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Environmental Research Oct 2023Poly- and perfluoroalkyl substances (PFAS) are used in a wide range of products. Experimental studies suggested impaired lung development and pro-inflammatory response...
BACKGROUND
Poly- and perfluoroalkyl substances (PFAS) are used in a wide range of products. Experimental studies suggested impaired lung development and pro-inflammatory response following exposure to some PFAS. We aimed to assess the associations between prenatal exposure to PFAS and children respiratory health.
METHODS
The study is based on 433 mother-child pairs. 26 PFAS were measured in maternal serum collected during pregnancy. Lung function parameters were measured at 2 months using tidal breathing flow-volume loops and multiple-breath nitrogen washout and at 36 months using oscillometry. Incidence of respiratory health diseases (asthma, wheeze, bronchitis, bronchiolitis) in the first 36 months of life was assessed by repeated questionnaires. A cluster-based analysis was applied to identify prenatal PFAS exposure patterns. Adjusted linear and logistic regressions were performed to assess the associations between PFAS exposure patterns as well as individual PFAS, and each respiratory health parameter.
RESULTS
We excluded 13 PFAS due to low quantification (<5%). Relying on the 13 remaining PFAS, we identified three exposure clusters, characterized by low (N = 163), medium (N = 236) and high (N = 51) pregnancy PFAS concentrations. Compared to children belonging to the low exposure group, children in the moderate exposure group had higher reactance at 7 Hz (X) and lower frequency dependence of resistance between 7 Hz and 19 Hz (R) at 36 months, suggesting better lung function. No association of any exposure metric was detected with respiratory diseases in the first 3 years of life.
CONCLUSIONS
Our study relying on both mixture and uni-pollutant analyses, does not provide evidence for a deleterious effect of prenatal PFAS exposure on respiratory health at an early age.
Topics: Pregnancy; Female; Humans; Prenatal Exposure Delayed Effects; Fluorocarbons; Environmental Pollutants; Asthma; Incidence; Alkanesulfonic Acids
PubMed: 37406719
DOI: 10.1016/j.envres.2023.116544 -
Pediatric Pulmonology Mar 2024Several factors may influence quality of life (QOL) for patients with primary ciliary dyskinesia (PCD). We aimed to evaluate the association between pulmonary functions,...
BACKGROUND
Several factors may influence quality of life (QOL) for patients with primary ciliary dyskinesia (PCD). We aimed to evaluate the association between pulmonary functions, nasal symptoms and QOL in PCD patients.
METHODS
A prospective single center study. Patients performed spirometry, whole body plethysmography, forced oscillation technique (FOT), lung clearance index (LCI), 6-min walk test (6MWT), and filled two questionnaires: a specific PCD QOL questionnaire (PCD-QOL) and Sino-nasal outcome test (SNOT-22) questionnaire, assessing symptoms of chronic rhinosinusitis and health related QOL.
RESULTS
Twenty-seven patients (56% females), age 19.4 ± 10.5 years were included; their, FEV1 was 74.6 ± 22.7%, and RV/TLC was (157.3 ± 39.3% predicted). Health perception and lower respiratory symptoms domains of PCD-QOL had the lowest score (median [IQR]: 50 [33.3-64.6] and 57.1 [38.9-72.2], respectively). FOT parameters correlated with several PCD-QOL domains. R5 z-score (indicating total airway resistance) and AX z-score (indicating airway reactance) correlated negatively with physical domain (r = -0.598, p = .001, and r = -0.42, p = .03, respectively); R5 z-score also correlated negatively with hearing domain (r = -0.57, p = .002). R5-20 z-score (indicating small airway resistance) correlated negatively with role domain (r = -0.49, p = .03). SNOT-22 score correlated negatively with several PCD-QOL domains (lower respiratory symptoms r = -0.77, p < .001; physical r = -0.72, p < .001; upper respiratory symptoms r = -0.66, p < .001). No correlations were found between spirometry values, LCI, 6MWT, and PCD-QOL.
CONCLUSIONS
FOT suggested small airway dysfunction, and correlated negatively with several PCD-QOL domains. Nasal symptoms had strong negative correlations with PCD-QOL. Larger longitudinal studies will further elucidate factors affecting QOL in PCD.
