Multifaceted associations between walking performance, physical fitness, extremity function, health status, and depression in individuals with COPD

BACKGROUND/OBJECTIVE(S)

Chronic obstructive pulmonary disease (COPD) can precipitate a deterioration of an individual's physical performance and overall health. Evidence suggests that, along with pulmonary functions, several other factors are related to the significant impairment of walking performance in individuals with COPD. This study compared the depressive symptoms, health status, upper and lower extremity functions, and peak oxygen uptake (VO2peak) in a group of individuals with COPD based on walking performance using a cutoff distance of 350 m in the six-minute walking test (6MWT). The study also investigated the associations between these factors and walking performance.

MATERIALS AND METHODS

Participants performed the 6MWT according to the guidelines and were classified into high (>350 m; n = 40) or low (<350 m; n = 30) walking performance groups according to distance. The forced expiratory volume (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio were recorded. Participants completed the Patient Health Questionnaire-9 (PHQ-9), St. George's Respiratory Questionnaire (SGRQ), and the Upper and Lower Extremity Functional Index (UEFI/LEFI). Predicted VO2peak was measured using the Duke Activity Status Index (DASI).

RESULTS

Seventy participants with a mean age of 63 ± 11 years (20% female) were enrolled in this study. Patients with high walking performance demonstrated significantly better health status than those with low walking performance (SGRQ: 49 ± 25 vs. 56 ± 21, p = 0.03). Participants with low walking performance had lower predicted VO2peak compared to their higher performing counterparts (p = 0.002). The overall model was significant (F(8, 61) = 7.48, p = 0.0006), with PHQ-9, SGRQ, UEFI/LEFI, VO2peak, and FEV1/FVC explaining approximately 49.5% of the variance in the 6MWT distance.

CONCLUSION

This study shed light on the association of depressive symptoms, health status, extremity function, and VO2peak with walking performance, providing valuable insights that may impact the management and care of individuals with COPD.

Diagnosis and Severity Assessment of COPD Using a Novel Fast-Response Capnometer and Interpretable Machine Learning

INTRODUCTION

Spirometry is the gold standard for COPD diagnosis and severity determination, but is technique-dependent, nonspecific, and requires administration by a trained healthcare professional. There is a need for a fast, reliable, and precise alternative diagnostic test. This study's aim was to use interpretable machine learning to diagnose COPD and assess severity using 75-second carbon dioxide (CO2) breath records captured with TidalSense's N-TidalTM capnometer.

METHOD

For COPD diagnosis, machine learning algorithms were trained and evaluated on 294 COPD (including GOLD stages 1-4) and 705 non-COPD participants. A logistic regression model was also trained to distinguish GOLD 1 from GOLD 4 COPD with the output probability used as an index of severity.

RESULTS

The best diagnostic model achieved an AUROC of 0.890, sensitivity of 0.771, specificity of 0.850 and positive predictive value (PPV) of 0.834. Evaluating performance on all test capnograms that were confidently ruled in or out yielded PPV of 0.930 and NPV of 0.890. The severity determination model yielded an AUROC of 0.980, sensitivity of 0.958, specificity of 0.961 and PPV of 0.958 in distinguishing GOLD 1 from GOLD 4. Output probabilities from the severity determination model produced a correlation of 0.71 with percentage predicted FEV1.

CONCLUSION

The N-TidalTM device could be used alongside interpretable machine learning as an accurate, point-of-care diagnostic test for COPD, particularly in primary care as a rapid rule-in or rule-out test. N-TidalTM also could be effective in monitoring disease progression, providing a possible alternative to spirometry for disease monitoring.

The association between cadmium exposure and the risk of chronic obstructive pulmonary disease: A systematic review and meta-analysis

According to the World Health Organization, chronic obstructive pulmonary disease (COPD) was one of the top ten causes of death worldwide in 2019. The ratio of forced expiratory volume in the first second to forced vital capacity (FEV1/FVC) provides a useful indicator for the diagnosis of COPD. Existing data have demonstrated that cadmium (Cd) exposure is associated with COPD. However, data concerning the incidence and progression of cadmium-induced COPD is inconsistent. To explore the relationship between cadmium exposure and the risk of COPD in humans, through January 12, 2023, we conducted a thorough search of the PubMed, Cochrane, Web of Science, Embase and Scopus databases for relevant material. In this study, a meta-analysis was conducted to evaluate the association between cadmium and COPD. This meta-analysis indicated that exposure to cadmium (per 1 μg/L increase) was associated with reduced FEV1/FVC (% change = -47.54%, 95% CI: -54.99% to -40.09%). Subgroup analysis showed that the combined effect estimates were significantly higher in the COPD patient group (% change = -54.66%, 95% CI: -83.32% to -26.00%) than in the general population (% change = -52.11%, 95%CI: -60.53% to -43.70%). Therefore, we conclude that cadmium exposure is associated with reduced FEV1/FVC, which suggests a risk for COPD.

Thoracic Society of Australia and New Zealand position statement: The safe clinical use of sputum induction for bio-sampling of the lower airways in children and adults

Sputum induction is widely used in clinical settings for collection of biological samples from the lower airways. However, in recent years sputum induction has been associated with serious adverse events and even death. This position statement was commissioned by the Thoracic Society of Australia and New Zealand to address major adverse events of two deaths associated with sputum induction that have occurred in Australia in 2021, and outlines best practice for the safe use of sputum induction. The statement resulted from systematic literature searches by a multi-disciplinary group including respiratory physicians, nurses and physiotherapists (paediatric and adults focused). Consumers had input to an advanced draft of the position statement. The position statement covers indications for sputum induction, informed consent, scope of practice of personnel administering the procedure, infection control considerations, details about the sputum induction procedure, safety considerations and risk assessment in clinical settings.

