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Self AA, Mesarwi OA. Intermittent Versus Sustained Hypoxemia from Sleep-disordered Breathing: Outcomes in Patients with Chronic Lung Disease and High Altitude. Sleep Med Clin 2024; 19:327-337. [PMID: 38692756 DOI: 10.1016/j.jsmc.2024.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
In a variety of physiologic and pathologic states, people may experience both chronic sustained hypoxemia and intermittent hypoxemia ("combined" or "overlap" hypoxemia). In general, hypoxemia in such instances predicts a variety of maladaptive outcomes, including excess cardiovascular disease or mortality. However, hypoxemia may be one of the myriad phenotypic effects in such states, making it difficult to ascertain whether adverse outcomes are primarily driven by hypoxemia, and if so, whether these effects are due to intermittent versus sustained hypoxemia.
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Affiliation(s)
- Alyssa A Self
- Division of Pulmonary, Critical Care, and Sleep Medicine and Physiology, University of California, San Diego, 9500 Gilman Drive Mail Code 0623A, La Jolla, CA 92093, USA
| | - Omar A Mesarwi
- Division of Pulmonary, Critical Care, and Sleep Medicine and Physiology, University of California, San Diego, 9500 Gilman Drive Mail Code 0623A, La Jolla, CA 92093, USA.
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2
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Patrician A, Anholm JD, Ainslie PN. A narrative review of periodic breathing during sleep at high altitude: From acclimatizing lowlanders to adapted highlanders. J Physiol 2024. [PMID: 38534039 DOI: 10.1113/jp285427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 02/15/2024] [Indexed: 03/28/2024] Open
Abstract
Periodic breathing during sleep at high altitude is almost universal among sojourners. Here, in the context of acclimatization and adaptation, we provide a contemporary review on periodic breathing at high altitude, and explore whether this is an adaptive or maladaptive process. The mechanism(s), prevalence and role of periodic breathing in acclimatized lowlanders at high altitude are contrasted with the available data from adapted indigenous populations (e.g. Andean and Tibetan highlanders). It is concluded that (1) periodic breathing persists with acclimatization in lowlanders and the severity is proportional to sleeping altitude; (2) periodic breathing does not seem to coalesce with poor sleep quality such that, with acclimatization, there appears to be a lengthening of cycle length and minimal impact on the average sleeping oxygen saturation; and (3) high altitude adapted highlanders appear to demonstrate a blunting of periodic breathing, compared to lowlanders, comprising a feature that withstands the negative influences of chronic mountain sickness. These observations indicate that periodic breathing persists with high altitude acclimatization with no obvious negative consequences; however, periodic breathing is attenuated with high altitude adaptation and therefore potentially reflects an adaptive trait to this environment.
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Affiliation(s)
- Alexander Patrician
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, BC, Canada
| | - James D Anholm
- Department of Medicine, Division of Pulmonary and Critical Care, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, BC, Canada
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Moya EA, Mesarwi OA. How far would you go to sleep better at high altitude? Sleep 2023; 46:6839988. [PMID: 36413093 PMCID: PMC9905773 DOI: 10.1093/sleep/zsac277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Indexed: 11/23/2022] Open
Affiliation(s)
- Esteban A Moya
- Section of Physiology, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Omar A Mesarwi
- Section of Physiology, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California San Diego, La Jolla, CA, USA
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4
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Sanchez-Azofra A, Villafuerte FC, DeYoung PN, Gilbertson D, Gu W, Moya EA, Vizcardo-Galindo G, Figueroa-Mujíca R, Anza-Ramirez C, Macarlupú JL, Pham LV, Wagner P, Malhotra A, Simonson TS, Mesarwi OA. Isovolemic hemodilution in chronic mountain sickness acutely worsens nocturnal oxygenation and sleep apnea severity. J Clin Sleep Med 2022; 18:2423-2432. [PMID: 35855526 PMCID: PMC9516589 DOI: 10.5664/jcsm.10136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 06/02/2022] [Accepted: 06/02/2022] [Indexed: 11/13/2022]
Abstract
