Higher Lung Function Research Articles

Clusters of multidimensional exercise response patterns and estimated heart failure risk in the Framingham Heart Study.

New tools are needed to identify heart failure (HF) risk earlier in its course. We evaluated the association of multidimensional cardiopulmonary exercise testing (CPET) phenotypes with subclinical risk markers and predicted long-term HF risk in a large community-based cohort. We studied 2532 Framingham Heart Study participants [age 53±9years, 52% women, body mass index (BMI) 28.0±5.3kg/m2, peak oxygen uptake (VO2) 21.1±5.9kg/m2 in women, 26.4±6.7kg/m2 in men] who underwent maximum effort CPET and were not taking atrioventricular nodal blocking agents. Higher peak VO2 was associated with a lower estimated HF risk score (Spearman correlation r: -0.60 in men and -0.55 in women, P<0.0001), with an observed overlap of estimated risk across peak VO2 categories. Hierarchical clustering of 26 separate CPET phenotypes (values residualized on age, sex, and BMI to provide uniformity across these variables) identified three clusters with distinct exercise physiologies: Cluster 1-impaired oxygen kinetics; Cluster 2-impaired vascular; and Cluster 3-favourable exercise response. These clusters were similar in age, sex distribution, and BMI but displayed distinct associations with relevant subclinical phenotypes [Cluster 1-higher subcutaneous and visceral fat and lower pulmonary function; Cluster 2-higher carotid-femoral pulse wave velocity (CFPWV); and Cluster 3-lower CFPWV, C-reactive protein, fat volumes, and higher lung function; all false discovery rate<5%]. Cluster membership provided incremental variance explained (adjusted R2 increment of 0.10 in women and men, P<0.0001 for both) when compared with peak VO2 alone in association with predicted HF risk. Integrated CPET response patterns identify physiologically relevant profiles with distinct associations to subclinical phenotypes that are largely independent of standard risk factor-based assessment, which may suggest alternate pathways for prevention.

Comparative assessment of the effect of anesthetics (propofol, sevoflurane, desflurane) on hemodynamics and gas exchange in the lungs during operations for acute pulmonary embolism

Introduction. To date, single studies have been published on the anesthesiological support of operations for acute pulmonary embolism. The issues of the influence of basic anesthetics on central hemodynamics and the functional state of lung tissue are not covered.The objective was to conduct a comparative assessment of the effect of anesthesia based on propofol, sevoflurane and desflurane on the parameters of central hemodynamics, myocardial contractility and functional state of the lungs during operations for acute pulmonary embolism.Materials and methods. The study included 75 patients (42 men and 33 women) aged 42.3 ± 14.3 years. All patients were operated for massive pulmonary embolism under cardiopulmonary bypass. The patients were randomized into three groups: in the first group (25 patients), propofol was used as the main anesthetic; in the secondgroup (25 patients) - sevoflurane; in the third group (25 patients) - desflurane. The indicators of central hemodynamics, myocardial contractile function and the functional state of the lungs during the operation were studied.Results. The comparative analysis of the anesthesia revealed that propofol had a more pronounced depressive effect on hemodynamics (a statistically significant decrease in blood pressure and EF LV), and desflurane had a moderate hyperdynamic effect (a statistically significant increase in heart rate). Anesthesia with propofol caused a statistically significant increase in the AAPO2 index (by 32.1%), a decrease in the PaO2/FiO2 index (by 24.1%) before cardiopulmonary bypass. After CPB, the oxygenation index decreased, intrapulmonary blood shunting increased, and pulmonary compliance decreased statistically significantly. The use of inhalation anesthetics (sevoflurane, desflurane) effectively preserved the functional parameters of the lungs: there were no statistically significant changes in the studied parameters.Conclusion. The inclusion of inhaled anesthetics (sevoflurane and desflurane) in the anesthesia regimen during surgery for acute pulmonary embolism ensures the stability of hemodynamic parameters and contractile function of the myocardium. The use of inhaled anesthetics maintains high lung function during surgery.

