Interpretative strategies for lung function tests

Quality of life and late therapy effects in pediatric non-Hodgkin lymphoma survivors: Insights from a single-institution study

BACKGROUND AND AIM

The survival outcomes of pediatric patients with mature B-non-Hodgkin lymphoma (NHL) have improved due to advances in treatment. We aimed to assess the frequency and severity of late effects and their impact on quality of life among pediatric NHL survivors.

PATIENTS AND METHODS

This retrospective study included patients diagnosed with mature B-NHL at Children's Cancer Hospital of Egypt (CCHE) 57357 from January 2012 through December 2015. Patients received treatment according to the modified LMB 96 protocol. The minimum follow-up period was 5 years. Assessments for toxicity and quality of life were conducted at regular intervals during and after treatment. Patients were assessed for toxicity including pulmonary dysfunction, cardiac dysfunction, lipid profile abnormalities, endocrine dysfunction (thyroid function, vitamin D levels, growth curves), and cognitive function (intelligence quotient [IQ] level using Stanford-Binet Intelligence Scales-5th Edition, and quality of life (QoL) assessment (PedsQoL).

RESULTS

A total of 273 patients were eligible, and 206 were evaluable. Median age was 5.45 (range: 2.4-18), with a male-to-female ratio 4:1. Pulmonary function abnormalities were detected in 119/203 (58.6%); most had mild dysfunction (72/119, 60.5%), while 17% had severe dysfunction. Cardiac toxicity occurred in 10% of the patients (n = 20). IQ testing showed that 52 patients had a low average IQ score, while 151 patients had either average or above average scores. The total mean QoL score was 99 ± 0.058 classified as "satisfactory." However, significant impairment of the physical domain of quality of life was observed among group C patients compared to A/B (p = .033), older age at diagnosis (p = .042), and those with pulmonary dysfunction (p < .001). Total score of quality of life was significantly impaired among patients with pulmonary dysfunction (p = .009), likewise older age at diagnosis (p = .017) and those with low average IQ scores (p = .033).

CONCLUSION

Childhood mature B-NHL survivors are at significant risk for late effects; pulmonary dysfunction and low average IQ that can subsequently impact QoL.

The Effect of the Cheneau Brace on Respiratory Function in Girls with Adolescent Idiopathic Scoliosis Participating in a Schroth Exercise Program

Objectives: The aim of this study was to evaluate the effect of brace use application and the Schroth intervention on lung ventilation and respiratory muscle strength in patients treated long-term with a Chaneau brace and the Schroth method. Methods: A total of 26 post-menarche females aged 15.7 ± 1.5 years, with a Cobb angle of 18-48° and a diagnosis of AIS in inpatient rehabilitation were examined. All participants received brace treatment for a minimum of 3 months with a dosage of 20-22 h/day. This study protocol was performed three times: 1-brace intervention-first day of the present study; 2-without the brace-second day of the present study; and 3-Schroth intervention on the same day. Results: During the period of brace use, girls treated with a long-term therapy showed significantly reduced values for VC, FVC, and FEV1 and significantly higher values for inspiratory muscle strength PImax compared to values obtained in studies without the brace and after single exercises. Expiratory muscle strength did not differ significantly. Conclusions: The majority showed restrictive lung ventilation disorders and decreased respiratory muscle strength in relation to norms. There was a significant correlation of PImax with the duration of wearing the brace and the duration of therapy.

Reference values for respiratory muscle strength and maximal voluntary ventilation in the Brazilian adult population: A multicentric study

AIM

To determine reference values and propose prediction equations for respiratory muscle strength, maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and endurance by means of maximal voluntary ventilation (MVV) in healthy Brazilian adults.

METHODS

Anthropometric data, level of physical activity, pulmonary function, and respiratory muscle strength and maximal voluntary ventilation of 243 participants (111 men and 132 women) aged 20 to 80 years were assessed at three cities in the southeast and northeast region of Brazil.

RESULTS

Mean maximal respiratory pressures and MVV were higher in men (MIP = 111.0 ± 28.0; MEP = 149.6 ± 40.3; MVV = 150.6 ± 35.2) than in women (MIP = 87.9 ± 17.6; MEP = 106.7 ± 25.2; MVV = 103.4 ± 23.2; all p < 0.05). Based on regression models, the following prediction equations were proposed for men: MIP = 137-0.57 (age), R2 = 0.13, standard error of estimate (SEE) = 26.11; MEP = 179.9-0.67 x (age), R2 = 0.08, SEE = 38.54; and MVV = 206.3-1.18 x (age), R2 = 0.36, SEE = 28.08. Prediction equations were also proposed for women: MIP = 107.3-0.4 x (age), R2 = 0.16, SEE = 16.10; MEP = 127.4-0.43 x (age), R2 = 0.08, SEE = 24.09; and MVV = 146.3-0.86 x (age), R2 = 0.42, SEE = 17.56.

CONCLUSION

Reference values for MIP, MEP, and MVV were determined in healthy Brazilian adults. Results from different Brazilian regions provided adequate prediction equations considering an ethnically heterogeneous population.

Rapid FEV1 decline and the effects of both FEV1 and FVC on cardiovascular disease: A UK biobank cohort analysis

BACKGROUND

The relationship between lung function and cardiovascular disease (CVD) has emerged as a significant research focus in recent years, but studies on the effects of both forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) remain limited.

METHODS

Among 29,662 participants in the UK Biobank study free of CVD, rapid lung function decline was defined as the decline in either FEV1 (greatest quartile), FVC (greatest quartile), or both (when both FEV1 and FVC exceeded the greatest quartile). CVDs include coronary heart disease (CHD), arrhythmias, heart failure (HF), peripheral arterial disease (PAD), and other CVDs (including endocarditis, stroke, and myocardial diseases). Cox proportional hazards models were used to explore the associations between lung function and CVD incidence. Fine‒Gray models were used to account for the competing risk of death.

RESULTS

Among 29,662 participants in the UK Biobank study free of CVD, the adjusted hazard ratios (HRs) for FEV1 rapid decline were 1.150 (95% CI: 1.009-1.311) for CHD, 1.307 (95% CI: 1.167-1.465) for arrhythmias, 1.406 (95% CI: 1.084-1.822) for HF, 1.287 (95% CI: 1.047-1.582) for PAD, 1.170 (95% CI: 1.022-1.340) for other CVDs, and 1.216 (95% CI: 1.124-1.315) for composite CVD. The adjusted HRs for the impact of both rapid decreases in FEV1 and FVC were 1.386 (95% CI: 1.226-1.567) for arrhythmias, 1.390 (95% CI: 1.041-1.833) for HF, 1.222 (95% CI: 1.054-1.417) for other CVDs, and 1.230 (95% CI: 1.128-1.340) for composite CVD.

CONCLUSIONS

The rapid decline in FEV1 and the impact of both FEV1 and FVC are closely associated with the subsequent incidence of various CVDs and composite CVD.

Autologous transplantation of P63+ lung progenitor cells in patients with bronchiectasis: A randomized, single-blind, controlled trial

Non-cystic fibrosis bronchiectasis is a progressive respiratory disease with limited treatment options, prompting the exploration of regenerative therapies. This study investigates the safety and efficacy of autologous P63+ progenitor cell transplantation in a randomized, single-blind, controlled, phase 1/2 trial. Thirty-seven patients receive bronchoscopic airway clearance (B-ACT) (n = 19) or B-ACT plus P63+ progenitor cells (n = 18). Results show that compared to the control group, the change in DLCO levels from baseline to 24 weeks post therapy is significantly higher in the cell treatment group (p value = 0.039). Furthermore, the patients in the cell treatment group demonstrate significantly reduced lung damaged area, improved SGRQ score, and ameliorated BSI and FACED scores within 4-12 weeks post therapy. Transcriptomic analysis reveals that progenitor cells with higher expression of P63 gene have better therapeutic efficacy. These findings suggest that P63+ progenitor cells may offer a promising therapeutic approach for bronchiectasis. This study was registered at ClinicalTrials.gov(NCT03655808).

Prediction of spirometry outcome in Croatian patients with chronic obstructive pulmonary disease

The current study offers an extensive examination of the influence of 29 diverse parameters on spirometry measurement variables in a cohort of 534 patients with chronic obstructive pulmonary disease (COPD) from five different centers in Croatia. The study elucidates both the magnitude and direction of the effect exerted by the 29 predictors on forced vital capacity (FVC), forced expiratory volume in one second (FEV1), the ratio FEV1/FVC, and predicted forced expiratory flow at 50% of FVC. Additionally, the development of prediction models for these parameters has been undertaken using several statistical methods. The study identifies fat-free mass index, 6-minute walk distance, predicted diffusing capacity of the lung for carbon monoxide, arterial partial pressure of oxygen, and both arterial and tissue hemoglobin oxygen saturation percentage as robust positive predictors for all four spirometry parameters. Body mass index is recognized as a weak positive predictor for FEV1 and FEV1/FVC, commonly observed in COPD patients. As expected, smoking years is identified as a strong negative predictor for all four spirometry parameters, while age and illness duration exhibit strong predictive negative associations. Furthermore, modified medical research council, arterial partial pressure carbon dioxide, St George's respiratory questionnaire, COPD assessment test, depression anxiety stress scales, and nutritional risk screening are identified as weak negative predictors. Charlson comorbidity index, phase angle, and number of comorbidities do not exhibit a significant impact on spirometry variables. Ultimately, the performed factorial analysis categorized the 29 parameters into five groups, which were identified as relating to lung function, health status, nutritional status, age, and smoking. Multiple regression analysis, including four newly derived parameters based on the results of factorial analysis, identified nutritional status as a positive predictor for spirometry readings, while smoking, poor health status, and age were identified as negative predictors in successive order.

