leptin receptor LepRb-deficient db/db mice have obesity hypoventilation and that restoration of leptin signaling in the DMH will increase ventilation during sleep in these animals. METHODS We measured arterial blood gas in unanesthetized awake db/db mice. We subsequently infected these animals with Ad-LepRb or control Ad-mCherry virus into the DMH and measured ventilation during sleep as well as CO2 production after intracerebroventricular (ICV) infusions of phosphate-buffered saline or leptin. RESULTS Awake db/db mice had elevated CO2 levels in the arterial blood. Ad-LepRb infection resulted in LepRb expression in the DMH neurons in a similar fashion to wildtype mice. In LepRb-DMH db/db mice, ICV leptin shortened REM sleep and increased inspiratory flow, tidal volume, and minute ventilation during NREM sleep without any effect on the quality of NREM sleep or CO2 production. Leptin had no effect on upper airway obstruction in these animals. CONCLUSION Leptin stimulates breathing and treats obesity hypoventilation acting on LepRb-positive neurons in the DMH.
Collapse
Affiliation(s)
- Huy Pho
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Slava Berger
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Carla Freire
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Lenise J Kim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mi-Kyung Shin
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Stone R Streeter
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nishitha Hosamane
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Meaghan E Cabassa
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Frederick Anokye-Danso
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Olga Dergacheva
- Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA
| | - Mateus R Amorim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Thomaz Fleury-Curado
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jonathan C Jun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Alan R Schwartz
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Rexford S Ahima
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - David Mendelowitz
- Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Corresponding author. Vsevolod (Seva) Y. Polotsky, Division of Pulmonary and Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, 5501 Hopkins Bayview Circle, Johns Hopkins Asthma and Allergy Center, Rm 4B65, Baltimore, MD 21224.
| |
Collapse
|
10
|
Duan D, Gu C, Polotsky VY, Jun JC, Pham LV. Effects of Dinner Timing on Sleep Stage Distribution and EEG Power Spectrum in Healthy Volunteers. Nat Sci Sleep 2021; 13:601-612. [PMID: 34017207 PMCID: PMC8131073 DOI: 10.2147/nss.s301113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 04/13/2021] [Indexed: 02/05/2023] Open
Abstract
PURPOSE Eating time and sleep habits are important modifiable behaviors that affect metabolic health, but the relationship between food intake and sleep remains incompletely understood. Observational data suggest that late food intake is associated with impaired sleep quality. We examined the effect of routine dinner (RD, 5 hours before bedtime) vs late dinner (LD, 1 hour before bedtime) on sleep architecture in healthy volunteers. PARTICIPANTS AND METHODS This was a post hoc analysis of a randomized crossover study of RD vs LD with a fixed sleep opportunity in a laboratory setting. On each of the two visits, 20 healthy adult volunteers (10 women) received an isocaloric meal followed by overnight polysomnography. Sleep architecture over the course of the night was assessed using visual sleep staging and EEG spectral power analysis and was compared between RD and LD. We modeled the proportions of spectral power in alpha, beta, delta, and theta bands as functions of dinner timing, time of night, and their interaction with mixed-effect spline regression. RESULTS Conventional sleep stages were similar between the 2 visits. LD caused a 2.5% initial increase in delta power and a reciprocal 2.7% decrease in combined alpha and beta power (p<0.0001). These effects diminished as sleep continued with a reversal of these patterns in the latter part of the night. CONCLUSION Contrary to the existing literature, shifting dinner timing from 5 hours before sleep to 1 hour before sleep in healthy volunteers did not result in significant adverse changes in overnight sleep architecture. In fact, LD was associated with deeper sleep in the beginning of the night and lighter sleep in the latter part of the night in healthy volunteers. This novel manifestation of postprandial hypersomnia may have therapeutic potential in patients with sleep disorders.
Collapse
Affiliation(s)
- Daisy Duan
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Chenjuan Gu
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jonathan C Jun
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Luu V Pham
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
11
|
Ryan S, Cummins EP, Farre R, Gileles-Hillel A, Jun JC, Oster H, Pepin JL, Ray DW, Reutrakul S, Sanchez-de-la-Torre M, Tamisier R, Almendros I. Understanding the pathophysiological mechanisms of cardiometabolic complications in obstructive sleep apnoea: towards personalised treatment approaches. Eur Respir J 2020; 56:13993003.02295-2019. [PMID: 32265303 DOI: 10.1183/13993003.02295-2019] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 03/15/2020] [Indexed: 12/19/2022]
Abstract
In January 2019, a European Respiratory Society research seminar entitled "Targeting the detrimental effects of sleep disturbances and disorders" was held in Dublin, Ireland. It provided the opportunity to critically review the current evidence of pathophysiological responses of sleep disturbances, such as sleep deprivation, sleep fragmentation or circadian misalignment and of abnormalities in physiological gases such as oxygen and carbon dioxide, which occur frequently in respiratory conditions during sleep. A specific emphasis of the seminar was placed on the evaluation of the current state of knowledge of the pathophysiology of cardiovascular and metabolic diseases in obstructive sleep apnoea (OSA). Identification of the detailed mechanisms of these processes is of major importance to the field and this seminar offered an ideal platform to exchange knowledge, and to discuss pitfalls of current models and the design of future collaborative studies. In addition, we debated the limitations of current treatment strategies for cardiometabolic complications in OSA and discussed potentially valuable alternative approaches.
Collapse
Affiliation(s)
- Silke Ryan
- Pulmonary and Sleep Disorders Unit, St Vincent's University Hospital, Dublin, Ireland .,School of Medicine, Conway Institute, University College Dublin, Dublin, Ireland
| | - Eoin P Cummins
- School of Medicine, Conway Institute, University College Dublin, Dublin, Ireland
| | - Ramon Farre
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona-IDIBAPS, and CIBER Enfermedades Respiratorias, Barcelona, Spain
| | - Alex Gileles-Hillel
- Pediatric Pulmonology and Sleep Unit, Dept of Pediatrics, and The Wohl Institute for Translational Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Jonathan C Jun
- Pulmonary and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Henrik Oster
- Institute of Neurobiology, University of Lübeck, Lübeck, Germany
| | | | - David W Ray
- NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford, UK.,Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
| | - Sirimon Reutrakul
- Division of Endocrinology, Diabetes, and Metabolism, Dept of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Manuel Sanchez-de-la-Torre
- Group of Precision Medicine in Chronic Diseases, Hospital Arnau de Vilanova-Santa Maria, IRBLleida, Lleida, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Renaud Tamisier
- HP2 INSERM U1042, Université Grenoble Alpes, Grenoble, France
| | - Isaac Almendros
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona-IDIBAPS, and CIBER Enfermedades Respiratorias, Barcelona, Spain
| |
Collapse
|
12
|
Gu C, Brereton N, Schweitzer A, Cotter M, Duan D, Børsheim E, Wolfe RR, Pham LV, Polotsky VY, Jun JC. Metabolic Effects of Late Dinner in Healthy Volunteers-A Randomized Crossover Clinical Trial. J Clin Endocrinol Metab 2020; 105:5855227. [PMID: 32525525 PMCID: PMC7337187 DOI: 10.1210/clinem/dgaa354] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/07/2020] [Accepted: 06/05/2020] [Indexed: 01/25/2023]
Abstract
CONTEXT Consuming calories later in the day is associated with obesity and metabolic syndrome. We hypothesized that eating a late dinner alters substrate metabolism during sleep in a manner that promotes obesity. OBJECTIVE The objective of this work is to examine the impact of late dinner on nocturnal metabolism in healthy volunteers. DESIGN AND SETTING This is a randomized crossover trial of late dinner (LD, 22:00) vs routine dinner (RD, 18:00), with a fixed sleep period (23:00-07:00) in a laboratory setting. PARTICIPANTS Participants comprised 20 healthy volunteers (10 male, 10 female), age 26.0 ± 0.6 years, body mass index 23.2 ± 0.7 kg/m2, accustomed to a bedtime between 22:00 and 01:00. INTERVENTIONS An isocaloric macronutrient diet was administered on both visits. Dinner (35% daily kcal, 50% carbohydrate, 35% fat) with an oral lipid tracer ([2H31] palmitate, 15 mg/kg) was given at 18:00 with RD and 22:00 with LD. MAIN OUTCOME MEASURES Measurements included nocturnal and next-morning hourly plasma glucose, insulin, triglycerides, free fatty acids (FFAs), cortisol, dietary fatty acid oxidation, and overnight polysomnography. RESULTS LD caused a 4-hour shift in the postprandial period, overlapping with the sleep phase. Independent of this shift, the postprandial period following LD was characterized by higher glucose, a triglyceride peak delay, and lower FFA and dietary fatty acid oxidation. LD did not affect sleep architecture, but increased plasma cortisol. These metabolic changes were most pronounced in habitual earlier sleepers determined by actigraphy monitoring. CONCLUSION LD induces nocturnal glucose intolerance, and reduces fatty acid oxidation and mobilization, particularly in earlier sleepers. These effects might promote obesity if they recur chronically.