Establishing a 4D-CT lung function related volumetric dose model to reduce radiation pneumonia

In order to study how to use pulmonary functional imaging obtained through 4D-CT fusion for radiotherapy planning, and transform traditional dose volume parameters into functional dose volume parameters, a functional dose volume parameter model that may reduce level 2 and above radiation pneumonia was obtained. 41 pulmonary tumor patients who underwent 4D-CT in our department from 2020 to 2023 were included. MIM Software (MIM 7.0.7; MIM Software Inc., Cleveland, OH, USA) was used to register adjacent phase CT images in the 4D-CT series. The three-dimensional displacement vector of CT pixels was obtained when changing from one respiratory state to another respiratory state, and this three-dimensional vector was quantitatively analyzed. Thus, a color schematic diagram reflecting the degree of changes in lung CT pixels during the breathing process, namely the distribution of ventilation function strength, is obtained. Finally, this diagram is fused with the localization CT image. Select areas with Jacobi > 1.2 as high lung function areas and outline them as fLung. Import the patient's DVH image again, fuse the lung ventilation image with the localization CT image, and obtain the volume of fLung different doses (V60, V55, V50, V45, V40, V35, V30, V25, V20, V15, V10, V5). Analyze the functional dose volume parameters related to the risk of level 2 and above radiation pneumonia using R language and create a predictive model. By using stepwise regression and optimal subset method to screen for independent variables V35, V30, V25, V20, V15, and V10, the prediction formula was obtained as follows: Risk = 0.23656–0.13784 * V35 + 0.37445 * V30-0.38317 * V25 + 0.21341 * V20-0.10209 * V15 + 0.03815 * V10. These six independent variables were analyzed using a column chart, and a calibration curve was drawn using the calibrate function. It was found that the Bias corrected line and the Apparent line were very close to the Ideal line, The consistency between the predicted value and the actual value is very good. By using the ROC function to plot the ROC curve and calculating the area under the curve: 0.8475, 95% CI 0.7237–0.9713, it can also be determined that the accuracy of the model is very high. In addition, we also used Lasso method and random forest method to filter out independent variables with different results, but the calibration curve drawn by the calibration function confirmed poor prediction performance. The function dose volume parameters V35, V30, V25, V20, V15, and V10 obtained through 4D-CT are key factors affecting radiation pneumonia. Establishing a predictive model can provide more accurate lung restriction basis for clinical radiotherapy planning.

Preoperative DLco and FEV1 are correlated with postoperative pulmonary complications in patients after esophagectomy

Limited information is available regarding the association between preoperative lung function and postoperative pulmonary complications (PPCs) in patients with esophageal cancer who undergo esophagectomy. This is a retrospective cohort study. Patients were classified into low and high lung function groups by the cutoff of the lowest fifth quintile of forced expiratory volume in 1 s (FEV1) %predicted (%pred) and diffusing capacity of the carbon monoxide (DLco) %pred. The PPCs compromised of atelectasis requiring bronchoscopic intervention, pneumonia, and acute lung injury/acute respiratory distress syndrome. Modified multivariable-adjusted Poisson regression model using robust error variances and inverse probability treatment weighting (IPTW) were used to assess the relative risk (RR) for the PPCs. A joint effect model considered FEV1%pred and DLco %pred together for the estimation of RR for the PPCs. Of 810 patients with esophageal cancer who underwent esophagectomy, 159 (19.6%) developed PPCs. The adjusted RR for PPCs in the low FEV1 group relative to high FEV1 group was 1.48 (95% confidence interval [CI] = 1.09–2.00) and 1.98 (95% CI = 1.46–2.68) in the low DLco group relative to the high DLco group. A joint effect model showed adjusted RR of PPCs was highest in patients with low DLco and low FEV1 followed by low DLco and high FEV1, high DLco and low FEV1, and high DLco and high FEV1 (Reference). Results were consistent with the IPTW. Reduced preoperative lung function (FEV1 and DLco) is associated with post-esophagectomy PPCs. The risk was further strengthened when both values decreased together.