Variability in forced expiratory volume in 1 s in children with symptomatically well-controlled asthma

AIMS

Spirometry is used by many clinicians to monitor asthma in children but relatively little is understood about its variability over time. The aim of this study was to determine the variability of forced expiratory volume in 1 s (FEV1) in children with symptomatically well-controlled asthma by applying three different methods of expressing change in FEV1 over 3-month intervals.

METHODS

Data from five longitudinal studies of children with asthma which measured FEV1 at 3-month intervals over 6 or 12 months were used. We analysed paired FEV1 measurements when asthma symptoms were controlled. The variability of FEV1% predicted (FEV1%), FEV1 z-score (FEV1z) and conditional z score for change (Zc) in FEV1 was expressed as limits of agreement.

RESULTS

A total of 881 children had 3338 FEV1 measurements on occasions when asthma was controlled; 5184 pairs of FEV1 measurements made at 3-month intervals were available. Each unit change in FEV1 z score was equivalent to a Zc 1.45 and an absolute change in FEV1% of 11.6%. The limits of agreement for change in FEV1% were -20 and +21, absolute change in FEV1 z were -1.7 and +1.7 and Zc were -2.6 and +2.1. Regression to the mean and increased variability in younger children were present for change in FEV1% and FEV1z comparisons, but not Zc.

CONCLUSION

Given the wide limits of agreement of paired FEV1 measurements in symptomatically well-controlled children, asthma treatment should primarily be guided by symptoms and not by a change in spirometry.

Modeling ventilation of patients with interstitial lung disease at rest and exercise: a bench study

BACKGROUND

The ventilatory physiopathology of patients with interstitial lung disease (ILD) remains poorly understood. We aimed to personalize a mechanical simulator to model healthy and ILD profiles ventilation, and to evaluate the effect of spontaneous breathing on respiratory mechanics at rest and during exercise.

METHODS

In a 2-compartment lung simulator (ASL 5000®), we modeled 1 healthy and 3 ILD profiles, at rest and during exercise, based on physiological data from literature and patients. Measurements were: tidal volume, end-expiratory lung volume, driving pressure, transpulmonary driving pressure, dynamic alveolar strain, mechanical power, and time lag of inspiratory flow between compartments 1 and 2.

RESULTS

Healthy and ILD models were validated: maximum differences between real and simulated tidal volume were 5% (96 ml) and 6% (54 ml) at rest and during exercise respectively, considered clinically negligible. When we simulated lung inhomogeneity (compliance in compartment 1 > compartment 2), tidal volume, end-expiratory lung volume, driving pressure and mechanical power increased in compartment 1 and decreased in compartment 2. Driving transpulmonary pressure and dynamic alveolar strain increased in compartment 2 and decreased in compartment 1. Time lag of inspiratory flow between compartments 1 and 2 was positively correlated with a difference of compliance between compartments (r = 0.98, CI95% (0.9106; 0.9962), p < 0.0001).

CONCLUSION

In this bench study, we personalized a mechanical simulator thatmodels the lung inhomogeneity and spontaneous breathing of healthy subjects and ILD patients at rest and during exercise. Our results suggest that lung inhomogeneity could increase lung vulnerability to volo-atelec-trauma mechanisms in ILD. Further physiological studies are needed to evaluate the impact of this vulnerability on acute or chronic ILD worsening.

Differential Clinical Significance of FENO200 and CANO in Asthma, Chronic Obstructive Pulmonary Disease (COPD), and Asthma-COPD Overlap (ACO)

Purpose

To investigate the differential clinical significance of fractional concentration of exhaled nitric oxide measured at a flow rate of 200 mL/s (FENO200) and concentration of nitric oxide in alveolar (CANO) in asthma, chronic obstructive pulmonary disease (COPD) or asthma-COPD Overlap (ACO).

Methods

A total of 178 patients were included, with 82 patients in asthma group, 47 patients in COPD group and 49 patients in ACO group. Data for demographic data, spirometry and exhaled nitric oxide were collected for comparative analysis, correlation analysis and discriminant canonical analysis.

Results

The values of FENO200 in asthma, COPD and ACO groups were 11.0(7.0-22.3), 8.0(6.0-11.0) and 9.0(6.5-19.5) ppb, respectively. In the asthma group, FENO200 exhibited negative correlations with FEV1/FVC, MMEF and MEF50. No significant correlation was observed between CANO and pulmonary function parameters. In the COPD group, both FENO200 and CANO showed negative correlation with pulmonary function parameters including FVC, FEV1, PEF, MMEF, MEF75, MEF50. In the ACO group, FENO200 demonstrated no significant correlation with pulmonary function parameters, while CANO was correlated with FEV1, PEF, MMEF and MEF50. In COPD group, ΔFEV1 in the bronchodilator test was correlated with FENO200. As for the ACO group, ΔFEV1 was correlated with CANO. In the discriminant canonical analysis, four parameters including gender, age, MEF75 and FENO50 discriminated between the three groups of asthma, COPD and ACO.

Conclusion

In asthma, COPD and ACO, FENO200 has demonstrated a robust correlation with CANO. Elevated FENO200 levels are predominantly indicative of pulmonary function impairment in asthma and COPD, whereas elevated CANO levels are mainly correlated with pulmonary function impairment in COPD and ACO. Compared with FENO200 and CANO, FENO50 may have a better discriminatory ability in distinguishing asthma, COPD and ACO.

Impulse oscillometry system and pulmonary function test assessment of the impact of tumor location, staging, and pathological type on lung function in primary lung cancer

PURPOSE

To study the effects of tumor site, stage, pathologic type and imaging findings on lung function in primary lung cancer, as well as the correlation between impulse oscillometry system (IOS) and pulmonary function test (PFT) parameters.

METHODS

The impact of tumor location, staging, and pathological type on lung function were evaluated in 219 patients with primary lung cancer through IOS and PFT. Spearman correlation coefficient was used to analyze the relationship between IOS parameters and PFT parameters.

RESULTS

The PFT parameters in adenocarcinoma were significantly higher than those in SCLC, while the other parameters in IOS were obviously lower than those in SCLC except X5Hz (P < 0.05). The PFT parameters of FVC%, FEV1% and MVV% in SCC were evidently higher than those in SCLC, while the parameters of IOS were significantly lower than those in SCLC (P < 0.05). The PFT parameters of adenocarcinoma were higher than those of SCC (P < 0.05). In the PFT parameters of stage I patients, FEV1/FVC%, MEF50%, MMEF75/25%, and DLCO% were markedly higher than those of stage II patients, and FVC%, FEV1%, FEV1/FVC%, MEF50%, MEF25%, PEF%, MMEF75/25%, TLC%, and DLCO% were obviously higher than those of stage III and IV patients; and the MVV%, Z5Hz%, R5Hz% in IOS parameters were obviously lower than those in stage III, while Fres (1/s) and X5Hz were significantly lower than those in stage IV (P < 0.05). Compared with Phase IV, the X5Hz of stage II patients was clearly higher (P = 0.023). Besides, PFT parameters of peripheral lung cancer were obviously higher than those of central lung cancer (P < 0.05), while Z5Hz%, Fres (1/s) and R5Hz% of IOS parameters were clearly lower than those of central lung cancer (P < 0.05). Moreover, for patients without and with other pulmonary imaging manifestations, the PFT parameters of the former were significantly higher than those of the latter (P < 0.05), while only Fres (1/s) of IOS parameters was significantly lower than the latter (P < 0.05). Furthermore, there is a low to moderate correlation between IOS parameters and PFT parameters.

CONCLUSION

Patients with central SCLC and SCC and advanced lung cancer had the worst lung function. The IOS parameters show a good correlation with the traditional PFT parameters, and IOS can be used as an alternative measurement method for PFT when necessary.

Decreases in lung volume and lung height among ankylosing spondylitis patients with pulmonary function impairment: a 3D CT investigation

BACKGROUND

Respiratory compromise among ankylosing spondylitis (AS) patients is characterized by restrictive pulmonary function, leading to the need for a meticulous assessment of lung volume. Compared with conventional pulmonary function tests (PFTs), CT-based lung volume measurements have superior accuracy and are crucial for understanding functional limitations in AS. This study investigated the correlation between CT lung volume and PFT parameters in AS patients, with a focus on changes in CT parameters and lung volume in patients with compromised pulmonary function.

METHODS

A total of 79 AS patients were included, and their full-length radiographs, thoracic CT scans, and PFT data were analysed. Specialized software was used to estimate the total and lobar lung volumes from the CT scans. The relationship between lung volume and PFT results was examined, and a multiple linear regression model was constructed to determine the influence of radiographic and CT parameters on total lung volume (TLV). Patients were classified into normal or impaired pulmonary function groups based on PFT outcomes, thus facilitating comparative analyses of radiographic and CT parameters and lung volumes between these groups.

RESULTS

Among the 79 AS patients, 19 had normal function, 4 had mixed dysfunction, and 56 experienced restrictive dysfunction. PFT parameters, including FVC, FEV1, TLC, FEV1%, and TLC%, showed varying correlations with TLV and individual lobe volume. Patients with compromised pulmonary function exhibited more pronounced spinal kyphosis and experienced a decline in TLV. Multiple regression analysis revealed that lung height and horizontal and vertical lung diameters independently influenced TLV. Notably, a decrease in lung height was observed in patients with impaired pulmonary function, whereas the horizontal and vertical diameters of the lungs remained stable.

CONCLUSIONS

In AS patients, TLV was found to be correlated with pulmonary function, particularly parameter such as FVC, FEV1, and TLC. A significant reduction in TLV was observed in those with impaired pulmonary function, with the primary contributing factor being a decrease in lung height.