Collapse
Affiliation(s)
- Chenjuan Gu
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Nga Brereton
- Institute for Clinical and Translational Research, Johns Hopkins University, Baltimore, Maryland
| | - Amy Schweitzer
- Institute for Clinical and Translational Research, Johns Hopkins University, Baltimore, Maryland
| | - Matthew Cotter
- Arkansas Children’s Nutrition Center, Arkansas Children’s Research Institute, Little Rock, Arkansas
| | - Daisy Duan
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Elisabet Børsheim
- Arkansas Children’s Nutrition Center, Arkansas Children’s Research Institute, Little Rock, Arkansas
- Department of Pediatrics, The University of Arkansas for Medical Sciences, Little Rock, Arkansas
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, The University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Robert R Wolfe
- Department of Pediatrics, The University of Arkansas for Medical Sciences, Little Rock, Arkansas
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, The University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Luu V Pham
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Jonathan C Jun
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, Maryland
- Correspondence and Reprint Requests: Jonathan C. Jun, MD, Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, 5501 Hopkins Bayview Circle, Room 5A50.B, Baltimore, MD 21224. E-mail:
| |
Collapse
|
13
|
Affiliation(s)
- Daisy Duan
- Division of Endocrinology, Diabetes and Metabolism, Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Chenjuan Gu
- Division of Pulmonary and Critical Care Medicine, Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jonathan C Jun
- Division of Pulmonary and Critical Care Medicine, Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
14
|
Berger S, Pho H, Fleury-Curado T, Bevans-Fonti S, Younas H, Shin MK, Jun JC, Anokye-Danso F, Ahima RS, Enquist LW, Mendelowitz D, Schwartz AR, Polotsky VY. Intranasal Leptin Relieves Sleep-disordered Breathing in Mice with Diet-induced Obesity. Am J Respir Crit Care Med 2020; 199:773-783. [PMID: 30309268 DOI: 10.1164/rccm.201805-0879oc] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
RATIONALE Leptin treats upper airway obstruction and alveolar hypoventilation in leptin-deficient ob/ob mice. However, obese humans and mice with diet-induced obesity (DIO) are resistant to leptin because of poor permeability of the blood-brain barrier. We propose that intranasal leptin will bypass leptin resistance and treat sleep-disordered breathing in obesity. OBJECTIVES To assess if intranasal leptin can treat obesity hypoventilation and upper airway obstruction during sleep in mice with DIO. METHODS Male C57BL/6J mice were fed with a high-fat diet for 16 weeks. A single dose of leptin (0.4 mg/kg) or BSA (vehicle) were administered intranasally or intraperitoneally, followed by either sleep studies (n = 10) or energy expenditure measurements (n = 10). A subset of mice was treated with leptin daily for 14 days for metabolic outcomes (n = 20). In a separate experiment, retrograde viral tracers were used to examine connections between leptin receptors and respiratory motoneurons. MEASUREMENTS AND MAIN RESULTS Acute intranasal, but not intraperitoneal, leptin decreased the number of oxygen desaturation events in REM sleep, and increased ventilation in non-REM and REM sleep, independently of metabolic effects. Chronic intranasal leptin decreased food intake and body weight, whereas intraperitoneal leptin had no effect. Intranasal leptin induced signal transducer and activator of transcription 3 phosphorylation in hypothalamic and medullary centers, whereas intraperitoneal leptin had no effect. Leptin receptor-positive cells were synaptically connected to respiratory motoneurons. CONCLUSIONS In mice with DIO, intranasal leptin bypassed leptin resistance and significantly attenuated sleep-disordered breathing independently of body weight.
Collapse
Affiliation(s)
- Slava Berger
- 1 Division of Pulmonary and Critical Care Medicine and
| | - Huy Pho
- 1 Division of Pulmonary and Critical Care Medicine and
| | | | | | - Haris Younas
- 1 Division of Pulmonary and Critical Care Medicine and
| | - Mi-Kyung Shin
- 1 Division of Pulmonary and Critical Care Medicine and
| | | | - Frederick Anokye-Danso
- 2 Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Rexford S Ahima
- 2 Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Lynn W Enquist
- 3 Department of Molecular Biology and.,4 Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey; and
| | - David Mendelowitz
- 5 Department of Pharmacology and Physiology, George Washington University, Washington, DC
| | | | | |
Collapse
|
15
|
Affiliation(s)
- David Kim
- Division of Pulmonary, Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Camilla Miranda Hoyos
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, University of Sydney, Camperdown, NSW, Australia
| | - Babak Mokhlesi
- Section of Pulmonary and Critical Care, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Sushmita Pamidi
- Division of Respiratory Medicine, Department of Medicine, McGill University, Montreal, QC, Canada
| | - Jonathan C. Jun
- School of Medicine, Johns Hopkins University, Baltimore, MD, United States
- *Correspondence: Jonathan C. Jun
| |
Collapse
|
16
|
Kim LJ, Freire C, Fleury Curado T, Jun JC, Polotsky VY. The Role of Animal Models in Developing Pharmacotherapy for Obstructive Sleep Apnea. J Clin Med 2019; 8:jcm8122049. [PMID: 31766589 PMCID: PMC6947279 DOI: 10.3390/jcm8122049] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/12/2019] [Accepted: 11/19/2019] [Indexed: 12/17/2022] Open
Abstract
Obstructive sleep apnea (OSA) is a highly prevalent disease characterized by recurrent closure of the upper airway during sleep. It has a complex pathophysiology involving four main phenotypes. An abnormal upper airway anatomy is the key factor that predisposes to sleep-related collapse of the pharynx, but it may not be sufficient for OSA development. Non-anatomical traits, including (1) a compromised neuromuscular response of the upper airway to obstruction, (2) an unstable respiratory control (high loop gain), and (3) a low arousal threshold, predict the development of OSA in association with anatomical abnormalities. Current therapies for OSA, such as continuous positive airway pressure (CPAP) and oral appliances, have poor adherence or variable efficacy among patients. The search for novel therapeutic approaches for OSA, including pharmacological agents, has been pursued over the past years. New insights into OSA pharmacotherapy have been provided by preclinical studies, which highlight the importance of appropriate use of animal models of OSA, their applicability, and limitations. In the present review, we discuss potential pharmacological targets for OSA discovered using animal models.
Collapse
|
17
|
Jun JC, Polotsky VY. Obstructive sleep apnoea and susceptibility to cardiovascular disease: A blessing or curse of old age? Respirology 2019; 25:242-243. [PMID: 31411783 DOI: 10.1111/resp.13679] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 07/30/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Jonathan C Jun
- Division of Pulmonary and Critical Care, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care, Johns Hopkins School of Medicine, Baltimore, MD, USA
| |
Collapse
|
18
|
Affiliation(s)
- Jonathan C Jun
- Pulmonary and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Erik R Swenson
- Pulmonary and Critical Care Medicine, University of Washington, Seattle, WA, United States
| |
Collapse
|
19
|
Gu C, Brereton N, Schweitzer A, Cotter M, Borsheim E, Wolfe RR, Jun JC. 0104 Effect of Dinner Timing on Nocturnal Metabolism in Healthy Volunteers. Sleep 2019. [DOI: 10.1093/sleep/zsz067.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Chenjuan Gu
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Nga Brereton
- Institute for Clinical and Translational Research, Johns Hopkins University, Baltimore, MD, USA
| | - Amy Schweitzer
- Institute for Clinical and Translational Research, Johns Hopkins University, Baltimore, MD, USA
| | - Matthew Cotter
- University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | | | - Robert R Wolfe
- University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Jonathan C Jun
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| |
Collapse
|
20
|
Abstract
In some organisms and cells, oxygen availability influences oxygen consumption. In this review, we examine this phenomenon of hypoxic hypometabolism (HH), discussing its features, mechanisms, and implications. Small mammals and other vertebrate species exhibit "oxyconformism," a downregulation of metabolic rate and body temperature during hypoxia which is sensed by the central nervous system. Smaller body mass and cooler ambient temperature contribute to a high metabolic rate in mammals. It is this hypermetabolic state that is suppressed by hypoxia leading to HH. Larger mammals including humans do not exhibit HH. Tissues and cells also exhibit reductions in respiration during hypoxia in vitro, even at oxygen levels ample for mitochondrial oxidative phosphorylation. The mechanisms of cellular HH involve intracellular oxygen sensors including hypoxia-inducible factors, AMP-activated protein kinase (AMPK), and mitochondrial reactive oxygen species (ROS) which downregulate mitochondrial activity and ATP utilization. HH has a profound impact on cardiovascular, respiratory, and metabolic physiology in rodents. Therefore, caution should be exercised when extrapolating the results of rodent hypoxia studies to human physiology.