Association between lung function and bone mineral density in children and adolescents: Insights from the NHANES.

Bone development and lung function are integral to child and adolescent health. Both influence an individual's overall well-being and potentially affect long-term health. Utilizing a comprehensive dataset from the National Health and Nutrition Examination Survey, this study aims to elucidate the relationship between lung function and bone mineral density (BMD) in a representative sample of children and adolescents. The analysis covered 3410 participants aged 8 to 19 years. We employed weighted multivariate linear regression and restricted cubic spline curve visualizations to explore the intricate association between lung function metrics, particularly first-second expiratory volume 1 second/forced vital capacity ratio, and lumbar BMD. Our data indicated a positive association between lung function and lumbar BMD in children and adolescents. Specifically, higher lung function metrics were linked with increased lumbar BMD. This association was more pronounced in younger participants or those with a lower body mass index. A significant positive relationship exists between lung function and BMD in the pediatric population. Recognizing this association is crucial for holistic health strategies for children and adolescents. This study underscores the need for integrated health monitoring during formative years, which can influence health trajectories as these individuals transition to adulthood.

Influence of lung function on macro‐ and micro‐structural brain changes in mid‐ and late‐ life: a large population‐based cohort study in the UK Biobank

AbstractBackgroundLung function has been associated with cognitive decline and dementia, but the extent to which lung function impacts brain structural changes remains unclear. We aimed to investigate the association of lung function with structural macro‐ and micro‐ brain changes across mid‐ and late‐ life in a large population‐based cohort study.MethodThe study included a total of 37,590 neurologic disorder‐free participants aged 40‐70 years from the UK Biobank, who underwent brain magnetic resonance imaging (MRI) scans 9 years after baseline. After 2.5 years, a subsample (n = 3,941) underwent a second MRI scan. Lung function was assessed using a composite score based on forced expiratory volume in 1 second, forced vital capacity, and peak expiratory flow, and divided into tertiles (i.e., low, moderate, and high). Regional brain volumes (including total brain, gray matter, white matter, hippocampus, and white matter hyperintensities) and diffusion markers (fractional anisotropy [FA] and mean diffusivity [MD]) were assessed. Data were analyzed using linear regression and mixed‐effects models.ResultAt baseline, lung function ranged from ‐3.43 to 22.91 among all participants. In multi‐adjusted linear regression, low lung function was dose‐dependently related to smaller brain volumes and lower white matter integrity. Compared to high lung function, low lung function was associated with smaller total brain (β [95% CI]: ‐0.083 [‐0.097, ‐0.070], gray matter ‐0.145 [‐0.161, ‐0.130], white matter ‐0.017 [‐0.031, ‐0.004], and hippocampal ‐0.102 [‐0.128, ‐0.075]) volume, as well as poor white matter health (FA ‐0.165 [‐0.195, ‐0.135] for lower, WMH 0.269 [0.242, 0.295] and MD 0.168 [0.140, 0.196] for higher). Over the 2.5 years follow‐up, low PF was associated with reduced white matter (‐0.021 [‐0.041, ‐0.002]) and hippocampal (‐0.078 [‐0.110, ‐0.046]) volume, reduced FA (‐0.063 [‐0.091, ‐0.035]), and increased WMH volume (0.065 [0.016, 0.114]) and MD (0.121 [0.089, 0.154]). After stratification by age, the associations remained significant among adults aged 40‐60 years and 60+ years.ConclusionLow lung function is associated with macro‐ and micro‐ structural brain changes involving both neurodegenerative and vascular pathologies. This association is significant in both mid‐ and late‐ life.

