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Duenas-Meza E, Severiche-Bueno DF, Santos Quintero C, Talani Ochoa J, Ronderos Dummit M, Stapper C, Granados G C. Prevalence of pulmonary hypertension in children with obstructive sleep apnea living at high altitude. Sleep Med X 2024; 7:100106. [PMID: 38356659 PMCID: PMC10864626 DOI: 10.1016/j.sleepx.2024.100106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 01/16/2024] [Accepted: 01/29/2024] [Indexed: 02/16/2024] Open
Abstract
Introduction The prevalence of obstructive sleep apnea (OSA) is 1-4 %. Some reports describe its association with pulmonary hypertension (PH), but its prevalence is unknown. No studies at high altitude have determined the relationship between OSA and PH. The aim of this study was to establish the prevalence of PH in children diagnosed with OSA living in a high-altitude city at 2640 m above sea level. Methods Children between 2 and 16 years of age referred to the Sleep Laboratory of the Fundación Neumológica Colombiana in Bogotá with a positive polysomnogram for OSA were included, and a two-dimensional transthoracic echocardiogram (TTE) was performed to evaluate PH. Statistical analysis was performed using median, interquartile range, chi-squared test, and Kruskall-Wallis test. Results Of the 55 patients (n: 55), 63.6 % were male, with a median age of 6 years, 14 children (25.5 %) were overweight; 12 children (21.8 %) had mild OSA, 12 (21.8 %) had moderate OSA and 31 (56.4 %) severe OSA. In patients with severe OSA, the minimum saturation during events was 78 % with a desaturation index (DI) of 33.8/hour (p < 0.01). T90 and T85 increased proportionally with OSA severity (p < 0.05). Of the 55 patients with OSA, none had PH according to echocardiography; 4 patients (7.2 %) had pulmonary artery systolic pressure (PASP) at the upper limit of normal (ULN), and it was not related to a higher body mass index (BMI). Conclusions We found no association between OSA and PH in children with OSA at high altitude.
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Affiliation(s)
| | | | | | - Jenny Talani Ochoa
- Departamento de Pediatría, Universidad de La Sabana, Chía, Cundinamarca, Colombia
| | | | | | - Carlos Granados G
- Departamento de Pediatría, Universidad de La Sabana, Chía, Cundinamarca, Colombia
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Aboouf MA, Thiersch M, Soliz J, Gassmann M, Schneider Gasser EM. The Brain at High Altitude: From Molecular Signaling to Cognitive Performance. Int J Mol Sci 2023; 24:10179. [PMID: 37373327 DOI: 10.3390/ijms241210179] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/13/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
The brain requires over one-fifth of the total body oxygen demand for normal functioning. At high altitude (HA), the lower atmospheric oxygen pressure inevitably challenges the brain, affecting voluntary spatial attention, cognitive processing, and attention speed after short-term, long-term, or lifespan exposure. Molecular responses to HA are controlled mainly by hypoxia-inducible factors. This review aims to summarize the cellular, metabolic, and functional alterations in the brain at HA with a focus on the role of hypoxia-inducible factors in controlling the hypoxic ventilatory response, neuronal survival, metabolism, neurogenesis, synaptogenesis, and plasticity.
