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González-García, Mauricio and Luis Ernesto Téllez. Adaptation to living at high altitude in patients with COPD. Comparative study of exercise capacity and ventilatory variables between patients residing at high and low altitudes in the Andes. High Alt Med Biol . 25:266-273, 2024. Introduction: Although some variables related to oxygen transport and utilization such as ventilation, pulmonary vascular responses to hypoxia, heart rate (HR), cardiac output, hemoglobin (Hb), and oxygen saturation (SpO 2 ) are used to compare adaptation to altitude between populations, peak oxygen consumption (VO 2 ) constitutes an integrative measure of total oxygen transport that may reflect successful adaptation to altitude. We designed this study to make a direct comparison of VO 2 in a cardiopulmonary exercise test (CPET) between chronic obstructive pulmonary disease (COPD) patients residing at high altitude (Bogotá, Colombia: 2,640 m) (COPD-HA) and those living at low altitude (Bucaramanga, Colombia: 959 m) (COPD-LA). Methods: All patients performed a CPET with measurements of VO 2 , minute ventilation (V E ), HR, oxygen pulse (VO 2 /HR), ventilatory equivalents (V E /VCO 2 ), and SpO 2 . Unpaired T-test or Mann-Whitney U test were used for comparisons between COPD-HA and COPD-LA. Results: We included 71 patients with COPD, 53 COPD-HA, and 18 COPD-LA. There were no differences between groups in age, sex, or forced expiratory volume in 1 second. The means ± SD of Hb, g/dl was slightly higher in COPD-HA (15.9 ± 1.9 vs. 14.7 ± 1.8, p = 0.048), without differences in VO 2 , % pred (71.6 ± 17.9 vs. 69.0 ± 17.0, p = 0.584), VO 2 /HR, % pred (92.1 ± 22.0 vs. 89.7 ± 19.8, p = 0.733) or V E /MVV, % (75.5 ± 14.1 vs. 76.5 ± 14.3, p = 0.790) at peak exercise between groups. Median (IQR) of V E /VCO 2 nadir [38.0 (37.0-42.0) vs. 32.5 (31.0-39.0), p = 0.005] was significantly higher, and SpO 2 , % at rest [88.0 (86.0-91.0) vs. 95.0 (94.0-96.0), p < 0.001] and at peak exercise [84.0 (77.0-90.0) vs. 93.0 (92.0-95.0), p < 0.001] were significantly lower in COPD-HA. Conclusions: Despite higher desaturation at rest and during exercise in COPD-HA, there were no differences in VO 2 peak between COPD-HA and COPD-LA, suggesting a potential altitude adaptation in those patients chronically exposed to hypoxia.

Introduction: There is a need to better understand the etiotypes of chronic obstructive pulmonary disease (COPD) beyond the tobacco-smoke (TS-COPD). Wood smoke COPD (WS-COPD) is characterized by greater airway compromise, milder emphysema, and slower rate of lung function decline than TS-COPD. However, it is unclear if these two etiotypes of COPD have differences in sputum biomarker concentrations. Objective was to compare sputum levels of selected sputum biomarkers between WS-COPD and TS-COPD, and healthy controls., Methods: Eighty-eight women (69±12 years) were recruited and classified into: WS-COPD (n=31), TS-COPD (n=29) and controls (n=28). Using ELISA, we determined induced sputum levels of metalloproteinase 9 (MMP-9), chemokine ligand 5 (CCL5), interleukin-8 (IL-8), chemokine ligand 16 (CCL16/HCC-4) and vascular endothelial growth factor (VEGF-1). Differences were analyzed by Kruskal-Wallis and Mann-Whitney- U tests and correlation between airflow limitation and biomarkers by Spearman's test., Results: At similar degree of airflow obstruction, anthropometrics and medications use, the level of sputum CCL5 was higher in TS-COPD than WS-COPD (p=0.03) without differences in MMP-9, IL-8, CCL16/HCC-4, and VEGF-1. Women with WS-COPD and TS-COPD showed significantly higher sputum levels of MMP-9, IL-8 and CCL5 compared with controls (p<0.001). FEV 1 % predicted correlated negatively with levels of MMP-9 (rho:-0.26; P=0.016), CCL5 (rho:-0.37; P=0.001), IL-8 (rho:-0.42; P<0.001) and VEGF (rho:-0.22; P=0.04)., Conclusion: While sputum concentrations of MMP-9, IL-8, and CCL5 were higher in COPD women compared with controls, women with TS-COPD had higher levels of CCL5 compared with those with WS-COPD. Whether this finding relates to differences in pathobiological pathways remains to be determined., Competing Interests: Dr Luis F Giraldo-Cadavid reports grants from Universidad de La Sabana, during the conduct of the study. Dr Maria E Laucho-Contreras is an Employee & Shareholder of GSK, outside the submitted work. All other authors declare that they have no competing interests in this work., (© 2024 Giraldo-Montoya et al.)