Interstitial lung diseases associated with ANCA positivity: A different disease spectrum from interstitial pneumonia with autoimmune features

BACKGROUND

Anti-neutrophil cytoplasmic antibody (ANCA) is a type of autoantibodies associated with vasculitis. ANCA positivity is commonly observed in interstitial lung disease (ILD) patients. 7%-10% of ANCA-positive ILD patients don't present any symptoms of systemic vasculitis and are termed ANCA-positive idiopathic interstitial pneumonia (ANCA-IIP). Some researchers propose that ANCA-IIP should be categorized as interstitial pneumonia with autoimmune features (IPAF), although the official ATS/ERS statements exclude ANCA-IIP from this classification. Whether ANCA-IIP should be categorized into the entity of IPAF is still debatable.

METHODS

Patients diagnosed with ANCA-IIP and those with IPAF were analyzed in a retrospective study of ILD. The clinical outcomes were determined through pulmonary function tests (PFTs) after a one-year follow-up, as well as assessing all-cause mortality.

RESULTS

27 patients with ANCA-IIP and 143 patients with IPAF were analyzed from a cohort of 995 patients with ILD. Patients in the ANCA-IIP group had an older age and a high proportion of males compared to those in the IPAF group. PFT results at baseline were similar between the two groups, except for a better FEV1% in the ANCA-IIP group. Glucocorticoid and immunosuppressive therapy improved pulmonary function in patients with IPAF, but it continued to deteriorate after one year of treatment in the ANCA-IIP group. Furthermore, the all-cause mortality rate was significantly higher in the ANCA-IIP group than in the IPAF group (22.2% vs. 6.3%, P = 0.017).

CONCLUSION

The responses to glucocorticoid and immunosuppressive therapy differ between the ANCA-IIP and IPAF groups, leading to divergent prognoses. Therefore, it is inappropriate to classify ANCA-IIP as part of IPAF.

Compatibility of the global lung function 2012 spirometry reference values in children, adolescents and young adults: a systematic review

INTRODUCTION

The Global Lung Function Initiative (GLI 2012) has published multiethnic spirometry reference values. To identify studies that evaluated the compatibility (applicability, validity, representativeness, agreement and/or adequacy) of the reference equations proposed by the GLI 2012 for spirometry tests in different populations.

METHODS

Systematic searches were carried out on the PubMed, LILACS (Latin American and Caribbean Health Sciences Literature), Scopus, Web of Science and Google Scholar databases. Cross-sectional observational studies published between 2012 and 2013 onwards that evaluated the compatibility of the GLI 2012 in children, adolescents and young adults (3-20 years old) were included. The references were manually searched and the Joanna Briggs Institute Critical Appraisal Checklist for Cross-Sectional Analytical Studies was applied to assess the methodological quality of the studies included.

RESULTS

All of the 5632 studies identified were classified as low risk of bias, but only 21 were deemed eligible for inclusion. Of these, 8 reported satisfactory GLI 2012 compatibility for their populations (Argentina, Spain, Columbia, Djibouti, Norway, Poland, Jordan and Zimbabwe), 5 cautious applicability, and the remaining 8 considered the equation unsatisfactory, since it over or underestimated spirometric parameters.

CONCLUSION

The GLI 2012 equations are not applicable to all populations and must be tested before being adopted.

Single breath nitrogen test as predictor of lung function decline and COPD over an 8-year follow-up

BACKGROUND

The single breath nitrogen (SBN2) test was proposed for early detection of "small airways disease" in the seventies. Few longitudinal studies have subsequently evaluated the relationships between SBN2 test measurements and lung function decline or COPD incidence.

AIM

This study evaluates whether SBN2 test abnormalities may be significant predictors of lung function decline and COPD incidence over an 8-year follow-up.

STUDY DESIGN AND METHODS

In this longitudinal study, 907 adults (20+ years old; 56% males) from the prospective Po River Delta epidemiological study underwent SBN2 test at baseline and spirometry testing at both baseline and follow-up 8-year apart. Multinomial and multiple regression models were used to assess associations of SBN2 indexes and rates of FEV1 decline or risk of COPD incidence over time, after adjusting for sex, height and baseline age, FEV1 and smoking status. COPD was defined according to either GOLD or ATS-ERS criteria.

RESULTS

Among SBN2 indexes, only the slope of alveolar plateau (N2-slope) was significantly associated with rates of FEV1 decline (7.93 mL/year for a one-unit change in N2-slope, p<0.0001), and with an increased risk of developing COPD as defined by GOLD (RR 1.81, 95%CI 1.29-2.52, mild; RR 2.78, 95%CI 1.70-4.53, moderate or severe obstruction) and ATS-ERS criteria (RR 1.62, 95%CI 1.14-2.29, mild; RR 3.40, 95%CI 1.72-6.73, moderate or severe obstruction).

CONCLUSION

In this population-based study, N2-slope from SBN2 test is a significant predictor of lung function decline and COPD incidence over an 8-year follow-up, confirming the role of the "small airways disease" in the natural history of COPD.

Restrictive Spirometric Pattern and Preserved Ratio Impaired Spirometry in a Population Aged 50-64 Years

Rationale: Knowledge regarding the prevalence and shared and unique characteristics of the restrictive spirometric pattern (RSP) and preserved ratio impaired spirometry (PRISm) is lacking for a general population investigated with post-bronchodilator spirometry and computed tomography of the lungs. Objectives: To investigate shared and unique features for RSP and PRISm. Methods: In the Swedish CArdioPulmonary bioImage Study (SCAPIS), a general population sample of 28,555 people aged 50-64 years (including 14,558 never-smokers) was assessed. The participants answered a questionnaire and underwent computed tomography of the lungs, post-bronchodilator spirometry, and coronary artery calcification score. Odds ratios with 95% confidence intervals (CIs) were calculated using adjusted logistic regression. RSP was defined as forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ≥0.70 and FVC <80%. PRISm was defined as FEV1/FVC ≥0.70 and FEV1 <80%. A local reference equation was applied. Results: The prevalence of RSP and PRISm were 5.1% (95% CI, 4.9-5.4) and 5.1% (95% CI, 4.8-5.3), respectively, with similar values seen in never-smokers. For RSP and PRISm, shared features were current smoking, dyspnea, chronic bronchitis, rheumatic disease, diabetes, ischemic heart disease, bronchial wall thickening, interstitial lung abnormalities, and bronchiectasis. Emphysema was uniquely linked to PRISm (odds ratio, 1.69; 95% CI, 1.36-2.10) versus 1.10 (95% CI, 0.84-1.43) for RSP. Coronary artery calcification score ≥300 was related to PRISm, but not among never-smokers. Conclusions: PRISm and RSP have respiratory, cardiovascular, and metabolic conditions as shared features. Emphysema is only associated with PRISm. Coronary atherosclerosis may be associated with PRISm. Our results indicate that RSP and PRISm may share more features than not.

Asthma and health-related quality of life at 16-20 years of age in a prospectively followed post-bronchiolitis cohort

The aim was to evaluate asthma and health-related quality of life (HRQoL) outcomes in adolescents, after hospital-treated bronchiolitis experienced in less than 6 months of age. A prospective cohort study started in 2001-2004 and followed up 166 children hospitalised for bronchiolitis in early infancy. At 16-20 years of age, 76 cases and 41 population-based controls without a history of bronchiolitis participated in the current study. Clinical asthma, presumptive symptoms and HRQoL data were collected with a structured questionnaire and the St. Georges Respiratory Questionnaire (SGRQ). Flow-volume spirometry was measured before and after bronchodilator administration. Asthma was present in 21.1% of cases in the post-bronchiolitis cohort compared to 9.8% in the control group (p = 0.21). Also, 35.5% of cases and 19.5% of controls reported dyspnea during the last 12 months (p = 0.04). In addition, total SGRQ scores were higher in the bronchiolitis group (4.26) than in the control group (1.67, p < 0.001) referring to a reduced health-related quality of life.

CONCLUSION

Viral bronchiolitis in early infancy was associated with increased respiratory symptoms and lower health-related quality of life at age 16-20 years.

WHAT IS KNOWN

• The prevalence of asthma at the school age and adolescence is increased after hospitalisation required bronchiolitis in infancy compared to those without hospitalisation due to bronchiolitis.

WHAT IS NEW

• Viral bronchiolitis requiring hospitalisation in early infancy was associated with increased respiratory symptoms, such as dyspnoea, and lower health-related quality of life at age 16-20 years in a prospectively followed post-bronchiolitis cohort.

Evaluating the Role of Maximal Expiratory Flow at 25% (MEF-25) in Detecting and Managing Patients With Small Airway Disease in the United Arab Emirates

Middle Eastern countries, such as the United Arab Emirates and Oman, are affected by frequent dust storms and extreme hot climatic conditions, which can exacerbate respiratory conditions. These environmental factors are particularly injurious to asthmatic patients, as they can aggravate small airway disease (SAD), leading to increased morbidity and healthcare challenges. The evaluation of maximal mid-expiratory flow (MEF-25) as a diagnostic and therapeutic tool for early-stage small airway dysfunction is of significant clinical importance, particularly in hot and arid metropolitan environments where dusty conditions exacerbate pulmonary issues. This study assesses the value of MEF-25 in clinical practice for detecting SAD and investigates the effectiveness of inhaled bronchodilator therapy with extra-fine particles augmented by a spacer in helping to manage the symptoms of these patients. This retrospective, single-center study was conducted at King's College Hospital Dubai, including 225 patients aged 18 and above, who presented with MEF-25 values less than 80%. Data were collected from the Electronic Medical Record system, including demographics, spirometry findings, and treatment outcomes. MEF-25 values were categorized into moderate (51-80%), severe (35-50%), and very severe (1-34%) grades. Statistical analysis was performed using IBM SPSS software. Results revealed significant correlations between MEF-25 severity and various clinical parameters. Notably, Immunoglobulin E (IgE) and Fractional Exhaled Nitric Oxide (FeNO) levels showed an inverse relationship with decreasing MEF-25 values. Symptoms such as wheezing were more prevalent as MEF-25 values decreased, indicating that MEF-25 is a sensitive indicator of small airway dysfunction (SAD). Additionally, treatment with an inhaled corticosteroid (ICS) combined with a long-acting beta-agonist (LABA), using an inhaler with a fine particle size and augmented by a spacer device, demonstrated substantial and prompt improvement of symptoms. Follow-up data showed a high rate of symptom resolution within one to six weeks after treatment initiation. This study underscores the importance of MEF-25 in the early detection of SAD in the setting of dusty, humid, and hot climatic conditions, and supports the use of beclomethasone-formoterol with a spacer as an effective treatment strategy in optimizing clinical outcomes. The findings advocate for the integration of MEF-25 in routine spirometry evaluation to enhance the diagnosis and management of SAD, particularly in environments prone to high amounts of respiratory allergens.