Collapse
|
21
|
Pham LV, Schwartz AR, Jun JC. Oxyhemoglobin Saturation Overshoot Following Obstructive Breathing Events Mitigates Sleep Apnea-Induced Glucose Elevations. Front Endocrinol (Lausanne) 2018; 9:477. [PMID: 30190705 PMCID: PMC6115486 DOI: 10.3389/fendo.2018.00477] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 08/01/2018] [Indexed: 01/09/2023] Open
Abstract
Background: Obstructive sleep apnea (OSA) and nocturnal hypoxia are associated with disturbances in glucose regulation and diabetes. Temporal associations between OSA, oxygenation profiles and glucose have not been well-described. We hypothesized that oxyhemoglobin desaturation during apneic events and subsequent post-apnea saturation overshoot predict nocturnal glucose. Methods: In 30 OSA patients who underwent polysomnography while subjected to CPAP withdrawal, we characterized SPO2 swings by frequency, desaturation depth, and overshoot height relative to baseline. We examined the associations between frequently sampled glucose and SPO2 swings during the preceding 10 min. We developed multi-variable mixed effects linear regression to examine the independent associations between glucose and each level of these SPO2 swings, while controlling for OSA severity. Results: Desaturation depth was not associated with glucose (p > 0.05). In contrast, overshoot was associated with glucose in a dose-dependent manner. Each SPO2 peak that did not rise to within 1% of baseline was associated with incremental glucose elevations of 0.49 mg/dL (p = 0.01), whereas peaks that exceeded baseline by >1% were associated with glucose reductions of 0.46 mg/dL. Overshoot remained an independent predictor of glucose after adjustment for mean SPO2 and OSA severity (p > 0.05). Conclusions: Vigorous SPO2 improvements after apneic events may protect patients against OSA-related glucose elevations.
Collapse
|
22
|
Abstract
PURPOSE OF REVIEW Hypoxia inducible factors (HIFs) mediate the transcription of hundreds of genes that allow cells to adapt to hypoxic environments. In this review, we summarize the current state of knowledge about mechanisms of HIF activation in cancer, as well as downstream cancer-promoting consequences such as altered substrate metabolism, angiogenesis, and cell differentiation. In addition, we examine the proposed relationship between respiratory-related hypoxia, HIFs, and cancer. RECENT FINDINGS HIFs are increased in many forms of cancer, and portend a poor prognosis and response to therapy. CONCLUSION HIFs play a critical role in various stages of carcinogenesis. HIF and its transcription targets may be useful as biomarkers of disease and therapeutic targets for cancer.
Collapse
Affiliation(s)
- Jonathan C Jun
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Aman Rathore
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Haris Younas
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Daniele Gilkes
- Division of Breast Cancer, Department of Oncology, Johns Hopkins University, Baltimore, MD
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| |
Collapse
|
23
|
Abstract
Obstructive sleep apnea (OSA) is a common sleep disorder associated with diabetes and cardiovascular disease. However, the mechanisms by which OSA causes cardiometabolic dysfunction are not fully elucidated. OSA increases plasma free fatty acids (FFA) during sleep, reflecting excessive adipose tissue lipolysis. In animal studies, intermittent hypoxia simulating OSA also increases FFA, and the increase is attenuated by beta-adrenergic blockade. In other contexts, excessive plasma FFA can lead to ectopic fat accumulation, insulin resistance, vascular dysfunction, and dyslipidemia. Herein, we propose that OSA is a cause of excessive adipose tissue lipolysis contributing towards systemic "lipotoxicity". Since visceral and upper-body obesity contributes to OSA pathogenesis, OSA-induced lipolysis may further aggravate the consequences of this metabolically harmful state. If this hypothesis is correct, then OSA may represent a reversible risk factor for cardio-metabolic dysfunction, and this risk might be mitigated by preventing OSA-induced lipolysis during sleep.
Collapse
Affiliation(s)
- Chenjuan Gu
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Pulmonary and Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Haris Younas
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Jonathan C Jun
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
24
|
Chopra S, Rathore A, Younas H, Pham LV, Gu C, Beselman A, Kim IY, Wolfe RR, Perin J, Polotsky VY, Jun JC. Obstructive Sleep Apnea Dynamically Increases Nocturnal Plasma Free Fatty Acids, Glucose, and Cortisol During Sleep. J Clin Endocrinol Metab 2017; 102:3172-3181. [PMID: 28595341 PMCID: PMC5587067 DOI: 10.1210/jc.2017-00619] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 05/12/2017] [Indexed: 11/19/2022]
Abstract
CONTEXT Obstructive sleep apnea (OSA) is associated with diabetes and cardiovascular disease. This association may be related to metabolic changes that transpire during sleep in OSA. OBJECTIVE To examine the impact of OSA, elicited by cessation of continuous positive airway pressure (CPAP), on frequently sampled nocturnal metabolic markers including plasma free fatty acids (FFAs), glucose, insulin, triglycerides (TGs), cortisol, and lactate, as well as glucose production, oral glucose tolerance, blood pressure (BP), endothelial function, cholesterol, and high-sensitivity C-reactive protein (hsCRP). DESIGN AND SETTING Randomized crossover trial of CPAP vs CPAP withdrawal. PATIENTS Thirty-one patients with moderate to severe OSA acclimated to CPAP. INTERVENTION Patients underwent attended polysomnography while sleeping with therapeutic CPAP, or after CPAP withdrawal, in random order. Venous blood was sampled at ∼20-minute intervals on both nights. In 11 patients, we assessed glucose kinetics with an infusion of 6,6-[2H2]glucose. RESULTS CPAP withdrawal caused recurrence of OSA associated with hypoxemia, sleep disruption, and heart rate (HR) elevation. CPAP withdrawal dynamically increased nocturnal FFA (P = 0.007), glucose (P = 0.028), and cortisol (P = 0.037), in proportion to respiratory event frequency, HR elevation, or sleep fragmentation. Diabetes predisposed to glucose elevation. CPAP withdrawal also increased systolic BP (P = 0.017) and augmentation index (P = 0.008), but did not affect insulin, TGs, glucose production, oral glucose tolerance, cholesterol, or hsCRP. CONCLUSION OSA recurrence during CPAP withdrawal increases FFA and glucose during sleep, associated with sympathetic and adrenocortical activation. Recurring exposure to these metabolic changes may foster diabetes and cardiovascular disease.
Collapse
Affiliation(s)
- Swati Chopra
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21224
| | - Aman Rathore
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21224
| | - Haris Younas
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21224
| | - Luu V. Pham
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21224
| | - Chenjuan Gu
- Department of Respiratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Aleksandra Beselman
- Department of Pharmacy Services, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224
| | - Il-Young Kim
- Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Robert R. Wolfe
- Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Jamie Perin
- School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
| | - Vsevolod Y. Polotsky
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21224
| | - Jonathan C. Jun
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21224
| |
Collapse
|
25
|
Miele CH, Schwartz AR, Gilman RH, Pham L, Wise RA, Davila-Roman VG, Jun JC, Polotsky VY, Miranda JJ, Leon-Velarde F, Checkley W. Increased Cardiometabolic Risk and Worsening Hypoxemia at High Altitude. High Alt Med Biol 2017; 17:93-100. [PMID: 27281472 DOI: 10.1089/ham.2015.0084] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Miele, Catherine H., Alan R. Schwartz, Robert H. Gilman, Luu Pham, Robert A. Wise, Victor G. Davila-Roman, Jonathan C. Jun, Vsevolod Y. Polotsky, J. Jaime Miranda, Fabiola Leon-Velarde, and William Checkley. Increased cardiometabolic risk and worsening hypoxemia at high altitude. High Alt Med Biol. 17:93-100, 2016.-Metabolic syndrome, insulin resistance, diabetes, and dyslipidemia are associated with an increased risk of cardiovascular disease. While excessive erythrocytosis is associated with cardiovascular complications, it is unclear how worsening hypoxemia of any degree affects cardiometabolic risk factors in high-altitude populations. We studied the relationship between daytime resting oxyhemoglobin saturation and cardiometabolic risk factors in adult participants living in Puno, Peru (3825 m above sea level). We used multivariable logistic regression models to study the relationship between having a lower oxyhemoglobin saturation and markers of cardiometabolic risk. Nine hundred and fifty-four participants (mean age 55 years, 52% male) had information available on pulse oximetry and markers of cardiometabolic risk. Average oxyhemoglobin saturation was 90% (interquartile range 88%-92%) and 43 (4.5%) had excessive erythrocytosis. Older age, decreased height-adjusted lung function, and higher body mass index (BMI) were associated with having an oxyhemoglobin saturation ≤85%. When adjusting for age, sex, socioeconomic status, having excessive erythrocytosis, and site, we found that each 5% decrease in oxyhemoglobin saturation was associated with a higher adjusted odds of metabolic syndrome (OR = 1.35, 95% CI: 1.07-1.72, p < 0.04), insulin resistance as defined by homeostasis model assessment-insulin resistance (HOMA-IR) >2 mass units (OR = 1.29, 95% CI: 1.00-1.67, p < 0.05), hemoglobin A1c ≥6.5% (OR = 1.66, 95% CI: 1.09-2.51, p < 0.04), and high sensitivity C-reactive protein (hs-CRP) ≥3 mg/L (OR = 1.46, 95% CI: 1.09-1.96, p < 0.01). In high-altitude populations in Puno, Peru, a higher BMI and lower pulmonary function were associated with lower resting daytime oxyhemoglobin saturation. Lower resting oxyhemoglobin saturation, in turn, was associated with higher odds of having multiple unfavorable cardiometabolic factors. Worsening hypoxia of any degree in high-altitude dwellers may be an independent risk factor for cardiovascular disease.