STUDY OBJECTIVES Chronic mountain sickness (CMS) is commonly observed among Andean and other highland populations. Sleep-disordered breathing (SDB) is highly prevalent at high altitude, and SDB and nocturnal hypoxemia have been observed in CMS. Phlebotomy is commonly performed to treat CMS, but it is unknown whether reducing hematocrit improves SDB. We hypothesized that isovolemic hemodilution (IVHD) in CMS would reduce SBD severity and improve sleep efficiency. METHODS Six participants with CMS and 8 without CMS, all residents of Cerro de Pasco, Peru (altitude 4340 m), completed baseline nocturnal sleep studies. CMS participants then underwent IVHD, and nocturnal sleep studies were repeated 24-48 hours after IVHD. We analyzed sleep apnea severity, nocturnal oxygenation, and sleep quality in those with CMS relative to those without CMS, and the effects of IVHD in CMS participants. RESULTS Participants with CMS did not have altered sleep architecture, sleep apnea severity, or nocturnal oxygenation relative to non-CMS participants. However, IVHD in CMS increased apnea-hypopnea index (40.9 ± 6.9 events/h to 61.5 ± 7.7 events/h, P = .009). IVHD increased oxyhemoglobin desaturation index (P = .008) and the percentage of sleep time spent with oxyhemoglobin saturation at or below 80% (P = .012). There was no effect of IVHD on sleep efficiency, arousal index, or sleep staging. CONCLUSIONS In this cohort, CMS was not associated with worsened SDB or changes in sleep architecture. IVHD, a putative therapeutic option for participants with CMS, appears to worsen nocturnal oxygenation and SDB within 48 hours post-IVHD. CITATION Sanchez-Azofra A, Villafuerte FC, DeYoung PN, et al. Isovolemic hemodilution in chronic mountain sickness acutely worsens nocturnal oxygenation and sleep apnea severity. J Clin Sleep Med. 2022;18(10):2423-2432.
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Affiliation(s)
- Ana Sanchez-Azofra
- Division of Pulmonary, Critical Care, & Sleep Medicine and Physiology, Department of Medicine, University of California, San Diego, California
- Servicio de Neumología, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, Madrid, España
| | - Francisco C. Villafuerte
- Laboratorio de Fisiología Comparada, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Pamela N. DeYoung
- Division of Pulmonary, Critical Care, & Sleep Medicine and Physiology, Department of Medicine, University of California, San Diego, California
| | - Dillon Gilbertson
- Division of Pulmonary, Critical Care, & Sleep Medicine and Physiology, Department of Medicine, University of California, San Diego, California
| | - Wanjun Gu
- Division of Pulmonary, Critical Care, & Sleep Medicine and Physiology, Department of Medicine, University of California, San Diego, California
| | - Esteban A. Moya
- Division of Pulmonary, Critical Care, & Sleep Medicine and Physiology, Department of Medicine, University of California, San Diego, California
| | - Gustavo Vizcardo-Galindo
- Laboratorio de Fisiología Comparada, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Rómulo Figueroa-Mujíca
- Laboratorio de Fisiología Comparada, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Cecilia Anza-Ramirez
- Laboratorio de Fisiología Comparada, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Jose L. Macarlupú
- Laboratorio de Fisiología Comparada, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Luu V. Pham
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Peter Wagner
- Division of Pulmonary, Critical Care, & Sleep Medicine and Physiology, Department of Medicine, University of California, San Diego, California
| | - Atul Malhotra
- Division of Pulmonary, Critical Care, & Sleep Medicine and Physiology, Department of Medicine, University of California, San Diego, California
- Center for Physiological Genomics of Low Oxygen, University of California, San Diego, California
| | - Tatum S. Simonson
- Division of Pulmonary, Critical Care, & Sleep Medicine and Physiology, Department of Medicine, University of California, San Diego, California
- Center for Physiological Genomics of Low Oxygen, University of California, San Diego, California
| | - Omar A. Mesarwi
- Division of Pulmonary, Critical Care, & Sleep Medicine and Physiology, Department of Medicine, University of California, San Diego, California
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Villafuerte FC, Simonson TS, Bermudez D, León-Velarde F. High-Altitude Erythrocytosis: Mechanisms of Adaptive and Maladaptive Responses. Physiology (Bethesda) 2022; 37:0. [PMID: 35001654 PMCID: PMC9191173 DOI: 10.1152/physiol.00029.2021] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Erythrocytosis, or increased production of red blood cells, is one of the most well-documented physiological traits that varies within and among in high-altitude populations. Although a modest increase in blood O2-carrying capacity may be beneficial for life in highland environments, erythrocytosis can also become excessive and lead to maladaptive syndromes such as chronic mountain sickness (CMS).