Trajectory of lung function in diabetic adults: A 16-year follow-up study of community-based prospective cohorts

BACKGROUND AND OBJECTIVE

To investigate the difference in lung function according to diabetes status in a community-based prospective study.

METHODS

Individuals aged 40-69 years from two community-based cohorts were followed prospectively for 16 years. A spirometer was used to evaluate lung function at baseline, and lung function tests were carried out biennially thereafter. Multivariable linear regression analysis was performed for the cross-sectional and longitudinal analyses based on diabetes status.

RESULTS

Among the 6483 subjects, 2114 (32.6%) had prediabetes and 671 (10.4%) had diabetes. The prediabetes and diabetes groups had lower baseline % predicted values of forced expiratory volume in 1 s (FEV1) (mean, -1.853; 95% confidence interval [CI] -2.715 to -0.990 for prediabetes and mean, -4.088; 95% CI -5.424 to -2.752 for diabetes) and forced vital capacity (FVC) (mean, -2.087; 95% CI -2.837 to -1.337 for prediabetes and mean, -4.622; 95% CI -5.784 to -3.460 for diabetes) compared to the normoglycemia group after adjusting for relevant covariates. The rate of decline in FEV1% predicted (mean, -0.227; 95% CI -0.366 to -0.089) and FVC % predicted (mean, -0.232; 95% CI -0.347 to -0.117) during follow-up were faster in the diabetes group than in the normoglycemia group. The diabetes group had a lower proportion of normal ventilation (ptrend = 0.048) and higher proportions of restrictive (ptrend = 0.001) and mixed (ptrend = 0.035) ventilatory disorders at the last follow-up.

CONCLUSION

Diabetes is associated with a lower baseline lung function and a faster rate of deterioration.

The Impact of Anterior Vertebral Body Tethering on Pulmonary Function

STUDY DESIGN

Retrospective, single-center study.

OBJECTIVE

To examine pulmonary function tests (PFTs) in patients undergoing anterior vertebral body tethering (AVBT).

SUMMARY OF BACKGROUND DATA

The effect of AVBT on pulmonary status remains unclear.

MATERIALS AND METHODS

The authors examined preoperative and postoperative PFTs following AVBT in a retrospective, single-center cohort of patients. Outcomes were compared using percent predicted values as continuous and categorical variables (using 10% change as significant) and divided into categorical values based on the American Thoracic Society standards.

RESULTS

Fifty-eight patients with adolescent idiopathic scoliosis were included, with a mean age of 12.5±1.4 years and a follow-up of 4.2±1.1 years. The mean thoracic curve was 47°±9°, which improved to 21°±12°. At baseline, the mean forced expiratory volume in one second (FEV1%) and forced vital capacity (FVC%) values were 79% and 82%, respectively. Four patients had normal FEV1% (≥100%), 67% had mild restrictive disease (70%-99%) and the rest had worse FEV1%. Mean FEV1 improved from 2.2 to 2.6 L ( P <0.05) and FVC improved from 2.5 to 3.0 L ( P <0.05); however, % predicted values remained unchanged (FEV1%: 79%-80%; FVC%: 82-80%, P >0.05) with mean postoperative PFTs at 37±12 months postoperative. The use of miniopen thoracotomy was not associated with worsening PFTs, but extension of the lowest instrumented vertebra below T12 was correlated with decreasing FEV1% in the bivariate analysis ( P <0.05). Patients with worse preoperative FVC% (80±13% vs. 90±11%, P =0.03) and FEV1% (77±17% vs. 87±12%, P =0.06) also had a greater likelihood of declining postoperative FEV1%.

CONCLUSION

Pulmonary function in most patients undergoing AVBT remained stable (76%) or improved (14%); however, a subset may worsen (10%). Further studies are needed to identify the risk factors for this group, but worse preoperative PFTs and extension below T12 may be risk factors for worsening pulmonary function.

Diabetes and lung function: Linked, but how?

See related article

Beyond forced exhalation: impulse oscillometry as a promising tool for bronchial hyperresponsiveness evaluation

Introduction: The multiple forced expiratory maneuvers that must be performed during methacholine test require a high degree of collaboration and can lead to fatigue. However, impulse oscillometry (IOS) is a noninvasive test, quick and easy to perform, that does not require effort-dependent maneuvers. Objectives: The primary endpoint was to evaluate the relationship between IOS and spirometry during the methacholine test. The secondary endpoint was to study the predictive value of baseline IOS in the development of bronchial hyperreactivity. Methods: Observational, prospective, cross-sectional study, with recruitment of consecutive patients from the pulmonology department with clinical suspicion of bronchial asthma with negative bronchodilator test and normal FeNO. Results: Twenty-five patients were included, with a mean age of 49 ± 18 years. Thirteen patients (52%) had a positive methacholine test. The correlation between IOS indices and FEV1 was significant (p < 0.05) in all cases. The indices with the highest predictive power were R5-20 and AX. The optimal cutoff points were an increase of greater than 32.96% in R5, greater than 120.83% for X5, an increase of 30.30 [kPa l-1s-1] in R5-20, and an increase of 1.01 [kPa l-1] for AX. Baseline oscillometry demonstrated a strong predictive value in the development of bronchial hyperreactivity, with a sensitivity of 61.5% and a specificity of 91.7%, using the cut-off point of 160.0% for R5. Conclusions: IOS may be a valuable alternative to forced spirometry in detecting bronchial hyperreactivity during the methacholine test, showing a good correlation between both tests.

