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Diekman CO, Thomas PJ, Wilson CG. COVID-19 and silent hypoxemia in a minimal closed-loop model of the respiratory rhythm generator. BIOLOGICAL CYBERNETICS 2024; 118:145-163. [PMID: 38884785 PMCID: PMC11289179 DOI: 10.1007/s00422-024-00989-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 03/28/2024] [Indexed: 06/18/2024]
Abstract
Silent hypoxemia, or "happy hypoxia," is a puzzling phenomenon in which patients who have contracted COVID-19 exhibit very low oxygen saturation ( SaO 2 < 80%) but do not experience discomfort in breathing. The mechanism by which this blunted response to hypoxia occurs is unknown. We have previously shown that a computational model of the respiratory neural network (Diekman et al. in J Neurophysiol 118(4):2194-2215, 2017) can be used to test hypotheses focused on changes in chemosensory inputs to the central pattern generator (CPG). We hypothesize that altered chemosensory function at the level of the carotid bodies and/or the nucleus tractus solitarii are responsible for the blunted response to hypoxia. Here, we use our model to explore this hypothesis by altering the properties of the gain function representing oxygen sensing inputs to the CPG. We then vary other parameters in the model and show that oxygen carrying capacity is the most salient factor for producing silent hypoxemia. We call for clinicians to measure hematocrit as a clinical index of altered physiology in response to COVID-19 infection.
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Affiliation(s)
- Casey O Diekman
- Department of Mathematical Sciences, New Jersey Institute of Technology, University Heights, Newark, NJ, 07102, USA.
| | - Peter J Thomas
- Department of Mathematics, Applied Mathematics and Statistics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Christopher G Wilson
- Department of Pediatrics and Basic Sciences, Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University, 11223 Campus St, Loma Linda, CA, 92350, USA
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Esteban C, Antón-Ladislao A, Aramburu A, Chasco L, Orive M, Sobradillo P, López-Roldan L, Jiménez-Puente A, de Miguel J, García-Talavera I, Quintana JM. Physical activity and sedentary behaviour in patients admitted with COPD: Associated factors. Respir Med Res 2023; 84:101052. [PMID: 37897880 DOI: 10.1016/j.resmer.2023.101052] [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] [Received: 12/30/2022] [Revised: 07/22/2023] [Accepted: 09/26/2023] [Indexed: 10/30/2023]
Abstract
AIM To establish amongst a cohort of patients admitted with Chronic Obstructive Pulmonary Disease which factors were associated with their level of Physical Activity and Sedentary Behavior prior to the admission event. METHODS Prospective observational cohort study. Nine Spanish hospitals participated. Patients were recruited consecutively. Variables relating to the patients' clinical baseline status were recorded, including the COPD Assessment test, the HADS anxiety-depression test, comorbidities and the Yale Physical Activity Survey. Data relating to admission and up to two months after discharge were also recorded. RESULTS 1638 COPD patients were studied, with a mean age of 72.39 (SD 10.33), 76.56 % male, FEV1 49.41 % (SD19.19), Charlson index 2. The level of PA at baseline was 30.79 points (SD 22.43). Multivariable linear regression analysis identified the following as being associated with low PA: older age, obesity, higher level of hemoglobin, lower score of Barthel index, which means disability, health related quality of life (EuroQoL-5d and CAT) and dyspnea. Variables associated with sedentary behavior were: older age, presence of obstructive apnea syndrome, higher disability, presence of depressive symptoms and dyspnea. CONCLUSIONS In a cohort of hospitalized COPD patients, we have found several variables, some of them modifiable, associated with physical activity/inactivity and sedentary behavior.
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Affiliation(s)
- Cristóbal Esteban
- Respiratory Department, Hospital Galdakao, Galdakao, Bizkaia, Spain; BioCruces-Bizkaia Health Research Institute, Barakaldo, Spain; Health Services Research on Chronic Patients Network (REDISSEC), Spain; Red de Investigación en Cronicidad, Atención Primaria y Promoción de la Salud (RICAPPS), Spain.