Topics: Female; Humans; Child; Adolescent; Young Adult; Adult; Male; Quality of Life; Ciliary Motility Disorders; Prospective Studies; Lung; Respiratory Function Tests
PubMed: 38116904
DOI: 10.1002/ppul.26814 -
Clinics (Sao Paulo, Brazil) 2024Studies suggest peripheral airway abnormalities in Pulmonary Arterial Hypertension (PAH). Impulse Oscillometry (IOS) is a noninvasive and sensitive technique for...
INTRODUCTION
Studies suggest peripheral airway abnormalities in Pulmonary Arterial Hypertension (PAH). Impulse Oscillometry (IOS) is a noninvasive and sensitive technique for assessing the small airways. It evaluates the impedance of the respiratory system ‒ Resistance (R) and reactance (X) ‒ to a pulse of sound waves sent to the lungs, in a range of frequencies (5‒20 Hz).
METHOD
Resistance variables: R5, R20, R5-R20 and reactance variables: AX (reactance area) and Fres (resonance frequency). The aim is to evaluate R and X in patients with idiopathic PAH (IPAH) and to investigate whether there is a correlation between IOS and spirometry.
RESULTS
Thirteen IPAH patients and 11 healthy subjects matched for sex and age underwent IOS and spirometry. IPAH patients had lower FVC and FEV values (p < 0.001), VEF/CVF (p = 0.049) and FEF 25-75 (p = 0.006) than healthy patients. At IOS, IPAH patients showed lower tidal volumes and higher AX (p < 0.05) compared to healthy individuals, and 53.8 of patients had R5-R20 values ≥ 0.07 kPa/L/s. Correlation analysis: X5, AX, R5-R20 and Fres showed moderate correlation with FVC (p = 0.036 r = 0.585, p = 0.001 r = -0.687, p = 0.005 r = -0.726 and p = 0.027 r = -0.610); Fres (p = 0.012 r = -0.669) and AX (p = 0.006 r = -0.711) correlated with FEV; [R5 and R20, (R5-R20)] also correlated with FEV (p < 0.001 r = -0.573, p = 0.020 r = -0.634 and p = 0.010 r = -0.683, respectively) in the IPAH group. There were also moderate correlations of FEF 25-75 % with Z5 (p = 0.041), R5 (p = 0.018), Fres (p = 0.043) and AX (p = 0.023).
DISCUSSION
Patients showed changes suggestive of increased resistance and reactance in the IOS compared to healthy individuals, and the IOS findings showed a good correlation with spirometry variables.
Topics: Humans; Pulmonary Arterial Hypertension; Oscillometry; Forced Expiratory Volume; Respiratory Function Tests; Lung; Spirometry
PubMed: 38490138
DOI: 10.1016/j.clinsp.2023.100313 -
Respiratory Research Mar 2024The clinical significance of the impulse oscillometry-defined small airway bronchodilator response (IOS-BDR) is not well-known. Accordingly, this study investigated the...
BACKGROUND
The clinical significance of the impulse oscillometry-defined small airway bronchodilator response (IOS-BDR) is not well-known. Accordingly, this study investigated the clinical characteristics of IOS-BDR and explored the association between lung function decline, acute respiratory exacerbations, and IOS-BDR.
METHODS
Participants were recruited from an Early Chronic Obstructive Pulmonary Disease (ECOPD) cohort subset and were followed up for two years with visits at baseline, 12 months, and 24 months. Chronic obstructive pulmonary disease (COPD) was defined as a post-bronchodilator forced expiratory volume in 1 s (FEV)/forced vital capacity (FVC) ratio < 0.70. IOS-BDR was defined as meeting any one of the following criteria: an absolute change in respiratory system resistance at 5 Hz ≤ - 0.137 kPa/L/s, an absolute change in respiratory system reactance at 5 Hz ≥ 0.055 kPa/L/s, or an absolute change in reactance area ≤ - 0.390 kPa/L. The association between IOS-BDR and a decline in lung function was explored with linear mixed-effects model. The association between IOS-BDR and the risk of acute respiratory exacerbations at the two-year follow-up was analyzed with the logistic regression model.
RESULTS
This study involved 466 participants (92 participants with IOS-BDR and 374 participants without IOS-BDR). Participants with IOS-BDR had higher COPD assessment test and modified Medical Research Council dyspnea scale scores, more severe emphysema, air trapping, and rapid decline in FVC than those without IOS-BDR over 2-year follow-up. IOS-BDR was not associated with the risk of acute respiratory exacerbations at the 2-year follow-up.
CONCLUSIONS
The participants with IOS-BDR had more respiratory symptoms, radiographic structural changes, and had an increase in decline in lung function than those without IOS-BDR.
