scholarly journals Dismantling airway disease with the use of new pulmonary function indices

2019 ◽  
Vol 28 (151) ◽  
pp. 180122 ◽  
Author(s):  
Sabine C. Zimmermann ◽  
Katrina O. Tonga ◽  
Cindy Thamrin

We are currently limited in our abilities to diagnose, monitor disease status and manage chronic airway disease like asthma and chronic obstructive pulmonary disease (COPD). Conventional lung function measures often poorly reflect patient symptoms or are insensitive to changes, particularly in the small airways where disease may originate or manifest. Novel pulmonary function tests are becoming available which help us better characterise and understand chronic airway disease, and their translation and adoption from the research arena would potentially enable individualised patient care.In this article, we aim to describe two emerging lung function tests yielding novel pulmonary function indices, the forced oscillation technique (FOT) and multiple breath nitrogen washout (MBNW). With a particular focus on asthma and COPD, this article demonstrates how chronic airway disease mechanisms have been dismantled with the use of the FOT and MBNW. We describe their ability to assess detailed pulmonary mechanics for diagnostic and management purposes including response to bronchodilation and other treatments, relationship with symptoms, evaluation of acute exacerbations and recovery, and telemonitoring. The current limitations of both tests, as well as open questions/directions for further research, are also discussed.

Diagnostics ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 33 ◽  
Author(s):  
Joshua Gawlitza ◽  
Timo Sturm ◽  
Kai Spohrer ◽  
Thomas Henzler ◽  
Ibrahim Akin ◽  
...  

Introduction: Quantitative computed tomography (qCT) is an emergent technique for diagnostics and research in patients with chronic obstructive pulmonary disease (COPD). qCT parameters demonstrate a correlation with pulmonary function tests and symptoms. However, qCT only provides anatomical, not functional, information. We evaluated five distinct, partial-machine learning-based mathematical models to predict lung function parameters from qCT values in comparison with pulmonary function tests. Methods: 75 patients with diagnosed COPD underwent body plethysmography and a dose-optimized qCT examination on a third-generation, dual-source CT with inspiration and expiration. Delta values (inspiration—expiration) were calculated afterwards. Four parameters were quantified: mean lung density, lung volume low-attenuated volume, and full width at half maximum. Five models were evaluated for best prediction: average prediction, median prediction, k-nearest neighbours (kNN), gradient boosting, and multilayer perceptron. Results: The lowest mean relative error (MRE) was calculated for the kNN model with 16%. Similar low MREs were found for polynomial regression as well as gradient boosting-based prediction. Other models led to higher MREs and thereby worse predictive performance. Beyond the sole MRE, distinct differences in prediction performance, dependent on the initial dataset (expiration, inspiration, delta), were found. Conclusion: Different, partially machine learning-based models allow the prediction of lung function values from static qCT parameters within a reasonable margin of error. Therefore, qCT parameters may contain more information than we currently utilize and can potentially augment standard functional lung testing.


1995 ◽  
Vol 151 (1) ◽  
pp. 61-65 ◽  
Author(s):  
D A Mahler ◽  
D Tomlinson ◽  
E M Olmstead ◽  
A N Tosteson ◽  
G T O'Connor

2011 ◽  
Vol 80 (2) ◽  
pp. e157-e163 ◽  
Author(s):  
Hiroaki Arakawa ◽  
Kiminori Fujimoto ◽  
Yasutugu Fukushima ◽  
Yasushi Kaji

2014 ◽  
Vol 83 (6) ◽  
pp. 1022-1028 ◽  
Author(s):  
Misuzu Yahaba ◽  
Naoko Kawata ◽  
Ken Iesato ◽  
Yukiko Matsuura ◽  
Toshihiko Sugiura ◽  
...  

2020 ◽  
Author(s):  
Pagé C. Goddard ◽  
Kevin L. Keys ◽  
Angel C.Y. Mak ◽  
Eunice Yujung Lee ◽  
Amy K. Liu ◽  
...  