Serum α-Klotho level, lung function, airflow obstruction and inflammatory markers in US adults.

α-Klotho is a pleiotropic protein that may have anti-oxidative and anti-inflammatory properties in the lung, but its role in airflow obstruction or lung function is largely unknown. This was a cross-sectional study of 6046 adults aged 40-79 years in the US National Health and Nutrition Examination Survey (NHANES) 2007-2012. We used multivariable logistic or linear regression to examine the relation between serum α-Klotho level and airflow obstruction, defined as forced expiratory volume in 1 s (FEV1) <80% of predicted and FEV1/forced vital capacity (FVC) ratio <0.70; FEV1, FVC and FEV1/FVC as percentage of predicted; and inflammatory markers in blood (white blood cell count, eosinophils, neutrophils and C-reactive protein (CRP)). α-Klotho levels in the second to fourth quartiles (Q2-Q4) were associated with significantly decreased odds of airflow obstruction (adjusted OR for Q2-Q4 versus lowest quartile (Q1) 0.54 (95% CI 0.35-0.81)) in never-smokers and ex-smokers with <10 pack-years of smoking, but not in current smokers or ex-smokers with ≥10 pack-years of smoking. In all participants, each unit increment in log10-transformed α-Klotho level was significantly associated with 5.0% higher FEV1 % pred and 3.7% higher FVC % pred. Higher α-Klotho was also associated with lower eosinophils, neutrophils and CRP in participants both with and without airflow obstruction. Higher serum α-Klotho is associated with lower inflammatory markers and higher lung function in adults with and without airflow obstruction, and with decreased odds of airflow obstruction in never-smokers and ex-smokers with <10 pack-years of smoking. Further studies are warranted to replicate our findings and evaluate underlying mechanisms.

401 Black and Hispanic people with cystic fibrosis (PwCF) and PwCF with high lung function are less likely to be prescribed elexacaftortezacaftor-ivacaftor despite having an eligible genotype

401 Black and Hispanic people with cystic fibrosis (PwCF) and PwCF with high lung function are less likely to be prescribed elexacaftortezacaftor-ivacaftor despite having an eligible genotype

Hypoglycemia in children and young adults with cystic fibrosis during oral glucose tolerance testing vs. continuous glucose monitoring.

Hypoglycemia is common in people with cystic fibrosis (pwCF) during oral glucose tolerance tests (OGTTs) and in the free-living setting, yet its pathophysiology remains unclear. To evaluate hypoglycemia in children and young adults with CF by OGTT and continuous glucose monitoring (CGM). A 3-h OGTT was performed in children and young adults with CF and healthy controls (HC). Individuals were classified as experiencing hypoglycemia on OGTT (glucose <70 mg/dL) or not. Insulin, C-peptide, glucose, glucagon, and incretins were measured. CGM was performed for 7 days in the free-living setting. Measures of insulin sensitivity, beta cell function accounting for insulin sensitivity, and insulin clearance were calculated. A total of 57 participants (40 CF and 17 HC) underwent assessment. Rates of hypoglycemia by OGTT were similar in pwCF (53%, 21/40) compared to HC (35%, 6/17), p = 0.23. PwCF compared to HC had higher A1c; on OGTT higher and later glucose peaks, later insulin peaks; and on CGM more glucose variability. CF Hypo+ versus CF Hypo- had higher lung function, higher insulin sensitivity, higher beta cell function accounting for insulin sensitivity, and decreased CGM variability. When comparing CF Hypo+ to HC Hypo+, although rates of hypoglycemia are similar, pwCF had blunted glucagon responses to hypoglycemia. OGTT hypoglycemia was not associated with CGM hypoglycemia in any group. Youth with CF have increased insulin sensitivity and impaired glucagon response to hypoglycemia on OGTT. Hypoglycemia on OGTT did not associate with free-living hypoglycemia.