Purpose: To compare the level of knowledge in vaccination against influenza and pneumococcus of patients with chronic obstructive pulmonary disease (COPD) who are managed in an Integrated Care Program (ICP) with those who receive usual care (UC)., Methods: A telephone survey of patients diagnosed with COPD registered in public care networks or private institutions was done. A descriptive and comparative analysis of the characteristics of the ICP and UC groups was carried out. The relationship between belonging to an ICP and the level of knowledge about vaccination was evaluated using Propensity Score Matching (PSM) and multivariate logistic and ordinal regression models., Results: Of 674 study participants, 27.2% were from the ICP group. ICP patients were older, more frequently men, from a higher socioeconomic stratum and a higher educational level (p<0.05). 75.5% of the patients in the ICP group had a high level of vaccination knowledge compared to 42.7% in the UC group (p<0.001). In the multivariate analysis, adjusting for sociodemographic variables, years of COPD diagnosis, and comorbidities, belonging to the ICP was associated with a higher probability of answering questions about vaccination correctly and having a high level of knowledge (OR 3.397, IC 95% 2.058-5.608, p<0.001)., Conclusion: Patients with COPD managed in an ICP have a higher level of knowledge in vaccination against influenza and pneumococcus, compared to patients in usual care., Competing Interests: The authors report no conflicts of interest in this work., (© 2023 Proaños et al.)

Chronic obstructive pulmonary disease (COPD) is a complex and heterogeneous entity that may result from different causative agents and risk factors and may follow diverse clinical courses, including COPD secondary to biomass smoke exposure. At present, this phenotype is becoming more important for two reasons: first, because at least almost half of the world's population is exposed to biomass smoke, and second, because the possibility of it being diagnosed is increasing. Biomass smoke exposure COPD affects primarily women and is related with insults to the airways occurred during early life. Although constituents of biomass smoke and tobacco smoke are similar, the physiopathological changes they induce differ depending not only on the chemical composition (related with the type of fuel used) but also on the particle size and the inhalation pattern. Evidence has shown that biomass smoke exposure affects the airway, predominantly the small airways causing anthracofibrosis and peribronchiolar fibrosis changes that will clinically translate into chronic bronchitis symptoms, with a high impact on the quality of life. In this review, we focus especially on the main epidemiological and clinical differences between COPD secondary to biomass exposure and COPD caused by tobacco exposure., (Copyright: © 2019 SecretarÍa de Salud.)

Background: COPD prevalence is highly variable and geographical altitude has been linked to it, yet with conflicting results. We aimed to investigate this association, considering well known risk factors., Methods: A pooled analysis of individual data from the PREPOCOL-PLATINO-BOLD-EPI-SCAN studies was used to disentangle the population effect of geographical altitude on COPD prevalence. Post-bronchodilator FEV1/FVC below the lower limit of normal defined airflow limitation consistent with COPD. High altitude was defined as >1500 m above sea level. Undiagnosed COPD was considered when participants had airflow limitation but did not report a prior diagnosis of COPD., Results: Among 30,874 participants aged 56.1 ± 11.3 years from 44 sites worldwide, 55.8% were women, 49.6% never-smokers, and 12.9% (3978 subjects) were residing above 1500 m. COPD prevalence was significantly lower in participants living at high altitude with a prevalence of 8.5% compared to 9.9%, respectively (p < 0.005). However, known risk factors were significantly less frequent at high altitude. Hence, in the adjusted multivariate analysis, altitude itself had no significant influence on COPD prevalence. Living at high altitude, however, was associated with a significantly increased risk of undiagnosed COPD. Furthermore, subjects with airflow limitation living at high altitude reported significantly less respiratory symptoms compared to subjects residing at lower altitude., Conclusion: Living at high altitude is not associated with a difference in COPD prevalence after accounting for individual risk factors. However, high altitude itself was associated with an increased risk of undiagnosed COPD.

