Interpretative strategies for lung function tests

Prevalence of asthma in Portuguese adults - the EPI-ASTHMA study, a nationwide population-based survey

INTRODUCTION

In 2010, 6.8% of the Portuguese adults had asthma. Contemporary studies employing more accurate methods are needed. We aimed to assess asthma prevalence in Portugal and to identify associated-factors.

METHODS

A population-based nationwide study was conducted from May 2021 to March 2024. A multistage random sampling approach was applied to select adults from primary care. Stage 1 involved a telephone screening interview to collect socio-demographic and clinical data. Patients with an Adult Asthma Score (A2 Score) ≥1 were eligible for Stage 2, and 5% of those with an A2 Score = 0 were also invited to participate in Stage 2, which consisted of a diagnostic visit with a physical examination and diagnostic tests. We computed weighted asthma prevalence estimates and multivariable logistic regression models were used.

RESULTS

A total of 7,556 participants completed Stage 1 and 1,857 Stage 2. The prevalence of asthma was 7.1% (95%CI = 6.3-8.0%), with slight differences by sex, age, and region. Education, family history of asthma, inhaler prescription, nasal/ocular symptoms, food allergies, and previous allergy skin tests were associated with an increased risk of asthma (R2 = 33%). Asthma diagnosis could also be predicted by the A2 score, either on its own (R2 = 43%) or in combination with family history and previous allergy skin tests (R2 = 45%).

DISCUSSION

Asthma affects 7.1% of Portuguese adults. Family history of asthma, nasal/ocular symptoms, and comorbid food allergy are associated with increased risk of asthma.

Development and evaluation of spirometry reference equations at high altitude

Approximately 400 million people live at high altitudes worldwide, yet reference equations for spirometry in these populations are inadequately documented. This study aims to develop reference equations for spirometry and assess their applicability to residents at altitudes ranging from 2,100 to 4,700 metres above sea level. This extensive cross-sectional study encompassed healthy non-smokers aged 15 years or older living at Xinjiang and Tibet autonomous region, which covered eight high-altitude areas by a multistage stratified sampling procedure. All individuals underwent pre- and post-bronchodilator measurement. We used the Lambda-Mu-Sigma (LMS) method to establish reference equations for various spirometry parameters. We assessed model fit using mean absolute error (MAE), mean absolute percentage error (MAPE), and residual values (standard deviation), relative to established benchmarks such as GLI, ECSC, and NHANES III, to evaluate the applicability of our equations to high-altitude residents. Between June 2015 and August 2016, 3174 healthy subjects were included. The reference equations utilise age and height as independent variables, with improved accuracy achieved through spline functions. Our spirometry reference equations demonstrate minimal MAE, MAPE, and residual values (standard deviation) for most of the analysed spirometry parameters, stratified by gender. Our spirometry reference equations are more applicable to residents of high-altitude regions.

Effect of native lung disease on post-transplant best lung function

BACKGROUND

Lung transplantation offers a life-saving treatment for patients with end-stage obstructive and restrictive lung diseases. However, differences in native lung disease types may influence post-transplant pulmonary function. This study evaluates the impact of native obstructive versus restrictive lung diseases on post-transplant best Forced Expiratory Volume in 1 s (FEV1) and Forced Vital Capacity (FVC).

METHODS

We conducted a retrospective cohort study of adult bilateral lung transplant recipients at Mayo Clinic Rochester from January 2009 to December 2021. Patients were categorized into obstructive and restrictive groups based on pre-transplant diagnoses. The primary outcomes were post-transplant best FEV1 and FVC Z-scores, defined as the average of the two highest values obtained at least three weeks apart. Statistical comparisons were performed using independent sample t-tests, Kaplan-Meier survival curves, and multivariable linear regression models.

RESULTS

Of the 148 patients included, 46 had obstructive and 102 had restrictive lung diseases. Patients with restrictive lung disease achieved lower post-transplant best FEV1 (Z-score: 0.70, p = 0.01) and FVC (Z-score: 0.61, p = 0.04) compared to those with obstructive lung disease. The restrictive group reached post-transplant best FVC significantly earlier (median: 142 days vs. 297 days, p = 0.03). After adjusting for donor and recipient characteristics, the type of native lung disease was not significantly associated with post-transplant best lung function.

CONCLUSION

Native restrictive lung disease is associated with lower post-transplant lung function compared to obstructive lung disease. However, when adjusting for other factors, native lung disease type does not independently predict post-transplant best FEV1 or FVC.

Diagnostic tools in respiratory medicine (Review)

Recent advancements in diagnostic technologies have significantly transformed the landscape of respiratory medicine, aiming for early detection, improved specificity and personalized therapeutic strategies. Innovations in imaging such as multi-slice computed tomography (CT) scanners, high-resolution CT and magnetic resonance imaging (MRI) have revolutionized our ability to visualize and assess the structural and functional aspects of the respiratory system. These techniques are complemented by breakthroughs in molecular biology that have identified specific biomarkers and genetic determinants of respiratory diseases, enabling targeted diagnostic approaches. Additionally, functional tests including spirometry and exercise testing continue to provide valuable insights into pulmonary function and capacity. The integration of artificial intelligence is poised to further refine these diagnostic tools, enhancing their accuracy and efficiency. The present narrative review explores these developments and their impact on the management and outcomes of respiratory conditions, underscoring the ongoing shift towards more precise and less invasive diagnostic modalities in respiratory medicine.

A computed tomography-based deep learning radiomics model for predicting the gender-age-physiology stage of patients with connective tissue disease-associated interstitial lung disease

OBJECTIVES

To explore the feasibility of using a diagnostic model constructed with deep learning-radiomics (DLR) features extracted from chest computed tomography (CT) images to predict the gender-age-physiology (GAP) stage of patients with connective tissue disease-associated interstitial lung disease (CTD-ILD).

MATERIALS AND METHODS

The data of 264 CTD-ILD patients were retrospectively collected. GAP Stage I, II, III patients are 195, 56, 13 cases respectively. The latter two stages were combined into one group. The patients were randomized into a training set and a validation set. Single-input models were separately constructed using the selected radiomics and DL features, while DLR model was constructed from both sets of features. For all models, the support vector machine (SVM) and logistic regression (LR) algorithms were used for construction. The nomogram models were generated by integrating age, gender, and DLR features.

RESULTS

The DLR model outperformed the radiomics and DL models in both the training set and the validation set. The predictive performance of the DLR model based on the LR algorithm was the best among all the feature-based models (AUC = 0.923). The comprehensive models had even greater performance in predicting the GAP stage of CTD-ILD patients. The comprehensive model using the SVM algorithm had the best performance of the two models (AUC = 0.951).

CONCLUSION

The DLR model extracted from CT images can assist in the clinical prediction of the GAP stage of CTD-ILD patients. A nomogram showed even greater performance in predicting the GAP stage of CTD-ILD patients.

Exacerbation during the first year of treatment affects lung function in subjects with asthma - a 10-year follow-up

BACKGROUND

Inhaled corticosteroids (ICS) are the preferred treatment for asthma. They improve symptoms and reduce exacerbations and deaths, but their long-term impact on lung function loss remains unclear, especially after delayed treatment. We aimed to characterize the lung function trajectories in subjects with previously untreated severe asthma. The secondary aim was to identify predictors of FEV1 decline, and future exacerbations.

METHODS

This is a post-hoc analysis that followed 184 subjects with asthma for 10 years after a delayed start of regular maintenance ICS treatment. Absolute lung function variation was calculated using two different baselines: (i) FEV1 after one year of regular treatment (V1) and (ii) best FEV1 observed any time before the final visit.

RESULTS

Most individuals were female (84%) over 50 years old and had early-onset asthma with a median of 30 years without regular ICS treatment. Ninety-nine (54%) had an FEV1 decline above 25ml/year, using strategy (i). Those subjects were younger, had shorter duration of asthma, and had better lung function at V1. Most of the participants without any obstructive pattern (74%) or with mild obstruction (64%) at V1 showed a faster absolute FEV1 decline, however PRISm showed faster relative decline than the other groups.

CONCLUSION

This study showed improved symptoms and quality of life with variable lung function trajectories among individuals with asthma who start regular treatment after decades of delay. Additionally, exacerbation during the first year was a strong predictor of absolute FEV1 decline and future exacerbations, while time without treatment was a predictor of relative reduction of FEV1.

Exploring Pulmonary Dysfunction in Parkinson's Disease: The Role of Impulse Oscillometry-A Systematic Review

Background/Objectives: This systematic review aimed to synthesize current evidence on the use of impulse oscillometry (IOS) in assessing pulmonary function in patients with Parkinson's disease (PD). IOS, as an effort-independent method, may offer advantages over conventional spirometry in detecting early or subclinical respiratory impairment in neurologically compromised populations. Methods: A systematic search was conducted across PubMed, Web of Science, Scopus, ScienceDirect and Google Scholar for observational studies published up to March 2025. The included studies involved patients diagnosed with PD who underwent respiratory assessment using IOS, either alone or in combination with spirometry. Data on IOS parameters (R5, R20, X5, AX) and their associations with disease severity, spirometric values or autonomic markers were extracted and analyzed qualitatively. Results: Four studies, published between 2020 and 2023, met the inclusion criteria. IOS revealed increased airway resistance in early-stage PD and inverse correlations with spirometric indices such as FEV1 and PEF. One study demonstrated significant correlations between IOS parameters and parasympathetic heart rate variable indices, suggesting autonomic involvement. IOS also showed stability across dopaminergic treatment states, highlighting its reliability in longitudinal monitoring. Conclusions: IOS appears to be a promising adjunct to traditional respiratory assessment in PD, capable of identifying subtle mechanical and autonomic dysfunctions. Despite encouraging results, the current evidence remains limited and further large-scale, longitudinal studies are needed to validate its clinical utility.