Six-minute walking distance and desaturation-distance ratio in allogeneic stem cell transplantation

BACKGROUND

Most patients with haematological malignancies who undergo allogeneic haematopoietic stem cell transplant (HSCT) receive chemotherapy before the transplant to control the disease. Certain chemotherapy drugs can cause lung toxicity. Conversely, in patients with chronic respiratory conditions, the 6-min walking test (6MWT) and the desaturation-distance ratio (DDR) have demonstrated prognostic significance. Our objective was to determine whether the 6MWD and DDR, assessed prior to HSCT, have a prognostic impact on survival at 24 months post-HSCT.

METHODS

A prospective experimental study was conducted in consecutive patients referred for allogeneic HSCT at Hospital Clinic, Barcelona, Spain. A complete functional respiratory study, including the 6MWT and DDR, was conducted prior to admission. The area under the curve (AUC) and cut-off points were calculated. Data on patients' characteristics, HSCT details, main events, with a focus on lung complications, and survival at 24 months were analysed.

RESULTS

One hundred and seventy-five patients (39% women) with mean age of 48 ± 13 years old were included. Before HSCT, forced vital capacity and forced expiratory volume in the first second were 96% ± 13% predicted and 92% ± 14% predicted, respectively; corrected diffusing capacity for carbon monoxide 79% ± 15% predicted; 6MWD was 568 ± 83 m and DDR of .27 (.20-.41). The cut-off points for 6MWD and DDR were 566 m, [.58 95% CI (.51-.64)], p = .024 and .306, [.63 95% CI (.55-.70)], p = .0005, respectively. The survival rate at 24 months was 55%.

CONCLUSION

Our results showed that individuals who exhibit a 6MWD shorter than 566 ms or a decline in DDR beyond .306 experienced reduced survival rates at 24 months after HSCT.

Development and validation of a pulmonary function test data extraction tool for the US department of veterans affairs electronic health record

OBJECTIVE

Pulmonary function test (PFT) results are recorded variably across hospitals in the Department of Veterans Affairs (VA) electronic health record (EHR), using both unstructured and semi-structured notes. We developed and validated a hospital-specific code to extract pre-bronchodilator measures of obstruction (ratio of forced expiratory volume in one second [FEV1] to forced vital capacity [FVC]) and severity of obstruction (percent predicted of FEV1).

RESULTS

Among 36 VA facilities with the most PFTs completed between 2018 and 2022 from a parent cohort of veterans receiving long-acting controller inhalers, 12 had a consistent syntactical convention or template for reporting PFT data in the EHR. Of the 42,718 PFTs identified from these 12 facilities, the hospital-specific text processing pipeline yielded 24,860 values for the FEV1:FVC ratio and 23,729 values for FEV1. A ratio of FEV1:FVC less than 0.7 was identified in 17,615 of 24,922 studies (70.7%); 8864 of 24,922 (35.6%) had a severe or very severe reduction in FEV1 (< 50% of the predicted value). Among 100 randomly selected PFT reports reviewed by two pulmonary physicians, the coding solution correctly identified the presence of obstruction in 99 out of 100 studies and the degree of obstruction in 96 out of 100 studies.

Effects and long-term outcomes of endurance versus resistance training as an adjunct to standard medication in patients with stable COPD: a multicenter randomized trial

BACKGROUND

Comparisons between endurance training (ET) and resistance training (RT) have produced equivocal findings in chronic obstructive pulmonary disease (COPD) patients. The purpose of our study is to investigate the effectiveness and long-term outcomes of adding ET and RT to conventional medical treatment in patients with COPD. A secondary objective is to investigate the clinical improvements resulting from exercise training in patients with different disease severities.

METHODS

The study was a multicenter, prospective trial in people with stable COPD. The cohort was randomized to three groups: individualized medical treatment group (MT), MT + endurance training group (MT + ET) and MT + resistance training group (MT + RT). Exercise was performed 3 times weekly over a 12-week period. The endpoints of exercise capacity, health-related quality of life, COPD symptoms, lung function, and anxiety and depression questionnaires were re-evaluated at baseline, at the completion of the intervention and at 6 and 12-month follow-up. According to the COPD assessment tool offered by GOLD guidelines, patients were stratified into GOLD A and B groups and GOLD C and D groups for further subgroup analysis.