AbstractBronchodilator drugs are commonly prescribed for treatment and management of obstructive lung function present with diseases such as asthma. Administration of bronchodilator medication can partially or fully restore lung function as measured by pulmonary function tests. The genetics of baseline lung function measures taken prior to bronchodilator medication has been extensively studied, and the genetics of the bronchodilator response itself has received some attention. However, few studies have focused on the genetics of post-bronchodilator lung function. To address this gap, we analyzed lung function phenotypes in 1,103 subjects from the Study of African Americans, Asthma, Genes, and Environment (SAGE), a pediatric asthma case-control cohort, using an integrative genomic analysis approach that combined genotype, locus-specific genetic ancestry, and functional annotation information. We integrated genome-wide association study (GWAS) results with an admixture mapping scan of three pulmonary function tests (FEV1, FVC, and FEV1/FVC) taken before and after albuterol bronchodilator administration on the same subjects, yielding six traits. We identified 18 GWAS loci, and 5 additional loci from admixture mapping, spanning several known and novel lung function candidate genes. Most loci identified via admixture mapping exhibited wide variation in minor allele frequency across genotyped global populations. Functional fine-mapping revealed an enrichment of epigenetic annotations from peripheral blood mononuclear cells, fetal lung tissue, and lung fibroblasts. Our results point to three novel potential genetic drivers of pre- and post-bronchodilator lung function: ADAMTS1, RAD54B, and EGLN3.


2021 ◽  
Vol 14 (3) ◽  
pp. e239146
Author(s):  
Thais Ferrari da Cruz ◽  
Rogério Rufino ◽  
Agnaldo Lopes ◽  
Cláudia Henrique Costa

We describe three cases of female subjects (aged 16, 44 and 41 years) with no respiratory symptoms, who have alpha-1 antitripsyn mutation (PiSZ, PiZZ and PiZZ) and who performed traditional pulmonary function tests and the single breath nitrogen washout test. They still did not have chronic obstructive pulmonary disease (COPD) or any identifiable change in traditional pulmonary function tests but already have change in nitrogen washout tests. Alpha-1 antitrypsin deficiency is a genetic disorder associated with early-onset COPD. There is evidence that although patients who have well-preserved FEV1 may already have signs of emphysema associated with symptoms. Therefore, the nitrogen washout test is considered to have more sensitive outcomes than other pulmonary function tests for early investigation of small airways disease and could allow the monitoring pulmonary function and evaluating of therapeutic decision.


Author(s):  
Hamidreza Pouragha ◽  
Hosein Kazemi ◽  
Gholamreza Pouryaghoub ◽  
Ramin Mehrdad

Background: Why is bodyweight not a predictor of lung function, while height, sex, race, and age are predictors of lung capacity and function? In this study, we want to investigate the association between body composition and pulmonary function. And, as much as possible, answer the question of why bodyweight is not predictive of lung function. Methods: This cross-sectional study was performed among 2967 employees of Tehran University of Medical Sciences (TUMS) who participated in the TUMS Employees Cohort (TEC) study. The body composition of the participants was measured using the Bioelectrical Impedance Analysis (BIA) method. Anthropometric variables were also measured as a confounder. The pulmonary function of participants was assessed by a forced spirometry test. Results: The correlation of BIA values including fat-free mass and total body water with a pulmonary function such as FEV1, FVC, and FEF25-75 is higher than most anthropometric values such as weight, wrist circumference, and the waist to hip ratio. Also, in regression analysis, age and sex had an association with pulmonary function, but the weight did not show a significant relationship. On the other hand, fat-free mass and visceral fat were significantly associated with pulmonary function. One is direct and the other is inverse. Conclusion: We observed a negative association between visceral fat and pulmonary function tests and a direct association between Fat-free mass pulmonary function tests (FEV1 and FVC) adjusted for age, sex, and anthropometric indices.


1991 ◽  
Vol 71 (2) ◽  
pp. 438-444 ◽  
Author(s):  
H. M. Hollingsworth ◽  
M. R. Pratter ◽  
J. M. Dubois ◽  
L. E. Braverman ◽  
R. S. Irwin

To determine whether thyrotoxicosis has an effect on the asthmatic state in subjects with mild asthma, airway responsiveness, lung function, and exercise capacity were measured in a randomized double-blind placebo-controlled trial before and after liothyronine (triiodothyronine, T3)-induced thyrotoxicosis. Baseline evaluation of 15 subjects with mild asthma included clinical evaluation, thyroid and routine pulmonary function tests, airway responsiveness assessment by methacholine inhalation challenge, and a symptom-limited maximal exercise test. For all subjects, the initial testing revealed that the dose of methacholine which provoked a 20% fall in forced expiratory volume in 1s (PD20) was in a range consistent with symptomatic asthma. There was no significant change in pulmonary function tests, airway reactivity (PD20), or exercise capacity in either the placebo or the T3-treated groups. Thyroid function tests confirmed mild sustained thyrotoxicosis in the T3-treated groups. We conclude that mild T3-induced thyrotoxicosis of 4-wk duration had no effect on lung function, airway responsiveness, or exercise capacity in subjects with mild asthma.


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