Collapse
Affiliation(s)
- Catherine H Miele
- 1 Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Alan R Schwartz
- 1 Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Robert H Gilman
- 2 Program in Global Disease Epidemiology and Control, Department of International Health, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, Maryland
| | - Luu Pham
- 1 Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Robert A Wise
- 1 Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Victor G Davila-Roman
- 3 Division of Cardiology, Department of Medicine, Washington University , St. Louis, Missouri
| | - Jonathan C Jun
- 1 Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Vsevolod Y Polotsky
- 1 Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University , Baltimore, Maryland
| | - J Jaime Miranda
- 4 CRONICAS Center of Excellence for Chronic Diseases, Universidad Peruana Cayetano Heredia , Lima, Peru .,5 Departamento de Medicina, Escuela de Medicina, Universidad Peruana Cayetano Heredia , Lima, Peru
| | - Fabiola Leon-Velarde
- 5 Departamento de Medicina, Escuela de Medicina, Universidad Peruana Cayetano Heredia , Lima, Peru
| | - William Checkley
- 1 Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University , Baltimore, Maryland.,2 Program in Global Disease Epidemiology and Control, Department of International Health, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, Maryland
| |
Collapse
|
26
|
Abstract
PURPOSE OF REVIEW Hypoxia inducible factors (HIFs) mediate the transcription of hundreds of genes that allow cells to adapt to hypoxic environments. In this review, we summarize the current state of knowledge about mechanisms of HIF activation in cancer, as well as downstream cancer-promoting consequences such as altered substrate metabolism, angiogenesis, and cell differentiation. In addition, we examine the proposed relationship between respiratory-related hypoxia, HIFs, and cancer. RECENT FINDINGS HIFs are increased in many forms of cancer, and portend a poor prognosis and response to therapy. CONCLUSION HIFs play a critical role in various stages of carcinogenesis. HIF and its transcription targets may be useful as biomarkers of disease and therapeutic targets for cancer.
Collapse
Affiliation(s)
- Jonathan C Jun
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Aman Rathore
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Haris Younas
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Daniele Gilkes
- Division of Breast Cancer, Department of Oncology, Johns Hopkins University, Baltimore, MD
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| |
Collapse
|
27
|
Abstract
Sleep apnoea is a disorder characterised by repetitive pauses in breathing during sleep caused by airway occlusion (obstructive sleep apnoea) or altered control of breathing (central sleep apnoea). In this Clinical Year in Review, we summarise high-impact research from the past year pertaining to management, diagnosis and cardio-metabolic consequences of sleep apnoea.
Collapse
Affiliation(s)
- Jonathan C Jun
- Dept of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Swati Chopra
- Dept of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Alan R Schwartz
- Dept of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| |
Collapse
|
28
|
Jun JC, Devera R, Unnikrishnan D, Shin MK, Bevans-Fonti S, Yao Q, Rathore A, Younas H, Halberg N, Scherer PE, Polotsky VY. Adipose HIF-1α causes obesity by suppressing brown adipose tissue thermogenesis. J Mol Med (Berl) 2016; 95:287-297. [PMID: 27738746 DOI: 10.1007/s00109-016-1480-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 09/27/2016] [Accepted: 10/06/2016] [Indexed: 12/18/2022]
Abstract
Hypoxia-inducible factor-1α (HIF-1α) in adipose tissue is known to promote obesity. We hypothesized that HIF-1α interferes with brown fat thermogenesis, thus decreasing energy expenditure. To test this hypothesis, we compared transgenic mice constitutively expressing HIF-1α in adipose tissues (HIF-1α++) at usual temperature (22 °C), where brown fat is somewhat active, or at thermoneutrality (30 °C), where brown fat is minimally active. HIF-1α++ mice or control litter mates were separated into room temperature (22 °C) or thermoneutrality (30 °C) groups. We assessed weight gain, food intake, calorimetry, activity, and oxygen consumption and transcriptional changes in isolated white and brown adipocytes. At 22 °C, HIF-1α++ mice exhibited accelerated weight gain, cold and glucose intolerance, hyperglycemia, and decreased energy expenditure without changes in food intake or activity. These changes were absent or minimal at thermoneutrality. In brown adipocytes of HIF-1α++ mice, oxygen consumption decreased ~50 % in association with reduced mitochondrial content, uncoupling protein 2, and peroxisome proliferator-activated receptor gamma coactivator 1 (PGC-1α). In conclusion, adipose HIF-1α overexpression inhibits thermogenesis and cellular respiration in brown adipose tissue, promoting obesity in the setting of reduced ambient temperature. KEY MESSAGE Constitutive HIF-1α activation in adipose tissue promotes weight gain in mice. The weight gain is associated with reduced brown adipose tissue function and oxygen consumption. Reduced oxygen consumption may be mediated by reductions in mitochondria.
Collapse
Affiliation(s)
- Jonathan C Jun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins, University School of Medicine, 5501 Hopkins Bayview Circle Room 4A30A, Baltimore, MD, 21224, USA.
| | - Ronald Devera
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins, University School of Medicine, 5501 Hopkins Bayview Circle Room 4A30A, Baltimore, MD, 21224, USA
| | - Dileep Unnikrishnan
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins, University School of Medicine, 5501 Hopkins Bayview Circle Room 4A30A, Baltimore, MD, 21224, USA
| | - Mi-Kyung Shin
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins, University School of Medicine, 5501 Hopkins Bayview Circle Room 4A30A, Baltimore, MD, 21224, USA
| | - Shannon Bevans-Fonti
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins, University School of Medicine, 5501 Hopkins Bayview Circle Room 4A30A, Baltimore, MD, 21224, USA
| | - Qiaoling Yao
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins, University School of Medicine, 5501 Hopkins Bayview Circle Room 4A30A, Baltimore, MD, 21224, USA
| | - Aman Rathore
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins, University School of Medicine, 5501 Hopkins Bayview Circle Room 4A30A, Baltimore, MD, 21224, USA
| | - Haris Younas
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins, University School of Medicine, 5501 Hopkins Bayview Circle Room 4A30A, Baltimore, MD, 21224, USA
| | - Nils Halberg
- Touchstone Diabetes Center, Departments of Internal Medicine and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Philipp E Scherer
- Touchstone Diabetes Center, Departments of Internal Medicine and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins, University School of Medicine, 5501 Hopkins Bayview Circle Room 4A30A, Baltimore, MD, 21224, USA
| |
Collapse
|
29
|
Owens RL, Gold KA, Gozal D, Peppard PE, Jun JC, Dannenberg AJ, Lippman SM, Malhotra A. Sleep and Breathing … and Cancer? Cancer Prev Res (Phila) 2016; 9:821-827. [PMID: 27604751 DOI: 10.1158/1940-6207.capr-16-0092] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 08/15/2016] [Indexed: 01/21/2023]
Abstract
Sleep, like eating and breathing, is an essential part of the daily life cycle. Although the science is still emerging, sleep plays an important role in immune, cardiovascular, and neurocognitive function. Despite its great importance, nearly 40% of U.S. adults experience problems with sleep ranging from insufficient total sleep time, trouble initiating or maintaining sleep (Insomnia), circadian rhythm disorders, sleep-related movement disorders, and sleep-related breathing disorders such as obstructive sleep apnea (OSA). Herein, we discuss new evidence that suggests that sleep may also affect carcinogenesis. Specifically, we review recent epidemiologic data suggesting links between cancer and OSA. As OSA is a common, underdiagnosed, and undertreated condition, this has public health implications. Intriguing animal model data support a link between cancer and sleep/OSA, although mechanisms are not yet clear. Leaders in the fields of sleep medicine, pulmonology, and oncology recently met to review and discuss these data, as well as to outline future directions of study. We propose a multidisciplinary, three-pronged approach to studying the associations between cancer and sleep, utilizing mutually interactive epidemiologic studies, preclinical models, and early-phase clinical trials. Cancer Prev Res; 9(11); 821-7. ©2016 AACR.