RESULTS

The intention-to-treat (ITT) population included 366 patients, 328 of them completed the study protocol over 12 months (the PP-population). There were no significant differences in the primary outcome, quality of life, between patients who underwent medical treatment (MT) alone, MT + endurance training (MT + ET), or MT + resistance training (MT + RT) at the completion of the intervention, 6-, or 12-month follow-up. Additionally, no significant differences were observed between MT, MT + RT, or MT + ET groups concerning the primary outcome, exercise capacity (3MWD), after initial 3 months of intervention. However, a small statistically significant difference was noted in favor of MT + ET compared to MT + RT at 12 months (ITT: Δ3MWD in ET vs RT = 5.53 m, 95% confidence interval: 0.87 to 13.84 m, P = 0.03) (PP: Δ3MWD in ET vs RT = 7.67 m, 95% confidence interval: 0.93 to 16.27 m, P = 0.04). For patients in the GOLD C and D groups, improvement in quality of life following ET or RT was significantly superior to medical intervention alone. Furthermore, upon completion of the exercise regimen, RT exhibited a greater improvement in anxiety compared to ET in these patients (ITT: ΔHAD-A at 3-month: RT = -1.63 ± 0.31 vs ET = -0.61 ± 0.33, p < 0.01) (PP: ΔHAD-A at 3-month: RT = -1.80 ± 0.36 vs ET = -0.75 ± 0.37, p < 0.01).

CONCLUSIONS

Our study presents evidence of the beneficial effects of ET and RT in combination with standard medical treatment, as well as the long-term effects over time after the intervention. While the statistically significant effect favoring ET over RT in terms of exercise capacity was observed, it should be interpreted cautiously. Patients in severe stages of COPD may derive greater benefits from either ET or RT and should be encouraged accordingly. These findings have implications for exercise prescription in patients with COPD.

TRIAL REGISTRATION

ChiCTR-INR-16009892 (17, Nov, 2016).

Neopterin in patients with COPD, asthma, and ACO: association with endothelial and lung functions

BACKGROUND AND OBJECTIVE

Endothelial dysfunction has been widely recognized in chronic airway diseases, including chronic obstructive pulmonary disease (COPD) and asthma; however, it remains unclear in asthma-COPD overlap (ACO). Neopterin (NP), a metabolite of guanosine triphosphate, is a novel biomarker for identifying the increased risk of adverse cardiovascular events. This study aims to investigate the association of NP with endothelial dysfunction and impaired lung function in COPD, asthma, and ACO patients.

METHODS

A total of 77 subjects were prospectively recruited. All the participants underwent lung function test, endothelial function evaluation, including pulse wave velocity (PWV) and flow-mediated dilation (FMD), and blood sample detection. Moreover, the effect of NP on endothelial cells (ECs) in anoxic environments was assessed in vitro.

RESULTS

Endothelial function was significantly decreased in the COPD and ACO patients compared with that in the healthy controls (P < 0.05). Forced expiratory volume in 1 s (FEV1) was negatively correlated with PWV and positively correlated with FMD (P < 0.05). NP was significantly increased in patients with chronic respiratory diseases compared with that in the control group, with COPD being the highest, followed by asthma, and ACO as the last (P < 0.05). The plasma level of NP exhibited negative correlations with FEV1 and positive correlations with PWV (P < 0.05). In vitro, a high level of NP increased the reactive oxygen species (ROS) and decreased the mitochondrial membrane potential (ΔΨm) of ECs dose-dependently in a hypoxic environment (P < 0.05).

CONCLUSION

NP was related to disease severity of chronic airway diseases and involved in the pathogenesis of endothelial dysfunction. A high NP level may contribute to endothelial dysfunction by increasing the oxidative stress of ECs dose-dependently in a hypoxic environment. Our findings may provide a novel evaluation and therapeutic target for endothelial dysfunction related to chronic airway diseases.

The value of lung function assessment and Testin expression detection in clinicopathological features and prognosis of NSCLC patients

OBJECTIVE

The aim of this study is to investigate the clinical value and potential prognostic significance of lung function assessment and Testin expression in non-small cell lung cancer (NSCLC) patients.

METHODS

The NSCLC patients were classified into three groups according to lung function: group of normal lung function, group of PRISm (preserved ratio impaired spirometry) (FEV1, forced expiratory volume during the first second < 80% predicted and FEV1/FVC (forced vital capacity) ≥ 70%) and group of COPD (chronic obstructive pulmonary disease) (FEV1/FVC < 70%). The pre-operational clinicopathological characteristics of these patients were recorded and the markers of systemic inflammatory response, including neutrophil to lymphocyte ratio (NLR), lymphocyte to monocyte ratio (LMR), platelet to lymphocyte ratio (PLR) and eosinophils (EOS), were compared between three groups. The expression of Testin in NSCLC samples was detected by IHC and we further explored the correlation between Testin expression and clinicopathological characteristics and prognosis of NSCLC patients. Finally, Cox regression analysis was conducted to study the prognostic factors of NSCLC patients.

RESULTS

Of the 158 NSCLC patients, percentages of normal lung function, PRISm and COPD were 41.4%, 22.8% and 36.1%, respectively. Patients with tumor in the left lung were more likely to have pulmonary dysfunction (PRISm and COPD) than the right lung. The markers of systemic inflammatory response showed differences to various degree in the three groups and NSCLC patients with PRISm or COPD presented more unfavorable prognosis than patients with normal function. The expression of Testin correlated with lymph node metastasis, TNM stage and tumor invasion of NSCLC patients. Moreover, patients with low Testin expression exhibited poorer disease-free survival and overall survival than those with high Testin expression. In Cox regression analysis, we found that PRISm, COPD and Testin expression served as prognostic factors in NSCLC patients.

CONCLUSIONS

The presence of COPD or PRISm influenced systemic inflammatory response and prognosis of NSCLC patients. Testin expression correlated with clinicopathological features and could be potentially used as a prognostic marker in NSCLC.