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Affiliation(s)
- Francisco C. Villafuerte
- 1Laboratorio de Fisiología Comparada/Laboratorio de Fisiología del Transporte de Oxígeno, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Tatum S. Simonson
- 2Division of Pulmonary, Critical Care, and Sleep Medicine, School of Medicine, University of California, San Diego, La Jolla, California
| | - Daniela Bermudez
- 1Laboratorio de Fisiología Comparada/Laboratorio de Fisiología del Transporte de Oxígeno, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Fabiola León-Velarde
- 1Laboratorio de Fisiología Comparada/Laboratorio de Fisiología del Transporte de Oxígeno, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
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Zhen X, Moya EA, Gautane M, Zhao H, Lawrence ES, Gu W, Barnes LA, Yuan JXJ, Jain PP, Xiong M, Catalan Serra P, Pham LV, Malhotra A, Simonson TS, Mesarwi OA. Combined intermittent and sustained hypoxia is a novel and deleterious cardio-metabolic phenotype. Sleep 2022; 45:zsab290. [PMID: 34893914 PMCID: PMC9189937 DOI: 10.1093/sleep/zsab290] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 12/01/2021] [Indexed: 11/14/2022] Open
Abstract
STUDY OBJECTIVES Chronic obstructive pulmonary disease and obstructive sleep apnea overlap syndrome is associated with excess mortality, and outcomes are related to the degree of hypoxemia. People at high altitudes are susceptible to periodic breathing, and hypoxia at altitude is associated with cardio-metabolic dysfunction. Hypoxemia in these scenarios may be described as superimposed sustained hypoxia (SH) plus intermittent hypoxia (IH), or overlap hypoxia (OH), the effects of which have not been investigated. We aimed to characterize the cardio-metabolic consequences of OH in mice. METHODS C57BL/6J mice were subjected to either SH (FiO2 = 0.10), IH (FiO2 = 0.21 for 12 h, and FiO2 oscillating between 0.21 and 0.06, 60 times/hour, for 12 h), OH (FiO2 = 0.13 for 12 h, and FiO2 oscillating between 0.13 and 0.06, 60 times/hour, for 12 h), or room air (RA), n = 8/group. Blood pressure and intraperitoneal glucose tolerance test were measured serially, and right ventricular systolic pressure (RVSP) was assessed. RESULTS Systolic blood pressure transiently increased in IH and OH relative to SH and RA. RVSP did not increase in IH, but increased in SH and OH by 52% (p < .001) and 20% (p = .001). Glucose disposal worsened in IH and improved in SH, with no change in OH. Serum low- and very-low-density lipoproteins increased in OH and SH, but not in IH. Hepatic oxidative stress increased in all hypoxic groups, with the highest increase in OH. CONCLUSIONS OH may represent a unique and deleterious cardio-metabolic stimulus, causing systemic and pulmonary hypertension, and without protective metabolic effects characteristic of SH.