Collapse
Affiliation(s)
- Robert L Owens
- Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, La Jolla, California.
| | - Kathryn A Gold
- Moores Cancer Center, University of California San Diego, La Jolla, California
| | - David Gozal
- Department of Pediatrics, Pritzker School of Medicine, The University of Chicago, Chicago, Illinois
| | - Paul E Peppard
- Department of Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Jonathan C Jun
- Division of Pulmonary and Critical Care, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Scott M Lippman
- Moores Cancer Center, University of California San Diego, La Jolla, California
| | - Atul Malhotra
- Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, La Jolla, California
| | | |
Collapse
|
30
|
Affiliation(s)
- Jonathan C Jun
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
31
|
Abstract
Obstructive sleep apnea (OSA) is a common disorder that describes recurrent collapse of the upper airway during sleep. Animal models have been pivotal to the understanding of OSA pathogenesis, consequences, and treatment. In this review, we highlight the history of OSA research in animals and include the discovery of animals with spontaneous OSA, the induction of OSA in animals, and the emulation of OSA using exposures to intermittent hypoxia and sleep fragmentation.
Collapse
Affiliation(s)
- Swati Chopra
- Division of Pulmonary and Critical Care Medicine Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care Medicine Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jonathan C Jun
- Division of Pulmonary and Critical Care Medicine Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| |
Collapse
|
32
|
Jun JC, Unnikrishnan D, Schneider H, Kirkness J, Schwartz AR, Smith PL, Polotsky VY. Effect of Acute Intermittent CPAP Depressurization during Sleep in Obese Patients. PLoS One 2016; 11:e0146606. [PMID: 26731735 PMCID: PMC4701426 DOI: 10.1371/journal.pone.0146606] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 12/18/2015] [Indexed: 11/18/2022] Open
Abstract
Background Obstructive Sleep Apnea (OSA) describes intermittent collapse of the airway during sleep, for which continuous positive airway pressure (CPAP) is often prescribed for treatment. Prior studies suggest that discontinuation of CPAP leads to a gradual, rather than immediate return of baseline severity of OSA. The objective of this study was to determine the extent of OSA recurrence during short intervals of CPAP depressurization during sleep. Methods Nine obese (BMI = 40.4 ± 3.5) subjects with severe OSA (AHI = 88.9 ± 6.8) adherent to CPAP were studied during one night in the sleep laboratory. Nasal CPAP was delivered at therapeutic (11.1 ± 0.6 cm H20) or atmospheric pressure, in alternating fashion for 1-hour periods during the night. We compared sleep architecture and metrics of OSA during CPAP-on and CPAP-off periods. Results 8/9 subjects tolerated CPAP withdrawal. The average AHI during CPAP-on and CPAP-off periods was 3.6 ± 0.6 and 15.8 ± 3.6 respectively (p<0.05). The average 3% ODI during CPAP-on and CPAP-off was 4.7 ± 2 and 20.4 ± 4.7 respectively (p<0.05). CPAP depressurization also induced more awake (p<0.05) and stage N1 (p<0.01) sleep, and less stage REM (p<0.05) with a trend towards decreased stage N3 (p = 0.064). Conclusion Acute intermittent depressurization of CPAP during sleep led to deterioration of sleep architecture but only partial re-emergence of OSA. These observations suggest carryover effects of CPAP.
Collapse
Affiliation(s)
- Jonathan C. Jun
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- * E-mail:
| | - Dileep Unnikrishnan
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Hartmut Schneider
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Jason Kirkness
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Alan R. Schwartz
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Philip L. Smith
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Vsevolod Y. Polotsky
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| |
Collapse
|
33
|
Mesarwi OA, Shin MK, Drager LF, Bevans-Fonti S, Jun JC, Putcha N, Torbenson MS, Pedrosa RP, Lorenzi-Filho G, Steele KE, Schweitzer MA, Magnuson TH, Lidor AO, Schwartz AR, Polotsky VY. Lysyl Oxidase as a Serum Biomarker of Liver Fibrosis in Patients with Severe Obesity and Obstructive Sleep Apnea. Sleep 2015; 38:1583-91. [PMID: 26085300 DOI: 10.5665/sleep.5052] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Indexed: 12/12/2022] Open
Abstract
STUDY OBJECTIVES Obstructive sleep apnea (OSA) is associated with the progression of nonalcoholic fatty liver disease (NAFLD). We hypothesized that the hypoxia of OSA increases hepatic production of lysyl oxidase (LOX), an enzyme that cross-links collagen, and that LOX may serve as a biomarker of hepatic fibrosis. DESIGN Thirty-five patients with severe obesity underwent liver biopsy, polysomnography, and serum LOX testing. A separate group with severe OSA had serum LOX measured before and after 3 mo of CPAP or no therapy, as did age-matched controls. LOX expression and secretion were measured in mouse hepatocytes following exposure to hypoxia. SETTING The Johns Hopkins Bayview Sleep Disorders Center, and the Hypertension Unit of the Heart Institute at the University of São Paulo Medical School. MEASUREMENTS AND RESULTS In the bariatric cohort, the apnea-hypopnea index was higher in patients with hepatic fibrosis than in those without fibrosis (42.7 ± 30.2 events/h, versus 16.2 ± 15.5 events/h; P = 0.002), as was serum LOX (84.64 ± 29.71 ng/mL, versus 45.46 ± 17.16 ng/mL; P < 0.001). In the sleep clinic sample, patients with severe OSA had higher baseline LOX than healthy controls (70.75 ng/mL versus 52.36 ng/mL, P = 0.046), and serum LOX decreased in patients with OSA on CPAP (mean decrease 20.49 ng/mL) but not in untreated patients (mean decrease 0.19 ng/mL). Hypoxic mouse hepatocytes demonstrated 5.9-fold increased LOX transcription (P = 0.046), and enhanced LOX protein secretion. CONCLUSIONS The hypoxic stress of obstructive sleep apnea may increase circulating lysyl oxidase (LOX) levels. LOX may serve as a biomarker of liver fibrosis in patients with severe obesity and nonalcoholic fatty liver disease.
Collapse
Affiliation(s)
- Omar A Mesarwi
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Mi-Kyung Shin
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Luciano F Drager
- Hypertension Unit, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
| | - Shannon Bevans-Fonti
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Jonathan C Jun
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nirupama Putcha
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | | | - Rodrigo P Pedrosa
- Sleep Laboratory, Pulmonary Division, University of São Paulo Medical School, São Paulo, Brazil
| | - Geraldo Lorenzi-Filho
- Sleep Laboratory, Pulmonary Division, University of São Paulo Medical School, São Paulo, Brazil
| | - Kimberley E Steele
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Michael A Schweitzer
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Thomas H Magnuson
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Anne O Lidor
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Alan R Schwartz
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Vsevolod Y Polotsky
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| |
Collapse
|
34
|
Abstract
NEFA are mobilised from adipose tissues during fasting or stress. Under conditions of acute or chronic NEFA excess, skeletal muscle and hepatic insulin resistance may ensue. Hence, a wealth of literature has focused on the crosstalk between NEFA and glucose in the pathogenesis of insulin resistance. Sleep restriction has also been shown to acutely induce insulin resistance, and self-reported short sleep duration is associated with diabetes. In this issue of Diabetologia (DOI: 10.1007/s00125-015-3500-4), Broussard and colleagues examine the impact of acute sleep restriction on detailed 24 h metabolic profiles, including plasma NEFA. Here, we address the potential clinical relevance of these findings and pose questions for further research.