Pulmonary Function in Pediatric Stem Cell Transplantation

BACKGROUND

Pediatric hematopoietic stem cell transplantation often results in pulmonary complications, yet limited data exist on pulmonary function in Thailand. This study aims to assess pulmonary function, investigating associated complications and identifying clinical factors linked to pre- and post-transplant pulmonary function defects.

METHODS

In this retrospective cohort study, we focused on children aged 6-18 years who underwent hematopoietic stem cell transplantation between 1999 and 2020, ensuring accessible pulmonary function tests results.

RESULTS

Among 48 patients, abnormal pulmonary function pre- and post-transplant (2-8 years) included a diffusion defect in 16.7% and 18.8%, a restrictive defect in 20.8% and 8.3%, and an obstructive defect in 4.2% and 10.4%, respectively. Pulmonary complications occurred in 16 patients (33.3%), including 15 infections and 1 case of bronchiolitis obliterans. While pretransplant pulmonary function defects were not significantly associated with specific characteristics, post-transplant pulmonary complications correlated with post-transplant pulmonary function defects (aOR = 4.11, 95% CI = 1.23-13.64, P = .02). Among the 6 patients with pre- and post-transplant follow-up, those with pulmonary complications showed a discernible decline in pulmonary function over time, while those without pulmonary complications remained stable or improved. However, the differences between these groups did not reach statistical significance (P = .13-.76).

CONCLUSIONS

Prevalent pulmonary function defects and complications in pediatric hematopoietic stem cell transplantation highlight the importance of close pulmonary function monitoring. Post-transplant pulmonary complications are associated with defects, suggesting a potential trend of a subsequent decline in lung function, warranting further prospective validation.

Lung function improvement on triple modulators: high-resolution, nationwide data from the Danish Cystic Fibrosis Cohort

Background

People living with cystic fibrosis in Denmark had early, universal access to triple modulator treatment with elexacaftor/tezacaftor/ivacaftor. Close monitoring allowed us to assess the impact of treatment on lung function and progression of lung disease in an unselected nationwide cystic fibrosis population from 6 years of age.

Methods

Data were analysed using linear mixed-effect models to assess changes in levels and annual rates of change (slopes) in percent predicted (pp) forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and forced expiratory flow at 25-75% of FVC (ppFEF25-75%) between the 12 months pre-treatment and treatment periods. Subgroup analyses assessed the impact of elexacaftor/tezacaftor/ivacaftor among those with/without previous modulator treatment, normal/mild/moderate/severe lung disease at treatment initiation, children/adults and birth cohorts.

Results

We included 392 people living with cystic fibrosis with a median (interquartile range) 12 (nine to 15) spirometry measurements per person. The mean (95% CI) improvement in ppFEV1 was 13.0 (11.3-14.6) 12 months after initiation of elexacaftor/tezacaftor/ivacaftor treatment. The annual rate of change improved from -1.4 (-2.1 - -0.6) ppFEV1 in the pre-treatment year to 2.7 (1.8-3.5) ppFEV1 per year during treatment. Similarly, ppFVC increased by 8.0 (7.1-8.9) and FEF25--75% by 19.5 (17.0-21.9).

Conclusions

Using high-resolution data from a nationwide real-world setting, our study documents the impact of elexacaftor/tezacaftor/ivacaftor on lung function across subgroups based on age, disease severity and treatment history. These findings point towards a new period of consistent lung function improvement among people living with cystic fibrosis on elexacaftor/tezacaftor/ivacaftor.

How safe is lung transplantation in patients of 65 years or older? A single-center retrospective cohort

INTRODUCTION

With increasing experience in high-volume centers, age alone should not be an absolute contra-indication to lung transplantation (LT) but be considered as part of the patient's initial characteristics. The objective of this study is to provide early and long-term outcomes of LT in recipients aged 65 or older, compared with their younger counterparts.

METHODS

This is a retrospective study, including all patients undergoing LT in Bichat Hospital (Paris, France) from January 2014 to March 2019. Two groups were defined depending on the patients' age when they were transplanted: patients older than 65 were defined as the "elderly group" and patients younger than 65 years old were defined as the « younger group ». Primary endpoint was 90-day mortality. Secondary endpoints included 1-year mortality, 1-year FEV1 (forced expiratory volume in one second), and 5-year overall survival.

RESULTS

From September 2014 to March 2019, 22 patients were included in the "elderly group" and 213 were included in the « younger group ». The elderly group had more single LT (SLT) (82% vs. 29%, p < 0.001), with a shorter cold ischemic time (243 min vs. 310 min, p = 0.001) and a lower rate of early humoral rejection (9% vs. 30%, p = 0.045) compared to the younger group. Ninety-day mortality was not significantly different between elderly and younger group (9% vs. 14%, p = 0.95, respectively), nor were 1-year mortality (23% vs. 25%, p = 0.9, respectively) and 5-year overall survival. Six months after LT, FEV1 was significantly better in the elderly group compared to the younger group (77.0% vs. 65.5%, p = 0.037 respectively), but the difference did not reach statistical significance after one year (78.5 vs. 68.3%, p = 0.18 respectively).

CONCLUSION

Elderly patients underwent more frequently single LT, and achieved similar short and long term postoperative outcomes compared to their younger counterparts. LT for patients 65 years or older should be routinely considered when carefully selected.

A novel method for determining ventilatory and gas exchange dynamics during exercise: the "chirp" waveform

Quantitating exercise ventilatory and gas exchange dynamics affords insights into physiological control processes and cardiopulmonary dysfunction. We designed a novel waveform, the chirp waveform, to efficiently extract moderate-intensity exercise response dynamics. In the chirp waveform, work rate fluctuates sinusoidally with constant amplitude as sinusoidal period decreases progressively from ∼8.5 to 1.4 min over 30 min of cycle ergometry. We hypothesized that response dynamics of pulmonary ventilation (V̇e) and gas exchange [oxygen uptake (V̇o2) and carbon dioxide output (V̇co2)] extracted from chirp waveform are similar to those obtained from stepwise transitions. Thirty-one participants [14 young healthy, 7 older healthy, and 10 patients with chronic obstructive pulmonary disease (COPD)] exercised on three occasions. Participants first performed ramp-incremental exercise for gas exchange threshold (GET) determination. In randomized order, the next two visits involved either chirp or stepwise waveforms. Work rate amplitude (20 W to ∼95% GET work rate) and exercise duration (30 min) were the same for both waveforms. A first-order linear transfer function with a single system gain (G) and time constant (τ) characterized response dynamics. Agreement between model parameters extracted from chirp and stepwise waveforms was established using Bland-Altman analysis and Rothery's concordance coefficient (RCC). V̇e, V̇o2, and V̇co2 Gs showed no systematic bias (P > 0.178) and moderate-to-good agreement (RCC > 0.772, P < 0.01) between waveforms. Similarly, no systematic bias (P = 0.815) and good agreement (RCC = 0.837, P < 0.001) was found for τV̇o2. Despite moderate agreement for τV̇co2 (RCC = 0.794, P < 0.001) and τV̇e (RCC = 0.722, P = 0.083), chirp τ was less [-6.9(11.7) s and -12.2(22.5) s, respectively]. We conclude that the chirp waveform is a promising method for measuring exercise response dynamics and investigating physiological control mechanisms.NEW & NOTEWORTHY We investigated the ability of a novel waveform to extract exercise ventilatory and gas exchange dynamics. In the chirp waveform, work rate fluctuates sinusoidally with constant amplitude as sinusoidal period decreases progressively over 30 min of exercise. In a study of 31 healthy individuals and patients with COPD, comparison of exercise dynamics derived from chirp to those from stepwise waveforms suggests that the chirp waveform is a promising method for derivation of exercise response dynamics.

30-day Spirometry Holter method design and prospective observational study

Asthma underdiagnosis and overdiagnosis remain significant problems for healthcare systems worldwide and indicate considerable pain points with current guidelines and diagnostic methods; therefore, new, targeted approaches seem crucial. This study introduces a novel spirometry-based approach using digital tools for objective asthma diagnosis support. This was a single-centre (Warsaw Medical University, Poland) prospective cohort study. It included adults with suspected asthma per GINA 2020, without confirmed obstruction in ambulatory spirometry. Patients were equipped and trained with a portable spirometer with built-in manoeuvre quality features AioCare® (HealthUp, Poland). The protocol included twice-daily spirometry examinations over four weeks and symptom reporting in the mobile app. The number of obstructions detected, probability of finding obstruction over time, spirometry values' variability, technical correctness, and reported symptoms were evaluated. 26 patients enrolled (14 females, mean age 37.6 years old, BMI 24.7 kg/m^2), with a primary outcome of observed obstruction in 42% of participants (3.08 per patient, 95%CI: 0.78-5.37). The detection probability of obstruction plateaued at 100% within the first 21 days of monitoring. Diurnal PEF and FEV1 variability were exceeded (≥ 10%) in 73% and 66% of patients, respectively. 88% of participants performed over half of their tests correctly. 85% of patients reported symptoms at least once. The Spirometry Holter is a novel and feasible tool for monitoring airway limitation variability in line with GINA guidelines. It shows promise in objectively supporting asthma diagnoses in treatment-naive patients lacking documented prior obstruction.