Body composition and respiratory outcomes in children: a population-based prospective cohort study

BACKGROUND

Body composition might influence lung function and asthma in children, but its longitudinal relations are unclear. We aimed to identify critical periods for body composition changes during childhood and adolescence in relation to respiratory outcomes in adolescents.

METHODS

In a population-based prospective cohort study, we measured body mass index, fat mass index (FMI), lean mass index (LMI) and the ratio of android fat mass divided by gynoid fat mass (A/G ratio) by dual-energy X-ray absorptiometry at 6, 10 and 13 years. At 13 years, lung function was measured by spirometry, and current asthma was assessed by questionnaire.

RESULTS

Most prominently and consistently, higher FMI and A/G ratio at age 13 years were associated with lower forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and forced expiratory flow after exhaling 75% of FVC (FEF75) (range Z-score difference -0.13 (95% CI -0.16 to -0.10) to -0.08 (95% CI -0.11 to -0.05) per SD score increase), and higher LMI at all ages was associated with higher FEF75 (range Z-score difference 0.05 (95% CI 0.01 to 0.08) to 0.09 (95% CI 0.06 to 0.13)). Between the ages of 6 and 13 years, normal to high FMI and A/G ratio were associated with lower FEV1/FVC and FEF75 (range Z-score difference -0.20 (95% CI -0.30 to -0.10) to -0.17 (95% CI -0.28 to -0.06)) and high to high LMI with higher FEF75 (range Z-score difference0.32 (95% CI 0.23 to 0.41)). Body composition changes were not associated with asthma.

CONCLUSION

Adolescents with higher total and abdominal fat indices may have impaired lung function, while those with a higher lean mass during childhood and adolescence may have better small airway function. Public health measures should focus on a healthy body composition in adolescents to minimise respiratory morbidity.

Airway Reactance Predicts Static Lung Hyperinflation in Severe Asthma

BACKGROUND AND OBJECTIVES

Background: Static lung hyperinflation (SLH) measured using body plethysmography in patients with asthma is associated with poor outcomes. The severity of SLH may be associated with small airway dysfunction (SAD), which can be measured using impulse oscillometry (IOS). Objective: This study aims to determine the correlation between SLH and SAD in patients with severe asthma and assess the improvement in SLH and SAD with treatment.

METHODS

We analyzed data from patients who were enrolled in the Taiwan Severe Asthma Registry, which comprises a prospective observational cohort. Plethysmography and IOS were performed regularly. The relationship between spirometry and IOS parameters was determined. Changes in the clinical outcomes in response to treatment were analyzed.

RESULTS

Of 107 patients with severe asthma, 83 (77.6%) had SLH based on an increased residual volume to total lung capacity ratio (RV/ TLC). Most patients were older women with worse pulmonary function and SAD than those without SLH. SAD, defined as increased airway resistance/reactance, was significantly correlated with SLH. Airway reactance at 5 Hz (X5) ≤-0.21 kPa/(L/s) detected SLH with an area under the receiver operating characteristic curve of 0.84 (P<.0001; sensitivity, 85.2%; and specificity, 83.3%). After 12 months, patients who received add-on biologics (vs those who did not) had significantly reduced exacerbations, fractional exhaled nitric oxide level, and blood eosinophil counts, as well as improved forced expiratory volume in the first second, X5, and a trend toward reduced RV/TLC ratio.

CONCLUSIONS

In severe asthma, airway reactance (X5) could be a novel parameter for assessing SLH.

Physical activity and lung function association in a healthy community-dwelling European population

BACKGROUND

The association of physical activity (PA) and lung function (LF) varies from no measurable effect to delayed LF decline. We assessed the association between accelerometery-assessed PA and LF in a sample of apparently healthy, community-dwelling subjects.

METHODS

We included two cross-sectional studies using data from the PneumoLaus study (2014-17 and 2018-21), conducted in Lausanne, Switzerland. PA was assessed by accelerometry and categorised as inactivity, light, moderate or vigorous. Forced expiratory volume in 1 second (FEV1), forced volume capacity (FVC) and maximal mid-expiratory flow (MMEF) were measured by spirometry and expressed in percentage of predicted value (PV).

RESULTS

Overall, 1'910 (54.7% women, 62.0 ± 9.7 years) and 1'174 (53.4% women, 65.8 ± 9.5 years) participants were included in the first and the second surveys, respectively. In both surveys, moderate and vigorous PA showed a weak but significant correlation with FEV1 in percentage (PV) (R = 0.106 and 0.132 for the first and 0.111 and 0.125 for the second surveys, p < 0.001). Similar correlations with FVC (p < 0.001) were found. Associations held irrespective of smoking status and remained after multivariable adjustment. Fewer associations were detected between LF and light PA or between MMEF and PA.

CONCLUSION

Moderate and vigorous intensity PA are associated with increased LF regardless of smoking status in apparently healthy community-dwelling European population. These associations are statistically but not clinically significant due to the small correlation coefficients (R < 0.30), corresponding to a weak association.

Endobronchial valves for emphysema and persistent air-leak: 10-year experience in an Asian country

BACKGROUND

Endobronchial valve (EBV) therapy, a validated method for bronchoscopic lung volume reduction (BLVR) in severe emphysema, has been explored for persistent air-leak (PAL) management. However, its effectiveness and safety in the Asian population require further real-world evaluation. In this study, we assessed the outcomes of treatment with EBV within this demographic.