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Affiliation(s)
- Xin Zhen
- University of California, San Diego, La Jolla, CA, USA
| | - Esteban A Moya
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA
| | - Mary Gautane
- University of California, San Diego, La Jolla, CA, USA
| | - Huayi Zhao
- University of California, San Diego, La Jolla, CA, USA
| | - Elijah S Lawrence
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA
| | - Wanjun Gu
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA
| | - Laura A Barnes
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA
| | - Jason X-J Yuan
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA
| | - Pritesh P Jain
- Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Mingmei Xiong
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA
| | | | - Luu V Pham
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, MD,USA
| | - Atul Malhotra
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA
- Center for Physiological Genomics of Low Oxygen, University of California, San Diego, CA, USA
| | - Tatum S Simonson
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA
- Center for Physiological Genomics of Low Oxygen, University of California, San Diego, CA, USA
| | - Omar A Mesarwi
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA
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7
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Ju JD, Zhang C, Sgambati FP, Lopez LM, Pham LV, Schwartz AR, Accinelli RA. Acute Altitude Acclimatization in Young Healthy Volunteers: Nocturnal Oxygenation Increases Over Time, Whereas Periodic Breathing Persists. High Alt Med Biol 2020; 22:14-23. [PMID: 33185483 DOI: 10.1089/ham.2020.0009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ju, Jia-Der, Cristian Zhang, Francis P. Sgambati, Lidia M. Lopez, Luu V. Pham, Alan R. Schwartz, and Roberto A. Accinelli. Acute altitude acclimatization in young healthy volunteers: nocturnal oxygenation increases over time whereas periodic breathing persists. High Alt Med Biol. 22:14-23, 2021. Study Objectives: This study aimed to examine the acute effects of high altitude (HA) on sleep disordered breathing (sleep apnea and nocturnal hypoxemia) and acute mountain sickness and to characterize acclimatization over time. Methods: Ten native lowlanders residing at sea level (SL) completed the Lake Louise Score (LLS) and underwent nocturnal polygraphy (ApneaLink Plus) for nine consecutive nights (N1-N9) at HA (2,761 m) and two nights before and after HA. Nocturnal oxygen profiles were assessed by measuring the mean nocturnal oxyhemoglobin saturation (SpO2) during sleep, and sleep apnea severity as assessed by measuring the Apnea-Hypopnea Index (AHI). Mixed-effects linear regression was used to model responses in outcomes (mean nocturnal SpO2, logAHI, and LLS) between HA and SL. Changes in SpO2 and AHI were examined in subgroups with mild versus marked nocturnal SpO2 and low versus high AHI during exposure to HA and compared between subgroups. Results: Compared with SL, the mean nocturnal SpO2 was lower (p < 0.0001) and AHI was higher (p < 0.0001) at HA. The mean nocturnal SpO2 increased progressively (p < 0.001), whereas AHI remained high (p < 0.978) and relatively unchanged over nine successive nights at HA. Those with markedly reduced SpO2 upon arrival at HA exhibited progressive increases in the mean nocturnal SpO2 over time at HA compared with those with mild nocturnal desaturation. LLS rose at HA, but no differences were observed between subgroups. Conclusions: In healthy HA sojourners, the mean nocturnal SpO2 increased progressively over time, whereas AHI remained elevated, suggesting distinctive phenotypes and acclimatization responses to HA.