WS04.04 CFTR modulator triple combination treatment modifies exhaled breath of children with cystic fibrosis within a week

Objectives: The triple combination of CFTR modulators ivacaftor/tezacaftor/elexacaftor restores some CFTR activity in patients with rescuable mutations which may translate into an increase in respiratory function and quality of life. Yet, novel biomarkers are needed to evaluate treatment efficacy in patients with high basal lung function such as children. Our primary objective was to demonstrate the value of breath analysis to monitor short-term response to the triple combination.

Asthma with recurrent middle lobe syndrome in children: Clinical features and lung function patterns.

Middle lobe syndrome (MLS) is a complication of childhood asthma. This study aimed to compare the clinical features and lung function between asthmatic children with recurrent MLS and transient right middle lobe (RML) and/or lingula atelectasis. This study retrospectively analyzed asthmatic children with RML and/or lingula atelectasis between 2010 and 2020 using data from the pediatric pulmonary department. According to the episodes of atelectasis, children were divided into recurrent (≥2 episodes) and non-recurrent (only 1 episode) MLS groups, to compare clinical features and lung function. Spirometry during acute asthma exacerbation and stable stages were recorded, and variations were calculated. A total of 35 children with asthma and RML and/or lingula atelectasis were included, 15 of whom had recurrent MLS. The recurrent MLS group had a higher proportion of girls, infections, family allergy history, severe asthma, severe exacerbation, and higher levels of total IgE than the non-recurrent MLS group (P < 0.05). The recurrent MLS group had a significantly higher % predicted and z-scores for forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), a greater proportion of high FEV1 and higher variations in FEV1 and FVC than that in the non-recurrent group (P < 0.05). After excluding children with mild to moderate asthma in the recurrent MLS group, the differences in clinical features disappeared, but the results regarding lung function remained similar, when compared to severe asthma patients without RML and/or lingula atelectasis. Childhood asthma with recurrent MLS has more frequent severe asthma and exacerbation but high lung function and variations.

Therapeutic beta-lactam dosages and broad-spectrum antibiotics are associated with reductions in microbial richness and diversity in persons with cystic fibrosis

Persons with cystic fibrosis (PwCF) suffer from pulmonary exacerbations (PEx) related in part to lung infection. While higher microbial diversity is associated with higher lung function, the data on the impact of short-term antibiotics on changes in microbial diversity is conflicting. Further, Prevotella secretes beta-lactamases, which may influence recovery of lung function. We hypothesize that sub-therapeutic and broad spectrum antibiotic exposure leads to decreasing microbial diversity. Our secondary aim was to evaluate the concerted association of beta-lactam pharmacokinetics (PK), antibiotic spectrum, microbial diversity, and antibiotic resistance on lung function recovery using a pathway analysis. This was a retrospective observational study of persons with CF treated with IV antibiotics for PEx between 2016 and 2020 at Children’s National Hospital; respiratory samples and clinical information were collected at hospital admission for PEx (E), end of antibiotic treatment (T), and follow-up (F). Metagenomic sequencing was performed; PathoScope 2.0 and AmrPlusPlus were used for taxonomic assignment of sequences to bacteria and antibiotic resistance genes (ARGs). M/W Pharm was used for PK modeling. Comparison of categorical and continuous variables and pathway analysis were performed in STATA. Twenty-two PwCF experienced 43 PEx. The study cohort had a mean age of 14.6 years. Only 12/43 beta-lactam courses had therapeutic PK, and 18/43 were broad spectrum. A larger decrease in richness between E and T was seen in the therapeutic PK group (sufficient − 20.1 vs. insufficient − 1.59, p = 0.025) and those receiving broad spectrum antibiotics (broad − 14.5 vs. narrow − 2.8, p = 0.030). We did not detect differences in the increase in percent predicted forced expiratory volume in one second (ppFEV1) at end of treatment compared to PEx based on beta-lactam PK (sufficient 13.6% vs. insufficient 15.1%) or antibiotic spectrum (broad 11.5% vs. narrow 16.6%). While both therapeutic beta-lactam PK and broad-spectrum antibiotics decreased richness between PEx and the end of treatment, we did not detect longstanding changes in alpha diversity or an association with superior recovery of lung function compared with subtherapeutic PK and narrow spectrum antimicrobials.