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Affiliation(s)
- Mostafa A Aboouf
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Department of Biochemistry, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Markus Thiersch
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Jorge Soliz
- Institute Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Faculty of Medicine, Université Laval, Québec, QC G1V 4G5, Canada
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Edith M Schneider Gasser
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Institute Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Faculty of Medicine, Université Laval, Québec, QC G1V 4G5, Canada
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, 8057 Zurich, Switzerland
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Sleep problems in low income, urban pediatric populations living at different altitudes in Colombia. Sleep Med 2022; 100:64-70. [PMID: 36027664 DOI: 10.1016/j.sleep.2022.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 01/12/2023]
Abstract
OBJECTIVE To determine the frequency of sleep problems in low-income, urban pediatric populations in cities at different altitudes in Colombia. METHODS A descriptive, cross-sectional population-based observational study was conducted in children aged between 2 and 12 years in the low income, urban areas of three cities in Colombia (Santa Marta, Bucaramanga, and Bogotá) located at 15, 959, and 2640 m above sea level, respectively. Sociodemographic data were collected, and the Spanish version of the Pediatric Sleep Questionnaire was used. RESULTS 1989 children were surveyed, distributed as follows: Santa Marta (32.0%), Bucaramanga (33.4%), and Bogotá (34.6%). The overall prevalence of sleep problems was 39.0%. Children from Santa Marta had the highest frequency of parasomnias (58.0%); those from Bucaramanga had the highest frequency of attention deficit symptoms (4.0%) and apneic pauses witnessed by parents or caregivers (5.7%). Finally, Bogotá, the only high-altitude location, had the highest frequency of sleep disordered breathing (17.2%). CONCLUSIONS The study found a high frequency of sleep problems in the pediatric population, especially at higher altitudes when compared to lower altitude settings. Sleep disorders warrant early detection and timely therapeutic intervention.
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Behavioral innovation and genomic novelty are associated with the exploitation of a challenging dietary opportunity by an avivorous bat. iScience 2022; 25:104973. [PMID: 36093062 PMCID: PMC9459691 DOI: 10.1016/j.isci.2022.104973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 06/12/2022] [Accepted: 08/15/2022] [Indexed: 11/21/2022] Open
Abstract
Foraging on nocturnally migrating birds is one of the most challenging foraging tasks in the animal kingdom. Only three bat species (e.g., Ia io) known to date can prey on migratory birds. However, how these bats have exploited this challenging dietary niche remains unknown. Here, we demonstrate that I. io hunts at the altitude of migrating birds during the bird migration season. The foraging I. io exhibited high flight altitudes (up to 4945 m above sea level) and high flight speeds (up to 143.7 km h−1). I. io in flight can actively prey on birds in the night sky via echolocation cues. Genes associated with DNA damage repair, hypoxia adaptation, biting and mastication, and digestion and metabolism have evolved to adapt to this species’ avivorous habits. Our results suggest that the evolution of behavioral innovation and genomic novelty are associated with the exploitation of challenging dietary opportunities. Predation on nocturnally migrating birds is rare and challenging in nature Bats exhibit high flight altitude and speed associated with foraging on migrating birds Bats can actively prey on birds in the night sky via echolocation cues The adaptive evolution of genes enables bats to adapt to the avivorous habits
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Wang H, Li X, Li J, Gao Y, Li W, Zhao X, Wen R, Han J, Chen K, Liu L. Sleep, short-term memory, and mood states of volunteers with increasing altitude. Front Psychiatry 2022; 13:952399. [PMID: 36311491 PMCID: PMC9600328 DOI: 10.3389/fpsyt.2022.952399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/30/2022] [Indexed: 11/24/2022] Open
Abstract
PURPOSE This study sought to identify the changes and potential association between sleep characteristics and short-term memory, and mood states among volunteers at different altitudes and times. METHOD A total of 26 healthy volunteers were recruited from the PLA General Hospital, and we conducted a longitudinal prospective survey for over 1 year from November 2019 to April 2021. First, we collected demographic data, sleep parameters by overnight polysomnography (PSG), short-term memory by digit span test, and mood states by completing a questionnaire with a brief profile of mood states among participants in the plain (53 m). Then, we continuously followed them up to collect data in the 3rd month at an altitude of 1,650 m (on the 3rd month of the 1-year survey period), the 3rd month at an altitude of 4,000 m (on the 6th month of the 1-year survey period), and the 9th month at an altitude of 4,000 m (on the 12th month of the 1-year survey period). Multiple linear regression analysis