Mechanical response to methacholine and deep inspiration in supine men

2007 ◽  
Vol 102 (1) ◽  
pp. 269-275 ◽  
Author(s):  
Maurizio Meinero ◽  
Giuseppe Coletta ◽  
Luca Dutto ◽  
Manlio Milanese ◽  
Giorgio Nova ◽  
...  
Keyword(s):  
Lung Function ◽  
Supine Position ◽  
Mechanical Response ◽  
Airflow Obstruction ◽  
Deep Inspiration ◽  
Muscle Adaptation ◽  
Nocturnal Asthma ◽  
Supine Posture ◽  
Residual Capacity ◽  
Airway Responses

The effects of supine posture on airway responses to inhaled methacholine and deep inspiration (DI) were studied in seven male volunteers. On a control day, subjects were in a seated position during both methacholine inhalation and lung function measurements. On a second occasion, the whole procedure was repeated with the subjects lying supine for the entire duration of the study. On a third occasion, methacholine was inhaled from the seated position and measurements were taken in a supine position. Finally, on a fourth occasion, methacholine was inhaled from the supine position and measurements were taken in the seated position. Going from sitting to supine position, the functional residual capacity decreased by ∼1 liter in all subjects. When lung function measurements (pulmonary resistance, dynamic elastance, residual volume, and maximal flows) were taken in supine position, the response to methacholine was greater than at control, and this was associated with a greater dyspnea and a faster recovery of dynamic elastance after DI. By contrast, when methacholine was inhaled in supine position but measurements were taken in sitting position, the response to methacholine was similar to control day. These findings document the potential of the decrease in the operational lung volumes in eliciting or sustaining airflow obstruction in nocturnal asthma. It is speculated that the exaggerated response to methacholine in the supine posture may variably contribute to airway smooth muscle adaptation to short length, airway wall edema, and faster airway renarrowing after a large inflation.

Effects of chest wall strapping on mechanical response to methacholine in humans

2006 ◽  
Vol 101 (2) ◽  
pp. 430-438 ◽  
Author(s):  
Roberto Torchio ◽  
Carlo Gulotta ◽  
Claudio Ciacco ◽  
Alberto Perboni ◽  
Marco Guglielmo ◽  
...  
Keyword(s):  
Chest Wall ◽  
Mechanical Response ◽  
Airflow Obstruction ◽  
Deep Inspiration ◽  
Contractile Apparatus ◽  
Pulmonary Resistance ◽  
Lung Volumes ◽  
Airway Narrowing ◽  
Maximal Expiratory Flow ◽  
Before And After

We examined the effects of chest wall strapping (CWS) on the response to inhaled methacholine (MCh) and the effects of deep inspiration (DI). Eight subjects were studied on 1 day with MCh inhaled without CWS (CTRL), 1 day with MCh inhaled during CWS (CWSon/on), and 1 day with MCh inhaled during temporary removal of CWS (CWSoff/on). On the CWSon/on day, MCh caused greater increases in pulmonary resistance, upstream resistance, dynamic elastance, residual volume, and greater decreases in maximal expiratory flow than on the CTRL day. On the CWSoff/on day, the changes in these parameters with MCh were not different from the CTRL day. Six of the subjects were again studied using the same protocol on CTRL and CWSon/on days, except that, on a third day, MCh was given after applying the CWS, but the measurements before and after the inhalation were made without CWS (CWSon/off). The latter sequence was associated with more severe airflow obstruction than during CTRL, but less than with CWSon/on. The bronchodilator effects of a DI were blunted when CWS was applied during measurements (CWSon/on and CWSoff/on) but not after it was removed (CWSon/off). We conclude that CWS is capable of increasing airway responsiveness only when it is applied during the inhalation of the constrictor agent. We speculate that breathing at low lung volumes induced by CWS enhances airway narrowing because the airway smooth muscle is adapted at a length at which the contractile apparatus is able to generate a force greater than normal.

Airway Responses to Deep Inspiration in Asthma by Different Bronchial Challenge

2012 ◽  
Vol 18 (2) ◽  
pp. 75-80
Author(s):  
Chang-Wook Min ◽  
An-Soo Jang ◽  
Young-Seok Ji ◽  
Nam-Jun Cho ◽  
Kang-Hyug Choi ◽  
...  
Keyword(s):  
Deep Inspiration ◽  
Bronchial Challenge ◽  
Airway Responses

Early changes of lung function and structure in an elastase model of emphysema—a hyperpolarized 3He MRI study