Polyhexamethylene Guanidine Phosphate Induces Restrictive Ventilation Defect and Alters Lung Resistance and Compliance in Mice

Polyhexamethylene guanidine phosphate (PHMG-p), a major ingredient of humidifier disinfectants, is known to induce inflammation, interstitial pneumonitis, and fibrosis in the lungs. While its histopathologic toxicities have been studied in rodents, research on pulmonary function test (PFT) changes following PHMG-p exposure is limited. This study aimed to investigate the acute and chronic effects, as well as the dose and time response, of PHMG-p on the lungs in mice using PFT and histopathologic examinations. In the single instillation model, mice received PHMG-p and were sacrificed at 2, 4, and 8 weeks. In the five-time instillation model, PHMG-p was administered five times at one-week intervals, and mice were sacrificed 10 weeks after the first instillation. Results showed that PHMG-p exposure reduced lung volume, increased resistance, and decreased compliance, indicating a restrictive ventilation defect. Histopathologic examination showed increases in lung inflammation and fibrosis scores. Changes in several lung volume and compliance parameters, as well as histopathology, were dose-dependent. Lung resistance and compliance parameters had significant correlations with lung inflammation and fibrosis scores. PHMG-p exposure in mice resulted in a restrictive ventilation defect with altered lung resistance and compliance, along with histopathologic lung inflammation and fibrosis.

Impact of post-pulmonary tuberculosis sequelae and its management in a tertiary care facility in South India

BACKGROUND

Post-pulmonary Tuberculosis (PTB) sequelae are chest alterations caused by pulmonary tuberculosis problems, even after treatment and infection elimination. These alterations can cause pulmonary dysfunction, ranging from mild irregularities to acute dyspnea, increasing the risk of respiratory-related deaths. Current research aims to investigate the type, severity, clinical management, and impact on quality of life in affected individuals.

MATERIALS AND METHODS

A prospective observational study with 66 patients was carried out in a South Indian tertiary care facility. We gathered sociodemographic and clinical data from the patients. Imaging investigations (chest X-ray, CT scans) and pulmonary function test reports (Spirometry) were used to assess the post-pulmonary TB sequelae. The patient's quality of life was evaluated using the WHOQoL-BREF questionnaire.

RESULTS

Out of 66 patients, 66.7% were men, and the average age was 57.2 years. According to radiological analysis, most patients had airway difficulties (38%), followed by parenchymal problems (36.3%). Obstruction was the most typical abnormality identified (81.9%). Bronchodilators, LABA + ICS, SABA, leukotriene antagonists, antibiotics, and other fixed medications treat post-PTB sequelae. Substantial impairment was observed in quality of life.

CONCLUSION

Patients who have had pulmonary TB are prone to post-TB respiratory symptoms and sequelae. The quality of life noticeably declined. This study's findings underscore the importance of robust, evidence-based guidelines and practical implementation techniques for managing post-pulmonary TB.

The Clinical Utility of Pulmonary Function Tests in the Diagnosis and Characterization of Central Airway Obstruction: A Narrative Review

Central airway obstruction is of major clinical importance since it is a major cause of morbidity and mortality and is usually clinically diagnosed late. Pulmonary function tests, with the recent incorporation of oscillometry, can have a crucial role in earlier diagnosis. In this review, we summarize all recent advances in that view, including the crucial role of oscillometry.

A Rare Case of Tracheal Schwannoma Successfully Treated With Endoscopic Resection and Cryoablation Under Rigid Bronchoscopy

We present a rare case of tracheal schwannoma, the first reported in Hong Kong, emphasizing the diagnostic challenges and treatment outcomes. A 54-year-old woman with respiratory symptoms underwent evaluations revealing a tracheal mass causing luminal narrowing. Emergency operation with rigid bronchoscopy and cryoablation successfully removed the tumor. Follow-up bronchoscopies showed a gradual reduction in residual tumor size, with no evidence of recurrence after 3.5 years postoperation. Tracheal schwannomas are exceedingly rare, often resulting in delayed diagnosis. Clinicians should maintain a high suspicion of tracheal tumors in patients with unexplained respiratory symptoms. Spirometry and flow volume loop analysis aid in identifying upper airway obstruction. Rigid bronchoscopy is preferred for diagnosis and treatment, ensuring airway stability and obtaining tissue samples. Surgical resection remains the mainstay, but observation after endoscopic resection may be considered. This case highlights the successful management of tracheal schwannoma through endoscopic resection and cryoablation, emphasizing the need for further studies and case reports on this rare entity.

Implications of the 2022 lung function update and GLI global reference equations among patients with interstitial lung disease

BACKGROUND

Lung function testing remains a cornerstone in the assessment and management of interstitial lung disease (ILD) patients. The clinical implications of the Global Lung function Initiative (GLI) reference equations and the updated interpretation strategies remain uncertain.

METHODS

Adult patients with ILD with baseline forced vital capacity (FVC) were included from the Australasian ILD registry and the National Healthcare Group ILD registry, Singapore.The European Coal and Steel Community and Miller reference equations were compared with the GLI reference equations to assess (a) differences in lung function percent predicted values; (b) ILD risk prediction models and (c) eligibility for ILD clinical trial enrolment.

RESULTS

Among 2219 patients with ILD, 1712 (77.2%) were white individuals. Idiopathic pulmonary fibrosis (IPF), connective tissue disease-associated ILD and unclassifiable ILD predominated.Median FVC was 2.60 (2.01-3.36) L, forced expiratory volume in 1 s was 2.09 (1.67-2.66) L and diffusing capacity of the lungs for carbon monoxide (DLCO) was 13.60 (10.16-17.60) mL/min/mm Hg. When applying the GLI reference equations, the mean FVC percentage predicted was 8.8% lower (87.7% vs 78.9%, p<0.01) while the mean DLCO percentage predicted was 4.9% higher (58.5% vs 63.4%, p<0.01). There was a decrease in 19 IPF and 119 non-IPF patients who qualified for the nintedanib clinical trials when the GLI reference equations were applied. Risk prediction models performed similarly in predicting mortality using both reference equations.

CONCLUSION

Applying the GLI reference equations in patients with ILD leads to higher DLCO percentage predicted values and smaller lung volume percentage predicted values. While applying the GLI reference equations did not impact on prognostication, fewer patients met the clinical trial criteria for antifibrotic agents.

Mediated relationship between Vitamin D deficiency and reduced pulmonary function by copper in Taiwanese young adults

BACKGROUND

Vitamin D deficiency is prevalent worldwide and associated with worse outcomes in various lung diseases. This study examines the association between vitamin D deficiency and pulmonary function in healthy young adults.

METHODS

This prospective cohort study (2017-2019) explored the impact of vitamin D deficiency on pulmonary function in a community-based young adult population. Pulmonary function was assessed via spirometry, with serum 25-hydroxyvitamin D [25(OH)D] and urinary copper levels quantified. Multivariate regression was used to estimate the relationship between vitamin D levels and lung function, with mediation analysis evaluating copper's role.

RESULTS

The study included 1034 participants, average age 33.45 years, 41.93 % male. The median 25(OH)D level was 19.20 ng/mL (Interquartile Range: 13.48-24.90 ng/mL). Over half (54.74 %) had 25(OH)D levels below 20 ng/mL. Higher 25(OH)D levels were associated with better forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁). Trends suggested subgroup differences, but these were not statistically significant, indicating a consistent effect of 25(OH)D on pulmonary function across groups. SEM analysis suggested urinary copper as a mediator between 25(OH)D levels and FVC.

CONCLUSION

Vitamin D deficiency is significantly associated with reduced pulmonary function in young adults in Taiwan.

Air pollution exposure, chemical compositions, and risk of expiratory airflow limitation in youth in Northeast China

BACKGROUND

Expiratory airflow limitation (EAL) is closely associated with respiratory health in youth and adulthood. Owing to limited evidence, we aim to estimate the association between air pollutants, both individually and in combination, along with their chemical compositions, and the risk of EAL in youth based on data obtained from Northeast China Biobank.

METHODS

Pulmonary function was evaluated using a medical-grade pulmonary function analyzer, with EAL defined as a forced expiratory flow in 1 s/ forced vital capacity ratio of < 0.8. Land use regression models were used to predict exposure to six air pollutants. Air pollution score (APS) for each participant was constructed as combined exposure. The chemical composition of particulate matter with an aerodynamic diameter of ≤ 2.5 µm (PM2.5) was determined using a validated machine-learning algorithm. Logistic regression models were employed to estimate effect sizes, and odds ratio (OR) and 95 % confidence intervals (CI) were calculated.

RESULTS

In total, 905 EAL cases were identified among the 4301 participants, with a prevalence of 21.04 %. Each inter-quartile range increase in APS was associated with a 25 % higher risk of EAL (OR = 1.25, 95 % CI: 1.12, 1.39). Among the pollutants analyzed, PM2.5 exposure had the strongest association with the risk of EAL (OR = 1.33, 95 % CI: 1.18, 1.52). Out of the five chemical components, sulfate (SO2-4) (OR = 1.39, 95 % CI: 1.24, 1.57) and ammonium (NH+4) (OR = 1.39, 95 % CI: 1.23, 1.57) exhibited the strongest associations with the risk of EAL.