Spirometric pattern transitions in a World Trade Center occupational cohort on longitudinal surveillance

BACKGROUND

Many workers and volunteers who participated in the rescue and recovery of the World Trade Center (WTC) disaster site in 2001-2002 manifest a heterogeneous group of chronic lower airway diseases, with variable spirometric patterns on longitudinal surveillance. We examined systematically the observed transitions among those spirometric patterns and assessed their association with BMI and occupational WTC exposure intensity.

METHODS

We selected 10,810 Mount Sinai WTC General Responders' Cohort members with at least three acceptable quality periodic spirometries (n = 56,312) performed between July 2002 and November 2019. We defined three spirometric patterns: (1) normal: prebronchodilator first-second forced expiratory volume (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio > lower limit of normal (LLN); (2) obstruction: pre-bronchodilator FEV1/FVC ratio LLN. We built a multi-state Markov-like model to analyze probabilities of transition between those three spirometric patterns.

RESULTS

Low FVC is the most frequent abnormal spirometric pattern in the WTC workers. Substantial stationary probabilities of stability (0.88) were observed for normal, and less so for low FVC (0.73) and obstructive (0.65) pattern. At least 80 % of the observed transitions involved the normal and low FVC patterns, and both higher WTC exposure intensity (early arrival at the site), and body mass index (BMI) were predictors of transitions to low FVC in this cohort.

CONCLUSION

Low FVC is relatively stable, and both WTC exposure intensity and BMI are independently and significantly associated with transitions to it. Transitions to obstruction are generally infrequent among the WTC workers and have greater instability.

Year in Review: Pulmonary Function Testing

Pulmonary function testing dates back to the 19th century, and the most commonly performed tests pre-date the use of computers. Despite its long and rich history, much is still unknown about how to best perform, interpret, and apply pulmonary function tests. This year-in-review article will discuss recently published papers covering important topics including the performance of lung volume testing, the definition and severity grading of air flow obstruction, the clinical utility of bronchodilator responsiveness, and the use of race-neutral reference equations.

Effects of Modified Thoracoabdominal Nerves Block Through Pericondrial Approach on Postoperative Pulmonary Functions in Laparoscopic Bariatric Surgery: A Randomized Controlled Study

BACKGROUND

We aimed to evaluate the effects of modified thoracoabdominal nerve block through perichondrial approach (M-TAPA) block on respiratory dysfunction after laparoscopic sleeve gastrectomy (LSG) in patients with obesity.

METHODS

In this prospective randomized-controlled study, 60 patients aged 18-65 years and ASA PS II-III were included. Patients were divided into two groups: group M-TAPA (n = 30) and group control (n = 30). The primary outcome was the results of spirometric respiratory function tests. The secondary outcomes were total opioid consumption, postoperative resting, dynamic pain scores, and assessing the functional recovery via quality of recovery (QoR)-15 on postoperative day 1.

RESULTS

The FVC, FEV1, PEF, and predicted FEV1 values were significantly different between the groups, whereas the results were similar for FEV1/FVC values in the postoperative first hour. The decreases in FVC, FEV1, PEF, and predicted FEV1 values were higher in the group control. Total tramadol consumption at 0-24 h was significantly higher in the group control than in the group M-TAPA (group M-TAPA = 170 (0-300), group control = 220 (80-300); p = 0.013). Resting and dynamic NRS pain scores at the 1st, 2nd, 6th, and 12th postoperative hours were significantly higher in the control group than in the M-TAPA group.

CONCLUSIONS

The M-TAPA block in patients with obesity undergoing LSG reduced postoperative respiratory dysfunction and opioid consumption.

A perioperative nursing care protocol for patients with spinal muscular atrophy (SMA) type II or type III undergoing spinal surgery: a 4-year experience in 24 patients

BACKGROUND

Perioperative nursing care for patients with neuromuscular disorders, especially spinal muscular atrophy (SMA), remains a challenge. There is an obvious lack of guidelines.

METHODS

We retrospectively reviewed the medical charts of patients with type II or III SMA who underwent spinal surgery from 2018 to 2022. Nursing assessments included muscle strength, pulmonary function, the Barthel Index, the Braden Scale, Nutrition Risk Screening 2002, and the Hamilton Anxiety Scale. Preoperative and postoperative anxiety levels were compared using a paired-samples t-test.

RESULTS

All 24 included patients had severe scoliosis, kyphosis, or kyphoscoliosis, with a mean Cobb angle of 102 degrees. Upon admission, all patients (24/24) presented with muscle weakness, were classified as having total or severe dependency, and were at risk of developing pressure sores; 58.3% (14/24) of the patients had severe pulmonary function impairment, and 50.0% (12/24) were at nutritional risk, with the score unable to be assessed in 8.3% (2/24) of the patients. All patients underwent posterior spinal fusion surgery with bone grafting. Only one patient experienced a major postoperative complication, pneumonia, which was effectively managed. Anxiety level decreased significantly (P < 0.01) at discharge compared to that on admission. Complementing regular nursing care, an SMA-specific perioperative nursing care protocol was implemented: (1) Respiratory care protocol: A. Confirmation of SMA type; B. Comprehensive evaluation of symptoms, signs, and pulmonary function test results; C. Development and implementation of a personalized plan including: Plan 1. Training on respiratory function including diaphragmatic breathing exercise, coughing exercise, inhaling exercise, and exhaling exercise; Plan 2. Use of cough assist device, and/or Plan 3. Use of non-invasive ventilator. (2) Postoperative three-step all-involved training protocol of postural adaptation from nurse-led to caregiver-led and inducing patient self-advocacy: A. Preparation for the training; B. Postural adaptation training; C. Postural switch from lying to sitting.

CONCLUSIONS

We implemented an SMA-specific perioperative nursing care protocol, including a respiratory care protocol and a postoperative three-step all-involved training protocol of postural adaptation, complementing standard nursing care. Our approach yielded positive patient outcomes, while we acknowledge the limitation that our protocol is pending comparative evaluations due to the rarity of the disease. The protocol was initially designed for patients with SMA but may also be suitable for other patients with profound muscle weakness.

Mild and moderate manifestations of SARS-CoV-2 infection, including hospitalization, in children and adolescents with cystic fibrosis

BACKGROUND

Santos et al. analyzed the clinical characteristics and pulmonary function of children with cystic fibrosis infected with SARS-CoV-2. Infected children showed higher rates of dyspnea, coughing, hospitalization, and pulmonary exacerbations. Despite a temporary decline in pulmonary function, the recovery rates matched those of the uninfected children during follow-up. ■ SARS-CoV-2 infection leads to mild-to-moderate disease in children with cystic fibrosis. ■ No worsening of cystic fibrosis was observed months after infection.

OBJECTIVE

This study aimed to evaluate the clinical manifestations of SARS-CoV-2 in children and adolescents with cystic fibrosis.

METHODS

This was a case-control analysis of clinical variables and pulmonary function test results in 43 children with cystic fibrosis, 17 (39.5%) of whom tested positive for SARS-CoV-2.

RESULTS

The infected children exhibited a higher frequency of dyspnea and cough and a greater need for hospitalization. One infected child died. Pulmonary exacerbations were more frequent among the infected children. Additional data indicated a subsequent reduction in pulmonary function in the infected children, although this was not significantly different from that in the uninfected children.

CONCLUSION

Children with cystic fibrosis who contracted SARS-CoV-2 experienced mild to moderate symptoms and required hospitalization but generally had high recovery rates.

Inhalable neutrophil-mimicking nanoparticles for chronic obstructive pulmonary disease treatment

Chronic obstructive pulmonary disease (COPD) is an intractable disease with thick mucus layer in bronchi and alveoli, frequently accompanied by bacterial infection. Anti-bacterial drugs with mucus penetrating are urgently needed for efficient COPD treatment. Here, a neutrophil-mimicking nanovehicle was developed by coating neutrophil membrane onto poly(lactic-co-glycolic acid) (PLGA) nanoparticles containing antibiotics levofloxacin (LVX). Neutrophil membrane coated nanoparticles (LVX@PLGA@Mem) reserved most of the membrane proteins and related membrane functions of neutrophil, exhibiting pro-inflammatory cytokines neutralization, inflammation inhibition, successfully delivering LVX through the mucus layer and achieving satisfactory anti-infection effects. Thus, LVX@PLGA@Mem after inhalation could remarkably reduce inflammation and infection in the lung with COPD. Therefore, neutrophil mimicking nanovehicles may be a feasible and desirable drug carrier for lung-related disease treatment in further clinic.

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 269 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. Among the entire study population, after adjusting for covariates including age, sex, smoking, education, and height, 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 serve as novel biomarker for arsenic exposure, warranting further investigation in diverse populations, and that arsenic likely acts on the lung through mechanisms other than inducing CFTR dysfunction. Alternative mechanisms by which environmental arsenic exposure may lead to obstructive lung disease, such as arsenic-induced direct lung injury and/or increase lung proteinase activity, require additional exploration in future work.

Multidisciplinary care in pediatric severe asthma: A comparative outcomes analysis

Background

There are limited data comparing the effectiveness of multidisciplinary severe asthma clinics (SACs) with that of conventional single-discipline clinics (SDCs) for pediatric severe asthma.

Objective

Our aim was to compare asthma outcomes between SACs and SDCs clinics and examine longitudinal health outcomes for patients with severe asthma who were followed in SACs.

Methods

We conducted a retrospective cohort study comparing pediatric asthma outcomes among patients with severe asthma between 2018 and 2022 who were treated at the multidisciplinary Arkansas Children's SAC with those of patients with severe asthma treated at SDCs. The primary outcome was acute health care utilization, including hospitalizations and emergency department visits. Secondary outcomes included systemic corticosteroid prescriptions and controller medications. For SAC enrollees, longitudinal outcomes including health care utilization, symptom control, and spirometry were evaluated 12 months before and after enrollment. Data sources included the electronic health record and SAC patient registry.