2008 ◽  
Vol 104 (3) ◽  
pp. 773-786 ◽  
Author(s):  
Kiarash Emami ◽  
Robert V. Cadman ◽  
John M. Woodburn ◽  
Martin C. Fischer ◽  
Stephen J. Kadlecek ◽  
...  
Keyword(s):  
Lung Function ◽  
Lung Ventilation ◽  
Unit Group ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Entire Lung ◽  
Residual Capacity ◽  
Regional Basis ◽  
Mean Linear Intercept ◽  
Mri Study

Early changes of lung function and structure were studied in the presence of an elastase-induced model of emphysema in 35 Sprague-Dawley rats at mild (5 U/100 g) and moderate (10 U/100 g) severities. Lung ventilation was measured on a regional basis (at a planar resolution of 3.2 mm) by hyperpolarized 3He MRI at 5 and 10 wk after model induction. Subsequent to imaging, average alveolar diameter was measured from histological slices taken from the centers of each lobe. Changes of mean fractional ventilation, mean linear intercept, and intrasubject heterogeneity of ventilation were studied during disease progression. Mean fractional ventilation was significantly different between healthy controls (0.23 ± 0.04) and emphysematous animals at both time points in the 10-unit group (0.06 ± 0.02 and 0.12 ± 0.05, respectively). Changes in average alveolar diameter were not statistically observable until the 10th wk between healthy (37 ± 10 μm) and emphysematous rats (73 ± 25 and 95 ± 31 μm, for 5 and 10 units, respectively). Assessment of function-structure correlation suggested that the majority of the decline in fractional ventilation occurred in the first 5 wk, while enlargement of alveolar diameters appeared primarily between the 5th and 10th wk. A thresholding metric, based on the 20th percentile of fractional ventilation over the entire lung, was utilized to detect the onset of the disease with confidence, independent of whether the regional ventilation measurements were normalized with respect to the delivered tidal volume and estimated functional residual capacity of each individual rat.

scholarly journals Serum bilirubin and chronic obstructive pulmonary disease (COPD): a systematic review

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
David M. MacDonald ◽  
Ken M. Kunisaki ◽  
Timothy J. Wilt ◽  
Arianne K. Baldomero
Keyword(s):  
Systematic Review ◽  
Health Status ◽  
Lung Function ◽  
Serum Bilirubin ◽  
Respiratory Health ◽  
Airflow Obstruction ◽  
Risk Of Bias ◽  
Chronic Obstructive ◽  
Strength Of Evidence ◽  
Acute Exacerbations

Abstract Background Bilirubin is a potent antioxidant and higher serum bilirubin levels have been associated with improved COPD outcomes. We performed a systematic review to evaluate the association between serum bilirubin levels and lung function (FEV1), prevalence/incidence of COPD, acute exacerbations of COPD, respiratory health status, and mortality. Methods MEDLINE® and Embase were searched using Ovid® (search updated October 1st, 2019). We included studies that measured serum bilirubin levels and outcomes of interest in adults with or without underlying lung disease. We excluded studies of those with liver disease or drug-induced elevations in bilirubin. We used the Newcastle–Ottawa scale to assess individual study risk of bias (ROB) and the US Agency for Healthcare Research and Quality—Evidence Based Practice tool to assess overall strength of evidence (SOE). Two authors independently determined eligibility, performed data abstraction, assessed ROB, and determined SOE. Results Thirteen studies (5 low risk of bias, 3 moderate and 5 high risk) were included. We found low strength of evidence for the association between higher bilirubin levels and lower risk of acute exacerbations of COPD (2 studies), mortality (3 studies), COPD diagnosis (4 studies), and lung function (FEV1) (8 studies). We found insufficient evidence on the relationship between serum bilirubin and respiratory health status/exercise capacity (1 study) and airflow obstruction (FEV1/FVC ratio) (4 studies). Conclusion Higher bilirubin levels may be associated with lower mortality and improved COPD outcomes. Randomized trials are needed to evaluate the effect of medications that raise serum bilirubin on COPD outcomes. PROSPERO registration: CRD42019145747.

scholarly journals DNA methylation is associated with airflow obstruction in patients living with HIV

Thorax ◽  
2020 ◽  
pp. thoraxjnl-2020-215866
Author(s):  
Ana I Hernandez Cordero ◽  
Chen Xi Yang ◽  
Maen Obeidat ◽  
Julia Yang ◽  
Julie MacIsaac ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Lung Function ◽  
Viral Infections ◽  
Airflow Obstruction ◽  
Normal Lung ◽  
People Living With Hiv ◽  
Global Methylation ◽  
Age Related ◽  
Impaired Lung Function ◽  
Living With Hiv