CONCLUSIONS

Overall, combined effects of air pollution increased the risk of EAL in youth, with SO2-4 and NH+4 emerging as the predominant contributing chemical components in Northeast China.

Race-Based Pulmonary Function Testing Correction in COPD Inhaler Therapy Trials: A Systematic Review

Purpose

Race-based correction is widely utilized in clinical practice, but may contribute to overestimation of lung function, underdiagnoses in minority groups, and exclusion of minority groups from research trials. The aim of this systematic review is to examine the usage of race-based correction in pulmonary function testing (PFT) within chronic obstructive lung disease (COPD) research and its impact on the exclusion of minority groups from research trials.

Methods

We systematically searched Medline from 2010 to 2022 to identify randomized controlled trials (RCTs) that examine inhaler therapy for COPD. Article screening, critical appraisal, and data extraction were completed in duplicate by independent reviewers. Data regarding study design, inclusion criteria, demographics, and race-based correction were extracted and synthesized narratively.

Results

Of the 774 screened articles, we included 21 RCTs in the review, which were multinational trials involving 70696 study participants. All studies had an inclusion criteria of an FEV1 cutoff of 50% to 80%. Racial minorities remained underrepresented in the trials, with the proportion of black participants ranging from <1% to 4.7%. Four studies directly mentioned race-based correction, while the remainder of the studies did not provide any explicit details. After obtaining additional information by contacting authors and reviewing the citations, 15 were estimated to utilize race-based correction.

Conclusion

Race-based correction may be frequently utilized in major COPD RCTs, but there remains inconsistent reporting regarding the usage of race-based correction. This may contribute to the exclusion of racialized populations from research trials as there remains significant underrepresentation of racialized populations from research.

Per and poly-fluoroalkyl substances and respiratory health in an Inuit community

BACKGROUND

Concentrations of plasma per and poly-fluoroalkyl substances (PFAS) are elevated in the Inuit population of Nunavik and may be causing adverse health effects. Respiratory health outcomes have been associated with PFAS, but have not been explored in Inuit communities. The aim of the study was to examine the association between PFAS and respiratory health outcomes, and the moderating role of nutritional biomarkers.

METHODS

We included up to 1298 participants of the Qanuilirpitaa? 2017 survey aged 16-80 years. Generalized regression models were used to estimate the associations between six individual PFAS congeners and four self-reported symptoms, four spirometry measures, and physician-diagnosed asthma. Outcomes associated with PFAS from single chemical models were further explored using Bayesian Kernel Machine Regression (BKMR). The modifying effect of n-3 PUFA in red blood cell quartiles and vitamin D deficiency were examined on the associations between PFAS and respiratory outcomes.

RESULTS

PFNA and PFOS were associated with asthma (odds ratio (OR) 1.61, 95% confidence interval (CI) 1.12, 2.32; OR 1.45 95% CI 1.04, 2.03). PFOA, PFNA, PFDA and PFHxS were associated with a decrease in the ratio between the forced expiratory volume in the first second and forced vital capacity (FEV1/FVC). No associations were observed with self-reported respiratory symptoms. No associations were observed between a PFAS mixture and asthma. Some associations were modified by nutritional factors, namely, stronger associations between PFOA and PFHxS and asthma with lower n-3 PUFA levels and stronger associations between PFDA, PFUnDA and PFOS and FEV1/FVC with vitamin D deficiency.

CONCLUSION

These findings add to the growing literature on the impacts of PFAS on respiratory health, and the importance of their global regulation. Associations were modified by nutritional factors pointing to the nutritional value of traditional Inuit foods.

Myositis-Associated Interstitial Lung Disease: The Experience of a Tertiary Center

Background: Interstitial lung disease (ILD) is a common extra-muscular manifestation of idiopathic inflammatory myopathies (IIMs), often associated with a poorer prognosis and increased mortality risk. Methods: This retrospective study aimed to characterize lung involvement and treatment response in an IIM cohort at a Portuguese tertiary center, followed between June 2016 and March 2024. We analyzed data from high-resolution computed tomography (HRCT) scans and pulmonary function tests (PFTs) to assess associations with autoantibody profiles and treatment regimens. Results: A total of 198 patients were included, with 69 (34.8%) exhibiting ILD. Antisynthetase syndrome (ASyS) and dermatomyositis were the most common diagnoses among IIM-ILD patients, with ASyS being significantly more frequent in this group than in non-ILD patients (p < 0.001). Anti-Jo1 and anti-MDA-5 antibodies were more frequent in ILD patients (p < 0.001 and p = 0.021), while anti-Mi2 antibodies were less common (p = 0.002). Non-specific interstitial pneumonia (NSIP) was the most common radiological pattern (69.5%). IIM-ILD patients presented with significantly lower forced vital capacity (FVC) and diffusing capacity of the lung for carbon monoxide (DLCO) compared to non-ILD patients (p < 0.001 for all values). Longitudinal analysis showed improved DLCO (p = 0.022) and stable or improved FVC (p = 0.097), especially with intravenous immunoglobulin (IVIg) and azathioprine (AZA). Combination therapies including IVIg with mycophenolate mofetil (MMF) or rituximab (RTX) also improved DLCO and FVC. Most ILD patients (89.6%) had stable HRCT patterns over time. Conclusions: Our findings highlight the potential for stabilizing or even improving lung function in IIM-ILD with appropriate immunosuppressive therapy, particularly with regimens incorporating IVIg and AZA, and combination therapies.

Fixed Airflow Obstruction in Asthma Can Be Identified Early by Low FEF25-75% and is Associated with Environmental Exposure

Purpose

This study aimed to identify environmental risk factors associated with asthmatic fixed airflow obstruction (FAO) and assess the relationship between small airway abnormalities defined by forced expiratory flow at 25-75% (FEF25-75%) and FAO.

Patients and Methods

We analyzed data from 312 han Chinese patients with stable asthma on standard treatment. Low FEF25-75% was defined as post-bronchodilator FEF25-75% z-score <-0.8435, and FAO as post-bronchodilator FEV1/FVC z-score <-1.645. Exposure levels were retrospectively analyzed in relation to FAO risk in asthmatics. Asthmatics were grouped by low FEF25-75% and FAO, and lung function, environmental exposure, daily symptoms, and exacerbations in the previous year were compared cross-sectionally across groups.

Results

In retrospective analyses, pack-years of smoking in male patients (adjusted odd ratio [95% confidence interval] 1.05 [1.03-1.07], P<0.001), biomass exposure for >20 years (2.65 [1.13-6.43], P=0.027), occupational exposure for >10 years (2.01 [1.06-3.86], P=0.035) and occupational exposure for >20 years (2.67 [1.24-5.91], P=0.013) were associated with asthmatic FAO. In cross-sectional analyses, compared with the normal FEF25-75%/ asthmatics without FAO (NON-FAO) group, the low FEF25-75%/ asthmatics with FAO (FAO) group had lower FEV1 z-scores and FEV1/FVC z-scores, more pack-years and years of biomass and occupational exposure, higher Asthma Control Questionnaire-5 and Chronic Obstructive Pulmonary Disease Assessment Test scores, and more frequent exacerbations. The low FEF25-75%/NON-FAO group showed the same trend, but to a lesser extent.

Conclusion

Chronic airway inflammation is not the only driver of asthmatic FAO, and management and treatment targeting environmental risk factors (smoking and biomass and occupational exposures) may slow FAO progression in asthmatics. The FEF25-75% determined by the z-score is a reliable marker of small airway abnormalities, and patients with low FEF25-75% are at greater risk for FAO, requiring more frequent follow-up.

Personality Traits and Self-Reported Vocal Fatigue and Other Voice Measures Among Teachers

BACKGROUND

Previous research has examined the correlation between certain personality traits and specific voice disorders. These studies indicated that a predictive relationship exists between an individual's personality and their likelihood of experiencing certain types of voice disorders. The personality type classified as "extravert" was most commonly correlated with voice problems associated with high vocal use such as inflammation or nodules.

AIM

The purpose of this study was to determine if a relationship exists between self-reported vocal fatigue, demographic characteristics, such as assigned sex at birth and age, perception of current voice condition, aerodynamic measures, and voice acoustic parameters with any of the five personality traits measured by the Big Five Personality Index: Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness. We hypothesized that vocal fatigue scores and spirometry measurements may be good predictors of specific personality traits, and therefore, can be useful measures to complement vocal assessment.

METHODS

Participants in this cross-sectional correlational study included 73 full-time elementary and middle school teachers. Participants completed the Vocal Fatigue Index (VFI) and the Big Five Inventory (BFI)-10 personality index; further, microphone recordings were collected from a battery of voice tasks in addition to spirometry. Descriptive analyzes of the dependent variables (BFI personality traits) and independent variables (demographics, acoustics, spirometry, and VFI total score) were performed, calculating frequency values. Kruskal-Wallis tests were conducted to evaluate independent variables' differences across the scores of the five BFI personality traits. The association between the independent and dependent variables was then investigated using a Generalized Estimating Equations multinomial logit model. The level of significance was defined at 0.05, and the associations are expressed as betas and standard error.

RESULTS AND CONCLUSION

The results suggest that high scores for the traits of extraversion and agreeableness were both predicted by lower scores on the VFI (P ≤ 0.05), indicating that individuals with lower perception of vocal fatigue may be more likely to be identified as extraverted and/or agreeable personalities. These results support previous study's conclusion as well as add additional insights that could be translated into screening protocols and additional supportive care of occupational voice users.