Results

The study population included 280 patients with severe asthma, aged 5 to 18 years, from the SAC (n = 56) and SDCs (n = 224). The SAC patients were more likely to be Black (79% vs 52% [P = .0002]), be non-Hispanic (100% vs 88% [P = .01]), have had at least 1 hospitalization (21% vs 10% [P = .04]), and have received at least 2 prescriptions for a systemic corticosteroid (34% vs 17% [P = .01]). Longitudinal outcomes among patients for the 12 months before SAC enrollment versus 12 months after SAC enrollment demonstrated significant reductions in acute exacerbations (from 35 to 8 [P < .001]), hospitalizations (from 21 to 1 [P < .001]), and intensive care unit admissions (from 8 to 1 [P = .02]).

Conclusions

The study highlights significant morbidity among predominately Black pediatric patients with severe asthma, particularly those followed in a SAC versus in SDCs at a tertiary care referral center. The findings demonstrate the value of targeted multidisciplinary approaches to reduce asthma utilization and improve outcomes among high-risk patients.

Progressive course of anti-nuclear matrix protein-2 (NXP-2) positive-interstitial lung disease

BACKGROUND

Evaluating the etiology of interstitial lung disease (ILD) commonly involves ordering a myositis panel containing myositis-specific antibodies (MSAs), including anti-NXP-2. However, little is known about the presentation of patients with ILD and anti-NXP-2 positivity. We sought to define the course of anti-NXP-2-positive ILD in order to guide prognosis and potential treatment strategies.

METHODS

We performed a retrospective chart review of patients with positive anti-NXP-2 antibodies who presented to two ILD referral centers in Boston, MA between 2012 and 2024. Patients were identified by query of the electronic medical record for patients positive for anti-NXP-2. We included those anti-NXP-2 positive patients with ILD on chest computed tomography (CT). Data regarding clinical presentation and disease course were abstracted from the medical record. For patients following longitudinally in the ILD clinic, we conducted survival analyses for ILD progression (composite of PFT progression, hospitalization, or death) using Kaplan-Meier curves and log-rank tests. Additionally, we used a Cox proportional-hazards model, adjusting for age, gender, forced vital capacity (FVC) at baseline, and immunosuppression to calculate hazard ratios. ILD patients with MSA-positive, NXP-2-negative ILD served as the comparator group.

RESULTS

31 patients were identified (mean 70 years, SD 9). Three were diagnosed with dermatomyositis (DM) prior to presentation, but the remaining had ILD as the only manifestation of connective tissue disease. Most (97%) patients were symptomatic with dyspnea and/or cough at presentation. Other autoantibody positivity was common; only 42% were positive for anti-NXP-2 alone without positivity for other autoimmune serologies, including MSAs known to be associated with ILD. Clinical follow up data were available for 28 patients for a median follow up period of 24 months (range <1 month-13 years). A majority (61%) were treated with immunosuppression, antifibrotics, or both. Over one third experienced acute exacerbation of ILD or death (N = 11, 35%). Progression-free survival was similar to that of other MSA-positive ILD patients, regardless of whether anti-NXP-2 was positive alone or co-positive for other autoantibodies.

CONCLUSIONS

We present the largest single series of anti-NXP-2-positive ILD. Anti-NXP-2-positive ILD can occur in the absence of DM/PM and can manifest as progressive pulmonary disease that is similar to other MSA-positive ILDs.

Quantitative CT Scan Analysis in Rheumatoid Arthritis-Related Interstitial Lung Disease

BACKGROUND

Quantitative CT imaging may be a useful predictor of outcome in rheumatoid arthritis-related interstitial lung disease (RA-ILD).

RESEARCH QUESTION

What is the utility of deep learning-based lung fibrosis quantitation on CT imaging in assessing disease severity, predicting mortality, and identifying progression in RA-ILD?

STUDY DESIGN AND METHODS

CT scans on a primary cohort of 289 patients and a validation cohort of 50 individuals with RA-ILD were assessed quantitatively by using the data-driven texture analysis (DTA) method. We examined associations between quantitative scores for extent of lung fibrosis and pulmonary function and survival.

RESULTS

DTA fibrosis score at baseline showed moderate negative correlation with FVC percent predicted (primary cohort rho = -0.55; validation cohort rho = -0.50; both, P < .001), and diffusing capacity for carbon monoxide percent predicted (primary cohort rho = -0.67; validation cohort rho = -0.65; both, P < .001). Longitudinal change in DTA fibrosis score was associated with changes in FVC and diffusing capacity for carbon monoxide in the primary cohort (rho = -0.46 and rho = -0.43, respectively; both, P < .001). Cox multivariable models adjusted for potentially influential variables showed that the baseline DTA fibrosis score was significantly associated with mortality risk (primary cohort hazard ratio [HR], 1.04 [95% CI, 1.03-1.05; P < .001]; validation cohort HR, 1.06 [95% CI, 1.01-1.11; P = .026]). In the primary cohort, the increase in DTA fibrosis score on sequential scans was associated with increased risk of mortality (HR, 1.04; 95% CI, 1.01-1.06; P = .003) independent of baseline DTA extent.

INTERPRETATION

In 2 cohorts of patients with RA-ILD, quantitative assessment of lung fibrosis on CT imaging was associated with worse lung function at baseline and risk of mortality. Increase in DTA-derived lung fibrosis score on sequential scans was associated with subsequent risk of mortality. Quantitative CT imaging should be considered for use as a clinical and research outcome assessment tool in RA-ILD.

Non-Invasive Assessment of Respiratory Mechanics Using Anatomical M-Mode Ultrasound in Acute Pulmonary Oedema With Impending Respiratory Failure: A Case Report

Assessing respiratory mechanics in critically ill patients is crucial for diagnosis and treatment monitoring. The Lung Curtain Swing vs. Time (LCST) graph using Anatomical M-mode (AMM) ultrasound provides a novel non-invasive approach to evaluating lung excursion and respiratory dynamics. An 83-year-old male with end-stage kidney disease on peritoneal dialysis presented with dyspnea and desaturation. Initial evaluation indicated hypertensive crisis with acute pulmonary oedema. NIV therapy improved oxygenation and ventilation, with concurrent lung ultrasound assessments. The LCST graph demonstrated abnormal inspiratory and expiratory waveforms, suggesting respiratory muscle fatigue and bronchial oedema. NIV led to improved lung excursion and retraction speed, correlating with clinical recovery. The LCST graph using AMM ultrasound offers real-time, non-invasive assessment of respiratory mechanics in critical care. This case highlights its potential utility in diagnosing and monitoring respiratory failure, warranting further research.

Exposure-effect of PFOS and PFOA on lung function: An integrated approach with epidemiological, cellular, and animal studies

Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are increasingly recognized for their adverse impact on human health, particularly on lung function. However, current research results are inconsistent and molecular mechanisms remain unclear, with no studies combining epidemiological, in vivo and in vitro investigations. Our population-based study revealed that PFOS and PFOA exposure is negatively associated with lung function. In vitro, PFOS and PFOA exposure significantly downregulated SP-B mRNA and protein levels, and SP-B expression was restored by overexpression of HSD17B1. PFOS induced hypermethylation and downregulated expression of HSD17B1 in tandem with SP-B. Notably, expression of SP-B was restored after treatment with demethyltransferase inhibitor. In vivo studies corroborated these findings, where PFOS exposure resulted in impaired lung function, histopathological changes, and decreased expression of SP-B and HSD17B1 in lung tissues. Our research demonstrates that PFOS downregulates SP-B expression by inducing hypermethylation and downregulating expression of HSD17B1, leading to impaired lung function.

Impact of L-arginine and liposomal vitamin C supplementation on quality of life and daily life activities in patients with COPD: a randomized, multicenter, single blind, placebo-controlled trial (ILDA study)

OBJECTIVE

Chronic Obstructive Pulmonary Disease (COPD) patients experience limitations in activities of daily living (ADL) despite optimal inhaled treatment. L-arginine depletion is associated with poor exercise performance. Our aim was to assess whether oral L-arginine supplementation improves dyspnea and ADL in COPD patients.

DESIGN AND METHODS

Randomized, multicenter, single blind, placebo-controlled study (NCT05412160). Stable COPD patients received L-arginine (1.66 g) plus liposomal vitamin C (500 mg) twice daily or placebo for 4 weeks. At baseline (T0) and after treatment (T1) lung function, six minutes walking test (6MWT), dyspnea and ADL perfomance, evaluated through: COPD assessment test (CAT), self-administered chronic respiratory questionnaire (CRQ-SA), Clinical COPD Questionnaire 24 h and 7 days (CCQ) and London Chest Activity of Daily Living Scale (LCADL) -were assessed. The primary endpoint was CRQ score change compared with placebo.

RESULTS

150 patients were enrolled (67 % males, median FEV1 57 %predicted), with 76 receiving L-arginine. Baseline characteristics and questionnaire scores were balanced between arms. At T1, L-arginine patients demonstrated significant improvements compared to placebo in CRQ total score (median (IQR) 3.5 (0.0;6.75); P = 0.006), CRQ dyspnea domain (3.0 (0.0;6.0); P < 0.001); LCADL total score (-1.0 (-3.0;0.0); P = 0.005); LCADL housework (-1.0 (-3.0;0.0); P < 0.001) and LCADL free time (0.0 (-1.0;0.0); P = 0.003). More L-arginine patients reached the minimal clinically important difference (MCID) in CRQ dyspnea and total LCADL. Baseline CRQ dyspnea<20 (OR (95 %CI): 4.296 (2.051-8.999); P < 0.001) and a LCADL score<27 (7.126 (2.729-18.609); P < 0.001) predicted MCID response.

CONCLUSION

Oral supplementation with L-arginine added to inhaled therapy appears to improve dyspnea and ADL in COPD.