Around 40% of the world's population continue using solid fuel, including wood, for cooking or heating their homes. Chronic exposure to wood smoke is a risk factor for developing chronic obstructive pulmonary disease (COPD). In some regions of the world, this can be a more important cause of COPD than exposure to tobacco smoke from cigarettes. Significant differences between COPD associated with wood smoke (W-COPD) and that caused by smoking (S-COPD) have led some authors to suggest that W-COPD should be considered a new COPD phenotype. We present a review of the differences between W-COPD and S-COPD. On the premise that wood smoke and tobacco smoke are not the same and the physiopathological mechanisms they induce may differ, we have analyzed whether W-COPD can be considered as another COPD phenotype or a distinct nosological entity., (Copyright © 2016 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.)

Background: COPD ranks within the top three causes of mortality in the global burden of disease, yet it remains largely underdiagnosed. We assessed the underdiagnosis of COPD and its determinants in national and international surveys of general populations., Methods: We analyzed representative samples of adults aged ≥ 40 years randomly selected from well-defined administrative areas worldwide (44 sites from 27 countries). Postbronchodilator FEV1/FVC < lower limit of normal (LLN) was used to define chronic airflow limitation consistent with COPD. Undiagnosed COPD was considered when participants had postbronchodilator FEV1/FVC < LLN but were not given a diagnosis of COPD., Results: Among 30,874 participants with a mean age of 56 years, 55.8% were women, and 22.9% were current smokers. Population prevalence of (spirometrically defined) COPD ranged from 3.6% in Barranquilla, Colombia, to 19.0% in Cape Town, South Africa. Only 26.4% reported a previous lung function test, and only 5.0% reported a previous diagnosis of COPD, whereas 9.7% had a postbronchodilator FEV1/FVC < LLN. Overall, 81.4% of (spirometrically defined) COPD cases were undiagnosed, with the highest rate in Ile-Ife, Nigeria (98.3%) and the lowest rate in Lexington, Kentucky (50.0%). In multivariate analysis, a greater probability of underdiagnosis of COPD was associated with male sex, younger age, never and current smoking, lower education, no previous spirometry, and less severe airflow limitation., Conclusions: Even with substantial heterogeneity in COPD prevalence, COPD underdiagnosis is universally high. Because effective management strategies are available for COPD, spirometry can help in the diagnosis of COPD at a stage when treatment will lead to better outcomes and improved quality of life.

Background: At Bogota's altitude (2640 m), the lower barometric pressure (560 mmHg) causes severe hypoxemia in COPD patients, limiting their exercise capacity. The aim was to compare the effects of breathing oxygen on exercise tolerance., Methods: In a blind, crossover clinical study, 29 COPD patients (FEV1 42.9 ± 11.9%) breathed room air (RA) or oxygen (FIO2 28% and 35%) during three treadmill exercise tests at 70% of their maximal capacity in a randomized order. Endurance time (ET), inspiratory capacity (IC), arterial blood gases and lactate were compared., Results: At the end of the exercise breathing RA, the ET was 9.7 ± 4.2 min, the PaO2 46.5 ± 8.2 mmHg, the lactate increased and the IC decreased. The oxygen significantly increased the ET (p < 0.001), without differences between 28% (16.4 ± 6.8 min) and 35% (17.6 ± 7.0 min) (p = 0.22). Breathing oxygen, there was an increase in the PaO2 and SaO2, higher with FIO2 35%, and a decrease in the lactate level. At "isotime" (ET at RA), with oxygen, the SpO2, the oxygen pulse and the IC were higher and the heart rate lower than breathing RA (p < 0.05)., Conclusion: Oxygen administration for COPD patients in Bogotá significantly increased ET by decreased respiratory load, improved cardiovascular performance and oxygen transport. The higher increases of the PaO2 and SaO2 with 35% FIO2 did not represent a significant advantage in the ET. This finding has important logistic and economic implications for oxygen use in rehabilitation programs of COPD patients at the altitude of Bogotá and similar altitudes.