Comparison of Exercise Protocols for Diagnosing Pediatric Unexplained Dyspnea on Exertion

PURPOSE

Clinicians evaluating pediatric patients with unexplained dyspnea on exertion (DOE) often obtain exercise testing with a treadmill-based exercise-induced bronchospasm (EIB) protocol measuring only changes in spirometry. We modified the EIB protocol to collect metabolic and lung volume endpoints as obtained in a cardiopulmonary exercise test (CPET). We tested the hypothesis that measuring metabolic data with the EIB protocol (EIB-CPET) would yield greater diagnostic information than the EIB protocol.

METHODS

Exercise test diagnosis for healthy children with DOE referred to the pulmonary exercise lab from January 2011 through July 2023 were retrospectively compared between those performing either the EIB or EIB-CPET protocols.

RESULTS

One hundred and twenty-seven patients with unexplained DOE were analyzed. Of the 72 patients tested on the EIB protocol, 49% had stridor and 5% with EIB. Of the 55 patients tested on the EIB-CPET protocol, 42% had stridor, 42% with normal physiologic limitation, 22% with dysfunctional breathing, 5% with deconditioning, 2% with EIB, and 2% with exercise-induced hypoxemia. Patients performing the EIB-CPET protocol had a significantly higher rate of any diagnosis compared with EIB (P = .0002).

CONCLUSIONS

There is a greater diagnostic yield in children with unexplained DOE performing the EIB-CPET protocol compared with patients performing the EIB protocol.

A Comparative Observational Study of the Diagnostic Utility of Impulse Oscillometry Versus Spirometry in Obstructive Airway Diseases

Background Obstructive airway diseases, including asthma and chronic obstructive pulmonary disease (COPD), significantly impact respiratory function, making accurate diagnosis and differentiation essential for proper management. While spirometry is the gold standard for assessing lung function, impulse oscillometry (IOS) has emerged as a complementary tool, especially when spirometry results are inconclusive. This study aimed to compare the diagnostic utility of IOS with spirometry in patients with obstructive airway diseases and evaluate the correlation between these two methods. Methods A comparative observational study was conducted over 18 months at a tertiary care hospital in central India, including 130 patients (65 with asthma and 65 with COPD). Diagnostic evaluations using spirometry and IOS were performed before and after bronchodilator administration. Spirometry parameters assessed were forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio, while IOS parameters evaluated included resistance at 5 Hz (R5), resistance at 20 Hz (R20), resonant frequency (Fres), reactance at 5 Hz (X5), and the area under the reactance curve (AX). Statistical analysis was conducted using IBM SPSS version 27.0 (IBM Corp., Armonk, USA) and GraphPad Prism version 7.0 (Dotmatics, Boston, USA). Results Significant differences were observed in spirometry parameters between asthma and COPD groups, with asthma patients showing better lung function (FEV1, FVC, and FEV1/FVC; p<0.05). No significant differences were found in IOS parameters between the groups except for a correlation between FEV1 (%) and IOS measurements in the asthma group. Spirometry demonstrated superior sensitivity in identifying airway obstruction compared to IOS. However, IOS was more effective in detecting peripheral airway obstruction in asthma patients, with 22 out of 65 (33.85%) asthma patients showing peripheral airway obstruction compared to six out of 65 (9.23%) COPD patients (p=0.001). Conclusion While spirometry remains the primary diagnostic tool for assessing obstructive airway diseases, IOS is a valuable adjunct, particularly for detecting peripheral airway involvement in asthma patients. Combining spirometry and IOS enhances diagnostic accuracy and provides a more comprehensive assessment of lung function in patients with asthma and COPD.

Clinimetric properties of field exercise tests in cystic fibrosis: a systematic review

OBJECTIVES

Accurate measurement of exercise capacity is an important prognostic indicator for people with cystic fibrosis (pwCF); however, gold-standard, cardiopulmonary exercise tests are commonly unavailable. This review systematically describes the clinimetric properties of field exercise tests for pwCF.

METHODS

A systematic review was undertaken for studies reporting field exercise tests in pwCF. Four electronic databases were searched for studies published from 1990 to January 2024. Where available, clinimetric properties reported included reliability, validity, responsiveness and interpretability.

RESULTS

4041 studies were identified with 153 eligible for inclusion. 10 different field exercise tests were described, including six walk/run tests (incremental shuttle walk test (ISWT), modified shuttle test-15 levels (MST-15), MST-25 levels (MST-25), 20-m shuttle test, 6-min walk test (6MWT) and 12-min walk test (12MWT)), three step tests (3-min step test (3MST), incremental step test and Alfred step test (A-STEP)) and the 1-min sit-to-stand test (1STS). Reliability was found for the ISWT, MST-15, 6MWT, 1STS and 3MST (intraclass correlation coefficients >0.80). The ISWT, MST-15 and 6MWT were found to be valid (concurrent and discriminate). Responsiveness was supported for the 6MWT only. Four tests (MST-15, 6MWT, 3MST and 1STS) demonstrated ceiling effects.

CONCLUSION

This review supports the reliability, validity and responsiveness of the 6MWT in pwCF. The ISWT and MST-15 were found to be valid. The 1STS is reliable and feasible, but its utility is limited by ceiling effects. The 3MST, MST-25, 20-m shuttle test, incremental step test, A-STEP and 12MWT require further investigations of their clinimetric properties.

ERS/ATS Global Lung Function Initiative normal values and classifying severity based on z-scores instead of per cent predicted

Among the most discussed issues in the field of pulmonary function testing are reference equations and standardised methods of interpreting pulmonary function test (PFT) results. The Global Lung Function Initiative (GLI) task force gathered information from multiple countries with diverse ethnicities to create a multi-ethnic reference formula suitable for a broad age range. Their first output was the GLI-2012 spirometry reference equations. Together with the GLI-2012 reference equations, the GLI document recommended the use of z-scores to standardise the interpretation of PFT results. Z-scores were introduced as an alternative to per cent predicted and fixed thresholds in interpreting PFTs. After more than a decade, there is still debate on which method of interpretation is better.

Impact of Using Pre- and Postbronchodilator Spirometry Reference Values in a Chinese Population

Rationale: Spirometry reference equations that are derived from a large, nationally representative general population are warranted in China, and the impact of using prebronchodilator (pre-BD) and post-BD spirometry reference values has yet to be assessed in Chinese populations. Objectives: To present the pre-BD and post-BD spirometry reference values for Chinese adults using the China Pulmonary Health (CPH) Study. Methods: A reference population of 17,969 healthy, nonsmoking participants in the CPH Study was used to calculate the pre- and post-BD reference values for FEV1, FVC, and FEV1/FVC ratio. Pre- and post-BD reference values were applied to the entire CPH population (N = 50,991) to illustrate the divergence between the use of different references in determining disease prevalence and severity grading. Measurements and Main Results: The prevalences of airflow limitation were 5.36% using the pre-BD reference and 8.02% using the post-BD reference. Individuals who had a post-BD FEV1/FVC ratio lower than the post-BD reference value but higher than the pre-BD reference value were found to have significantly higher rates of self-reported respiratory symptoms and significantly lower values on spirometry indicators than those whose post-BD FEV1/FVC ratio was greater than the post-BD reference value. An additional 3.51% of participants were identified as having grade II-IV chronic obstructive pulmonary disease using the post-BD FEV1 predicted values. Conclusions: This study generated and applied pre- and post-BD spirometry reference values in a nationally representative Chinese adult population. Post-BD reference values may serve as an additional criterion in identifying individuals at risk for obstructive pulmonary diseases, and their diagnostic and prognostic values should be further investigated.

Association between plasma CC16 levels and lung function changes in coke oven workers: A cohort study from 2014 to 2023

Club cell secretory protein (CC16) is considered a biological marker indicating lung epithelial and lung permeability. The joint effect of polycyclic aromatic hydrocarbons (PAHs) exposure on CC16 levels and the association between CC16 levels and long-term lung function changes lacks epidemiological evidence. To investigate the effect of PAHs exposure on plasma CC16 levels and the association between CC16 levels and long-term lung function changes, this study enrolled 307 coke oven workers in 2014, measured their baseline concentrations of urinary PAHs metabolites and plasma CC16, with follow-up after nine years. Bayesian kernel machine regression (BKMR) was employed to analyze the effect of mixed PAHs metabolites. The dose-effect association between baseline CC16 levels and lung function during 2014-2023 was explored using restricted cubic spline (RCS) models, and stratified analysis investigated the effect modification of PAHs exposure and smoking status on this association. The median age of the participants was 40 years, with 93.81 % male. The results showed that plasma CC16 levels decreased by 2.02 ng/mL (95 % CI: -3.77, -0.27) among all participants and FVC (% predicted) decreased by 2.87 % (95 % CI: -5.59, -0.14) in the low CC16 group with each unit increase in log-transformed 2-OHNAP. The BKMR model revealed a negative association between PAHs metabolites and both plasma CC16 levels and FVC (% predicted). Plasma CC16 decreased by 1.05 units when all PAHs metabolites at P65 compared to those at P50. After 9 years of follow-up, baseline CC16 levels were significantly associated with follow-up FVC (% predicted), FEV1 (% predicted), and small airway dysfunction risk. Furthermore, high PAHs exposure and smoking enhanced the association between CC16 and lung function. In conclusion, PAHs exposure decreases CC16 levels, and coking workers with low baseline CC16 levels may experience more severe future lung function decline.

The Secondary Pulmonary Hypertension Diagnosis is Not Useful in Lung Allocation

BACKGROUND

In lung transplant, the United Network for Organ Sharing (UNOS) contains a diagnosis of secondary pulmonary hypertension (SPH). SPH and pulmonary arterial hypertension are treated the same in the allocation scoring system. It is not clear whether utilizing the SPH diagnosis instead of the primary diagnosis is helpful to patients or providers.