Collapse
Affiliation(s)
- Jonathan C Jun
- Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, 5501 Hopkins Bayview Circle, Rm 4A30, Baltimore, MD, 21224, USA,
| | | |
Collapse
|
35
|
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: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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
| |
Collapse
|
36
|
Mesarwi OA, Sharma EV, Jun JC, Polotsky VY. Metabolic dysfunction in obstructive sleep apnea: A critical examination of underlying mechanisms. Sleep Biol Rhythms 2014; 13:2-17. [PMID: 26412981 DOI: 10.1111/sbr.12078] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
It has recently become clear that obstructive sleep apnea (OSA) is an independent risk factor for the development of metabolic syndrome, a disorder of defective energy storage and use. Several mechanisms have been proposed to explain this finding, drawing upon the characteristics that define OSA. In particular, intermittent hypoxia, sleep fragmentation, elevated sympathetic tone, and oxidative stress - all consequences of OSA - have been implicated in the progression of poor metabolic outcomes in OSA. In this review we examine the evidence to support each of these disease manifestations of OSA as a unique risk for metabolic dysfunction. Tissue hypoxia and sleep fragmentation are each directly connected to insulin resistance and hypertension, and each of these also may increase sympathetic tone, resulting in defective glucose homeostasis, excessive lipolysis, and elevated blood pressure. Oxidative stress further worsens insulin resistance and in turn, metabolic dysfunction also increases oxidative stress. However, despite many studies linking each of these individual components of OSA to the development of metabolic syndrome, there are very few reports that actually provide a coherent narrative about the mechanism underlying metabolic dysfunction in OSA.
Collapse
Affiliation(s)
- Omar A Mesarwi
- Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Jonathan C Jun
- Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | |
Collapse
|
37
|
Shin MK, Han W, Bevans-Fonti S, Jun JC, Punjabi NM, Polotsky VY. The effect of adrenal medullectomy on metabolic responses to chronic intermittent hypoxia. Respir Physiol Neurobiol 2014; 203:60-7. [PMID: 25179887 DOI: 10.1016/j.resp.2014.08.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 08/22/2014] [Accepted: 08/24/2014] [Indexed: 01/14/2023]
Abstract
Obstructive sleep apnea causes intermittent hypoxia (IH) and is associated with insulin resistance and type 2 diabetes. IH increases plasma catecholamine levels, which may increase insulin resistance and suppress insulin secretion. The objective of this study was to determine if adrenal medullectomy (MED) prevents metabolic dysfunction in IH. MED or sham surgery was performed in 60 male C57BL/6J mice, which were then exposed to IH or control conditions (intermittent air) for 6 weeks. IH increased plasma epinephrine and norepinephrine levels, increased fasting blood glucose and lowered basal and glucose-stimulated insulin secretion. MED decreased baseline epinephrine and prevented the IH induced increase in epinephrine, whereas the norepinephrine response remained intact. MED improved glucose tolerance in mice exposed to IH, attenuated the impairment in basal and glucose-stimulated insulin secretion, but did not prevent IH-induced fasting hyperglycemia or insulin resistance. We conclude that the epinephrine release from the adrenal medulla during IH suppresses insulin secretion causing hyperglycemia.
Collapse
Affiliation(s)
- Mi-Kyung Shin
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, United States
| | - Woobum Han
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, United States
| | - Shannon Bevans-Fonti
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, United States
| | - Jonathan C Jun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, United States
| | - Naresh M Punjabi
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, United States
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, United States.
| |
Collapse
|
38
|
Shin MK, Yao Q, Jun JC, Bevans-Fonti S, Yoo DY, Han W, Mesarwi O, Richardson R, Fu YY, Pasricha PJ, Schwartz AR, Shirahata M, Polotsky VY. Carotid body denervation prevents fasting hyperglycemia during chronic intermittent hypoxia. J Appl Physiol (1985) 2014; 117:765-76. [PMID: 25103977 DOI: 10.1152/japplphysiol.01133.2013] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Obstructive sleep apnea causes chronic intermittent hypoxia (IH) and is associated with impaired glucose metabolism, but mechanisms are unknown. Carotid bodies orchestrate physiological responses to hypoxemia by activating the sympathetic nervous system. Therefore, we hypothesized that carotid body denervation would abolish glucose intolerance and insulin resistance induced by chronic IH. Male C57BL/6J mice underwent carotid sinus nerve dissection (CSND) or sham surgery and then were exposed to IH or intermittent air (IA) for 4 or 6 wk. Hypoxia was administered by decreasing a fraction of inspired oxygen from 20.9% to 6.5% once per minute, during the 12-h light phase (9 a.m.-9 p.m.). As expected, denervated mice exhibited blunted hypoxic ventilatory responses. In sham-operated mice, IH increased fasting blood glucose, baseline hepatic glucose output (HGO), and expression of a rate-liming hepatic enzyme of gluconeogenesis phosphoenolpyruvate carboxykinase (PEPCK), whereas the whole body glucose flux during hyperinsulinemic euglycemic clamp was not changed. IH did not affect glucose tolerance after adjustment for fasting hyperglycemia in the intraperitoneal glucose tolerance test. CSND prevented IH-induced fasting hyperglycemia and increases in baseline HGO and liver PEPCK expression. CSND trended to augment the insulin-stimulated glucose flux and enhanced liver Akt phosphorylation at both hypoxic and normoxic conditions. IH increased serum epinephrine levels and liver sympathetic innervation, and both increases were abolished by CSND. We conclude that chronic IH induces fasting hyperglycemia increasing baseline HGO via the CSN sympathetic output from carotid body chemoreceptors, but does not significantly impair whole body insulin sensitivity.
Collapse
Affiliation(s)
- Mi-Kyung Shin
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Qiaoling Yao
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jonathan C Jun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Shannon Bevans-Fonti
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Doo-Young Yoo
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Woobum Han
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Omar Mesarwi
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ria Richardson
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ya-Yuan Fu
- Division of Gastroenterology and Hepatology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Pankaj J Pasricha
- Division of Gastroenterology and Hepatology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Alan R Schwartz
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Machiko Shirahata
- Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland;
| |
Collapse
|
39
|
Drager LF, Yao Q, Hernandez KL, Shin MK, Bevans-Fonti S, Gay J, Sussan TE, Jun JC, Myers AC, Olivecrona G, Schwartz AR, Halberg N, Scherer PE, Semenza GL, Powell DR, Polotsky VY. Chronic intermittent hypoxia induces atherosclerosis via activation of adipose angiopoietin-like 4. Am J Respir Crit Care Med 2013; 188:240-8. [PMID: 23328524 DOI: 10.1164/rccm.201209-1688oc] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
RATIONALE Obstructive sleep apnea is a risk factor for dyslipidemia and atherosclerosis, which have been attributed to chronic intermittent hypoxia (CIH). Intermittent hypoxia inhibits a key enzyme of lipoprotein clearance, lipoprotein lipase, and up-regulates a lipoprotein lipase inhibitor, angiopoietin-like 4 (Angptl4), in adipose tissue. The effects and mechanisms of Angptl4 up-regulation in sleep apnea are unknown. OBJECTIVES To examine whether CIH induces dyslipidemia and atherosclerosis by increasing adipose Angptl4 via hypoxia-inducible factor-1 (HIF-1). METHODS ApoE(-/-) mice were exposed to intermittent hypoxia or air for 4 weeks while being treated with Angptl4-neutralizing antibody or vehicle. MEASUREMENTS AND MAIN RESULTS In vehicle-treated mice, hypoxia increased adipose Angptl4 levels, inhibited adipose lipoprotein lipase, increased fasting levels of plasma triglycerides and very low density lipoprotein cholesterol, and increased the size of atherosclerotic plaques. The effects of CIH were abolished by the antibody. Hypoxia-induced increases in plasma fasting triglycerides and adipose Angptl4 were not observed in mice with germline heterozygosity for a HIF-1α knockout allele. Transgenic overexpression of HIF-1α in adipose tissue led to dyslipidemia and increased levels of adipose Angptl4. In cultured adipocytes, constitutive expression of HIF-1α increased Angptl4 levels, which was abolished by siRNA. Finally, in obese patients undergoing bariatric surgery, the severity of nocturnal hypoxemia predicted Angptl4 levels in subcutaneous adipose tissue. CONCLUSIONS HIF-1-mediated increase in adipose Angptl4 and the ensuing lipoprotein lipase inactivation may contribute to atherosclerosis in patients with sleep apnea.