was used to construct models between sleep parameters and short-term memory, and mood states. RESULTS The prevalence of sleep apnea syndrome (SAS) significantly increased with rising elevation (P < 0.01). The apnea-hypopnea index (AHI), the mean apnea time (MAT), the longest apnea time (LAT), and the duration of time with SaO2 < 90% (TSA90) were increased (P < 0.05), and the mean pulse oxygen saturation (MSpO2), the lowest pulse oxygen saturation (LSpO2), and heart rate were significantly decreased with increasing altitude (P < 0.05). Digit span scores were decreased with increasing altitude (P < 0.001). A negative mood was more severe and a positive mood increasingly faded with rising elevation (P < 0.001). Additionally, linear correlation analysis showed that higher AHI, LAT, and MAT were strongly associated with a greater decline in short-term memory (in the 3rd and 9th month at an altitude of 4,000 m, respectively: r s = -0.897, -0.901; r s = -0.691, -0.749; r s = -0.732, -0.794, P < 0.001), and also were strongly associated with more severe negative mood (in the 3rd month at altitudes of 1,650 m and 4,000 m, respectively: r s = 0.655, 0.715, 0.724; r s = 0.771, 0.638, 0.737, P < 0.000625). Multiple linear regression pointed out that AHI was a significant predictor of negative mood among people at different altitudes (in the 3rd month at an altitude of 1,650 m: TMD = 33.161 + 6.495*AHI; in the 3rd month at an altitude of 4,000 m: TMD = 74.247 + 1.589*AHI, P < 0.05). CONCLUSION SAS developed easily in high altitudes, most often in CSA (central sleep apnea, CSA). The sleep, short-term memory, and negative mood were significantly more damaged with elevation in volunteers. Sleep parameters were closely associated with short-term memory and mood states in volunteers at high altitudes; the higher the sleep parameters (AHI, LAT, and MAT) scores, the more significant the mood disorders and the more obvious impairment of short-term memory. AHI was a critical predictor of the negative mood of volunteers at different altitudes. This study provides evidence that could help with the prevention and control of sleep disorder, cognitive disorder, and negative mood among populations with high altitudes.
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Affiliation(s)
| | - Xueyan Li
- Gansu University of Chinese Medicine, Lanzhou, China
| | - Jianhua Li
- Department of Cardiology, The Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
| | - Yinghui Gao
- PKU-UPenn Sleep Center, Peking University International Hospital, Beijing, China
| | - Weihua Li
- Gansu Armed Police Corps Hospital, Lanzhou, China
| | - Xinke Zhao
- Sleep Center, The Affiliated Hospital of Gansu University of Chinese Medicine, Lanzhou, China
| | - Ruoqing Wen
- Gansu University of Chinese Medicine, Lanzhou, China
| | - Jiming Han
- Medical College, Yan'an University, Yan'an, China
| | - Kaibing Chen
- Sleep Center, The Affiliated Hospital of Gansu University of Chinese Medicine, Lanzhou, China
| | - Lin Liu
- Department of Respiratory and Critical Care Medicine of the Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
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Ucrós Rodríguez S. Questionnaires for snoring children: Altitude matters. Pediatr Pulmonol 2021; 56:2782. [PMID: 34033696 DOI: 10.1002/ppul.25467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 05/08/2021] [Indexed: 11/08/2022]
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Ucros S, Granados C, Hill C, Castro-Rodriguez JA, Ospina JC. Normal values for respiratory sleep polygraphy in children aged 4 to 9 years at 2,560 m above sea level. J Sleep Res 2021; 30:e13341. [PMID: 33723892 DOI: 10.1111/jsr.13341] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 02/15/2021] [Accepted: 03/02/2021] [Indexed: 01/26/2023]
Abstract
Obstructive sleep apnea syndrome affects 1%-4% of all children worldwide. Currently, diagnosis of obstructive sleep apnea is based on sea-level guidelines, without taking into account the altitude at which the populations live. It has been shown that at 3,200 m of altitude there is an increase in obstructive events in healthy children aged 7 to 16 years; on the other hand, it is known that SpO2 dispersion between individuals becomes wider as altitude increases, a phenomenon that is more marked during sleep. About 17 million Colombians live in regions between 2,500 m and 2,700 m, as do significant populations in other Latin American countries. This research aimed to characterize respiratory polygraphy sleep parameters in healthy, non-snoring children aged 4-9 years living at 2,560 m. We carried out home respiratory polygraphy in 32 children with a mean age of 6.2 years (range 4-9 years). The average recorded sleep time was 7.8 h, the median apnea-hypopnea index was 9.2/h, the obstructive apnea-hypopnea index had a median of 8.8/h (p5 4.2 to p95 17.9) and central apnea a median of 0.4/h. The median SpO2 was 93% (p5 90.5 to p95 94) and transcutaneous CO2 had a median of 39.4 mmHg (p531.7 to p95 42.3). The median oxygen desaturation index ≥ 3% was 11.2 and median oxygen desaturation index ≥ 4% was 3.9. Normal measurements for respiratory polygraphy obtained at sea level do not apply to children at altitude. If such guidelines are used, obstructive sleep apnea will be over-diagnosed, resulting in unnecessary adenotonsillectomies, among other interventions.