| | - Ane Antón-Ladislao
- Research Unit, Hospital Galdakao, Galdakao, Bizkaia, Spain; Health Services Research on Chronic Patients Network (REDISSEC), Spain
| | - Amaia Aramburu
- Respiratory Department, Hospital Galdakao, Galdakao, Bizkaia, Spain; BioCruces-Bizkaia Health Research Institute, Barakaldo, Spain
| | - Leyre Chasco
- Respiratory Department, Hospital Galdakao, Galdakao, Bizkaia, Spain; BioCruces-Bizkaia Health Research Institute, Barakaldo, Spain
| | - Miren Orive
- Departamento Psicología Social, Facultad Farmacia, UPV/EHU, Vitoria-Gasteiz, Spain; Health Services Research on Chronic Patients Network (REDISSEC), Spain; Red de Investigación en Cronicidad, Atención Primaria y Promoción de la Salud (RICAPPS), Spain
| | - Patricia Sobradillo
- Servicio de Respiratorio, Hospital Cruces, Barakaldo, Spain; BioCruces-Bizkaia Health Research Institute, Barakaldo, Spain
| | | | - Alberto Jiménez-Puente
- Unidad de Evaluación, Hospital Costa del Sol, Marbella, Malaga, Spain; Health Services Research on Chronic Patients Network (REDISSEC), Spain; Red de Investigación en Cronicidad, Atención Primaria y Promoción de la Salud (RICAPPS), Spain
| | - Javier de Miguel
- Servicio de Respiratorio, Hospital Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM)., Madrid, Spain; Health Services Research on Chronic Patients Network (REDISSEC), Spain; Red de Investigación en Cronicidad, Atención Primaria y Promoción de la Salud (RICAPPS), Spain
| | - Ignacio García-Talavera
- Servicio de Respiratorio, Hospital Nuestra Señora de la Candelaria, Santa Cruz de Tenerife, Spain; Health Services Research on Chronic Patients Network (REDISSEC), Spain; Red de Investigación en Cronicidad, Atención Primaria y Promoción de la Salud (RICAPPS), Spain
| | - José M Quintana
- Research Unit, Hospital Galdakao, Galdakao, Bizkaia, Spain; Health Services Research on Chronic Patients Network (REDISSEC), Spain; Kronikgune Research Institute, Barakaldo, Spain; Red de Investigación en Cronicidad, Atención Primaria y Promoción de la Salud (RICAPPS), Spain
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Ma H, Yang L, Liu L, Zhou Y, Guo X, Wu S, Zhang X, Xu X, Ti X, Qu S. Using inflammatory index to distinguish asthma, asthma-COPD overlap and COPD: A retrospective observational study. Front Med (Lausanne) 2022; 9:1045503. [PMID: 36465915 PMCID: PMC9714673 DOI: 10.3389/fmed.2022.1045503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/03/2022] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND Although asthma and chronic obstructive pulmonary disease (COPD) are two well-defined and distinct diseases, some patients present combined clinical features of both asthma and COPD, particularly in smokers and the elderly, a condition termed as asthma-COPD overlap (ACO). However, the definition of ACO is yet to be established and clinical guidelines to identify and manage ACO remain controversial. Therefore, in this study, inflammatory biomarkers were established to distinguish asthma, ACO, and COPD, and their relationship with the severity of patients' symptoms and pulmonary function were explored. MATERIALS AND METHODS A total of 178 patients, diagnosed with asthma (n = 38), ACO (n = 44), and COPD (n = 96) between January 2021 to June 2022, were enrolled in this study. The patients' pulmonary function was examined and routine blood samples were taken for the analysis of inflammatory indexes. Logistic regression analysis was used to establish inflammatory biomarkers for distinguishing asthma, ACO, and COPD; linear regression analysis was used to analyze the relationship between inflammatory indexes and symptom severity and pulmonary function. RESULT The results showed that, compared with ACO, the higher the indexes of platelet, neutrophil-lymphocyte ratio (NLR) and eosinophil-basophil ratio (EBR), the more likely the possibility of asthma and COPD in patients, while the higher the eosinophils, the less likely the possibility of asthma and COPD. Hemoglobin and lymphocyte-monocyte ratio (LMR) were negatively correlated with the severity of patients' symptoms, while platelet-lymphocyte ratio (PLR) was negatively correlated with forced expiratory volume in the 1 s/forced vital capacity (FEV1/FVC) and FEV1 percent predicted (% pred), and EBR was positively correlated with FEV1% pred. CONCLUSION Inflammatory indexes are biomarkers for distinguishing asthma, ACO, and COPD, which are of clinical significance in therapeutic strategies and prognosis evaluation.