Identification of Asthma Phenotypes in the Spanish MEGA Cohort Study Using Cluster Analysis

IntroductionThe definition of asthma phenotypes has not been fully established, neither there are cluster studies showing homogeneous results to solidly establish clear phenotypes. The purpose of this study was to develop a classification algorithm based on unsupervised cluster analysis, identifying clusters that represent clinically relevant asthma phenotypes that may share asthma-related outcomes. MethodsWe performed a multicentre prospective cohort study, including adult patients with asthma (N=512) from the MEGA study (Mechanisms underlying the Genesis and evolution of Asthma). A standardised clinical history was completed for each patient. Cluster analysis was performed using the kernel k-groups algorithm. ResultsFour clusters were identified. Cluster 1 (31.5% of subjects) includes adult-onset atopic patients with better lung function, lower BMI, good asthma control, low ICS dose, and few exacerbations. Cluster 2 (23.6%) is made of adolescent-onset atopic asthma patients with normal lung function, but low adherence to treatment (59% well-controlled) and smokers (48%). Cluster 3 (17.1%) includes adult-onset patients, mostly severe non-atopic, with overweight, the worse lung function and asthma control, and receiving combination of treatments. Cluster 4 (26.7%) consists of the elderly-onset patients, mostly female, atopic (64%), with high BMI and normal lung function, prevalence of smokers and comorbidities. ConclusionWe defined four phenotypes of asthma using unsupervised cluster analysis. These clusters are clinically relevant and differ from each other as regards FEV1, age of onset, age, BMI, atopy, asthma severity, exacerbations, control, social class, smoking and nasal polyps.

A SYSTEMATIC REVIEW OF NUTRITOINS IMPACT ON ASTHMA PREVENTION AND MANAGEMENT

Introduction: Asthma is a chronic respiratory disorder characterized by airway inflammation and hyperreactivity. Prevalence has continued to climb in recent decades as Western food habits have become more popular. Methods: We searched PubMed, Embase, and Scopus (January 2000--October 2022) for randomized clinical trials that evaluated the effects of diet in adults with asthma. Results: Among the 12,215 studies that were searched, only 12 were included. Obese people with asthma may benefit from a drop in weight of at least 7.5% from baseline due to calorie restriction. The influence of a diet high in items with putative antioxidant effect on asthma management was small and not clinically significant. Antioxidant supplements studies have shown positive results, with magnesium supplementation improving asthma management and vitamin C supplementation slowing the decrease of lung function. Studies on the impact of fatty acid supplementation on weight reduction, asthma management, and lung function all showed positive results. Propolis and caffeine have been shown to significantly improve lung function in clinical trials. But the opposite was found in research on high salt diets and lung function reductions. Conclusions: For individuals who are overweight and suffer from asthma, the optimal dietary strategy seems to be calorie restriction rather than focusing on individual food groups.

Asthma-related lung function and physical activity patterns among children living in urban neighborhoods