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Affiliation(s)
- Jia-Der Ju
- Instituto de Investigaciones de la Altura, Facultad de Medicina Alberto Hurtado, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Cristian Zhang
- Instituto de Investigaciones de la Altura, Facultad de Medicina Alberto Hurtado, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Francis P Sgambati
- Johns Hopkins Sleep Center and Center for Interdisciplinary Sleep Research Education, Baltimore, Maryland, USA
| | - Lidia M Lopez
- Instituto de Investigaciones de la Altura, Facultad de Medicina Alberto Hurtado, Universidad Peruana Cayetano Heredia, Lima, Peru.,Hospital Cayetano Heredia, Lima, Perú
| | - Luu V Pham
- Johns Hopkins Sleep Center and Center for Interdisciplinary Sleep Research Education, Baltimore, Maryland, USA.,Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Alan R Schwartz
- Adjunct Professor, Perelman School of Medicine, University of Pennsylvania, Lima, Perú.,Distinguished Visiting Professor, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Roberto A Accinelli
- Instituto de Investigaciones de la Altura, Facultad de Medicina Alberto Hurtado, Universidad Peruana Cayetano Heredia, Lima, Peru.,Hospital Cayetano Heredia, Lima, Perú
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8
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Bilo G, Acone L, Anza-Ramírez C, Macarlupú JL, Soranna D, Zambon A, Vizcardo-Galindo G, Pengo MF, Villafuerte FC, Parati G. Office and Ambulatory Arterial Hypertension in Highlanders: HIGHCARE-ANDES Highlanders Study. Hypertension 2020; 76:1962-1970. [PMID: 33175629 DOI: 10.1161/hypertensionaha.120.16010] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Millions of people worldwide live at high altitude, being chronically exposed to hypobaric hypoxia. Hypertension is a major cardiovascular risk factor but data on its prevalence and determinants in highlanders are limited, and systematic studies with ambulatory blood pressure monitoring are not available. Aim of this study was to assess the prevalence of clinic and ambulatory hypertension and the associated factors in a sample of Andean highlanders. Hypertension prevalence and phenotypes were assessed with office and ambulatory blood pressure measurement in a sample of adults living in Cerro de Pasco, Peru (altitude 4340 m). Basic clinical data, blood oxygen saturation, hematocrit, and Qinghai Chronic Mountain Sickness score were obtained. Participants were classified according to the presence of excessive erythrocytosis and chronic mountain sickness diagnosis. Data of 289 participants (143 women, 146 men, mean age 38.3 years) were analyzed. Office hypertension was present in 20 (7%) participants, while ambulatory hypertension was found in 58 (20%) participants. Masked hypertension was common (15%), and white coat hypertension was rare (2%). Among participants with ambulatory hypertension, the most prevalent phenotypes included isolated nocturnal hypertension, isolated diastolic hypertension, and systodiastolic hypertension. Ambulatory hypertension was associated with male gender, age, overweight/obesity, 24-hour heart rate, and excessive erythrocytosis. Prevalence of hypertension among Andean highlanders may be significantly underestimated when based on conventional blood pressure measurements, due to the high prevalence of masked hypertension. In highlanders, ambulatory hypertension may be independently associated with excessive erythrocytosis.
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Affiliation(s)
- Grzegorz Bilo
- From the Department of Cardiovascular, Neural and Metabolic Sciences (G.B., M.F.P., G.P.), University of Milano-Bicocca, Milan, Italy.,Istituto Auxologico Italiano, IRCCS, Milan, Italy Department of Medicine and Surgery (G.B., L.A., G.P.), University of Milano-Bicocca, Milan, Italy
| | - Lorenzo Acone
- Istituto Auxologico Italiano, IRCCS, Milan, Italy Department of Medicine and Surgery (G.B., L.A., G.P.), University of Milano-Bicocca, Milan, Italy
| | - Cecilia Anza-Ramírez
- Laboratorio de Fisiología Comparada/Fisiología del Transporte de Oxígeno-LID. Universidad Peruana Cayetano Heredia, Lima, Perú (C.A.-R., J.L.M., G.V.-G., F.C.V.)
| | - José Luis Macarlupú
- Laboratorio de Fisiología Comparada/Fisiología del Transporte de Oxígeno-LID. Universidad Peruana Cayetano Heredia, Lima, Perú (C.A.-R., J.L.M., G.V.-G., F.C.V.)
| | - Davide Soranna
- Biostatistics Unit (D.S., A.Z.), University of Milano-Bicocca, Milan, Italy
| | - Antonella Zambon
- Biostatistics Unit (D.S., A.Z.), University of Milano-Bicocca, Milan, Italy.,Department of Statistics and Quantitative Methods (A.Z.), University of Milano-Bicocca, Milan, Italy
| | - Gustavo Vizcardo-Galindo
- Laboratorio de Fisiología Comparada/Fisiología del Transporte de Oxígeno-LID. Universidad Peruana Cayetano Heredia, Lima, Perú (C.A.-R., J.L.M., G.V.-G., F.C.V.)