METHODS

We conducted a retrospective analysis of medical records from 11 Korean centers. For the emphysema cohort, inclusion criteria were patients diagnosed with emphysema who underwent bronchoscopy intended for BLVR. We assessed these patients for clinical outcomes of chronic obstructive pulmonary disease. All patients with PAL who underwent treatment with EBV were included. We identified the underlying causes of PAL and evaluated clinical outcomes after the procedure.

RESULTS

The severe emphysema cohort comprised 192 patients with an average age of 70.3 years, and 95.8% of them were men. Ultimately, 137 underwent treatment with EBV. Three months after the procedure, the BLVR group demonstrated a significant improvement in forced expiratory volume in 1 s (+160 mL vs. +30 mL; P = 0.009). Radiographic evidence of lung volume reduction 6 months after BLVR was significantly associated with improved survival (adjusted hazard ratio 0.020; 95% confidence interval 0.038-0.650; P = 0.010). Although pneumothorax was more common in the BLVR group (18.9% vs. 3.8%; P = 0.018), death was higher in the no-BLVR group (38.5% vs. 54.5%, P = 0.001), whereas other adverse events were comparable between the groups. Within the subset of 18 patients with PAL, the predominant causes of air-leak included spontaneous secondary pneumothorax (44.0%), parapneumonic effusion/empyema (22.2%), and post-lung resection surgery (16.7%). Following the treatment, the majority (77.8%) successfully had their chest tubes removed. Post-procedural complications were minimal, with two incidences of hemoptysis and one of empyema, all of which were effectively managed.

CONCLUSIONS

Treatment with EBV provides substantial clinical benefits in the management of emphysema and PAL in the Asian population, suggesting a favorable outcome for this therapeutic approach.

Updated reference values for static lung volumes from a healthy population in Austria

BACKGROUND

Reference values for lung volumes are necessary to identify and diagnose restrictive lung diseases and hyperinflation, but the values have to be validated in the relevant population. Our aim was to investigate the Global Lung Function Initiative (GLI) reference equations in a representative healthy Austrian population and create population-derived reference equations if poor fit was observed.

METHODS

We analysed spirometry and body plethysmography data from 5371 respiratory healthy subjects (6-80 years) from the Austrian LEAD Study. Fit with the GLI equations was examined using z-scores and distributions within the limits of normality. LEAD reference equations were then created using the LMS method and the generalized additive model of location shape and scale package according to GLI models.

RESULTS

Good fit, defined as mean z-scores between + 0.5 and -0.5,was not observed for the GLI static lung volume equations, with mean z-scores > 0.5 for residual volume (RV), RV/TLC (total lung capacity) and TLC in both sexes, and for expiratory reserve volume (ERV) and inspiratory capacity in females. Distribution within the limits of normality were shifted to the upper limit except for ERV. Population-derived reference equations from the LEAD cohort showed superior fit for lung volumes and provided reproducible results.

CONCLUSION

GLI lung volume reference equations demonstrated a poor fit for our cohort, especially in females. Therefore a new set of Austrian reference equations for static lung volumes was developed, that can be applied to both children and adults (6-80 years of age).

Efficacy and safety of the Spiration Valve System™ for the treatment of severe emphysema in patients with Alpha-1 antitrypsin deficiency (EMPROVE)

OBJECTIVES

Alpha-1 antitrypsin deficiency (AATD) is a hereditary condition associated with emphysema. This study analyzed the efficacy and safety of Spiration Valve System TM (SVS) among AATD patients with severe emphysema.

METHODS

This multicenter prospective study included 20 patients demonstrating AATD as assessed by quantitative levels of AAT and genotype containing two ZZ alleles. Most diseased lobe based on high resolution computed tomography was selected for treatment with endobronchial SVS. The change from baseline in forced expiratory volume in 1 s (FEV1) at 6 months (Primary outcome) and at 12 months, quality-of-life (QoL) measured by St. George's Respiratory Questionnaire (SGRQ) as health status, dyspnea scale measured by mMRC, Chronic obstructive pulmonary disease (COPD) Assessment Test (CAT), 36-item Short Form Health Survey (SF-36) physical component summary (PCS) and safety were assessed.

RESULTS

Lung function (FEV1) significantly improved at 6 months (P = 0.02); but did not reach statistical significance at 12 months (P = 0.22). Significant improvement was observed in dyspnea (at all time points), QoL measures (3, 6, and 12 months), CAT score and PCS of SF-36 (1, 3 and 6 months). Response rates based on minimal clinically important difference reached 50-80% for all variables. Overall, 4.4 valves/patient were used to isolate the target lobe, with a mean procedure time of 20.3 min. Serious adverse events included COPD exacerbations (5%), pneumonia (10%), pneumothorax (15%) and death (5%), occurring within first three months.

CONCLUSION

SVS endobronchial valve treatment showed improvement in lung function, dyspnea, and QoL in AATD patients with severe emphysema.

Impulse Oscillometry Versus Spirometry to Detect Bronchiolitis Obliterans Syndrome in Bilateral Lung Transplant Recipients: A Prospective Diagnostic Study

BACKGROUND

Chronic lung allograft dysfunction (CLAD), and especially bronchiolitis obliterans syndrome (BOS), remain dominant causes of morbidity and mortality after lung transplantation. Interest is growing in the forced oscillation technique, of which impulse oscillometry (IOS) is a form, as a tool to improve our understanding of these disorders. However, data remain limited and no longitudinal studies have been published, meaning there is no information regarding any capacity IOS may have for the early detection of CLAD.