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Affiliation(s)
- Santiago Ucros
- Pediatrics Department, Fundación Santa Fe de Bogota, Bogota, Colombia
| | - Claudia Granados
- Pediatrics Department, Pontifical Xavierian University, Bogota, Colombia
| | - Catherine Hill
- School of Clinical and Experimental Sciences, University of Southampton, Hampshire, UK
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Ucrós S, Castro-Guevara JA, Hill CM, Castro-Rodriguez JA. Breathing Patterns and Oxygenation Saturation During Sleep in Children Habitually Living at High Altitude in the Andes: A Systematic Review. Front Pediatr 2021; 9:798310. [PMID: 35295318 PMCID: PMC8918657 DOI: 10.3389/fped.2021.798310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 12/30/2021] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Human respiratory physiology changes significantly in high altitude settings and these changes are particularly marked during sleep. It is estimated that 170 million people live above 2,500 m in environments where normal sleep parameters differ from those established at sea level or low altitude. METHODS We conducted a systematic review of publications reporting sleep studies in healthy children living at high altitude. For this purpose, data from PubMed, EMBASE, SciELO and Epistemomikos bases were retrieved up to August 2021. RESULTS Six articles met specified inclusion criteria; all reporting data were from South America involving 245 children (404 sleep studies) in children aged 0.6 months to 18 years, at altitudes between 2,560 to 3,775 m. The main results were: (1) Central apnea index decreased as the age increased. (2) The obstructive apnea/hypopnea index showed a bimodal profile with an increase in young infants up to age of 4 months, decreasing to 15 months of age, and then a second peak in children aged 4 to 9 years of age, dropping in older schoolchildren and adolescents. (3) Periodic breathing in the first months of life is more marked with increasing altitude and decreases with age. CONCLUSIONS There are few studies of sleep physiology in children living at high altitude. The international parameters defining normal apnea indices currently used at low altitude cannot be applied to high altitude settings. The interpretation of sleep studies in children living at high altitude is complex because there are important developmental changes across childhood and a wide range of altitude locations. More normative data are required to determine thresholds for respiratory pathology at a variety of high altitude settings.