| | - Martino F Pengo
- From the Department of Cardiovascular, Neural and Metabolic Sciences (G.B., M.F.P., G.P.), University of Milano-Bicocca, Milan, Italy
| | - Francisco C Villafuerte
- Laboratorio de Fisiología Comparada/Fisiología del Transporte de Oxígeno-LID. Universidad Peruana Cayetano Heredia, Lima, Perú (C.A.-R., J.L.M., G.V.-G., F.C.V.)
| | - Gianfranco Parati
- From the Department of Cardiovascular, Neural and Metabolic Sciences (G.B., M.F.P., G.P.), University of Milano-Bicocca, Milan, Italy.,Istituto Auxologico Italiano, IRCCS, Milan, Italy Department of Medicine and Surgery (G.B., L.A., G.P.), University of Milano-Bicocca, Milan, Italy
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9
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Heinrich EC, Orr JE, Gilbertson D, Anza-Ramirez C, DeYoung PN, Djokic MA, Corante N, Vizcardo-Galindo G, Macarlupu JL, Gaio E, Powell FL, Malhotra A, Villafuerte FC, Simonson TS. Relationships Between Chemoreflex Responses, Sleep Quality, and Hematocrit in Andean Men and Women. Front Physiol 2020; 11:437. [PMID: 32435207 PMCID: PMC7219107 DOI: 10.3389/fphys.2020.00437] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/08/2020] [Indexed: 12/12/2022] Open
Abstract
Andean highlanders are challenged by chronic hypoxia and many exhibit elevated hematocrit (Hct) and blunted ventilation compared to other high-altitude populations. While many Andeans develop Chronic Mountain Sickness (CMS) and excessive erythrocytosis, Hct varies markedly within Andean men and women and may be driven by individual differences in ventilatory control and/or sleep events which exacerbate hypoxemia. To test this hypothesis, we quantified relationships between resting ventilation and ventilatory chemoreflexes, sleep desaturation, breathing disturbance, and Hct in Andean men and women. Ventilatory measures were made in 109 individuals (n = 63 men; n = 46 women), and sleep measures in 45 of these participants (n = 22 men; n = 23 women). In both men and women, high Hct was associated with low daytime SpO2 (p < 0.001 and p < 0.002, respectively) and decreased sleep SpO2 (mean, nadir, and time <80%; all p < 0.02). In men, high Hct was also associated with increased end-tidal PCO2 (p < 0.009). While ventilatory responses to hypoxia and hypercapnia did not predict Hct, decreased hypoxic ventilatory responses were associated with lower daytime SpO2 in men (p < 0.01) and women (p < 0.009) and with lower nadir sleep SpO2 in women (p < 0.02). Decreased ventilatory responses to CO2 were associated with more time below 80% SpO2 during sleep in men (p < 0.05). The obstructive apnea index and apnea-hypopnea index also predicted Hct and CMS scores in men after accounting for age, BMI, and SpO2 during sleep. Finally, heart rate response to hypoxia was lower in men with higher Hct (p < 0.0001). These data support the idea that hypoventilation and decreased ventilatory sensitivity to hypoxia are associated with decreased day time and nighttime SpO2 levels that may exacerbate the stimulus for erythropoiesis in Andean men and women. However, interventional and longitudinal studies are required to establish the causal relationships between these associations.