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Affiliation(s)
- Haiman Ma
- Department of Pulmonary and Critical Care Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Liu Yang
- Department of Clinical Laboratory, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Lingli Liu
- Department of Pulmonary and Critical Care Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Ying Zhou
- Department of Pulmonary and Critical Care Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Xiaoya Guo
- Department of Pulmonary and Critical Care Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Shuo Wu
- Department of Pulmonary and Critical Care Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Xiaoxiao Zhang
- Department of Pulmonary and Critical Care Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Xi Xu
- Department of Pulmonary and Critical Care Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Xinyu Ti
- Department of Pulmonary and Critical Care Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Shuoyao Qu
- Department of Pulmonary and Critical Care Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
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The role of iron in chronic inflammatory diseases: from mechanisms to treatment options in anemia of inflammation. Blood 2022; 140:2011-2023. [PMID: 35994752 DOI: 10.1182/blood.2021013472] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 08/09/2022] [Indexed: 11/20/2022] Open
Abstract
Anemia of inflammation (AI) is a highly prevalent comorbidity in patients affected by chronic inflammatory disorders, such as chronic kidney disease, inflammatory bowel disease, or cancer, that negatively affect disease outcome and quality of life. The pathophysiology of AI is multifactorial, with inflammatory hypoferremia and iron-restricted erythropoiesis playing a major role in the context of disease-specific factors. Here, we review the recent progress in our understanding of the molecular mechanisms contributing to iron dysregulation in AI, the impact of hypoferremia and anemia on the course of the underlying disease, and (novel) therapeutic strategies applied to treat AI.
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Alisamir M, Ebrahimi M, Rahim F. Anemia in chronic obstructive pulmonary disease: A systematic review. Respir Investig 2022; 60:510-521. [PMID: 35484075 DOI: 10.1016/j.resinv.2022.03.006] [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] [Received: 02/24/2022] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 06/14/2023]
Abstract
INTRODUCTION Chronic obstructive pulmonary disease (COPD) is a type of obstructive lung disease that is characterized by poor airflow and airway inflammation. It is estimated that the global prevalence of COPD is about 13.1%. Anemia is associated with increased morbidity and hospitalization duration. In this systematic review, we investigate the association between all types of anemia and COPD progression. METHODS We systematically searched electronic databases, including Scopus, Medline/PubMed, EMBASE, Web of Sciences (WOS), and Cochrane Library, using the following mesh-standardized keywords: (((anemia∗ OR anaemia∗) OR "chronic anemia disease" [Mesh] OR "CAD" OR "iron deficiency anemia" OR" IDA" OR) AND ("COPD" [Mesh] OR "chronic obstructive pulmonary disease")) until February 2022. RESULTS Overall of 11,158 studies were included. Ultimately, 59 studies were included in the analysis. The most apparent findings from the analysis were that exacerbation of COPD, increased hospitalization, and increased long-term mortality were associated with anemia. Further analysis showed that iron deficiency (ID) is a common finding in COPD and is accompanied by an increase in the systolic pulmonary artery pressure. CONCLUSION Despite the comfortable control of anemia, the absence of treatment can be life-threatening in patients with COPD. Our systematic results showed significant homogeneity between studies on the increased mortality rate in anemic COPD, increased hospitalization, and decreased quality of life.
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Affiliation(s)
- Mohsen Alisamir
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mina Ebrahimi
- Thalassemia and Hemoglobinopathy Research Center, Research Institute of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Fakher Rahim
- Thalassemia and Hemoglobinopathy Research Center, Research Institute of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
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Correlation Analysis between Hemoglobin and C-Reactive Protein in Patients Admitted to an Emergency Unit. J Clin Med 2021; 10:jcm10225411. [PMID: 34830693 PMCID: PMC8622244 DOI: 10.3390/jcm10225411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/13/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022] Open
Abstract
Anemia and inflammation are common clinical conditions in emergency departments. This study explored a cohort of patients admitted to the emergency department with a particular interest in determining the frequency of anemia and inflammation and the association between hemoglobin (Hb) and C-reactive protein (CRP) concentrations. The study included 125 patients categorized according to their demographic (gender and age) and clinical condition (Hb and CRP concentrations, pathological background, and diagnostic). We found that anemia and inflammation were simultaneously present in 36.0% of the cohort, reaching 67.0% in patients that were subsequently hospitalized. The Hb level was significantly lower in patients with elevated concentration of CRP when compared to individuals with normal CRP levels (11.58 ± 2.23 vs. 13.25 ± 1.80, p = 0.001); furthermore, we found a significantly negative correlation between Hb concentration and the CRP level (rs = −0.42, p < 0.001). The linear regression model applied to the cohort showed that CRP levels explain 15% of Hb variations. The sensitivity of the CRP/Hb ratio (cut-off = 1.32) as a predictor of hospitalization was 80.0%, with a specificity of 68.4% for all patients. These findings confirmed the prevalence of anemia and inflammation and identified a moderate but significant association between Hb and serum CRP in a heterogeneous group of patients admitted to the emergency department.
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