Interactions of physical activity and lung function on cognitive health in older adults: Joint association and mediation analysis

BACKGROUND

Maintaining cognitive health in old adults has become a significant public health challenge, with lung function and physical activity (PA) as essential modifiable factors. However, the joint and mediation effects of these two factors with cognition remain unclear.

OBJECTIVES

This study assesses the joint association and mediation effects of lung function and PA with cognition.

DESIGN, SETTING, AND PARTICIPANTS

We utilized cross-sectional data from the 2011-2012 U.S. National Health and Nutrition Examination Survey, including adults aged 60-79 assessed for lung function, PA, and cognition.

MAIN OUTCOMES AND MEASURES

Lung function included forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF) and FEV1/FVC. PA was assessed using the Global Physical Activity Questionnaire, covering occupational PA (OPA), transportation-related PA (TPA), and leisure-time PA (LTPA). Cognition was evaluated using the Digit Symbol Substitution Test, Animal Fluency Test, Delayed Recall Test and Immediate Recall Test. Weighted multiple linear regression models were used to analyze the separate and joint associations of lung function and PA with cognition, while also exploring potential mediation effects between these factors.

RESULTS

A total of 927 participants, representing 35,525,782 U.S. residents, were included, with a weighted median age of 65 (IQR, 63 -71) years, and 53.6 % were female. The results showed a significant positive association between lung function and cognitive function, with FEV1, FVC, and PEF all positively correlated, while the FEV1/FVC showed no notable link. Further analysis revealed the best cognitive performance observed in participants with active LTPA and the highest quartile of lung function, indicating a joint association of LTPA and lung function with cognition. Mediation analysis indicated that lung function mediated 24.1 % (95 %CI: 6.3 % - 47.0 %, P = 0.03) of the relationship between LTPA and cognition, while cognition mediated 10.2 % (95 %CI: 0.5 % - 27.0 %, P = 0.04) of the relationship between LTPA and lung function.

CONCLUSION

Lung function and cognition may have a bidirectional relationship. The combination of active LTPA and better lung function was strongly associated with higher cognition, highlighting the need to strengthen exercise focused on lung function to maintain cognitive health in older adults.

The Relationship Between Anthropometric Variables and Lung Function in a Severe Smoking Community Population With Ventilatory Dysfunction

BACKGROUND

The World Health Organization estimated that 65 million individuals have chronic obstructive pulmonary disease (COPD). However, large numbers remain undiagnosed. Anthropometric variables and lung function are closely related, such as body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR). Therefore, it is essential to explore the relationship between anthropometric variables and lung function.

METHODS

We recruited 7679 severe smokers. Severe smoking was defined as a smoking index ≥ 20 pack-years. Among these participants, there are 6214 severe smokers with mild, moderate, and moderately severe obstructive ventilation dysfunction and 1465 severe smokers with severe and very severe obstructive ventilation dysfunction. Otherwise, participants were divided into different groups according to questionnaires and sex.

RESULTS

Lung function in the severe smoking community population was associated with anthropometric variables. The study results showed that BMI was negatively associated with the risk of severe and very severe obstructive ventilation dysfunction in a severe smoking community population with ventilatory dysfunction (OR 0.791, 95% CI 0.691-0.907, p = 0.001), the COPD Population Screener (COPD-PS) scores ≥ 5 group (OR 0.787, 95% CI 0.688-0.902, p = 0.001), the COPD Screening Questionnaire (COPD-SQ) scores ≥ 16 group (OR 0.791, 95% CI 0.689-0.908, p = 0.001), the COPD-PS scores ≥ 5 and COPD-SQ scores ≥ 16 group (OR 0.730, 95% CI 0.603-0.884, p = 0.001) and the male group (OR 0.813, 95% CI 0.708-0.933, p = 0.003). The study showed that WC was also associated with obstructive ventilation dysfunction.

CONCLUSION

Low BMI and WC were independent risk factors for severe and very severe obstructive ventilation dysfunction in the severe smoking community Chinese population with ventilatory dysfunction. Collecting COPD questionnaires may help manage lung function in the community population.

Bone Marrow-Derived Mesenchymal Stem Cells Alleviate Posthemorrhagic Shock Mesenteric Lymph-Induced Acute Lung Injury

INTRODUCTION

Mesenteric lymph is recognized as a conduit in the gut-lung axis. Posthemorrhagic shock mesenteric lymph (PHSML) contains proinflammatory substances and can exacerbate the acute lung injury (ALI) induced by hemorrhagic shock (HS). Mesenchymal stem cells (MSCs) possess anti-inflammatory properties and hold therapeutic potential for ALI. However, the effect and mechanism of MSCs in alleviating PHSML-mediated ALI remains unclear.

METHODS

Rat hemorrhage shock model and PHSML infusion model were used to induce ALI. MSCs were administrated intravenously to treat ALI. Pulmonary function of rats was assessed by a Buxco pulmonary function analysis system. Hematoxylin and eosin staining was used for histological analysis. Western blot and quantitative real-time polymerase chain reaction were used to detect the expressions of inflammation-related genes.

RESULTS

Intravenous infusion of bone marrow-derived MSCs (BMSCs) prolonged the survival of HS rats. Both HS and PHSML could cause pulmonary tissue damage, lung edema, and pulmonary dysfunction, which were all alleviated by BMSC treatment. The pulmonary dysfunction indices (inspiratory resistance, functional residual capacity, and mean mid expiratory flow) were significantly improved by BMSC treatment in the two models. C-X-C motif chemokine ligand and inducible nitric oxide synthase, which are important for neutrophil recruitment and infiltration to the injured site, were down-regulated by BMSCs in the lung tissues of rats with HS or PHSML injury. As a neutrophil marker, myeloperoxidase is also decreased by BMSC treatment. These results indicated that BMSCs may reduce neutrophil recruitment and infiltration through inhibiting C-X-C motif chemokine ligand and inducible nitric oxide synthase expressions.

CONCLUSIONS

The current findings demonstrate that BMSC therapy can alleviate the ALI induced by PHSML. In mechanism, BMSCs can protect lungs from the inflammatory response mediated by neutrophils. Our study provides novel insight to treat ALI in the gut lymphatics-lung axis.

Assessment of lung function and severity grading in interstitial lung diseases (% predicted versus z-scores) and association with survival: A retrospective cohort study of 6,808 patients

BACKGROUND

Pulmonary function tests (PFTs) are essential for predicting outcomes in interstitial lung disease (ILD). In 2022, an expert panel recommended using z-scores instead of the traditional % predicted cut-off values to interpret the severity of PFT abnormalities which may lead to discordant classifications in some patients. To assess the magnitude and prognostic impact of this phenomenon we compared these two approaches in predicting all-cause mortality in a large cohort of patients with ILDs.

METHODS AND FINDINGS

We retrospectively analyzed data from a tertiary referral center for patients with ILDs. Absolute FEV1, FVC, TLC, and TLCO values from patients' first presentations were transformed and presented as % predicted and z-scores using the most recent global lung initiative (GLI) reference values. Results were categorized for severity according to % predicted and z-score levels. Predictors of all-cause mortality over a 14-year follow-up were determined using Kaplan-Meier survival analysis and Cox proportional hazards regression. Between January 2009 and March 2023, 6,808 patients with ILDs were evaluated at the National TB and Lung Diseases Research Institute in Warsaw, Poland. Most were diagnosed with sarcoidosis, fibrotic ILD, or non-fibrotic ILD. At their first presentation, 13.2% had airway obstruction, 23.1% had low FVC (indicative of restriction by spirometry), and 45.6% had a reduced lung transfer factor (TLCO). Reclassification of spirometric indices occurred in 26.8% of patients for FEV1 and 24.6% for FVC among those with abnormal results, with most being reassigned to a less severe categories. For TLCO, 28.1% of patients with reduced values were reclassified, with most shifting to more severe categories. During the follow-up, 1,525 (22.4%) of patients died. Both low FVC and low TLCO predicted all-cause mortality, with z-score thresholds showing stronger associations with mortality. A one-unit decrease in the FVC z-score was associated with a 10.3% increase in the risk of death, while a one-unit decrease in TLCO z-score was linked to an over 30% increase in mortality risk. Limitations of this retrospective single-center study include lack of data on cause-specific mortality, potential residual confounding, and limited generalizability to non-Caucasian or younger populations.

CONCLUSIONS

The recently recommended use of z-scores leads to significant reclassification of lung function results in patients with ILDs, largely driven by age. This approach is justified by its stronger prognostic associations. Severe TLCO impairment remains a robust predictor of mortality in ILDs.

Effects of Oral Doxofylline and Procaterol on Chronic Obstructive Pulmonary Disease: A Randomized Crossover Study

Background: Oral bronchodilators may serve as an adjunctive therapy in patients with chronic obstructive pulmonary disease (COPD). This study aimed to evaluate the effects of oral doxofylline and oral procaterol on lung function and clinical symptoms in COPD patients. Methods: A crossover randomized controlled trial was conducted in patients with clinically stable COPD. Participants first received either doxofylline or procaterol for 4 weeks, followed by a 1-week washout period. Assessments included the modified Medical Research Council (mMRC) dyspnea scale, COPD assessment test (CAT) scores, and 6-minute walking distance (6MWD). Pulmonary function was evaluated using spirometry with bronchodilator (BD) testing and all adverse events were recorded. Results: Twenty patients were randomly assigned to begin treatment with either doxofylline or procaterol. Their mean age was 71.7 ± 9.4 years. After four weeks of treatment, the doxofylline group showed significantly greater improvement in pulmonary function parameters (post-BD peak expiratory flow and post-BD forced expiratory flow 25-75) compared to the procaterol group. However, there were no significant differences in mMRC scores, CAT scores, or 6MWD between the two groups. More neurological adverse events were observed in the doxofylline group compared to the procaterol group (35% vs. 5%, p = 0.044). Conclusions: Doxofylline improved pulmonary function in COPD patients but did not provide superior functional performance compared to procaterol. Neurological adverse events were more frequently associated with doxofylline. Doxofylline may serve as an adjunctive therapy to enhance pulmonary function in COPD patients, but caution is advised due to its potential side effects.