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Affiliation(s)
- Santiago Ucrós
- Department of Pediatrics, School of Medicine, Universidad de los Andes, Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | | | - Catherine M Hill
- School of Clinical and Experimental Sciences, University of Southampton, Hampshire, United Kingdom
| | - Jose A Castro-Rodriguez
- Department of Pediatric Pulmonology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
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Ucrós S, Granados CM, Castro-Rodríguez JA, Hill CM. Oxygen Saturation in Childhood at High Altitude: A Systematic Review. High Alt Med Biol 2020; 21:114-125. [DOI: 10.1089/ham.2019.0077] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Santiago Ucrós
- Department of Pediatrics, Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - Claudia M. Granados
- Departments of Pediatrics, Clinical Epidemiology, and Biostatistics, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - José A. Castro-Rodríguez
- Pulmonology Unit, Department of Pediatrics, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Catherine M. Hill
- School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- Southampton Children's Hospital, Southampton, United Kingdom
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10
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Hill CM, Bucks RS, Cellini N, Motamedi S, Carroll A, Heathcote K, Webster R, Simpson D. Cardiac autonomic activity during sleep in high-altitude resident children compared with lowland residents. Sleep 2019; 41:5096697. [PMID: 30219885 DOI: 10.1093/sleep/zsy181] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Indexed: 12/19/2022] Open
Abstract
Study Objectives We aimed to characterize heart-rate variability (HRV) during sleep in Andean children native to high altitude (HA) compared with age, gender, and genetic ancestry-similar low-altitude (LA) children. We hypothesized that the hypoxic burden of sleep at HA could induce variation in HRV. As children have otherwise healthy cardiovascular systems, such alterations could provide early markers of later cardiovascular disease. Methods Twenty-six LA (14F) and 18 HA (8F) children underwent a single night of attended polysomnography. Sleep parameters and HRV indices were measured. Linear mixed models were used to assess HRV differences across sleep stage and altitude group. Results All children showed marked fluctuations in HRV parameters across sleep stages, with higher vagal activity during nonrapid eye movement sleep and greater variability of the heart rate during rapid eye movement (REM). Moreover, HA children showed higher very low-frequency HRV in REM sleep and, after adjusting for heart rate, higher low-to-high frequency ratio in REM sleep compared with children living at lower altitude. Conclusions We confirmed previous findings of a stage-dependent modulation of HRV in Andean children living at both HA and LA. Moreover, we showed subtle alteration of HRV in sleep in HA children, with intriguing differences in the very low-frequency domain during REM sleep. Whether these differences are the results of an adaptation to high-altitude living, or an indirect effect of differences in oxyhemoglobin saturation remains unclear, and further research is required to address these questions.
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Affiliation(s)
- Catherine Mary Hill
- Division of Clinical Experimental Sciences, Faculty of Medicine, University of Southampton, UK.,Southampton Children's Hospital Department of Sleep Medicine, Southampton, UK.,School of Psychological Science, University of Western Australia, Perth, Australia
| | - Romola Starr Bucks
- School of Psychological Science, University of Western Australia, Perth, Australia
| | - Nicola Cellini
- Department of General Psychology, University of Padova, Veneto, Italy
| | - Shayan Motamedi
- Department of Mechanical Engineering, University of Southampton, UK
| | | | - Kate Heathcote
- Department of Otolaryngology, Poole General Hospital, UK
| | - Rebecca Webster
- Laboratory for Cancer Medicine, Harry Perkins Institute of Medical Research and University of Western Australia Centre for Medical Research, Perth, Australia
| | - David Simpson
- Institute of Sound and Vibration Research, University of Southampton, UK
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11
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The Impact of Altitude on Sleep-Related Breathing Disorders in Infants and Children. CURRENT SLEEP MEDICINE REPORTS 2019. [DOI: 10.1007/s40675-019-00137-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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12
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Human Genetic Adaptation to High Altitude: Evidence from the Andes. Genes (Basel) 2019; 10:genes10020150. [PMID: 30781443 PMCID: PMC6410003 DOI: 10.3390/genes10020150] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 01/29/2019] [Accepted: 02/11/2019] [Indexed: 12/31/2022] Open
Abstract
Whether Andean populations are genetically adapted to high altitudes has long been of interest. Initial studies focused on physiological changes in the O₂ transport system that occur with acclimatization in newcomers and their comparison with those of long-resident Andeans. These as well as more recent studies indicate that Andeans have somewhat larger lung volumes, narrower alveolar to arterial O₂ gradients, slightly less hypoxic pulmonary vasoconstrictor response, greater uterine artery blood flow during pregnancy, and increased cardiac O2 utilization, which overall suggests greater efficiency of O₂ transfer and utilization. More recent single nucleotide polymorphism and whole-genome sequencing studies indicate that multiple gene regions have undergone recent positive selection in Andeans. These include genes involved in the regulation of vascular control, metabolic hemostasis, and erythropoiesis. However, fundamental questions remain regarding the functional links between these adaptive genomic signals and the unique physiological attributes of highland Andeans. Well-designed physiological and genome association studies are needed to address such questions. It will be especially important to incorporate the role of epigenetic processes (i.e.; non-sequence-based features of the genome) that are vital for transcriptional responses to hypoxia and are potentially heritable across generations. In short, further exploration of the interaction among genetic, epigenetic, and environmental factors in shaping patterns of adaptation to high altitude promises to improve the understanding of the mechanisms underlying human adaptive potential and clarify its implications for human health.