Objective Black and Latino American children residing in urban environments are at increased risk for comorbid asthma and obesity. Physical activity (PA) is a modifiable behavior known to contribute to the asthma-obesity phenotype. While research has indicated links between optimal asthma status and high PA among children, little is documented about whether this group may display other asthma and PA patterns that warrant clinical attention and tailored interventions. Methods Children with persistent asthma (N = 97) ages 7–9 and their caregivers from urban neighborhoods completed daily measures of asthma status and moderate-to-vigorous physical activity (MVPA) and questionnaires about health and sociodemographic characteristics. Clinical asthma guidelines (e.g. FEV1 ≥ 80%) and sample means were used to categorize children into high or low lung function and MVPA patterns. Individual, family, and contextual differences across lung function and MVPA patterns were investigated. Results Twenty-nine percent of participants displayed optimal lung function and high MVPA. The remainder of the sample exhibited various less optimal patterns (e.g. poorer lung function and high MVPA). Caregivers of children displaying poorer lung function and high MVPA levels were more likely to report asthma related fears than caregivers of children with low MVPA levels regardless of lung function status. Conclusions Asthma and PA interventions can be tailored to better address each child’s unique clinical and behavioral patterns. An enhanced understanding of risk factors for suboptimal patterns of asthma status and PA may aid in multicomponent intervention efforts.

Polygenic scores for low lung function and the future risk of adverse health outcomes

AimsReduced lung function and adverse health outcomes are often observed. This study characterizes genetic susceptibility for reduced lung function and risk of developing a range of adverse health outcomes.MethodsWe studied 27,438 middle-aged adults from the Malmö Diet and Cancer study (MDCS), followed up to 28.8 years. Trait-specific Polygenic scores (PGS) for forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were constructed for each participant using MDCS genetic data and summary statistics from the latest GWAS of lung function. Linear regression models and cox proportional hazards regression models were used to assess associations between adverse health outcomes and lung function-PGS.ResultsFEV1-PGS and FVC-PGS were significantly associated with mean sBP at baseline after adjustments (FEV1-PGS Q1 (highest PGS = highest lung function): 140.7mmHg vs. Q4: 141.5mmHg, p-value 0.008). A low FVC-PGS was significantly associated with the risk of future diabetic events after adjustments (Q4 vs. Q1 HR: 1.22 (CI 1.12–1.32), p-trend < 0.001) and had added value to risk prediction models for diabetes. Low FEV1-PGS was significantly associated with future coronary events (Q4 vs. Q1 HR: 1.13 (CI: 1.04–1.22), p-trend 0.008). No significant association was found between PGS and sudden cardiac death, chronic kidney disease or all-cause mortality. Results remained largely unchanged in a subgroup of subjects when further adjusted for apolipoproteins.ConclusionGenetic susceptibility for reduced lung function is associated with higher sBP, increased risk of diabetes and to a lesser extent, future coronary events, suggesting etiological roles of lung function on these outcomes. Using PGS, high-risk groups could be early detected to implement early lifestyle changes to mitigate the risk.

IMPULSE OSCILLOMETRY IDENTIFIES DISTINCT ASTHMA PHENOTYPES ON CLUSTER ANALYSIS

IMPULSE OSCILLOMETRY IDENTIFIES DISTINCT ASTHMA PHENOTYPES ON CLUSTER ANALYSIS

Longitudinal lung function in urban firefighters: A group-based multi-trajectory modelling approach.

Urban firefighters are routinely exposed to both physical and chemical hazards that can negatively impact lung health, but it is unclear if firefighters experience accelerated decline in spirometry parameters due to chronic exposure and acute insults. This study aimed to describe sub-groups of firefighters with differing spirometry trajectories and examine the relationship between the identified trajectories and demographic, lifestyle and occupational characteristics. Data from six waves of the Respiratory Function Measurement and Surveillance for South Australian Metropolitan Fire Service Study (2007-2019) were used to identify spirometry parameter z-score trajectories, using group-based multi-trajectory modelling (GBMTM). Analysis of variance and chi-square statistics were used to assess trajectory group differences in baseline self-reported demographic, lifestyle and occupational characteristics. In the 669 included firefighters, we identified five trajectories for the combination of Forced Expiratory Volume in the first second z-score (FEV1 z), Forced Vital Capacity z-score (FVCz) and the ratio of FEV1 and FVC z-score (FEV1 /FVCz). There were three stable trajectories of low, average and very high lung function and two declining trajectories of average and high lung function. Analysis of subgroup characteristics revealed no significant differences between expected and actual group proportions for the occupational characteristics of years of service and respiratory protection use. Significant differences were seen in respiratory health and body mass index. GBMTM defined distinct, plausible spirometry trajectory sub-groups. Firefighter longitudinal spirometry trajectory group membership was associated with BMI and respiratory disease or symptoms but not with self-reported smoking history or occupational factors.