Corticosteroids and long-term pulmonary function after critical illness due to COVID-19- a single-center cohort study

BACKGROUND

Early in the pandemic, corticosteroids became standard treatment for patients with critical COVID-19 infections. This study aimed to investigate the possible long-term pulmonary consequences after corticosteroid treatment in patients with critical COVID-19 requiring ventilatory support.

METHODS

This observational single-center cohort study included patients treated for critical COVID-19 requiring ventilatory support between March 1, 2020, and August 1, 2021, with a 6-month follow-up after discharge from the intensive care unit. Corticosteroid treatment was defined according to the RECOVERY trial (6 mg dexamethasone daily or equivalent dose of another corticosteroid, initiated within eight days of hospital admittance and continued for at least one day) Pulmonary function was assessed by diffusion capacity for carbon monoxide. Health-related quality of life was measured with the questionnaire RAND-36. General linear regression was used to present mean score differences with 95% confidence intervals.

RESULTS

Among the 456 (69%) critically ill COVID-19 patients who survived at least 90 days after ICU discharge, 286 (63%) attended the follow-up six months later. The groups were balanced regarding invasive ventilation; 47% received invasive ventilation in both groups. Corticosteroid treatment was associated with a lower diffusion capacity for carbon monoxide (MSD - 8.3, 95% CI: -14.2 to -2.4) 6 months after ICU discharge (change > 10% were regarded as clinically significant). There were no differences in health-related quality of life between the groups.

CONCLUSIONS

Corticosteroids might negatively impact pulmonary function after critical COVID-19. The decrease did not seem to influence health-related quality of life. Future studies are needed to confirm the results.

The association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio and preserved ratio impaired spirometry: NHANES 2007-2012

BACKGROUND

Preserved ratio impaired spirometry (PRISm) refers to a form of lung function deterioration, and previous studies have established the association with Chronic Obstructive Pulmonary Disease (COPD). Research has also shown the association between COPD and lipid metabolism disturbances. Despite these findings, the association between lipid metabolism markers and PRISm remains poorly understood.

METHODS

This analysis was conducted on the 2007-2012 data from the National Health and Nutrition Examination Survey (NHANES), including a total of 9,431 participants. The Non-High-Density Lipoprotein Cholesterol to High-Density Lipoprotein Cholesterol Ratio (NHHR) was calculated based on lipid profiles, and PRISm patients were classified according to pulmonary function tests. To explore the association between NHHR and PRISm, multivariable logistic regression analysis was used.

RESULTS

A strong linear association was observed between NHHR and PRISm. In Adjusted Model 2, the weighted multivariable logistic regression analysis revealed that each unit increase in NHHR increased the chance of developing PRISm by 8% (OR:1.08, 95%CI:1.01-1.16, P = 0.039).Participants within the highest NHHR tertile demonstrated a 1.36-fold increased likelihood of presenting with PRISm compared to those in the lowest NHHR tertile (OR:1.36, 95% CI: 1.01-1.83, P = 0.048). Additionally, weighted Restricted Cubic Spline affirmed a linear association between NHHR and PRISm (P for non-linearity = 0.637), while clear non-linear associations were found between NHHR and FEV1% predicted (P for non-linearity = 0.010) and FEV1/FVC (P for non-linearity = 0.023). Subgroup analysis and interaction tests revealed a significant interaction effect among different waist circumference categories (P for interaction = 0.020). Notably, in individuals without abdominal obesity, NHHR showed a strong positive association with PRISm (OR = 1.23, 95% CI: 1.07-1.42, P = 0.01).

CONCLUSION

These results indicate that NHHR is positively associated with PRISm and is significantly associated with the decline in lung function. This study offers distinctive perspectives that may contribute to the avoidance and management of early-stage pulmonary dysfunction.

Longitudinal study of COPD phenotypes using integrated SPECT and qCT imaging

Introduction

The aim of this research is to elucidate chronic obstructive pulmonary disease (COPD) progression by quantifying lung ventilation heterogeneities using single-photon emission computed tomography (SPECT) images and establishing correlations with quantitative computed tomography (qCT) imaging-based metrics. This approach seeks to enhance our understanding of how structural and functional changes influence ventilation heterogeneity in COPD.

Methods

Eight COPD subjects completed a longitudinal study with three visits, spaced about a year apart. CT scans were performed at each visit and qCT-based variables were derived to measure the structural and functional characteristics of the lungs, while the SPECT-based variables were used to quantify lung ventilation heterogeneity. The correlations between key qCT-based variables and SPECT-based variables were examined.

Results

The SPECT-based ventilation heterogeneity (CVTotal) showed strong correlations with the qCT-based functional small airway disease percentage (fSAD%Total) and emphysematous tissue percentage (Emph%Total) in the total lung, based on cross-sectional data. Over the 2-year period, changes in SPECT-based hot spots (TCMax) exhibited strong negative correlations with changes in fSAD%Total, Emph%Total, and the average airway diameter in the left upper lobe, as well as a strong positive correlation with alternations in airflow distribution between the upper and lower lobes.

Discussion

In conclusion, this study found strong positive cross-sectional correlations between CVTotal and both fSAD% and Emph%, suggesting that these markers primarily reflect static disease severity at a single time point. In contrast, longitudinal correlations between changes in TCMax and other variables over 2 years may capture the dynamic process of hot spot formation, independent of disease severity. These findings suggest that changes in TCMax may serve as a more sensitive biomarker than changes in CVTotal for tracking the underlying mechanisms of COPD progression.

Effect of small airway dysfunction on large airway function parameters in elderly adults

BACKGROUND

To investigate the effect of simple small airway dysfunction (SAD) on large airway function parameters in old people.

METHODS

Elderly patients aged 60-80 years with complete pulmonary function data including the measured/predicted values of ≥ 80% for each of forced expiratory capacity (FVC), forced expiratory volume in one second (FEV1), and peak expiratory flow (PEF), and FEV1/FVC ≥ 70% were included. Patients with no known smoking history, normal chest computerized tomography, and the measured/predicted values of ≥ 70% for each of maximal flows at 50% and 25% of remaining FVC (MEF50 and MEF25) and maximum mid-expiratory flow (MMEF) were categorized into the control group, whereas patients with the measured/predicted values of < 65% for more than 2 of MEF50, MEF25, and MMEF were divided into the observation group. 104 patients with simple SAD (observation group) and 102 patients with normal pulmonary function (control group) were selected.

RESULTS

The parameters of small airway function including MEF50, MEF25, and MMEF were positively correlated with slow vital capacity (SVC), FVC, FEV1, PEF, and MEF75 in the large airway in both groups (r = 0.280-0.634). Except for PEF, the other 5 parameters in the observation group were significantly different from those in the control group. There was no significant difference between total lung capacity (TLC) and functional residual capacity (FRC), but there were significant differences between residual volume (RV), RV/TLC, diffusion capacity for carbon monoxide (DLCO), and specific diffusing capacity (KCO). There were 66 cases of SVC-FVC > 0 (FVC/SVC < 1) (66/104, 63.46%) in the observation group) and 45 cases of the control group (45/102, 44.12%), and the difference between the two groups was statistically significant. The area under the curve (AUC) of SVC-FVC and FVC/SVC in the prediction of SAD was 0.631 and 0.639, respectively, with a sensitivity and specificity of 63%.

CONCLUSIONS

Simple SAD was associated with large airway pulmonary function, and PEF may not be a suitable parameter for large airway pulmonary function in the old adults. SVC-FVC > 0.02 L had a certain predictive value for SAD in the elderly.

Prevalence of respiratory symptoms and lung function impairments among woodworkers in Gondar City

Respiratory symptoms and lung function impairments are concerns in the woodworking industry. In Ethiopia, the woodwork industry has been growing; however, there is limited data on pulmonary function, respiratory symptoms, and risk factors among woodworkers. This study aimed to assess the prevalence of impaired lung function and respiratory symptoms and determine their associated risk factors among woodworkers in Gondar City, Ethiopia. A comparative cross-sectional study was conducted, involving 185 woodworkers and 176 controls. Spirometry was used for Lung function tests. The data were collected using a questionnaire in Kobo Toolbox software. Statistical analyses, including ANOVA, t-test, and logistic regression were done in SPSS version 26. Almost all participants (96.4%) were male. The proportions of obstructive, restrictive, and mixed lung function impairments in woodworkers and control groups were 7.6% vs. 2.8%, 4.86% vs. 3.98%, and 1.08% vs.0%, respectively. The proportion of chronic respiratory symptoms in woodworkers and control groups was 35.5% vs. 12.7% with the proportion of cough (19.9% Vs 6.6%), phlegm (21.1% Vs 5.8%), wheezing (9.4% Vs 3.9%), shortness of breath (19.9Vs 6.6%), and breathlessness (13.3% Vs 8.3%). In woodworkers, and pooled models, the absence of a local exhaust ventilation system, working more than eight hours per day, being unable to use filter masks, and being unable to do physical exercise were significantly associated with respiratory symptoms. Forced Expiratory Volume in 1 s/Forced Vital Capacity ratio (FEV1/FVC ratio) (P = 0.001) and Mid-Expiratory Flow between 25% and 75% (MEF25%-75%) significantly decreased with work experience (P = 0.001). Woodworkers had higher rates of obstructive, restrictive, and mixed lung function impairments and more respiratory symptoms. Prioritizing workplace ventilation and the use of respiratory protective devices is crucial for mitigating these risks.