TRIAL REGISTRATION
Chinese Clinical Trial Registry, ChiCTR1900024643. Registered on 19 July, 2019.
Topics: Humans; Asthma; Bronchodilator Agents; Forced Expiratory Volume; Oscillometry; Pulmonary Disease, Chronic Obstructive; Respiratory Function Tests; Spirometry
PubMed: 38555433
DOI: 10.1186/s12931-024-02765-7 -
Transplant International : Official... 2023Peak spirometry after single lung transplantation (SLTx) for interstitial lung disease (ILD) is lower than after double lung transplantation (DLTx), however the...
Peak spirometry after single lung transplantation (SLTx) for interstitial lung disease (ILD) is lower than after double lung transplantation (DLTx), however the pathophysiologic mechanisms are unclear. We aim to assess respiratory mechanics in SLTx and DLTx for ILD using oscillometry. Spirometry and oscillometry (tremoflo C-100) were performed in stable SLTx and DLTx recipients in a multi-center study. Resistance (R, R) and reactance (X) were compared between LTx recipient groups, matched by age and gender. A model of respiratory impedance using ILD and DLTx data was performed. In total, 45 stable LTx recipients were recruited (SLTx = 23, DLTx = 22; males: 87.0% vs. 77.3%; median age 63.0 vs. 63.0 years). Spirometry was significantly lower after SLTx compared with DLTx: %-predicted mean (SD) FEV [70.0 (14.5) vs. 93.5 (26.0)%]; FVC [70.5 (16.8) vs. 90.7 (12.8)%], . R and R were similar between groups ( and , respectively) yet X was significantly worse after SLTx: median (IQR) X [-1.88 (-2.89 to -1.39) vs. -1.22 (-1.87 to -0.86)] cmHO.s/L], . R and X measurements from the model were congruent with measurements in SLTx recipients. The similarities in resistance, yet differences in spirometry and reactance between both transplant groups suggest the important contribution of elastic properties to the pathophysiology. Oscillometry may provide further insight into the physiological changes occurring post-LTx.
Topics: Male; Humans; Middle Aged; Oscillometry; Forced Expiratory Volume; Australia; Lung; Lung Diseases, Interstitial; Allografts
PubMed: 38116170
DOI: 10.3389/ti.2023.11758 -
ERJ Open Research Sep 2023Impulse oscillometry (IOS) is sensitive in detecting lung function impairment. In small studies, impaired IOS relates better to respiratory symptoms than spirometry. We...
BACKGROUND
Impulse oscillometry (IOS) is sensitive in detecting lung function impairment. In small studies, impaired IOS relates better to respiratory symptoms than spirometry. We studied how IOS related to spirometry and respiratory symptoms in a large population of individuals (n=10 360) in a cross-sectional analysis.
METHODS
Normal values for IOS and spirometry were defined in healthy, never-smoking individuals, aged 50-64 years, from the Swedish CArdioPulmonary bioImage Study (n=3664 for IOS and 3608 for spirometry). For IOS, abnormal values for resistance at 5 Hz () and at 20 Hz and area of reactance were defined using the 95th percentile. Abnormal reactance at 5 Hz for IOS and abnormal conventional spirometry indices (forced expiratory volume in 1 s (FEV), forced and slow vital capacity and their ratios) were defined using the 5th percentile.
RESULTS
Abnormal IOS parameters were found in 16% of individuals and were associated with increased odds ratios for nearly all respiratory symptoms when adjusted for age, gender and smoking. In individuals with normal spirometry, abnormal IOS resistance was related to cough and dyspnoea, while abnormal reactance was related to wheeze. In these individuals, the combination of abnormal with abnormal reactance resulted in approximately two-fold higher likelihood for having cough, chronic bronchitis and dyspnoea, even when further adjusting for FEV, expressed as % predicted.
CONCLUSIONS
Abnormal IOS is related to increased respiratory burden in middle-aged individuals with normal spirometry, especially when resistance and reactance parameters are combined. The different relationships between respiratory symptoms and reactance and resistance warrant further research.
PubMed: 37753278
DOI: 10.1183/23120541.00736-2022 -
The Journal of Asthma : Official... Apr 2024Asthmatic children present variable degrees of airway inflammation, remodeling, and resistance, which correlate with disease control and severity. The chronic...