Relationship of Peripheral Blood Counts with Asthma Control.

To determine the association between blood eosinophil and neutrophil counts with asthma control. This retrospective study, conducted in tertiary care hospital of western India, evaluated the hospital electronic medical record (HEMR) of children aged 5 to 18 y who were diagnosed with asthma as per the Global Initiative for Asthma (GINA) guidelines in the pediatric chest clinic (PCC). Eosinophil and neutrophil counts were recorded from HEMR and asthma control was determined as per the GINA guidelines on follow-up. A total of 742 children attended the PCC in the last 2 y from March 2017 to February 2019; out of which, blood eosinophil and neutrophil counts were done in 116 children with asthma. The median eosinophil and neutrophil count were 0.46 (0.13, 0.78) × 109/L and 5.08 (3.50, 7.53) × 109/L cells, respectively. Eosinophil count was significantly higher in children with well-controlled asthma as compared to partly/uncontrolled asthma [median eosinophil count 0.46 (0.13, 0.78) vs. 0.40 (0.1, 0.66) × 109/L; p = 0.04]; while the neutrophil count was significantly higher in children with partly/uncontrolled asthma as compared to well-controlled asthma [median neutrophil 6.54 (4.32, 7.92) vs. 4.85 (2.96,6.86) × 109/L; p = 0.04]. High lung function is associated with good asthma control. Although not independently associated, the high absolute eosinophil counts (AEC) is associated with better asthma control, while high absolute neutrophil counts (ANC) is associated with poor asthma control.

Cluster phenotypes in a non-idiopathic pulmonary fibrosis fibrotic interstitial lung diseases cohort in Singapore.

BackgroundNon-idiopathic pulmonary fibrosis fibrosing interstitial lung diseases (F-ILDs) may demonstrate a progressive disease trajectory similar to idiopathic pulmonary fibrosis (IPF). We aimed to identify novel F-ILD phenotypes in a multi-ethnic South-East Asian population.MethodsF-ILD subjects (n=201) were analysed using unsupervised hierarchical cluster analysis and their outcomes compared against IPF (n=86).ResultsFour clusters were identified. Cluster 1 (n=53, 26.4%) comprised older Chinese males with high body mass index (BMI) and comorbidity burden, higher baseline forced vital capacity (FVC) percentage predicted and lower diffusing capacity of the lung for carbon monoxide (DLCO) percentage predicted. They had similar mortality to IPF. Cluster 2 (n=67, 33.3%) had younger female non-smokers with low comorbidity burden, groundglass changes on high-resolution chest computed tomography (HRCT) and a positive anti-nuclear antibody (ANA) titre ≥1:160. They had lower baseline FVC and higher DLCO, low mortality and slower lung function decline. Cluster 3 (n=42, 20.9%) consisted male smokers with low comorbidity burden, emphysema on HRCT and high baseline lung function. They had low mortality and slow lung function decline. Cluster 4 (n=39, 19.4%) was the highest risk and comprised of mainly Indians with high BMI. They had the highest proportion of ischemic heart disease (IHD) and previous pulmonary tuberculosis. Subjects had the lowest baseline lung function, highest mortality, and fastest lung function decline. Survival differences across clusters remained significant following adjustment for treatment.ConclusionsWe identified four distinct F-ILD clinical phenotypes with varying disease trajectories. This demonstrates heterogeneity in F-ILD and the need for complementary approaches for classification and prognostication beyond ATS/ERS guideline diagnosis.