METHODS

Analysis of UNOS data from May 2005 through July 2021, comparing patients listed under the SPH diagnosis with patients listed under COPD and interstitial lung disease (ILD) who met criteria for PH (COPD-PH and ILD-PH, respectively), as well as patients listed under pulmonary arterial hypertension (primary pulmonary hypertension, PPH). Competing-risk analysis examined waitlist and post-transplant outcomes. An exploratory analysis of UNOS spirometry data was performed.

RESULTS

Compared to patients listed under the SPH diagnosis, patients with ILD-PH were more likely to undergo transplantation (adjusted HR: 1.34, 95% confidence interval: 1.16-1.54, P < .001), with no significant difference comparing the SPH diagnosis to PPH or to COPD-PH. Waitlist mortality did not vary between groups. Post-transplant survival was lower in patients with PPH (adjusted HR: 1.35, 95% confidence interval: 1.04-1.75, P = .025), with no significant difference comparing the SPH diagnosis to COPD-PH or ILD-PH. Spirometry failed to demonstrate a clear phenotype within the SPH diagnosis.

CONCLUSION

In an adjusted analysis, patients with advanced lung disease and secondary PH were more likely to undergo transplantation when listed for ILD than when listed under the SPH diagnosis. The SPH diagnosis is too clinically heterogeneous to be useful in predictive models and should be considered for removal from UNOS.

Larger Airway Functions in Poultry and Dairy Confinement Workers: A Cross-Sectional Study

BACKGROUND

The peak expiratory flow (PEF) test is a crucial tool for assessing larger airway functions, particularly in individuals exposed to occupational hazards. This study aims to compare PEF values between animal workers (poultry and dairy farm workers) who are regularly exposed to animal allergens and other respiratory irritants and normal workers who do not have such exposures.

METHODS

A cohort of animal workers from poultry and dairy farms were evaluated alongside a control group of normal workers without known respiratory hazards. PEF measurements were taken using a computerized spirometer, and results were analyzed to determine differences in respiratory function between the two groups.

RESULTS

There was a significant difference in PEF values, with animal workers exhibiting lower PEF compared to their control group. Further, poultry farm workers had a significant decrease in PEF when compared to dairy farm workers. This study represents a pioneering effort in the comparative analysis of respiratory health among workers in poultry and dairy farms.

CONCLUSIONS

The findings indicate that occupational exposure to allergens and irritants associated with animal environments may have deleterious effects on respiratory health. Further analysis, controlling for confounding variables such as smoking status, age, and baseline health conditions, reinforces the initial observation of compromised respiratory function in animal workers. This study underscores the importance of regular respiratory health monitoring and implementation of protective measures for individuals in occupations with high exposure to respiratory irritants. Enhanced awareness and preventive strategies could mitigate the long-term health impacts on animal workers, ensuring safer working environments and improved overall health outcomes.

Bronchoscopic Lung Volume Reduction: A Review

Bronchoscopic lung volume reduction (BLVR) is an established treatment modality for the management of advanced chronic obstructive pulmonary disease complicated by severe emphysema and hyperinflation refractory to other therapies. BLVR aims to reduce hyperinflation and residual volume, thereby improving pulmonary function, symptom control, and quality of life. Multiple distinct devices and technologies, including endobronchial coils, thermal vapor ablation, bio-lung volume reduction, and airway bypass stenting, have been developed to achieve lung volume reduction with varying degrees of accessibility and evidence. The most promising BLVR treatment modality to date has been the placement of one-way endobronchial valves (EBVs), with more than 25,000 cases performed worldwide. Identifying symptomatic patients who would benefit from BLVR is challenging and can be time and resource intensive, and candidacy may be limited by physiologic parameters. Additional new technologies may be able to improve the identification and evaluation of candidates as well as increase the portion of evaluated patients who ultimately qualify for BLVR. In this review, we aim to provide historical context to BLVR, summarize the available evidence regarding its use, discuss potential complications, and provide readers with a clear guide to patient selection and referral for BLVR, with a focus on EBV placement. In addition, we will highlight potential future directions for the field.

Reference charts for the six-minute walk test in healthy school-aged children from the city of Zaragoza, Spain

INTRODUCTION

The six-minute walk test is a stress test that provides information about exercise tolerance in chronic diseases. The aim of the study was to develop reference equations with normal values for the test in healthy children aged 6-12 years in our paediatric reference population.

PATIENTS AND METHODS

The six-minute walk test was carried out in a sample of 236 healthy children, analyzing pre- and post-test variables, and we developed reference equations selecting variables that turned out to be significant (P < .05).

RESULTS

The pre- and post-test values, respectively, were 97.82% (SD, 0.64) vs 97.82% (SD, 0.59) for oxygen saturation; 96.59 bpm (SD, 16.11) vs 131.89 bmp (SD, 22.64) for the heart rate; 0.52 (SD, 0.83) vs 3.01 (SD, 2.42) for the degree of dyspnea (Borg scale) and 0.68 (SD, 0.98) vs 2.95 (SD, 2.26) for the degree of lower extremities fatigue (Borg scale). The average distance walked was 668.03 m (SD, 87.36) (671.42 m in boys [SD, 92.2] vs 664.22 m in girls [SD, 81.81]). We fitted predictive equations that included the variables age, height and difference between baseline and final heart rate. We also generated percentile charts of the distance walked for height.

CONCLUSIONS

Age, height, regular physical activity and obesity had an impact on test results. Obtaining reference values for the 6-min walk test in healthy children is necessary for its application in clinical practice.

Role of fractional exhaled nitric oxide in patients with sickle cell disease

INTRODUCTION

Patients with sickle cell disease exhibit different patterns in pulmonary function tests. In particular, there is little evidence on the fractional exhaled nitric oxide (FeNO) test, and its value ranges and its interpretation in these patients have been under debate in recent years.

METHODS

We conduced a cross-sectional, observational and descriptive study between November 2021 and January 2023 including patients aged 6-18 years with sickle cell disease able to perform the FeNO test. We applied the GLI-2012 reference values and the ERS/ATS standards. We defined statistical significance as P < 0.05.

RESULTS

The sample included 43 patients with a median age of 12 years (IQR, 10-15). We did not find an association between significantly elevated FeNO (≥25 ppb) and the diagnosis of asthma (P = 0.37), an obstructive pattern in spirometry (P = 0.67), a positive bronchodilator test (P = 0.53), clinical bronchial hyperreactivity in the context of cold or flu-like symptoms (P = 0.48), cough with exercise (P = 0.42) or nocturnal cough (P = 1.0), but found an association with peripheral eosinophilia (P < 0.01).

CONCLUSIONS

We found no association between FeNO values and the classic features of asthma (clinical or spirometric) in patients with sickle cell disease. Therefore, airway inflammation mechanisms are probably different in these patients.

Arsenic exposure is associated with elevated sweat chloride concentration and airflow obstruction among adults in Bangladesh: a cross sectional study

Arsenic is associated with lung disease and experimental models suggest that arsenic-induced degradation of the chloride channel CFTR (cystic fibrosis transmembrane conductance regulator) is a mechanism of arsenic toxicity. We examined associations between arsenic exposure, sweat chloride concentration (measure of CFTR function), and pulmonary function among 285 adults in Bangladesh. Participants with sweat chloride ≥ 60 mmol/L had higher arsenic exposures than those with sweat chloride < 60 mmol/L (water: median 77.5 μg/L versus 34.0 μg/L, p = 0.025; toenails: median 4.8 μg/g versus 3.7 μg/g, p = 0.024). In linear regression models, a one-unit μg/g increment in toenail arsenic was associated with a 0.59 mmol/L higher sweat chloride concentration, p < 0.001. We found that toenail arsenic concentration was associated with increased odds of airway obstruction (OR: 1.97, 95%: 1.06, 3.67, p = 0.03); however, sweat chloride concentration did not mediate this association. Our findings suggest that sweat chloride concentration may be a novel biomarker for arsenic exposure and also that arsenic likely acts on the lung through mechanisms other than CFTR dysfunction.

The Impact of COVID-19 on Functional Capacity and Pulmonary Outcomes in the Hail Region: A Cross-Sectional Study

Background/Objectives: COVID-19, caused by the novel coronavirus SARS-CoV-2, has had a significant impact on life worldwide since its emergence in late 2019. The virus has caused a global pandemic, leading to widespread health, social, economic, and psychological effects. COVID-19 mainly affects the respiratory system. This study aimed to compare the functional capacity and pulmonary function outcomes between COVID-19 patients and individuals who have not been infected in the Hail region. Methods: Individuals of both genders above 18 years old who had been infected with COVID-19 in the previous 6 months or had never been infected were eligible to participate. Local hospitals and social media apps were used to recruit willing participants. Heart rate, pulse oxygen saturation, blood pressure, pulmonary function test, hand grip strength, and functional tests (6 min walk test, 30 s sit-to-stand test, and timed up and go test) were measured and compared between the groups. Statistical analysis was performed using SPSS Version 25. Results: Forty individuals affected with COVID-19 and forty-one healthy individuals were recruited. Our results showed that in individuals affected with COVID-19, scores on the minute ventilation, 30 s sit-to-stand, and 6 min walk tests were significantly lower than among healthy individuals. Other outcomes did not show any statistical differences between the groups. Conclusion: This study contributes to a greater understanding of the functional capacity status of individuals with COVID-19. Patients affected by COVID-19 may develop an impaired lung capacity and a decreased function capacity. These factors may negatively affect physical and cognitive health status. Future studies should evaluate the benefits of interventions with rehabilitation exercises following COVID-19. In light of the functional capacity and pulmonary function decline in individuals affected by COVID-19, interventions encompassing pulmonary and functional rehabilitation exercises are recommended to improve physical fitness and pulmonary function post-COVID-19.