BACKGROUND
Asthmatic children present variable degrees of airway inflammation, remodeling, and resistance, which correlate with disease control and severity. The chronic inflammatory process of the airway triggers airway remodeling, which reflects the degree of airway resistance. Pro-inflammatory and pro-fibrotic mediators are centrally involved in this process.
OBJECTIVE
To investigate whether the levels of pulmonary and systemic pro-inflammatory and pro-fibrotic mediators present a correlation with the resistance of the respiratory system and of the proximal and distal airways.
METHODS
39 Asthmatic children (persistent mild and moderate) and 39 non-asthmatic children (both between 6 and 13 years old) were evaluated for anthropometric characteristics, lung function and mechanics, and pulmonary and systemic immune responses.
RESULTS
Asthmatic children showed an increased number of blood eosinophils ( < 0.04), basophils ( < 0.04), monocytes ( < 0.002) and lymphocytes ( < 0.03). In addition, asthmatic children showed impaired lung function, as demonstrated by FEV1 ( < 0.0005) and FEV1/FVC ( < 0.004), decreased total resistance of the respiratory system (R5Hz; < 0.009), increased resistance of the proximal airways (R20Hz; < 0.02), increased elastance (Z5Hz; < 0.02) and increased reactance (X5Hz; < 0.002) compared to non-asthmatic children. Moreover, the following inflammatory factors were significantly higher in asthmatic than non-asthmatic children: GM-CSF in the breath condensate (BC) ( < 0.0001) and in the serum ( < 0.0001); TGF-beta in the BC ( < 0.0001) and in the serum ( < 0.004); IL-5 in the BC ( < 0.02) and in the serum ( < 0.01); IL-4 in the serum ( < 0.0002).
CONCLUSIONS
Impulse oscillometry is a sensitive method to detect airway resistance in persistent mild and moderate asthmatic children, an event followed by increased levels of pro-inflammatory and pro-fibrotic mediators.
PubMed: 38577973
DOI: 10.1080/02770903.2024.2338862 -
Lung Aug 2023Respiratory mechanics and the role of sex hormones in pregnancy are not well elucidated. We examined longitudinal and positional changes in lung mechanics in pregnancy...
PURPOSE
Respiratory mechanics and the role of sex hormones in pregnancy are not well elucidated. We examined longitudinal and positional changes in lung mechanics in pregnancy and investigated the role of sex hormones.
METHODS
A longitudinal study enrolled 135 women with obesity in early pregnancy. Fifty-nine percent of women identified as White; median body mass index at enrollment was 34.4 kg/m. Women with respiratory disease were excluded. We obtained measurements of airway resistance and respiratory system reactance in various positions using impedance oscillometry and sex hormones in early and late pregnancy.
RESULTS
With pregnancy progression, there was a significant increase in resonant frequency (Fres) (p = 0.012), integrated area of low frequency reactance (AX) (p = 0.0012) and R5-R20Hz (p = 0.038) in the seated position, and a significant increase in R5Hz (p = 0.000), Fres (p = 0.001), AX (p < 0.001 = 0.000), and R5-R20Hz (p = 0.014) in the supine position. Compared to the seated position, the supine position was associated with a significant increase in R5Hz, R20Hz, X5Hz, Fres, and AX in early (p-values < 0.026) and late pregnancy (p-values ≤ 0.001). Changes in progesterone levels between early and late pregnancy predicted the change in R5, Fres, and AX (p-values ≤ 0.043).
CONCLUSION
Resistive and elastic loads increase with pregnancy progression and a change in body position from seated to supine increases resistive and elastic loads in both early and late pregnancies. The increase in airway resistance is primarily related to an increase in peripheral rather than central airways resistance. There was an association between the change in progesterone levels and airway resistance.
Topics: Humans; Female; Pregnancy; Pregnant Women; Overweight; Longitudinal Studies; Progesterone; Lung; Airway Resistance; Respiratory Mechanics; Obesity; Spirometry
PubMed: 37421433
DOI: 10.1007/s00408-023-00633-7 -
Military Medicine Nov 2023Evaluation of chronic respiratory symptoms in deployed military personnel has been conducted at Brooke Army Medical Center as part of the Study of Active Duty Military...
INTRODUCTION
Evaluation of chronic respiratory symptoms in deployed military personnel has been conducted at Brooke Army Medical Center as part of the Study of Active Duty Military for Pulmonary Disease Related to Environmental Deployment Exposures III study. Although asthma and airway hyperreactivity have been the most common diagnoses, the clinical findings in these patients may be multifactorial. This study aims to evaluate the utility of impulse oscillometry (IOS) in diagnosing airway obstruction in patients undergoing multiple pulmonary function testing (PFT) studies.