Collapse
Affiliation(s)
- Luciano F Drager
- Division of Pulmonary and Critical Care Medicine, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Abstract
Hypoxia has been shown to rapidly increase triglycerides in mice by decreasing plasma lipoprotein clearance. However, the usual temperature of hypoxic exposure is below thermoneutrality for mice, which may increase thermogenesis and energy requirements, resulting in higher tissue lipid uptake. We hypothesize that decreased lipid clearance and ensuing hyperlipidemia are caused by hypoxic suppression of metabolism at cold temperatures and, therefore, would not occur at thermoneutrality. Twelve-week-old, male C57BL6/J mice were exposed to 6 h of 10% O₂ at the usual temperature (22°C) or thermoneutrality (30°C). Acclimation to 22°C increased lipid uptake in the heart, lungs, and brown adipose tissue, resulting in lower plasma triglyceride and cholesterol levels. At this temperature, hypoxia attenuated lipid uptake in most tissues, thereby raising plasma triglycerides and LDL cholesterol. Thermoneutrality decreased tissue lipid uptake, and hypoxia did not cause a further reduction in lipid uptake in any organs. Consequently, hypoxia at thermoneutrality did not affect plasma triglyceride levels. Unexpectedly, plasma HDL cholesterol increased. The effect of hypoxia on white adipose tissue lipolysis was also modified by temperature. Independent of temperature, hypoxia increased heart rate and glucose and decreased activity, body temperature, and glucose sensitivity. Our study underscores the importance of ambient temperature for hypoxia research, especially in studies of lipid metabolism.
Collapse
Affiliation(s)
- Jonathan C Jun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
| | | | | | | | | | | |
Collapse
|
41
|
Yao Q, Shin MK, Jun JC, Hernandez KL, Aggarwal NR, Mock JR, Gay J, Drager LF, Polotsky VY. Effect of chronic intermittent hypoxia on triglyceride uptake in different tissues. J Lipid Res 2013; 54:1058-65. [PMID: 23386706 DOI: 10.1194/jlr.m034272] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chronic intermittent hypoxia (CIH) inhibits plasma lipoprotein clearance and adipose lipoprotein lipase (LPL) activity in association with upregulation of an LPL inhibitor angiopoietin-like protein 4 (Angptl4). We hypothesize that CIH inhibits triglyceride (TG) uptake via Angptl4 and that an anti-Angptl4-neutralizing antibody would abolish the effects of CIH. Male C57BL/6J mice were exposed to four weeks of CIH or intermittent air (IA) while treated with Ab (30 mg/kg ip once a week). TG clearance was assessed by [H(3)]triolein administration retroorbitally. CIH delayed TG clearance and suppressed TG uptake and LPL activity in all white adipose tissue depots, brown adipose tissue, and lungs, whereas heart, liver, and spleen were not affected. CD146+ CD11b- pulmonary microvascular endothelial cells were responsible for TG uptake in the lungs and its inhibition by CIH. Antibody to Angptl4 decreased plasma TG levels and increased TG clearance and uptake into adipose tissue and lungs in both control and CIH mice to a similar extent, but did not reverse the effects of CIH. The antibody reversed the effects of CIH on LPL in adipose tissue and lungs. In conclusion, CIH inactivates LPL by upregulating Angptl4, but inhibition of TG uptake occurs predominantly via an Angptl4/LPL-independent mechanism.
Collapse
Affiliation(s)
- Qiaoling Yao
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
42
|
|
43
|
Shin MK, Drager LF, Yao Q, Bevans-Fonti S, Yoo DY, Jun JC, Aja S, Bhanot S, Polotsky VY. Metabolic consequences of high-fat diet are attenuated by suppression of HIF-1α. PLoS One 2012; 7:e46562. [PMID: 23049707 PMCID: PMC3462192 DOI: 10.1371/journal.pone.0046562] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 08/31/2012] [Indexed: 12/16/2022] Open
Abstract
Obesity is associated with tissue hypoxia and the up-regulation of hypoxia inducible factor 1 alpha (HIF-1α). Prior studies in transgenic mice have shown that HIF-1α plays a role in the metabolic dysfunction associated with obesity. Therefore, we hypothesized that, after the development of diet-induced obesity (DIO), metabolic function could be improved by administration of HIF-1α antisense oligonucleotides (ASO). DIO mice were treated with HIF-1α ASO or with control ASO for 8 weeks and compared with an untreated group. We found that HIF-1α ASO markedly suppressed Hif-1α gene expression in adipose tissue and the liver. HIF-1α ASO administration induced weight loss. Final body weight was 41.6±1.4 g in the HIF-1α ASO group vs 46.7±0.9 g in the control ASO group and 47.9±0.8 g in untreated mice (p<0.001). HIF-1α ASO increased energy expenditure (13.3±0.6 vs 12±0.1 and 11.9±0.4 kcal/kg/hr, respectively, p<0.001) and decreased the respiratory exchange ratio (0.71±0.01 vs 0.75±0.01 and 0.76±0.01, respectively, p<0.001), which suggested switching metabolism to fat oxidation. In contrast, HIF-1a ASO had no effect on food intake or activity. HIF-1α ASO treatment decreased fasting blood glucose (195.5±8.4 mg/dl vs 239±7.8 mg/dl in the control ASO group and 222±8.2 mg/dl in untreated mice, p<0.01), plasma insulin, hepatic glucose output, and liver fat content. These findings demonstrate that the metabolic consequences of DIO are attenuated by HIF-1α ASO treatment.
Collapse
Affiliation(s)
- Mi-Kyung Shin
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Luciano F. Drager
- Hypertension Unit, Heart Institute (InCor), University of Saõ Paulo Medical School, Saõ Paulo, Brazil
| | - Qiaoling Yao
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Shannon Bevans-Fonti
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Doo-Young Yoo
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Jonathan C. Jun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Susan Aja
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Sanjay Bhanot
- Isis Pharmaceuticals, Inc., Carlsbad, California, United States of America
| | - Vsevolod Y. Polotsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
| |
Collapse
|
44
|
Jun JC, Shin MK, Yao Q, Bevans-Fonti S, Poole J, Drager LF, Polotsky VY. Acute hypoxia induces hypertriglyceridemia by decreasing plasma triglyceride clearance in mice. Am J Physiol Endocrinol Metab 2012; 303:E377-88. [PMID: 22621867 PMCID: PMC3423119 DOI: 10.1152/ajpendo.00641.2011] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 05/16/2012] [Indexed: 12/16/2022]
Abstract
Obstructive sleep apnea (OSA) induces intermittent hypoxia (IH) during sleep and is associated with elevated triglycerides (TG). We previously demonstrated that mice exposed to chronic IH develop elevated TG. We now hypothesize that a single exposure to acute hypoxia also increases TG due to the stimulation of free fatty acid (FFA) mobilization from white adipose tissue (WAT), resulting in increased hepatic TG synthesis and secretion. Male C57BL6/J mice were exposed to FiO(2) = 0.21, 0.17, 0.14, 0.10, or 0.07 for 6 h followed by assessment of plasma and liver TG, glucose, FFA, ketones, glycerol, and catecholamines. Hypoxia dose-dependently increased plasma TG, with levels peaking at FiO(2) = 0.07. Hepatic TG levels also increased with hypoxia, peaking at FiO(2) = 0.10. Plasma catecholamines also increased inversely with FiO(2). Plasma ketones, glycerol, and FFA levels were more variable, with different degrees of hypoxia inducing WAT lipolysis and ketosis. FiO(2) = 0.10 exposure stimulated WAT lipolysis but decreased the rate of hepatic TG secretion. This degree of hypoxia rapidly and reversibly delayed TG clearance while decreasing [(3)H]triolein-labeled Intralipid uptake in brown adipose tissue and WAT. Hypoxia decreased adipose tissue lipoprotein lipase (LPL) activity in brown adipose tissue and WAT. In addition, hypoxia decreased the transcription of LPL, peroxisome proliferator-activated receptor-γ, and fatty acid transporter CD36. We conclude that acute hypoxia increases plasma TG due to decreased tissue uptake, not increased hepatic TG secretion.
Collapse
Affiliation(s)
- Jonathan C Jun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
| | | | | | | | | | | | | |
Collapse
|
45
|
Abstract
Obesity causes insulin resistance (IR) and nonalcoholic fatty liver disease (NAFLD), but the relative contribution of sleep apnea is debatable. The main aim of this study is to evaluate the effects of chronic intermittent hypoxia (CIH), a hallmark of sleep apnea, on IR and NAFLD in lean mice and mice with diet-induced obesity (DIO). Mice (C57BL/6J), 6-8 weeks of age were fed a high fat (n = 18) or regular (n = 16) diet for 12 weeks and then exposed to CIH or control conditions (room air) for 4 weeks. At the end of the exposure, fasting (5 h) blood glucose, insulin, homeostasis model assessment (HOMA) index, liver enzymes, and intraperitoneal glucose tolerance test (1 g/kg) were measured. In DIO mice, body weight remained stable during CIH and did not differ from control conditions. Lean mice under CIH were significantly lighter than control mice by day 28 (P = 0.002). Compared to lean mice, DIO mice had higher fasting levels of blood glucose, plasma insulin, the HOMA index, and had glucose intolerance and hepatic steatosis at baseline. In lean mice, CIH slightly increased HOMA index (from 1.79 ± 0.13 in control to 2.41 ± 0.26 in CIH; P = 0.05), whereas glucose tolerance was not affected. In contrast, in DIO mice, CIH doubled HOMA index (from 10.1 ± 2.1 in control to 22.5 ± 3.6 in CIH; P < 0.01), and induced severe glucose intolerance. In DIO mice, CIH induced NAFLD, inflammation, and oxidative stress, which was not observed in lean mice. In conclusion, CIH exacerbates IR and induces steatohepatitis in DIO mice, suggesting that CIH may account for metabolic dysfunction in obesity.