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Affiliation(s)
- Erica C Heinrich
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Jeremy E Orr
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Dillon Gilbertson
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Cecilia Anza-Ramirez
- Laboratorio de Fisiología Comparada/Fisiología del Transporte de Oxígen, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Pamela N DeYoung
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Matea A Djokic
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Noemi Corante
- Laboratorio de Fisiología Comparada/Fisiología del Transporte de Oxígen, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Gustavo Vizcardo-Galindo
- Laboratorio de Fisiología Comparada/Fisiología del Transporte de Oxígen, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Jose L Macarlupu
- Laboratorio de Fisiología Comparada/Fisiología del Transporte de Oxígen, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Eduardo Gaio
- Faculty of Medicine, University of Brasília, Brasília, Brazil
| | - Frank L Powell
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Atul Malhotra
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Francisco C Villafuerte
- Laboratorio de Fisiología Comparada/Fisiología del Transporte de Oxígen, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Tatum S Simonson
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California, San Diego, San Diego, CA, United States
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SOD2 ameliorates pulmonary hypertension in a murine model of sleep apnea via suppressing expression of NLRP3 in CD11b + cells. Respir Res 2020; 21:9. [PMID: 31915037 PMCID: PMC6951024 DOI: 10.1186/s12931-019-1270-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Accepted: 12/23/2019] [Indexed: 12/12/2022] Open
Abstract
Background High prevalence of obstructive sleep apnea (OSA) in the pulmonary hypertension (PH) population suggests that chronic intermittent hypoxia (CIH) is an important pathogenic factor of PH. However, the exact mechanism of CIH induced PH is not clear. One of the molecules that plays a key role in regulating pulmonary artery function under hypoxic conditions is superoxide dismutase 2 (SOD2). Methods Our study utilized heterozygous SOD2−/+ mice firstly in CIH model to explore the exact role of SOD2 in CIH causing PH. Expression of SOD2 was analyzed in CIH model. Echocardiography and pulmonary hypertension were measured in wild type (WT) and SOD2−/+ mice under normal air or CIH condition. Hematoxylin–Eosin (H&E) staining and masson staining were carried out to evaluate pulmonary vascular muscularization and remodeling. Micro-PET scanning of in vivo 99mTc-labelled- MAG3-anti-CD11b was applied to assess CD11b in quantification and localization. Level of nod-like receptor pyrin domain containing 3 (NLRP3) was analyzed by real time PCR and immunohistochemistry (IHC). Results Results showed that SOD2 was down-regulated in OSA/CIH model. Deficiency of SOD2 aggravated CIH induced pulmonary hypertension and pulmonary vascular hypertrophy. CD11b+ cells, especially monocytic myeloid cell line-Ly6C+Ly6G− cells, were increased in the lung, bone marrow and the blood under CIH condition, and down-regulated SOD2 activated NLRP3 in CD11b+ cells. SOD2-deficient-CD11b+ myeloid cells promoted the apoptosis resistance and over-proliferation of human pulmonary artery smooth muscle cells (PASMCs) via up-regulating NLRP3. Conclusion CIH induced down-regulating of SOD2 increased pulmonary hypertension and vascular muscularization. It could be one of the mechanism of CIH leading to PH.
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Arias RS, Etienne B, Polotsky VY, Checkley W, Schwartz AR, Pham LV. Upright posture increases oxyhemoglobin saturation in Peruvian highlanders. Respir Physiol Neurobiol 2019; 266:138-143. [PMID: 31048020 DOI: 10.1016/j.resp.2019.04.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 04/24/2019] [Accepted: 04/28/2019] [Indexed: 02/02/2023]
Abstract
At high altitude, hypoxia amplifies oxyhemoglobin saturation (SPO2) swings with changes in respiratory mechanics. Our objective was to examine the effects of posture on SPO2 and determine predictors of postural SPO2 changes in highlanders. 50 native highlanders from Puno, Peru (3825 m) assumed supine and upright-seated postures, in rotating sequence, while undergoing continuous pulse-oximetry. We compared mean SpO2 in each posture with a paired t-test. We examined associations of BMI, age, sex and spirometry with postural SpO2 changes with mixed-effects linear regression. In highlanders, SpO2 was 84% in the supine posture and was 1.0% ± 1.1 (p < 0.0001) greater in the upright-seated posture. Greater postural changes in SpO2 were associated with older age (p = 0.01 for interaction) but not with sex, BMI, FVC or FEV1. In highlanders, SpO2 is higher in the upright-seated compared to supine posture, especially with older age. Because we generally sleep flat, posture may contribute significantly to highlanders' hypoxemic burden during sleep. Postural intervention during sleep may mitigate nocturnal hypoxemia.