Objective: Wood smoke exposure is a risk factor for COPD. For a given degree of airway obstruction, the reduction in DLCO is smaller in individuals with wood smoke-related COPD than in those with smoking-related COPD, suggesting that there is less emphysema in the former. The objective of this study was to compare HRCT findings between women with wood smoke-related COPD and women with smoking-related COPD., Methods: Twenty-two women with severe COPD (FEV₁/FVC ratio < 70% and FEV₁ < 50%) were divided into two groups: those with wood smoke-related COPD (n = 12) and those with smoking-related COPD (n = 10). The two groups were compared regarding emphysema scores and airway involvement (as determined by HRCT); and functional abnormalities-spirometry results, DLCO, alveolar volume (VA), the DLCO/VA ratio, lung volumes, and specific airway resistance (sRaw)., Results: There were no significant differences between the two groups in terms of FEV₁, sRaw, or lung hyperinflation. Decreases in DLCO and in the DLCO/VA ratio were greater in the smoking-related COPD group subjects, who also had higher emphysema scores, in comparison with the wood smoke-related COPD group subjects. In the wood smoke-related COPD group, HRCT scans showed no significant emphysema, the main findings being peribronchial thickening, bronchial dilation, and subsegmental atelectasis., Conclusions: Female patients with severe wood smoke-related COPD do not appear to develop emphysema, although they do show severe airway involvement. The reduction in DLCO and VA, with a normal DLCO/VA ratio, is probably due to severe bronchial obstruction and incomplete mixing of inspired gas during the determination of single-breath DLCO.

Purpose: Chronic obstructive pulmonary disease (COPD) related to wood smoke exposure is characterized by important inflammation of the central and peripheral airways without significant emphysema. The objective of this study is to describe the bronchial hyperresponsiveness (BHR) level in women with COPD related to wood smoke exposure and to compare it with the BHR in women with COPD related to tobacco smoking., Materials and Methods: TWO GROUPS OF WOMEN WITH STABLE COPD WERE STUDIED: (1) wood smoke exposed (WS-COPD); and (2) tobacco smoke exposed (TS-COPD). A methacholine challenge test (MCT) was performed in all patients according to American Thoracic Society criteria. BHR levels were compared using the methacholine concentration, which caused a 20% fall in the FEV1 (PC20)., Results: Thirty-one patients, 19 with WS-COPD and 12 with TS-COPD, were included. There were no significant differences between the groups in baseline FVC, FEV1, IC, FEF25-75, and FEF25-75/FVC. All 31 patients had a positive MCT (PC20<16 mg/mL) and the fall in the FEV1 and IC was similar in both groups. The severity of BHR was significantly higher in the WS-COPD patients (PC20: 0.39 mg/mL) than in the TS-COPD patients (PC20: 1.24 mg/mL) (P=0.028). The presence of cough, phlegm, and dyspnea during the test were similar in both groups., Conclusion: We found moderate to severe BHR in women with WS-COPD, which was more severe than in the TS-COPD women with similar age and airflow obstruction. This paper suggests that the structural and inflammatory changes induced by the chronic exposure to wood smoke, described in other studies, can explain the differences with TS-COPD patients. Future studies may clarify our understanding of the impact of BHR on COPD physiopathology, phenotypes, and treatment strategies.

Objective: To describe the response to exercise of normal subjects and patients with chronic obstructive pulmonary disease (COPD) in Bogota, Colombia (altitude: 2640 m; atmospheric pressure: 560 mm Hg) and compare it with data published on COPD patients at sea level. Healthy people increase their minute ventilation to attenuate hypoxemia (PaCO2: 30 mm Hg; PaO2: 63 mm Hg)., Material and Method: A descriptive study was carried out on healthy subjects and COPD patients. Exercise limitation was determined by an incremental test on a cycle ergometer., Results: The study enrolled 16 healthy subjects and 25 COPD patients (forced expiratory volume in 1 second: 43.3% [SD 13%]). Minute ventilation at rest was greater in COPD patients compared with healthy subjects, it was not adequately sustained during exercise, and there was a reduction in peak oxygen uptake (53.0% [15%]). At peak exercise, inspiratory capacity decreased (-0.62 [0.34] L), the ratio of minute ventilation to maximal voluntary ventilation increased, and severe hypoxemia occurred (PaO2: 49.9 [9.9] mm Hg). There was significant correlation between hypoxemia and the percentage of predicted peak oxygen uptake (r=0.60), leg fatigue (r=-0.62), percentage of predicted peak inspiratory capacity (r=0.61), and the percentage of predicted peak tidal volume (r=0.49). Minute ventilation at rest was shown to be higher, there was a greater reduction in the inspiratory capacity during exercise, and hypoxemia was more severe at rest and during exercise for patients with COPD in Bogota, compared with those at sea level., Conclusions: Patients with COPD living in Bogota were shown to have lower tolerance to exercise evidenced by ventilatory limitation and severe hypoxemia. Increased minute ventilation at rest, greater reduction in inspiratory capacity, and severity of hypoxemia during exercise were the main differences between COPD in Bogota and at sea level.