IntroductionPeople living with HIV (PLWH) suffer from age-related comorbidities such as COPD. The processes responsible for reduced lung function in PLWH are largely unknown. We performed an epigenome-wide association study to investigate whether blood DNA methylation is associated with impaired lung function in PLWH.MethodsUsing blood DNA methylation profiles from 161 PLWH, we tested the effect of methylation on FEV1, FEV1/FVC ratio and FEV1 decline over a median of 5 years. We evaluated the global methylation of PLWH with airflow obstruction by testing the differential methylation of transposable elements Alu and LINE-1, a well-described marker of epigenetic ageing.ResultsAirflow obstruction as defined by a FEV1/FVC<0.70 was associated with 1393 differentially methylated positions (DMPs), while 4676 were associated with airflow obstruction based on the FEV1/FVC<lower limit of normal. These DMPs were enriched for biological pathways associated with chronic viral infections. The airflow obstruction group was globally hypomethylated compared with those without airflow obstruction. 103 and 7112 DMPs were associated with FEV1 and FEV1/FVC, respectively. No positions were associated with FEV1 decline.ConclusionA large number of DMPs were associated with airflow obstruction and lung function in a unique cohort of PLWH. Airflow obstruction in even relatively young PLWH is associated with global hypomethylation, suggesting advanced epigenetic ageing compared with those with normal lung function. The disturbance of the epigenetic regulation of key genes not previously identified in non-HIV COPD cohorts could explain the unique risk of COPD in PLWH.

scholarly journals Household Food Insecurity, Lung Function, and COPD in US Adults

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 2098
Author(s):  
Francisca de Castro Mendes ◽  
Kirstie Ducharme-Smith ◽  
Gustavo Mora-Garcia ◽  
Saleh A. Alqahtani ◽  
Maria Stephany Ruiz-Diaz ◽  
...  
Keyword(s):  
Lung Function ◽  
Food Insecurity ◽  
Representative Sample ◽  
Airflow Obstruction ◽  
Forced Expiratory Volume ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
The Us ◽  
Nationally Representative ◽  
Lung Health

Increasing epidemiological evidence suggests that optimal diet quality helps to improve preservation of lung function and to reduce chronic obstructive pulmonary disease (COPD) risk, but no study has investigated the association of food insecurity (FI) and lung health in the general population. Using data from a representative sample of US adults who participated in the National Health and Nutrition Examination Survey (NHANES) 2007–2012 cycles, we investigated the association between FI with lung function and spirometrically defined COPD in 12,469 individuals aged ≥ 18 years of age. FI (high vs. low) was defined using the US Department of Agriculture’s Food Security Scale). Population-weighted adjusted regression models were used to investigate associations between FI, and forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), their ratio, and spirometrically defined restriction (FVC below the lower limit of normal) and airflow obstruction (COPD). The prevalence of household FI was 13.2%. High household FI was associated with lower FVC (adjusted β-coefficient −70.9 mL, 95% CI −116.6, −25.3), and with higher odds (OR) of spirometric restriction (1.02, 95% CI 1.00, 1.03). Stratified analyses showed similar effect sizes within specific ethnic groups. High FI was associated with worse lung health in a nationally representative sample of adults in the US.

scholarly journals Prevalence and burden of chronic bronchitis symptoms: results from the BOLD study

2017 ◽  
Vol 50 (5) ◽  
pp. 1700621 ◽  
Author(s):  
Filip Mejza ◽  
Louisa Gnatiuc ◽  
A. Sonia Buist ◽  
William M. Vollmer ◽  
Bernd Lamprecht ◽  
...  
Keyword(s):  
Lung Function ◽  
Lung Disease ◽  
Chronic Bronchitis ◽  
Airflow Obstruction ◽  
Population Based ◽  
Normal Lung ◽  
Increased Risk ◽  
Potential Risk Factors ◽  
Definition Of ◽  
Disease Study

We studied the prevalence, burden and potential risk factors for chronic bronchitis symptoms in the Burden of Obstructive Lung Disease study.Representative population-based samples of adults aged ≥40 years were selected in participating sites. Participants completed questionnaires and spirometry. Chronic bronchitis symptoms were defined as chronic cough and phlegm on most days for ≥3 months each year for ≥2 years.Data from 24 855 subjects from 33 sites in 29 countries were analysed. There were significant differences in the prevalence of self-reported symptoms meeting our definition of chronic bronchitis across sites, from 10.8% in Lexington (KY, USA), to 0% in Ile-Ife (Nigeria) and Blantyre (Malawi). Older age, less education, current smoking, occupational exposure to fumes, self-reported diagnosis of asthma or lung cancer and family history of chronic lung disease were all associated with increased risk of chronic bronchitis. Chronic bronchitis symptoms were associated with worse lung function, more dyspnoea, increased risk of respiratory exacerbations and reduced quality of life, independent of the presence of other lung diseases.The prevalence of chronic bronchitis symptoms varied widely across the studied sites. Chronic bronchitis symptoms were associated with significant burden both in individuals with chronic airflow obstruction and those with normal lung function.