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Affiliation(s)
- Rafael S Arias
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, USA
| | - Branden Etienne
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, USA; Department of Computer Science, University of Maryland, College Park, USA
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, USA
| | - William Checkley
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, USA; Center for Global Non-Communicable Disease Research and Training, Johns Hopkins University, Baltimore, USA; Division of Global Disease Epidemiology and Control, School of Public Health, Johns Hopkins University, Baltimore, USA
| | - Alan R Schwartz
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, USA
| | - Luu V Pham
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, USA.
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Orr JE, Heinrich EC, Djokic M, Gilbertson D, Deyoung PN, Anza-Ramirez C, Villafuerte FC, Powell FL, Malhotra A, Simonson T. Adaptive Servoventilation as Treatment for Central Sleep Apnea Due to High-Altitude Periodic Breathing in Nonacclimatized Healthy Individuals. High Alt Med Biol 2018; 19:178-184. [PMID: 29641294 PMCID: PMC6014053 DOI: 10.1089/ham.2017.0147] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 01/20/2018] [Indexed: 12/17/2022] Open
Abstract
Orr, Jeremy E., Erica C. Heinrich, Matea Djokic, Dillon Gilbertson, Pamela N. Deyoung, Cecilia Anza-Ramirez, Francisco C. Villafuerte, Frank L. Powell, Atul Malhotra, and Tatum Simonson. Adaptive servoventilation as treatment for central sleep apnea due to high-altitude periodic breathing in nonacclimatized healthy individuals. High Alt Med Biol. 19:178-184, 2018. AIMS Central sleep apnea (CSA) is common at high altitude, leading to desaturation and sleep disruption. We hypothesized that noninvasive ventilation using adaptive servoventilation (ASV) would be effective at stabilizing CSA at altitude. Supplemental oxygen was evaluated for comparison. METHODS Healthy subjects were brought from sea level to 3800 m and underwent polysomnography on three consecutive nights. Subjects underwent each condition-No treatment, ASV, and supplemental oxygen-in random order. The primary outcome was the effect of ASV on oxygen desaturation index (ODI). Secondary outcomes included oxygen saturation, arousals, symptoms, and comparison to supplemental oxygen. RESULTS Eighteen subjects underwent at least two treatment conditions. There was a significant difference in ODI across the three treatments. There was no statistical difference in ODI between no treatment and ASV (17.1 ± 4.2 vs. 10.7 ± 2.9 events/hour; p > 0.17) and no difference in saturation or arousal index. Compared with no treatment, oxygen improved the ODI (16.5 ± 4.5 events/hour vs. 0.5 ± 0.2 events/hour; p < 0.003), in addition to saturation and arousal index. CONCLUSIONS We found that ASV was not clearly efficacious at controlling CSA in persons traveling to 3800 m, whereas supplemental oxygen resolved CSA. Adjustment in the ASV algorithm may improve efficacy. ASV may have utility in acclimatized persons or at more modest altitudes.
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Affiliation(s)
- Jeremy E. Orr
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California
| | - Erica C. Heinrich
- Department of Medicine, Division of Physiology, University of California San Diego, La Jolla, California
| | - Matea Djokic
- Department of Medicine, Division of Physiology, University of California San Diego, La Jolla, California
| | - Dillon Gilbertson
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California
| | - Pamela N. Deyoung
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California
| | - Cecilia Anza-Ramirez
- Departamento de Ciencias Biológicas y Fisiológicas, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Francisco C. Villafuerte
- Departamento de Ciencias Biológicas y Fisiológicas, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Frank L. Powell
- Department of Medicine, Division of Physiology, University of California San Diego, La Jolla, California
| | - Atul Malhotra
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California
| | - Tatum Simonson
- Department of Medicine, Division of Physiology, University of California San Diego, La Jolla, California
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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] [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.
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