METHODS

We conducted a prospective longitudinal study enrolling a consecutive sample of adult bilateral lung transplant recipients with healthy lung allografts or CLAD and performed ongoing paired IOS and spirometry tests on a clinically determined basis. We assessed for correlations between IOS and spirometry and examined any predictive value either modality may hold for the early detection of BOS.

RESULTS

We enrolled 91 patients and conducted testing for 43 mo, collecting 558 analyzable paired IOS and spirometry tests, with a median of 9 tests per subject (interquartile range, 5-12) and a median testing interval of 92 d (interquartile range, 62-161). Statistically significant moderate-to-strong correlations were demonstrated between all IOS parameters and spirometry, except resistance at 20 Hz, which is a proximal airway measure. No predictive value for the early detection of BOS was found for IOS or spirometry.

CONCLUSIONS

This study presents the first longitudinal data from IOS after lung transplantation and adds considerably to the growing literature, showing unequivocal correlations with spirometry but failing to demonstrate a predictive value for BOS.

Interpretation of Spirometry, Peak Flow, and Provocation Testing for Asthma

Spirometry plays a crucial role in the diagnosis of asthma. The hallmark spirometry finding of expiratory airflow variability can be demonstrated in several ways including peak airflow and bronchodilator and bronchoprovocation testing. Challenges of overdiagnosis and underdiagnosis underscore the need to consider clinical context while interpreting these tests. A meticulous and multifaceted approach prioritizing objective testing is imperative while diagnosing asthma.

FEV1Q: a race-neutral approach to assessing lung function

BACKGROUND

Forced expiratory volume in 1 s quotient (FEV1Q) is a simple approach to spirometry interpretation that compares measured lung function to a lower boundary. This study evaluated how well FEV1Q predicts survival compared with current interpretation methods and whether race impacts FEV1Q.

METHODS

White and Black adults with complete spirometry and mortality data from the National Health and Nutrition Examination Survey (NHANES) III and the United Network for Organ Sharing (UNOS) database for lung transplant referrals were included. FEV1Q was calculated as FEV1 divided by 0.4 L for females or 0.5 L for males. Cumulative distributions of FEV1 were compared across races. Cox proportional hazards models tested mortality risk from FEV1Q adjusting for age, sex, height, smoking, income and among UNOS individuals, referral diagnosis. Harrell's C-statistics were compared between absolute FEV1, FEV1Q, FEV1/height2, FEV1 z-scores and FEV1 % predicted. Analyses were stratified by race.

RESULTS

Among 7182 individuals from NHANES III and 7149 from UNOS, 1907 (27%) and 991 (14%), respectively, were Black. The lower boundary FEV1 values did not differ between Black and White individuals in either population (FEV1 first percentile difference ≤0.01 L; p>0.05). Decreasing FEV1Q was associated with increasing hazard ratio (HR) for mortality (NHANES III HR 1.33 (95% CI 1.28-1.39) and UNOS HR 1.18 (95% CI 1.12-1.23)). The associations were not confounded nor modified by race. Discriminative power was highest for FEV1Q compared with alternative FEV1 approaches in both Black and White individuals.

CONCLUSIONS

FEV1Q is an intuitive and simple race-neutral approach to interpreting FEV1 that predicts survival better than current alternative methods.

Treatable traits in advanced emphysema patients eligible for bronchoscopic lung volume reduction with endobronchial valves

INTRODUCTION

Patients with advanced emphysema eligible for bronchoscopic lung volume reduction (BLVR) using endobronchial valves (EBV) are characterized by severe static lung hyperinflation, which can be considered a treatable trait. Other treatable traits (TTs), which are assumed to be present in this highly selected patient group, have not been studied in detail nor how they may affect health-related quality of life (HRQL).

AIMS

We aimed to evaluate a spectrum of TTs in COPD patients eligible for EBV treatment and their association with HRQL.

METHODS

The SoLVE study (NCT03474471) was a prospective multicenter randomized controlled trial to examine the impact of pulmonary rehabilitation in COPD patients receiving EBV. The presence/absence of 16 TTs was based on pre-defined thresholds. HRQL was assessed with the St. George's Respiratory Questionnaire (SGRQ). Subjects were stratified into two groups, using the median split method, into higher or lower SGRQ total score. Logistic regression assessed the odds ratio (OR) of having a higher SGRQ total score per TT.

RESULTS

Ninety-seven subjects were included, the mean number of TTs per patient was 8.1 ± 2.5. Low physical activity (95%), poor exercise capacity (94%) and severe fatigue (75%) were the most prevalent TTs. The sum of TTs present in a subject was associated with the SGRQ total score (r = 0.53; p < 0.001). Severe fatigue, depression, and anxiety were predictors of having a higher SGRQ total score.

CONCLUSIONS

A high prevalence and co-occurrence of multiple TTs were identified in emphysema patients eligible for EBV. Patients with a higher number of TTs were more likely to have worse HRQL.

Predicting exacerbations in COPD in the Danish general population

BACKGROUND

Risk of exacerbations in individuals with mild chronic obstructive pulmonary disease (COPD) in the general population is less well described than in more advanced disease. We hypothesized that in addition to history of previous exacerbation also other clinical characteristics predict future moderate exacerbations.