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Hughes BH, Brinton JT, Ingram DG, Halbower AC. The Impact of Altitude on Sleep-Disordered Breathing in Children Dwelling at High Altitude: A Crossover Study. Sleep 2018; 40:3932553. [PMID: 28934528 DOI: 10.1093/sleep/zsx120] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Study Objectives Sleep-disordered breathing (SDB) is prevalent among children and is associated with adverse health outcomes. Worldwide, approximately 250 million individuals reside at altitudes higher than 2000 meters above sea level (masl). The effect of chronic high-altitude exposure on children with SDB is unknown. This study aims to determine the impact of altitude on sleep study outcomes in children with SDB dwelling at high altitude. Methods A single-center crossover study was performed to compare results of high-altitude home polysomnography (H-PSG) with lower altitude laboratory polysomnography (L-PSG) in school-age children dwelling at high altitude with symptoms consistent with SDB. The primary outcome was apnea-hypopnea index (AHI), with secondary outcomes including obstructive AHI; central AHI; and measures of oxygenation, sleep quality, and pulse rate. Results Twelve participants were enrolled, with 10 included in the final analysis. Median altitude was 1644 masl on L-PSG and 2531 masl on H-PSG. Median AHI was 2.40 on L-PSG and 10.95 on H-PSG. Both obstructive and central respiratory events accounted for the difference in AHI. Oxygenation and sleep fragmentation were worse and pulse rate higher on H-PSG compared to L-PSG. Conclusions These findings reveal a clinically substantial impact of altitude on respiratory, sleep, and cardiovascular outcomes in children with SDB who dwell at high altitude. Within this population, L-PSG underestimates obstructive sleep apnea and central sleep apnea compared to H-PSG. Given the shortage of high-altitude pediatric sleep laboratories, these results suggest a role for home sleep apnea testing for children residing at high altitude.
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Affiliation(s)
- Benjamin H Hughes
- School of Medicine, Department of Pediatrics, The University of Colorado Anschutz Medical Campus, Aurora, CO.,The Breathing Institute, Section of Pediatric Pulmonary Medicine, Children's Hospital Colorado, Aurora, CO
| | - John T Brinton
- School of Medicine, Department of Pediatrics, The University of Colorado Anschutz Medical Campus, Aurora, CO.,Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, CO
| | - David G Ingram
- Department of Pediatrics, University of Missouri Kansas City School of Medicine, Kansas City, MO.,Department of Pulmonology and Sleep Medicine, Children's Mercy Hospital, Kansas City, MO
| | - Ann C Halbower
- School of Medicine, Department of Pediatrics, The University of Colorado Anschutz Medical Campus, Aurora, CO.,The Breathing Institute, Section of Pediatric Pulmonary Medicine, Children's Hospital Colorado, Aurora, CO
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Early Detection with Pulse Oximetry of Hypoxemic Neonatal Conditions. Development of the IX Clinical Consensus Statement of the Ibero-American Society of Neonatology (SIBEN). Int J Neonatal Screen 2018; 4:10. [PMID: 33072936 PMCID: PMC7548897 DOI: 10.3390/ijns4010010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 02/11/2018] [Indexed: 11/16/2022] Open
Abstract
This article reviews the development of the Ninth Clinical Consensus Statement by SIBEN (the Ibero-American of Neonatology) on "Early Detection with Pulse Oximetry (SpO2) of Hypoxemic Neonatal Conditions". It describes the process of the consensus, and the conclusions and recommendations for screening newborns with pulse oximetry.