METHODS
Military personnel referred for deployed-related pulmonary symptoms underwent a standardized evaluation at Brooke Army Medical Center and Walter Reed National Military Medical Center over a 5-year span. Initial studies included laboratory tests, high-resolution computed tomography imaging, cardiac evaluation with electrocardiogram, and echocardiography. PFT consisted of full PFTs, forced inspiratory/expiratory pressures, post-spirometry bronchodilator testing, IOS, exhaled nitric oxide, and methacholine challenge testing.
RESULTS
A total of 360 patients have completed an evaluation to date. In this cohort, 108 patients (30.0%) have evidence of obstruction by spirometry, whereas 74 (20.6%) had IOS values of both an R5 > 150% and X5 < -1.5. Only 32 (8.9%) had evidence of obstruction by both spirometry and IOS, whereas 210 (57.3%) had neither. A comparison among R5 (resistance at 5 Hz), R20 (resistance at 20 Hz), and X5 (reactance at 5 Hz) was performed in those individuals with and without spirometric obstruction. R5 (% predicted) was 156.2 ± 57.4% (obstruction) vs. 129.1 ± 39.6% (no obstruction) (P < .001); R20 (% predicted) was 138.1 ± 37.7% (obstruction) vs. 125.3 ± 31.2% (no obstruction) (P = .007); and X5 (cmH2O/L/s) was -1.62 ± 1.28 (obstruction) vs. -1.25 ± 0.55 (no obstruction) (P < .001).
DISCUSSION
Impulse oscillometry has been advocated as a supplemental pulmonary function test to aid in the diagnosis of airway obstruction. The use of IOS has been primarily used in pediatrics and elderly populations as a validated tool to establish a diagnosis of airway obstruction but is limited in the adult population because of a well-validated set of reference values. Prior studies in adults have most often demonstrated a correlation with an elevated R5 > 150%, elevated resonant frequency, and a negative X5 < -1.5 or a decrease of 30 to 35% in R5 post-bronchodilator.
CONCLUSION
Impulse oscillometry may serve as an adjunct to diagnosis but likely cannot replace a standard spirometric evaluation. Our study highlights the future utility for diagnosing early obstructive disease in the symptomatic individual.
Topics: Adult; Humans; Child; Aged; Military Personnel; Bronchodilator Agents; Oscillometry; Forced Expiratory Volume; Respiratory Function Tests; Airway Obstruction; Spirometry; Asthma
PubMed: 37948261
DOI: 10.1093/milmed/usad171 -
Diagnostics (Basel, Switzerland) May 2024The fact that some SARS-CoV-2 pneumonia patients benefit from changing body position, and some from continuous positive airways pressure (CPAP), indicates the functional...
The fact that some SARS-CoV-2 pneumonia patients benefit from changing body position, and some from continuous positive airways pressure (CPAP), indicates the functional character of hypoxia. We hypothesize that such effects could be explained by the closure of small airways. To prove the hypothesis, we evaluated the patency of small airways in 30 oxygen-dependent, spontaneously breathing patients with SARS-CoV-2 pneumonia during their hospital stay using the FOT method and then compared the results with data obtained three months later. During the acute period, total resistance (R5) and peripheral resistance (R5-20) rose above the upper limit of normal (ULN) in 28% and 50% of all patients, respectively. Reactance indices X5, AX and Fres exceeded ULN in 55%, 68% and 66% of cases. Significant correlations were observed between PaO/FiO, the time spent in the hospital and R5, X5, AX and Fres. After 3 months, 18 patients were re-examined. During the hospital stay, 11 of them had risen above the upper limit of normal (ULN), for both resistance (R5-20) and reactance (X5, AX) values. Three months later, ULN for R5-20 was exceeded in only four individuals, but ULN for X5 and AX was exceeded in five individuals. Lung function examination revealed a combined restrictive/obstructive ventilatory failure and reduced CO transfer factor. We interpret these changes as lung tissue remodeling due to the process of fibrosis. We conclude that during acute period of SARS-CoV-2 pneumonia, dilated pulmonary blood vessels and parenchymal oedema induce functional closure of small airways, which in turn induce atelectasis with pulmonary right-to-left shunting, followed by the resulting hypoxemia.
PubMed: 38893686
DOI: 10.3390/diagnostics14111160