A systematic review of the role of quantitative CT in the prognostication and disease monitoring of interstitial lung disease

BACKGROUND

The unpredictable trajectory and heterogeneity of interstitial lung disease (ILDs) make prognostication challenging. Current prognostic indices and outcome measures have several limitations. Quantitative computed tomography (qCT) provides automated numerical assessment of CT imaging and has shown promise when applied to the prognostication and disease monitoring of ILD. This systematic review aims to highlight the current evidence underpinning the prognostic value of qCT in predicting outcomes in ILD.

METHODS

A comprehensive search of four databases (Medline, EMCare, Embase and CINAHL (Cumulative Index to Nursing and Allied Health Literature)) was conducted for studies published up to and including 22 November 2024. A modified CHARMS (CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling Studies) checklist was used for data extraction. The risk of bias was assessed using a Quality in Prognostic Studies template.

RESULTS

The search identified 1134 unique studies, of which 185 studies met inclusion and exclusion criteria. Commonly studied ILD subtypes included idiopathic pulmonary fibrosis (41%, n=75), mixed subtypes (26%, n=48) and systemic sclerosis ILD (16%, n=30). Numerous studies showed significant prognostic signals, even when adjusted for common covariates and/or significant correlation between serial qCT biomarkers and conventional outcome measures. Heterogenous and nonstandardised reporting methods meant that direct comparison or meta-analysis of studies was not possible. Studies were limited by the use of retrospective methodology without prospective validation and significant study attrition.

DISCUSSION

qCT has shown efficacy in the prognostication and disease monitoring of a range of ILDs. Hurdles exist to widespread adoption including governance concerns, appropriate algorithm anchoring and standardisation of image acquisition. International collaboration is underway to address these hurdles, paving the way for regulatory approval and ultimately patient benefit.

Impact of patient safety on outcomes. From prevention to the treatment of post-intensive care syndrome

Survivors of critical illness may present physical, psychological, or cognitive symptoms after hospital discharge, encompassed within what is known as post-intensive care syndrome. These alterations result from both the critical illness itself and the medical interventions surrounding it. For its prevention, the implementation of the ABCDEF bundle (Assess/treat pain, Breathing/awakening trials, Choice of sedatives, Delirium reduction, Early mobility and exercise, Family) has been proposed, along with additional strategies grouped under the acronym GHIRN (Good communication, Handout materials, Redefined ICU architectural design, Respirator, Nutrition). In addition to these preventive measures during the ICU stay, high-risk patients should be identified for subsequent follow-up through multidisciplinary teams coordinated by Intensive Care Medicine Departments.

Trends and inequalities in physical fitness and nutritional status among 0.72 million Chinese adults aged 20-59 years: an analysis of five successive national surveillance surveys, 2000-2020

Background

Few comprehensive studies have assessed the long-term trends in physical fitness and nutritional status among Chinese adults, along with the socioeconomic inequalities. This study aimed to bridge this gap by examining the temporal changes and the evolution of socioeconomic disparities in physical fitness and nutritional status among Chinese adults aged 20-59, based on five successive national surveillance surveys.

Methods

We integrated data from five consecutive rounds of National Physical Fitness Surveillance (2000, 2005, 2010, 2014, and 2020) among Chinese adults aged 20-59 years. BMI was categorized into underweight (<18.5 kg/m2), overweight (24.0-27.9 kg/m2), and obesity (≥28.0 kg/m2). Central obesity was defined as a waist circumference ≥90 cm for males and ≥85 cm for females. A composite physical fitness indicator (PFI) was calculated by aggregating the Z-scores of all six components. Provinces were ranked by GDP per capita ($) and stratified into three socioeconomic strata from least (T1) to most developed (T3). Generalized additive models (GAMs), adjusted for age and sex, were employed to assess the associations between nutritional status, PFI, and both per capita GDP and urbanization levels.

Findings

A total of 716,790 Chinese adults aged 20-59 were included in the analysis. The PFI score declined from 0.71 in 2000 to -0.84 in 2020, with a particularly sharp annual decline between 2014 and 2020. The underweight prevalence declined from 5.54% in 2000 to 3.51% in 2020, while the prevalence of overweight, obesity, and central obesity increased to 35.84%, 15.05%, and 32.10% in 2020, respectively. After 2005, the urban-rural disparities in physical fitness narrowed, whereas the gap between most and least developed regions widened, with urban and high-SES regions consistently showing better fitness. The prevalence of overweight, obesity, and central obesity in urban and economically developed regions was higher than in less economically developed and rural regions in earlier years, but this pattern reversed over time. The underweight prevalence showed the opposite trend. With increasing GDP per capita, PFI initially rose before declining at higher levels, and it showed a positive correlation with urbanization. Overweight prevalence increased with GDP per capita but slowed at higher levels, while obesity and central obesity exhibited an N-shaped relationship with GDP per capita. Moreover, prevalence of overweight, obesity, and central obesity were positively correlated with urbanization.

Interpretation

During the first two decades of the 21st century, China experienced rapid economic growth accompanied by declining physical fitness and rising prevalence of overweight, obesity, and central obesity among adults aged 20-59 years. Inequalities in nutritional status between urban and rural areas and across socioeconomic strata reversed. Less developed and rural regions may face dual challenges of deteriorating physical fitness and the growing burden of overnutrition, which requires urgent attention. The complex interplay between socioeconomic development, urbanization, and physical health further emphasizes the need for health policies tailored to diverse socioeconomic contexts and subpopulations.

Funding

National Natural Science Foundation of China (72474005, 72122001) and the Peking University Health Science Center-Weifang Joint Research Center for Maternal and Child Health (PKUWF-Y12).

Maximal exercise capacity, peripheral muscle strength, sleep quality, and quality of life in adult patients with stable asthma

OBJECTIVE

The prevalence of asthma is increasing gradually worldwide. The pathophysiological process of asthma causes some alterations in the respiratory system and decreases oxygen-carbon dioxide exchange and respiration volume. These alterations may affect maximal exercise capacity, peripheral muscle strength, sleep quality, and disease-specific quality of life but have yet to be comprehensively investigated. To compare maximal exercise capacity, pulmonary function, peripheral muscle strength, dyspnea, sleep quality, and quality of life in adult patients with asthma, healthy controls were aimed.

METHODS

Forty-one adult stable asthmatic patients (GINA I-III) and 41 healthy subjects were compared. Exercise capacity (cardiopulmonary exercise test [CPET]), pulmonary function (spirometry), peripheral muscle strength (dynamometer), dyspnea (modified Medical Research Council [mMRC] dyspnea scale), quality of life (Asthma Quality of Life Questionnaire [AQLQ]) and sleep quality (Pittsburgh Sleep Quality Index [PSQI]) were evaluated.

RESULTS

Peak VO2, VO2kg, MET, VE, HR, %VE, %HR, VCO2 parameters of CPET, FVC, FEV1, FEF25-75%, and FEV1/FVC and quadriceps femoris, shoulder abductors, and hand grip muscle strength were significantly decreased in patients with asthma (p < 0.05). MMRC dyspnea scale score was increased, and AQLQ and PSQI scores decreased in asthma patients (p < 0.05).

CONCLUSIONS

Cardiac and pulmonary system responses to peak exercise worsened, and maximal exercise capacity and peripheral muscle strength decreased in adult patients with stable asthma. In addition, dyspnea during daily activities increases, and quality of life and sleep quality are impaired. A variety of exercise training that would benefit asthmatic patients' outcomes should be investigated.

Comparison of GLI-2021 standards with ECSC standards for static lung volume interpretation in patients with respiratory diseases

BACKGROUND

In 2021, the Global Lung Function Initiative (GLI) has published new reference equations for static lung volumes (GLI-2021). Many learned societies recommend the use of GLI reference values for interpreting pulmonary function tests (PFT), while pointing out the need for clinicians to be aware of the consequences for their routine practice. We aimed to compare the GLI-2021 reference values and the 1993 European Coal and Steel Community (ECSC) standards on the interpretation of static lung volume data in patients with a probable static hyperinflation or a probable restrictive ventilatory disorder.

METHODS

We analyzed plethysmographic PFT data from 2 groups of patients: a group of patients with symptoms compatible with chronic bronchitis (CB) and a group of patients with symptoms compatible with interstitial lung disease (ILD). We investigated discrepancies in the evaluations of static lung volumes when using the ECSC vs. the GLI-2021 reference values.

RESULTS

2897 sets of PFT results (including 1598 in men) were included. In the CB group, the proportion of hyperinflation was higher for both sexes with the GLI-2021 standards. In the ILD group, the proportion of restrictive ventilatory disorders was higher in women but lower in men with the GLI-2021 standards.

CONCLUSION

A move from use of the ECSC standards for static lung volumes to the GLI-2021 standards might lead to a higher estimated proportion of hyperinflation (particularly in participants with CB), together with changes in the proportion of restrictive ventilatory disorders (a lower value in men and a higher value in women with ILD).

Distinct risks of exacerbation and lung function decline between never-smokers and ever-smokers with COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) can occur in patients without a history of smoking, which is a strong risk factor for COPD. However, few studies have focused on the prognosis of never-smokers with COPD. We investigated the difference of the longitudinal clinical outcomes between never-smokers and ever-smokers with COPD.

METHODS

We retrospectively analyzed patients with COPD who underwent chest computed tomography and longitudinal lung function tests from January 2013 to December 2020. We classified patients according to smoking status and examined their histories of acute exacerbation and long-term changes in lung function.