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15
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Gupta R, Ulfberg J, Allen RP, Goel D. Comparison of Subjective Sleep Quality of Long-Term Residents at Low and High Altitudes: SARAHA Study. J Clin Sleep Med 2018; 14:15-21. [PMID: 29198293 DOI: 10.5664/jcsm.6870] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 09/26/2017] [Indexed: 12/21/2022]
Abstract
STUDY OBJECTIVES To study the effect of altitude on subjective sleep quality in populations living at high and low altitudes after excluding cases of restless legs syndrome (RLS). METHODS This population-based study was conducted at three different altitudes (400 m, 1,900-2,000 m, and 3,200 m above sea level). All consenting subjects available from random stratified sampling in the Himalayan and sub-Himalayan regions of India were included in the study (ages 18 to 84 years). Sleep quality and RLS status were assessed using validated translations of Pittsburgh Sleep Quality Index (PSQI) and Cambridge Hopkins RLS diagnostic questionnaire. Recent medical records were screened to gather data for medical morbidities. RESULTS In the total sample of 1,689 participants included, 55.2% were women and average age of included subjects was 35.2 (± 10.9) years. In this sample, overall 18.4% reported poor quality of sleep (PSQI ≥ 5). Poor quality of sleep was reported more commonly at high altitude compared to low altitude (odds ratio [OR] = 2.65; 95% CI = 1.9-3.7; P < .001). It was more frequently reported among patients with RLS (29.7% versus 17.1% without RLS; P < .001). Other factors that were associated with poor quality of sleep were male sex, smoking, chronic obstructive pulmonary disease (COPD), and varicose veins. Binary logistic regression indicated that COPD (OR = 1.97; 95% CI = 1.36-2.86; P < .001), high altitude (OR = 2.22; 95% CI = 1.55-3.18; P < .001), and RLS (OR = 1.66; 95% CI = 1.12-2.46; P = .01) increased the odds for poor quality of sleep. CONCLUSIONS This study showed that poor quality of sleep was approximately twice as prevalent at high altitudes compared to low altitudes even after removing the potential confounders such as RLS and COPD.
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Affiliation(s)
- Ravi Gupta
- Department of Psychiatry, Himalayan Institute of Medical Sciences, Swami Ram Nagar, Jolly Grant, Dehradun, India.,Sleep Clinic, Himalayan Institute of Medical Sciences, Swami Ram Nagar, Jolly Grant, Dehradun, India
| | - Jan Ulfberg
- Sleep Clinic, Capio Medical Center, Hamnplan, Örebro, Sweden
| | - Richard P Allen
- Department of Neurology, John Hopkins University, Baltimore, Maryland
| | - Deepak Goel
- Sleep Clinic, Himalayan Institute of Medical Sciences, Swami Ram Nagar, Jolly Grant, Dehradun, India.,Department of Neurology, Himalayan Institute of Medical Sciences, Swami Ram Nagar, Jolly Grant, Dehradun, India
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Moore LG. Measuring high-altitude adaptation. J Appl Physiol (1985) 2017; 123:1371-1385. [PMID: 28860167 DOI: 10.1152/japplphysiol.00321.2017] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 08/15/2017] [Accepted: 08/15/2017] [Indexed: 12/12/2022] Open
Abstract
High altitudes (>8,000 ft or 2,500 m) provide an experiment of nature for measuring adaptation and the physiological processes involved. Studies conducted over the past ~25 years in Andeans, Tibetans, and, less often, Ethiopians show varied but distinct O2 transport traits from those of acclimatized newcomers, providing indirect evidence for genetic adaptation to high altitude. Short-term (acclimatization, developmental) and long-term (genetic) responses to high altitude exhibit a temporal gradient such that, although all influence O2 content, the latter also improve O2 delivery and metabolism. Much has been learned concerning the underlying physiological processes, but additional studies are needed on the regulation of blood flow and O2 utilization. Direct evidence of genetic adaptation comes from single-nucleotide polymorphism (SNP)-based genome scans and whole genome sequencing studies that have identified gene regions acted upon by natural selection. Efforts have begun to understand the connections between the two with Andean studies on the genetic factors raising uterine blood flow, fetal growth, and susceptibility to Chronic Mountain Sickness and Tibetan studies on genes serving to lower hemoglobin and pulmonary arterial pressure. Critical for future studies will be the selection of phenotypes with demonstrable effects on reproductive success, the calculation of actual fitness costs, and greater inclusion of women among the subjects being studied. The well-characterized nature of the O2 transport system, the presence of multiple long-resident populations, and relevance for understanding hypoxic disorders in all persons underscore the importance of understanding how evolutionary adaptation to high altitude has occurred.NEW & NOTEWORTHY Variation in O2 transport characteristics among Andean, Tibetan, and, when available, Ethiopian high-altitude residents supports the existence of genetic adaptations that improve the distribution of blood flow to vital organs and the efficiency of O2 utilization. Genome scans and whole genome sequencing studies implicate a broad range of gene regions. Future studies are needed using phenotypes of clear relevance for reproductive success for determining the mechanisms by which naturally selected genes are acting.