Persistent airflow obstruction in inner-city children with asthma

2021 ◽  
Vol 42 (4) ◽  
pp. 310-316
Author(s):  
Kenny Y. Kwong ◽  
Yang Z. Lu ◽  
Emilio Jauregui ◽  
Lyne Scott
Keyword(s):  
Lung Function ◽  
Inner City ◽  
Airway Remodeling ◽  
Airflow Obstruction ◽  
Later Life ◽  
Forced Expiratory Volume ◽  
Initial Visit ◽  
Asthma Care ◽  
Increased Risk ◽  
Children With Asthma

Background: Airway remodeling has been shown to be persistent in patients with asthma despite treatment with controller medications. Patients with early airflow obstruction may continue to experience poor lung function despite treatment. Objectives: To determine whether early airflow obstruction in inner-city children with asthma persists despite guideline-based asthma care. Methods: In a retrospective study that used a cohort of inner-city children with asthma treated by using an asthma-specific disease management system, the patients were stratified into “low” or “high” lung function groups at the time of the initial visit (high, forced expiratory volume in the first second of expiration [FEV1] % predicted and FEV1/forced vital capacity [FVC] ≥ 80%; and low, FEV1% predicted and FEV1/FVC < 80%). These patients then received National Heart, Lung, and Blood Institute guideline‐based asthma treatment at regular follow-up intervals with spirometry performed at these visits as part of regular care. FEV1% predicted and FEV1/FVC were followed up for up to 10 years for both the high and low cohorts. Results: Over 10 years, the patients initially in the “high” group maintained FEV1% predicted and FEV1/FVC at values similar to the initial visit (94 to 96% and 87 to 89%, respectively), whereas those in the low group had only slight increases of FEV1% predicted and FEV1/FVC over the same time (77 to 82% and 78 to 82%, respectively). Low FEV1% predicted and FEV1/FVC at the time of the first visit was significantly associated with an increased risk of low values of these lung functions over the next 3‐5 years despite treatment. African American ethnicity and male gender were also associated with lower lung function over time. Conclusion: Early airflow obstruction in inner city children asthma is associated with poor lung function in later life despite guideline-based asthma care. Current asthma therapy may not affect pathways and leads to airway remodeling in children with asthma.

Airflow obstruction, impaired lung function and risk of sudden cardiac death: a prospective cohort study

Thorax ◽  
2021 ◽  
pp. thoraxjnl-2020-215632
Author(s):  
Yun-Jiu Cheng ◽  
Zhen-Guang Chen ◽  
Feng-Juan Yao ◽  
Li-Juan Liu ◽  
Ming Zhang ◽  
...  
Keyword(s):  
Sudden Cardiac Death ◽  
Lung Function ◽  
Cardiac Death ◽  
Airflow Obstruction ◽  
Partial Likelihood ◽  
Race And Gender ◽  
Increased Risk ◽  
Impaired Lung Function ◽  
And Gender ◽  
Lung Health

BackgroundGrowing evidence suggests that compromised lung health may be linked to cardiovascular disease. However, little is known about its association with sudden cardiac death (SCD).ObjectivesWe aimed to assess the link between impaired lung function, airflow obstruction and risk of SCD by race and gender in four US communities.MethodsA total of 14 708 Atherosclerosis Risk in Communities (ARIC) study participants who underwent spirometry and were asked about lung health (1987–1989) were followed. The main outcome was physician-adjudicated SCD. Fine-Gray proportional subdistribution hazard models with Firth’s penalised partial likelihood correction were used to estimate the HRs.ResultsOver a median follow-up of 25.4 years, 706 (4.8%) subjects experienced SCD. The incidence of SCD was inversely associated with FEV1 in each of the four race and gender groups and across all smoking status categories. After adjusting for multiple measured confounders, HRs of SCD comparing the lowest with the highest quintile of FEV1 were 2.62 (95% CI 1.62 to 4.26) for white males, 1.80 (95% CI 1.03 to 3.15) for white females, 2.07 (95% CI 1.05 to 4.11) for black males and 2.62 (95% CI 1.21 to 5.65) for black females. The above associations were consistently observed among the never smokers. Moderate to very severe airflow obstruction was associated with increased risk of SCD. Addition of FEV1 significantly improved the predictive power for SCD.ConclusionsImpaired lung function and airflow obstruction were associated with increased risk of SCD in general population. Additional research to elucidate the underlying mechanisms is warranted.

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