RESULTS

Among 583 patients with COPD, 75 (12.9%) had no smoking history. These never-smokers with COPD were predominantly women; they had a lower forced vital capacity and a higher prevalence of asthma, history of tuberculosis, tuberculosis-destroyed lung, and bronchiectasis, but a lower prevalence of emphysema, relative to ever-smokers with COPD. Never-smokers with COPD had significantly lower risks of subsequent moderate to severe exacerbation (β ± standard error, - 0.4 ± 0.12; P = 0.001), any exacerbation (adjusted odds ratio, 0.46; 95% confidence interval, 0.26 - 0.8; P = 0.006), and frequent exacerbation (adjusted odds ratio, 0.28; 95% confidence interval, 0.09 - 0.89; P = 0.03) than ever-smokers with COPD. Never-smokers with COPD also showed significantly slower annual decline of forced expiratory volume in 1 s than ever-smokers with COPD (- 15.7 ± 4.7 vs. -30.4 ± 2.9 mL, respectively; P = 0.03).

CONCLUSIONS

Never-smokers with COPD had significantly fewer acute exacerbations and slower decline of lung function than ever-smokers with COPD during longitudinal follow-up.

Spirometry as a diagnostic tool to assess respiratory health in beached bottlenose dolphins Tursiops spp

In this study, we used a dataset including 42 individual bottlenose dolphins (Tursiops spp.) to determine the reliability of lung function testing as a method for assessing respiratory health. Each dolphin was trained to beach voluntarily, allowing researchers to measure respiratory flow in a controlled, beached state. From the collected respiratory flow data, alongside timing parameters, we extracted 18 specific variables, supplemented by additional factors such as body mass, age, and sex. These variables were hypothesized to serve as potential variables for identifying respiratory compromise. A model was developed that reduced the number of predictive variables, showing that 4 specific variables were particularly effective, yielding an accuracy of 88.4% in determining whether a dolphin was free from respiratory disease. This high level of accuracy underscores the potential of lung function testing as a diagnostic tool in the context of stranded dolphins, where rapid, non-invasive methods are crucial for assessing health status. These results suggest that lung function testing provides a non-invasive and efficient method for evaluating respiratory health in stranded dolphins and supports the use of lung function assessments in wildlife management and conservation. By enabling early detection of respiratory issues, this approach can enhance the success of rehabilitation efforts, potentially improving the survival rates of dolphins that have stranded, which is often a critical concern in marine conservation initiatives.

Treatable Trait Guided Asthma Management: A Feasibility Study

BACKGROUND AND OBJECTIVES

Treatable trait-based personalised medicine improves outcomes in severe asthma clinics. We assessed the feasibility of a randomised controlled trial (RCT) of protocolised treatable trait-guided asthma management in patients not under a severe asthma clinic.

METHODS

Ten week single-group cohort study. Participants had a doctor's diagnosis of asthma, Asthma Control Questionnaire-5 (ACQ-5) score > 1, and ≥ 1 exacerbation in the last year.

INTERVENTION

biomarker-guided asthma medication according to a protocolised algorithm, targeting traits of type-2 inflammation and airflow obstruction. Feasibility outcomes: recruitment rates, acceptability of intervention, willingness to enrol in an RCT, need for 'extended' trait assessment after 10 weeks, and estimation of trait prevalence.

RESULTS

Recruitment ceased with 29/50 participants after 14 months due to difficulties associated with COVID-19. Recruitment rate: 29/118 (25%) of those invited to participate (95% CI 17 to 33). 24/26 (92%) participants found the intervention acceptable and were willing to participate in a future study. After 10 weeks, 65% remained not well controlled (ACQ-5 > 1) and would have required the 'extended' assessment. Participants had a mean (SD) 4.8 (2.3) of 13 traits assessed. ACQ-5 improved during the study by -1.0 (0.3 to 1.8) units, and post-bronchodilator airflow limitation reduced from 59% of participants to 35%. 12/29 (41%) participants received continuous oral corticosteroids at some point during the study.

CONCLUSION

Protocolised treatable trait management was acceptable to participants, associated with significant clinical benefit, and a full RCT appears feasible. Targeting type-2 inflammation and airflow obstruction was insufficient to control asthma in the majority of patients, despite marked systemic corticosteroid exposure.

TRIAL REGISTRATION

ACTRN12620000935932.

Insights into associations between Life's essential 8 and lung function from NHANES data

The Life's Essential 8 (LE8) is a novel indicator of cardiovascular health proposed by the American Heart Association. While numerous studies have demonstrated its guiding value in chronic diseases, research on its role in lung function remains limited. This study utilized data from the National Health and Nutrition Examination Surveys (NHANES 2007-2012), which included comprehensive measurements of lung function, diet, physical activity, nicotine exposure, sleep patterns, body mass index (BMI), blood glucose, blood pressure, blood lipids, and relevant covariates. We calculated lung function Z-score and LE8 scores, employing multiple linear regression, multivariable logistic regression, and restricted cubic spline models to evaluate their correlations. In this study of 10,400 participants (mean age 44 years; 48.75% male), participants were classified into threeforcedexpiratory volume in one second (FEV1) Z-score groups: Z1 (normal lung function, n = 9,600), Z2 (mild impairment, n = 618), and Z3 (moderate to severe impairment, n = 182). Significant differences in demographic characteristics and health parameters were observed among the groups. Notably, variations in the Healthy Eating Index 2015 (HEI-2015), physical activity, nicotine exposure, and sleep patterns were identified within the LE8 health behavior domain. Higher LE8 scores were found to be positively associated with lung function, even after adjusting for demographic and health factors. Further analysis revealed positive correlations between lung function and favorable dietary habits, higher physical activity levels, reduced nicotine exposure, and improved sleep quality. Conversely, BMI, blood lipids, blood glucose, and blood pressure exhibited variable effects. Subgroup and sensitivity analyses consistently supported findings, confirming a positive correlation between LE8 and lung function. Our study highlights significant associations between LE8 scores and lung function, demonstrating that higher LE8 scores, which reflect better cardiovascular health behaviors, are positively correlated with improved lung function.

Baseline total lung capacity and all-cause mortality in restrictive pulmonary disorders: a meta-analysis

RATIONALE

Forced vital capacity (FVC) has been utilized as a surrogate for vital capacity (VC) in monitoring the progression of restrictive pulmonary disorders, particularly in clinical trials of idiopathic pulmonary fibrosis (IPF). A dose-response relationship between decreased FVC and mortality in IPF has also been established. Since 2005, total lung capacity (TLC) has been routinely required to differentiate and diagnose restrictive pulmonary disorders. However, the relationship between changes in TLC change and the risk of mortality remains unclear.

OBJECTIVES

To investigate and quantify the relationship between changes in TLC and the risk of mortality in patients with restrictive pulmonary disorders.

METHODS

This study employed a systematic review and meta-analysis following the PRISMA 2020 guidelines.

RESULTS

A total of 26 studies were included in the meta-analysis, comprising a combined sample of 16,579 subjects, which included 7,961 females, 4,460 subjects in the relative low TLC group, and 12,119 subjects in the high TLC group. A reduced TLC was associated with an increased risk of all-cause mortality, as indicated by both unadjusted and adjusted hazard ratios. The unadjusted hazard ratio (95% CI) was 1.76 (1.32, 2.35), while the adjusted hazard ratio (95% CI) was 1.70 (1.31, 2.20). The risk ratio (RR) estimated from the studies that reported both the number of participants and deaths was RR (95% CI) = 2.01 (1.56, 2.60). The included studies demonstrated significant heterogeneity.

CONCLUSION

A low TLC at baseline, in comparison to individuals with relatively higher TLC, may increase the risk of all-cause mortality by at least 42-70% in cases of restrictive pulmonary disorders, although this conclusion is primarily based on observational studies, which carry low to moderate certainty.

Serum carbohydrate antigen 153 as a predictor of interstitial lung disease associated with rheumatoid arthritis is positively correlated with serum Krebs von den Lungen-6

OBJECTIVE

The objective of this study was to evaluate the clinical significance of carbohydrate antigen (CA) 153 and its correlation with Krebs von den Lungen-6 (KL-6) in the prediction and determination of the severity of interstitial lung disease (ILD) in rheumatoid arthritis (RA) patients.

METHODS

Data was collected retrospectively on a cohort of 357 RA patients who were admitted to our hospital from January 2018 to December 2020. The classification of patients into subgroups was based on high-resolution computed tomography (HRCT) of the chest, resulting in 135 patients with RA but no ILD, 107 patients with RA and indeterminate ILD, 91 patients with RA and mild ILD, and 24 patients with RA and advanced ILD. The levels of CA153 and KL-6 were determined by chemiluminescence analysis.

RESULTS

The serum levels of CA153 were found to be significantly higher in both the RA-mild ILD group and the RA-advanced ILD group compared to the RA-no ILD group (8.00 vs. 6.40, q = 0.039; 20.30 vs. 6.40, q < 0.001). Multivariate analysis demonstrated that CA153 was an independent risk factor for RA-ILD (RA-mild ILD + RA-advanced ILD) [odds ratio (OR) = 1.124, 95% confidence interval (CI) = (1.060-1.191), p < 0.001] and RA-advanced ILD (OR = 1.583, 95% CI = 1.247-2.010, p < 0.001). Furthermore, the receiver operating characteristic (ROC) analysis indicated that CA153 had diagnostic value for both RA-ILD (RA-mild ILD + RA-advanced ILD) and RA-advanced ILD. The best area under ROC curve (AUC) of CA153 for RA-ILD (RA-mild ILD + RA-advanced ILD) was 0.66 (p < 0.001; sensitivity = 57.27%; specificity = 72.03%). The AUC of CA153 for RA-advanced ILD was 0.95 (p < 0.001; sensitivity = 95.65%; specificity = 83.05%). Moreover, CA153 was negatively correlated with forced vital capacity percent predicted (FVC% pred) (r = -0.383, p = 0.037) but positively related to KL-6 (r = 0.762, p < 0.001).

CONCLUSION

It was concluded that CA153 was positively associated with KL-6 and might be a significant and clinical availably measurable serum marker to predict the diagnosis and severity of ILD in RA patients.

Can the single-breath alveolar volume be adjusted to estimate true total lung capacity?