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Affiliation(s)
- Lorna G Moore
- Division of Reproductive Sciences, Department of Obstetrics & Gynecology, University of Colorado Denver-Anschutz Medical Campus, Aurora, Colorado
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Hill CM, Carroll A, Dimitriou D, Gavlak J, Heathcote K, L'Esperance V, Baya A, Webster R, Pushpanathan M, Bucks RS. Polysomnography in Bolivian Children Native to High Altitude Compared to Children Native to Low Altitude. Sleep 2016; 39:2149-2155. [PMID: 27634793 PMCID: PMC5103803 DOI: 10.5665/sleep.6316] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 08/02/2016] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES To compare polysomnographic parameters in high altitude (HA) native Andean children with low altitude (LA) native peers in order to explain the nocturnal oxyhemoglobin saturation (SpO2) instability reported in HA native children and to study the effect on sleep quality. METHODS Ninety-eight healthy children aged 7-10 y and 13-16 y were recruited at LA (500 m) or HA (3,650 m) above sea level. Physical examination was undertaken and genetic ancestry determined from salivary DNA to determine proportion of European ancestry, a risk factor for poor HA adaptation. Attended polysomnography was carried out over 1 night for 58 children at their resident location. RESULTS Of 98 children recruited, 85 met inclusion criteria, 58 of 85 (68.2%) completed polysomnography, of which 56 were adequate for analysis: 30 at LA (17 male) and 26 at HA (16 male). There were no altitude differences in genetic ancestry, but a high proportion of European admixture (median 50.6% LA; 44.0% HA). SpO2 was less stable at HA with mean 3% and 4% oxygen desaturation indices greater (both P < 0.001) than at LA. This was not explained by periodic breathing. However, more obstructive hypopnea was observed at HA (P < 0.001), along with a trend toward more central apnea (P = 0.053); neither was explained by clinical findings. There was no difference in sleep quality between altitudes. CONCLUSIONS HA native Andean children have more respiratory events when scoring relies on SpO2 desaturation due to inherent SpO2 instability. Use of American Academy of Sleep Medicine scoring criteria may yield false-positive results for obstructive sleep-disordered breathing at HA.
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Affiliation(s)
- Catherine Mary Hill
- Division of Clinical Experimental Sciences, Faculty of Medicine, University of Southampton, UK
- Southampton Children's Hospital, Southampton, UK
| | | | - Dagmara Dimitriou
- Lifespan Learning and Sleep Laboratory, UCL Institute of Education, UK
| | - Johanna Gavlak
- Southampton Children's Hospital, Southampton, UK
- Neurosciences Unit, UCL Institute of Child Health, UK
| | - Kate Heathcote
- Department of Otolaryngology, Poole General Hospital, UK
| | - Veline L'Esperance
- Department of Primary Care and Population Health, Kings College London, UK
| | - Ana Baya
- Department of Psychology, Universidad Privada de Santa Cruz de la Sierra, Santa Cruz, Bolivia
| | - Rebecca Webster
- Laboratory for Cancer Medicine, Harry Perkins Institute of Medical Research and University of Western Australia Centre for Medical Research, Perth, Australia
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