Collapse
Affiliation(s)
- Luciano F. Drager
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jianguo Li
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Christian Reinke
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Shannon Bevans-Fonti
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jonathan C. Jun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Vsevolod Y. Polotsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
46
|
Jun JC, Drager LF, Najjar SS, Gottlieb SS, Brown CD, Smith PL, Schwartz AR, Polotsky VY. Effects of sleep apnea on nocturnal free fatty acids in subjects with heart failure. Sleep 2011; 34:1207-13. [PMID: 21886358 PMCID: PMC3157662 DOI: 10.5665/sleep.1240] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
STUDY OBJECTIVES Sleep apnea is common in patients with congestive heart failure, and may contribute to the progression of underlying heart disease. Cardiovascular and metabolic complications of sleep apnea have been attributed to intermittent hypoxia. Elevated free fatty acids (FFA) are also associated with the progression of metabolic, vascular, and cardiac dysfunction. The objective of this study was to determine the effect of intermittent hypoxia on FFA levels during sleep in patients with heart failure. DESIGN AND INTERVENTIONS During sleep, frequent blood samples were examined for FFA in patients with stable heart failure (ejection fraction < 40%). In patients with severe sleep apnea (apnea-hypopnea index = 65.5 ± 9.1 events/h; average low SpO₂ = 88.9%), FFA levels were compared to controls with milder sleep apnea (apnea-hypopnea index = 15.4 ± 3.7 events/h; average low SpO₂ = 93.6%). In patients with severe sleep apnea, supplemental oxygen at 2-4 liters/min was administered on a subsequent night to eliminate hypoxemia. MEASUREMENTS AND RESULTS Prior to sleep onset, controls and patients with severe apnea exhibited a similar FFA level. After sleep onset, patients with severe sleep apnea exhibited a marked and rapid increase in FFA relative to control subjects. This increase persisted throughout NREM and REM sleep exceeding serum FFA levels in control subjects by 0.134 mmol/L (P = 0.0038). Supplemental oxygen normalized the FFA profile without affecting sleep architecture or respiratory arousal frequency. CONCLUSION In patients with heart failure, severe sleep apnea causes surges in nocturnal FFA that may contribute to the accelerated progression of underlying heart disease. Supplemental oxygen prevents the FFA elevation.
Collapse
Affiliation(s)
- Jonathan C. Jun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Luciano F. Drager
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
- Hypertension Unit, Heart Institute (InCor), University of Sao Paulo Medical School, Brazil
| | - Samer S. Najjar
- Heart Failure Service, Washington Hospital Center, Washington, DC
| | - Stephen S. Gottlieb
- Division of Cardiology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD
| | - Cynthia D. Brown
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, Charlottesville, VA
| | - Philip L. Smith
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Alan R. Schwartz
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Vsevolod Y. Polotsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| |
Collapse
|
47
|
Drager LF, Li J, Shin MK, Reinke C, Aggarwal NR, Jun JC, Bevans-Fonti S, Sztalryd C, O'Byrne SM, Kroupa O, Olivecrona G, Blaner WS, Polotsky VY. Intermittent hypoxia inhibits clearance of triglyceride-rich lipoproteins and inactivates adipose lipoprotein lipase in a mouse model of sleep apnoea. Eur Heart J 2011; 33:783-90. [PMID: 21478490 DOI: 10.1093/eurheartj/ehr097] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
AIMS Delayed lipoprotein clearance is associated with atherosclerosis. This study examined whether chronic intermittent hypoxia (CIH), a hallmark of obstructive sleep apnoea (OSA), can lead to hyperlipidaemia by inhibiting clearance of triglyceride rich lipoproteins (TRLP). METHODS AND RESULTS Male C57BL/6J mice on high-cholesterol diet were exposed to 4 weeks of CIH or chronic intermittent air (control). FIO(2) was decreased to 6.5% once per minute during the 12 h light phase in the CIH group. After the exposure, we measured fasting lipid profile. TRLP clearance was assessed by oral gavage of retinyl palmitate followed by serum retinyl esters (REs) measurements at 0, 1, 2, 4, 10, and 24 h. Activity of lipoprotein lipase (LpL), a key enzyme of lipoprotein clearance, and levels of angiopoietin-like protein 4 (Angptl4), a potent inhibitor of the LpL activity, were determined in the epididymal fat pads, skeletal muscles, and heart. Chronic intermittent hypoxia induced significant increases in levels of total cholesterol and triglycerides, which occurred in TRLP and LDL fractions (P< 0.05 for each comparison). Compared with control mice, animals exposed to CIH showed increases in REs throughout first 10 h after oral gavage of retinyl palmitate (P< 0.05), indicating that CIH inhibited TRLP clearance. CIH induced a >5-fold decrease in LpL activity (P< 0.01) and an 80% increase in Angptl4 mRNA and protein levels in the epididymal fat, but not in the skeletal muscle or heart. CONCLUSIONS CIH decreases TRLP clearance and inhibits LpL activity in adipose tissue, which may contribute to atherogenesis observed in OSA.
Collapse
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
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Drager LF, Reinke C, Jun JC, Bevans‐Fonti S, Polotsky VY. Acute Intermittent Hypoxia Inhibits Triglycerides Clearance And Has a Tissue‐Specific Effect on Lipoprotein Lipase Activity. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.1103.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
49
|
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.
Collapse
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
| | | | | |
Collapse
|
50
|
Drager LF, Lopes HF, Maki-Nunes C, Trombetta IC, Toschi-Dias E, Alves MJNN, Fraga RF, Jun JC, Negrão CE, Krieger EM, Polotsky VY, Lorenzi-Filho G. The impact of obstructive sleep apnea on metabolic and inflammatory markers in consecutive patients with metabolic syndrome. PLoS One 2010; 5:e12065. [PMID: 20711453 PMCID: PMC2920316 DOI: 10.1371/journal.pone.0012065] [Citation(s) in RCA: 182] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 07/14/2010] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Obstructive Sleep Apnea (OSA) is tightly linked to some components of Metabolic Syndrome (MetS). However, most of the evidence evaluated individual components of the MetS or patients with a diagnosis of OSA that were referred for sleep studies due to sleep complaints. Therefore, it is not clear whether OSA exacerbates the metabolic abnormalities in a representative sample of patients with MetS. METHODOLOGY/PRINCIPAL FINDINGS We studied 152 consecutive patients (age 48+/-9 years, body mass index 32.3+/-3.4 Kg/m2) newly diagnosed with MetS (Adult Treatment Panel III). All participants underwent standard polysomnography irrespective of sleep complaints, and laboratory measurements (glucose, lipid profile, uric acid and C-reactive protein). The prevalence of OSA (apnea-hypopnea index>or=15 events per hour of sleep) was 60.5%. Patients with OSA exhibited significantly higher levels of blood pressure, glucose, triglycerides, cholesterol, LDL, cholesterol/HDL ratio, triglycerides/HDL ratio, uric acid and C-reactive protein than patients without OSA. OSA was independently associated with 2 MetS criteria: triglycerides: OR: 3.26 (1.47-7.21) and glucose: OR: 2.31 (1.12-4.80). OSA was also independently associated with increased cholesterol/HDL ratio: OR: 2.38 (1.08-5.24), uric acid: OR: 4.19 (1.70-10.35) and C-reactive protein: OR: 6.10 (2.64-14.11). Indices of sleep apnea severity, apnea-hypopnea index and minimum oxygen saturation, were independently associated with increased levels of triglycerides, glucose as well as cholesterol/HDL ratio, uric acid and C-reactive protein. Excessive daytime sleepiness had no effect on the metabolic and inflammatory parameters. CONCLUSIONS/SIGNIFICANCE Unrecognized OSA is common in consecutive patients with MetS. OSA may contribute to metabolic dysregulation and systemic inflammation in patients with MetS, regardless of symptoms of daytime sleepiness.
Collapse
Affiliation(s)
- Luciano F Drager
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|