Background

Total lung capacity (TLC) measured with single-breath gas diffusion (TLCsb) is systematically lower than TLC measured with whole-body plethysmography (TLCwbp) especially in patients with obstructive defects. We aimed to develop and validate a regression correction equation to reduce the discrepancy between the two measurements of TLC. Second, we compared the ability to detect restriction (reduced TLC) from adjusted TLC measured by single-breath (TLCsbadj) with gold standard TLCwbp.

Methods

Lung function data from 800 consecutive patients were analysed with multivariable linear regression. A group of 530 were included for model development, and 270 were used for model validation.

Results

TLCsb was found to be on average 1.1 L lower than TLCwbp (p < 0.001). This difference increased with degree of airway obstruction. After adjustment TLCsbadj did not significantly differ from TLCwbp in obstructive and mixed obstructive-restrictive subjects. TLCsbadj had a sensitivity of 70% and a specificity of 99% to predict restriction on an individual basis, with a 95% confidence interval (CI) of [-19.6%; 17.7%] percentage when comparing adjusted values of TLCsb with the true TLCwbp value.

Conclusions

After adjustment TLCsb was no longer significantly underestimated in obstructive and mixed restrictive-obstructive groups compared to TLCwbp. The adjustment can be used on individual subjects to estimate restriction via the TLCsb, thereby making the single-breath gas diffusion method a more valid alternative than without adjustment, when compared with the gold standard whole-body plethysmography to measure TLC.

Relationship of perfluoroalkyl chemicals with chronic obstructive pulmonary disease: A cross-sectional study

Perfluoroalkyl chemicals are one of the most stable substances in industry and have become ubiquitous contaminants owing to their persistence in the environment. This study enrolled 1,953 participants aged ≥40 years old using data from the National Health and Nutrition Examination Survey (NHANES). We selected four perfluoroalkyl chemicals with a detection frequency of more than 80%, including perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS). Multivariate logistic regression was performed to determine the relationship of serum perfluoroalkyl chemicals with COPD and airflow limitation. We evaluated the interaction between perfluoroalkyl chemicals and lung function using multivariate linear regression analyses. Our results showed that the prevalence of COPD was not significantly related to serum PFHxS, PFNA, PFOA, and PFOS. Airflow limitation was positively linked with serum PFHxS, PFOA, and PFOS. However, these significant differences were not robust after adjustment of all confounders of interest. Serum PFHxS, PFOA, and PFOS were all positively related to the forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF). However, only PFOA remained significantly linked with the FEV1 and FVC after covariate adjustment. These results indicated that there was no significant interaction between exposure to perfluoroalkyl chemicals and the prevalence of COPD. Higher levels of serum PFOA appeared to be related to higher measures of FEV1 and FVC.

Is Disease Stability an Attainable Chronic Obstructive Pulmonary Disease Treatment Goal?

Chronic obstructive pulmonary disease (COPD) is a heterogeneous lung condition characterized by progressive airflow obstruction. Despite advancements in diagnosis and treatment, the disease burden remains high; although clinical trials have shown improvements in outcomes such as exacerbations, quality of life, and lung function, improvement may not be attainable for many patients. For patients who do experience improvement, it is challenging to set management goals given the progressive nature of COPD. We therefore propose disease stability as an appropriate and attainable treatment goal. Other disease areas have developed definitions of no disease activity or remission, which provide relevant information for defining and achieving stability for patients with COPD. Disease stability builds on related concepts already defined in COPD, such as clinical control and clinically important deterioration. Current components that could form part of a disease stability definition include exacerbations, health status (including quality of life and symptoms), and lung function. Considerations should be given to intervals over which stability is defined and assessed, appropriate thresholds, and defining a composite. Ensuring a holistic approach, objective measurements, and harmonious, clear communication between patients and physicians can further support establishing disease stability. Here we propose a preliminary definition of disease stability, informed by existing research in COPD. Further research will be needed to validate the framework for use in clinical and research settings. Exploring disease stability as a goal, however, is an opportunity to develop and validate an attainable treatment target to advance the standard of care for patients with COPD.

Peak Flow Feedback Intervention Improves Underperception of Airflow Limitation in Pediatric Asthma: A Randomized Clinical Trial

Rationale: Underperception of asthma symptoms is associated with poor asthma outcomes. Objectives: We assessed the effects of a behavioral intervention for improving perception of airflow limitation and asthma outcomes. Methods: A two-arm randomized controlled trial compared peak expiratory flow (PEF) feedback versus supportive counseling. Latino and Black adolescents with asthma ages 10-17 years old and caregivers were recruited from hospitals in the Bronx, New York. PEF feedback sessions reviewed accuracy of PEF guesses and medication adherence data and targeted behavior change using motivational interviewing and problem-solving skills training. The supportive counseling group received emotional support related to asthma. Both groups received three sessions across 6 weeks. All participants were blinded to PEF while guessing PEF before intervention and at 1, 6, and 12-month follow-up. Children in the PEF feedback group saw actual PEF after guesses were locked in during the 6-week intervention. Participants and assessors were blinded to group assignment. The primary outcome was underperception of airflow limitation (divergence between actual PEF and guesses) on home spirometers. Secondary outcomes included daily PEF and forced expiratory volume in 1 second (FEV1), inhaled corticosteroid adherence measured by electronic monitors, Asthma Control Test, and emergency health care use for asthma. Results: The sample comprised 354 children (mean = 13.2 ± 2.2 yr; 62% Latino, 38% Black) and caregivers. The PEF feedback group (N = 153 analyzed) demonstrated greater improvements at 1-month follow-up on underperception of airflow limitation (difference-in-differences, -12.64; 95% confidence interval [CI], -17.54 to -7.74), percent personal best PEF (9.89; 95% CI, 7.13 to 12.65), percent predicted FEV1 (4.93; 95% CI, 0.95 to 8.90), and inhaled corticosteroid adherence (16.02; 95% CI, 7.15 to 24.89) compared with the supportive counseling group (N = 152 analyzed). At 12-month follow-up, the PEF feedback group maintained improvements on underperception of airflow limitation (-13.87; 95% CI, -19.03 to -8.71), maintained higher percentage personal best PEF (14.23; 95% CI, 11.37 to 17.08) and percent predicted FEV1 (5.62; 95% CI, 1.56 to 9.67), and had smaller declines in inhaled corticosteroid adherence (17.51; 95% CI, 7.12 to 27.89) versus before intervention than the supportive counseling group. No between-group differences existed for asthma control or health care use. Conclusions: The efficacy and sustainability of PEF feedback was established in improving children's perception of airflow limitation, pulmonary function, and medication adherence. Clinical trial registered with www.clinicaltrials.gov (NCT02702687).

Pulmonary function tests in infants following SARS-CoV-2 infection

INTRODUCTION

The clinical spectrum of SARS-CoV-2 infection is well-established. However, understanding its long-term implications, especially in infants, remains limited. We aimed to evaluate pulmonary function tests in infants (iPFT) several months after a documented SARS-CoV-2 infection.

METHODS

An observational case-control study was performed. iPFT results in infants with persistent respiratory complaints several months after a SARS-CoV-2 infection were compared to a registry of patients assessed at our center between 2008 and 2019 using the Mann-Whitney U and Fisher's exact tests. Excluded from the study were infants with chronic diseases and extreme prematurity.

RESULTS

iPFT data from sixteen infants with respiratory complaints and a history of SARS-CoV-2 infection and 475 controls were evaluated in the study. The median time between the SARS-CoV-2 infection and iPFT evaluation was 5.5 months (IQR = 2.8-8.0). There were no differences between cases and controls in clinical characteristics and reason for iPFT evaluation. iPFT results showed no significant differences between cases and controls in lung volumes, compliance, or resistance. Expiratory airflow limitation was observed in both groups, with better low lung volume flows in the SARS-CoV-2 group. Categorization according to iPFT physiologic alteration and bronchodilator responsiveness were similar in the two groups.

CONCLUSION

This study provides the first comprehensive iPFT data in infants following a SARS-CoV-2 infection. The findings suggest that SARS-CoV-2 infection does not cause unique long-term effects on pulmonary function in infants with chronic respiratory symptoms. Further studies in larger cohorts, particularly in infants with severe acute SARS-CoV-2 infection, are warranted to validate these findings.

Computed tomography-based measurements associated with rapid lung function decline in severe asthma

BACKGROUND

Patients with severe asthma are susceptible to lung function decline (LFD), but biomarkers that reliably predict an accelerated LFD have not been fully recognized.

OBJECTIVE

To identify variables associated with previous LFD occurrences in patients with severe asthma by exploring the computed tomography (CT) imaging features within predefined LFD groups.

METHODS

We obtained inspiratory and expiratory CT images of 102 patients with severe asthma and derived 2 airway structural parameters (wall thickness [WT] and hydraulic diameter) and 2 parenchymal variables (functional small airway disease and emphysema). We retrospectively calculated the annual changes in forced expiratory volume in 1 second and grouped participants by their values determined. The 4-imaging metrics, along with levels of several biomarkers, were compared among the LFD groups.

RESULTS

Patients with severe asthma with enhanced LFD exhibited significantly lower WT and smaller hydraulic diameter compared with those with minimal change or slight decline in lung function, after an adjustment of smoking status. Conversely, CT-based percentages of emphysema and functional small airway disease did not significantly differ according to LFD. Furthermore, fractional exhaled nitric oxide (FeNO) level and the blood matrix metalloproteinase-9/TIMP metallopeptidase inhibitor 1 ratio were significantly higher in patients with severe asthma with enhanced LFD compared with those in the others.

CONCLUSION

Lower WT on CT scans with increased FeNO that may represent increased airway inflammation significantly correlated with enhanced LFD in patients with severe asthma. Consequently, active management plans may help to attenuate LFD for patients with severe asthma with lower WT and high FeNO.