Relation of concavity in the expiratory flow-volume loop to dynamic hyperinflation during exercise in COPD

Varga, János; Casaburi, Richard; Ma, Shuyi; Hecht, Ariel; Hsia, David; Somfay, Attila; Pórszász, János

doi:10.1016/j.resp.2016.08.005

Cited by 38 publications

(36 citation statements)

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“…vs. 54 (44-64); p < 0.001). This particular group also performed shorter 6-minute walking distance (250 (150-330) vs. 277 (162-360); p = 0.235), they experienced worse dyspnoe on the mMRC (p = 0.714), they also had lower quality of life and they had signi cantly more exacerbations in the previous years (3 (1)(2)(3)(4)(5)(6) vs. 1 (0-3); p < 0.001) compared to those who did not suffer from MetS (Table 7).…”

Section: Resultsmentioning

confidence: 91%

“…The prevalence of MetS in the entire patient population was 59.1%: it was signi cantly more common in women (67.6%) (142/210) than in men (49.7%) (95/191; p < 0.001) ( Table 6). CRP serum levels were measured higher in patients with metabolic syndrome, however the difference was not signi cant (7.0 (2-18) vs. 5.1 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17); p = 0.064) ( Table 7). vs. 54 (44-64); p < 0.001).…”

Section: Resultsmentioning

confidence: 94%

“…Chronic obstructive pulmonary disease is a terminal disease of the respiratory system, in addition it is currently the fourth leading cause of death worldwide, however according to some predictions it will become the third leading cause of mortality until 2030 [1]. One of the most important risk factors of developing chronic obstructive pulmonary disease is smoking [2].…”

Section: Introductionmentioning

confidence: 99%

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Metabolic and Inflammatory Profile in Patients with COPD

Fekete

Szöllösi

Tarantini

et al. 2020

Preprint

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Background: In COPD, aside from obesity, decreased physical activity significantly increases the probability of developing metabolic syndrome, which can have a great impact on the natural course of COPD. Objective: The purpose of our study was to evaluate the prevalence of metabolic syndrome and whether it is related to age, sex, comorbidities, drug intake, degree of impairment of lung function, nutritional status, physical activity and quality of life. Methods: A cross-sectional study was performed on patients in Budapest at the Department of Pulmonary Rehabilitation of the National Koranyi Institute of Pulmonology between March 1, 2019 and March 1, 2020. The anthropometric and respiratory function tests and laboratory parameters of a random sample of 401 patients were known. Metabolic syndrome was determined according to IDF criteria and by definition CRP levels above 5.0 mg/L were considered elevated. Results: Metabolic syndrome occurred in 59.1% of COPD patients, male: 49.7% female: 67.6% (p <0.001). Patients with metabolic syndrome had worse FEV1%pred (43 (30-56) vs. 47 (36-61); p=0.028), lower 6MWD (250 (150-330) vs. 277 (162-360); p=0.235), lower quality of life, and significantly higher number of exacerbations (3 (1-6) vs.1 (0-3); p <0.001), than patients without metabolic syndrome. C-Reactive protein level was elevated in 55.1% of patients, higher in patients with metabolic syndrome, but the difference was not significant (7.0 (2-18) vs. 5.1 (1-17); p = 0.064). Conclusions: MetS can affect respiratory function, physical activity, quality of life and the number of exacerbations and is related to nutritional status and the level of systemic inflammation.

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Section: Resultsmentioning

confidence: 91%

Section: Resultsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

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Metabolic and Inflammatory Profile in Patients with COPD

Fekete

Szöllösi

Tarantini

et al. 2020

Preprint

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“…During exercise in COPD, as hyperinflation develops, the elastic recoil decreases lengthening the expiratory time constants of these lung units, necessitates increased intrathoracic pressure to maintain flow. Greater expiratory pressures augment gas compression and dynamic airway compression, leading to a progressive fall in expiratory flow, which manifests as concavity in the spontaneous expiratory flow-volume (SEFV) curve (Lee et al, 2016;Ma et al, 2010;Varga et al, 2016). Expiratory flow limitation contributes to dynamic hyperinflation during exercise, whereby the end-expiratory lung volume progressively increases and inspiratory capacity (IC) and inspiratory reserve volume are reduced, and which is associated with dyspnea and exercise intolerance in COPD (O'Donnell et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

“…In case of these events, the following is our working hypothesis: i) the shape of the flow-volume loop becomes concave; ii) the concavity reflects increased airway resistance; iii) reduced elastic recoil in COPD (particularly in emphysema) increases expiratory time constants, which necessitates increased intrathoracic pressure to maintain flow; this should further worsen the concavity of the flow-volume loop; iv) bronchodilation should improve this situation and, as such, it should reflect in analysis of the concavity of the flow-volume loop which could then be useful to evaluate the effects of bronchodilators. Breath-by-breath quantification of SEFV curve concavity has been used to describe progressive shape changes denoting expiratory flow limitation during incremental exercise in patients with COPD (Ma et al, 2010;Varga et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Effect of tiotropium on spontaneous expiratory flow–volume curves during exercise in GOLD 1-2 COPD

Pórszász

Carraro

Cao

et al. 2018

Respiratory Physiology & Neurobiology

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This substudy of a large, randomized, controlled trial (NCT01072396) examined tiotropium (18 μg qd) effects on dynamic hyperinflation during constant work rate treadmill exercise. Areas-under-the-spontaneous expiratory flow-volume (SEFV)-curves were compared in 20 COPD patients and 16 age-matched untreated controls, using rectangular area ratio (RAR) between peak intrabreath and end-expiratory flow. Seven patients exhibited SEFV curve concavity with RAR ≤ 0.5 (RAR) in ≥1 test without tiotropium; (mean ± SD FEV: 1.60 ± 0.59 L; 63.4 ± 14.0%predicted). In RAR patients, tiotropium increased end-exercise inspiratory capacity (IC, 2.10 ± 0.05 vs. 1.89 ± 0.05 L, tiotropium vs. placebo; p = 0.045) and RAR (0.57 ± 0.02 vs. 0.53 ± 0.02; p < 0.001). Patients without SEFV curve concavity with RAR > 0.5 (n = 13; RAR), had higher screening FEV (2.15 ± 0.47 L; 79.6 ± 10.1%predicted) versus RAR patients and no difference in end-exercise IC and RAR between tiotropium and placebo (IC: 2.24 ± 0.03 vs. 2.17 ± 0.03 L; RAR: 0.63 ± 0.005 vs. 0.62 ± 0.005). RAR and%predicted IC at peak exercise were positively correlated in RAR patients (R = 0.43, p = 0.0002). Tiotropium increased exercise RAR in GOLD 1-2 patients with SEFV curve concavity.

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Lung Volume Measurement

Zhou

Jian-xin

2021

Respiratory Monitoring in Mechanical Ventilation

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Relation of concavity in the expiratory flow-volume loop to dynamic hyperinflation during exercise in COPD

Cited by 38 publications

References 24 publications

Metabolic and Inflammatory Profile in Patients with COPD

Metabolic and Inflammatory Profile in Patients with COPD

Effect of tiotropium on spontaneous expiratory flow–volume curves during exercise in GOLD 1-2 COPD

Lung Volume Measurement

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