METHODS

In 96,462 individuals in the Copenhagen General Population Study, we identified 3175 with clinical COPD defined as forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < 0.70 and FEV1 <80% predicted in symptomatic individuals without asthma. We estimated the importance of age, sex, FEV1, modified Medical Research Council (mMRC) dyspnea scale, chronic bronchitis, exacerbation history, comorbidities, cohabitation, body mass index, smoking, and blood eosinophils for the 1-year and 3-year future risk of moderate COPD exacerbations and developed a prediction tool for future exacerbations in COPD in the general population based on easily available clinical information.

RESULTS

We observed 265 exacerbations in 2543 maintenance treatment naïve individuals with COPD and 197 exacerbations in 632 individuals with COPD on maintenance treatment. In the maintenance treatment naïve group, exacerbation history (hazard ratio (HR): 8.53), low FEV1 (HR: 4.82 for <30% predicted versus 50-79% predicted), and higher age (HR: 1.46 for ≥75 years versus <65 years) were significant predictors of future exacerbations. In the group on maintenance treatment, male sex and mMRC ≥2 also predicted higher risk with borderline significance.

CONCLUSIONS

In addition to exacerbation history also higher age and lower FEV1 predict future exacerbation risk in COPD in the general population.

Comparison of Postoperative Respiratory Function Between Patients After Thoracoscopic and Open Lobectomy

Purpose: This study aimed to compare respiratory functions of patients after thoracoscopic lobectomy (TS) with those after thoracotomy (TR). Methods: This retrospective study was conducted in two centers, one of which adapted TS as a standard procedure in 2009 and the other performs it via TR. Data on patients who underwent lobectomy for congenital lung disease between 2009 and 2021 and underwent pulmonary function test (spirometry) were collected. Results: Ten patients underwent TS and 36 underwent TR. Distribution based on sex, prenatal diagnosis, pathological diagnosis, and resected lobe were similar between the two groups. The median [interquartile range] age at procedure in the TR group was significantly smaller than that in the TS group (13 [11-18] months versus 38 [13-79] months, P = .03). The procedure duration in the TR group was significantly shorter than that in the TS group (230 [171-264] minutes versus 264 [226-420] minutes, P = .02). Pulmonary function test was conducted at the age of eight in both groups, but the interval between the procedure, and the test was significantly shorter in the TS group (TR: 7 [5-8] years versus TS: 5 [2-7] years, P = .03). The ratio of forced vital capacity compared to predicted one (TR: 86.6 [76.6-95.3] versus TS: 88.7 [86.8-89.1], P = .58) and the ratio of forced expiratory volume in 1 second against that predicted (TR: 84.0 [80.5-88.7] versus TS: 88.7 [86.8-89.1], P = .08) were not significantly different between the two groups. Conclusions: Although TR was performed earlier than TS, respiratory function was similar between the two groups.

Increased blood eosinophils and airflow obstruction as new-onset asthma predictors in the elderly: The Nagahama study

BACKGROUND

Asthma in the elderly needs more attention in an aging society. However, it is likely to remain underdiagnosed and undertreated. This study aimed to clarify clinical characteristics of new-onset asthma in the elderly, describing the prevalence, predictive factors, and comorbidities after asthma diagnosis of new-onset asthma in the elderly in the general population.

METHODS

This community-based prospective cohort study enrolled 9804 generally healthy participants (30-74 years old) in Nagahama City, and conducted a follow-up assessment after 5 years. Elderly participants were those aged ≥65 years at baseline. Patients with new-onset asthma were defined as participants without asthma at baseline assessment and with asthma at the follow-up assessment.

RESULTS

Among the 7948 participants analyzed in this study, 28 (1.4%) elderly and 130 (2.2%) non-elderly had new-onset asthma. Multiple logistic regression analysis revealed low forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and high blood eosinophil counts at baseline as predicting factors for new-onset asthma in the elderly. Additionally, subsequent incidence of new-onset asthma was higher in elderly participants with both predictors (high blood eosinophil counts and low FEV1/FVC at baseline) than those with none or one of the predictors before asthma diagnosis. Lastly, elderly patients with new-onset asthma had more frequent comorbidity of moderate to severe sleep disordered breathing than those non-elderly.

CONCLUSIONS

Eosinophilic inflammation and airflow obstruction may predict subsequent new-onset asthma after the age of 65 years. Revealing the characteristics of new-onset asthma in the elderly can aid in the prevention of underdiagnosed asthma.

Ventilation Heterogeneity Is a Treatable Trait in Severe Asthma

BACKGROUND

Ventilation heterogeneity (VH) is a feature of asthma and indicates small airway disease. Nuclear imaging methods assess VH, which can facilitate clinical diagnosis and further our understanding of disease aetiology.

OBJECTIVE

We sought to assess VH in severe eosinophilic asthma (SEA) using ventilation/perfusion single-photon emission computed tomography (V/P SPECT), and to assess its use as an objective test of the effect of biologic treatment for ventilation defects in SEA.

METHODS

Adults (≥18 y) with severe asthma were recruited to participate in a cross-sectional observational study. Participants underwent a clinical assessment and V/P SPECT CT using Technegas as the ventilation agent. Measures were repeated for a nested before-after treatment study in people with SEA commencing biologics.

RESULTS

A total of 62 participants with severe asthma were recruited. From this, 38 participants with SEA were included in the before-after study. The VH was associated with clinical variables such as lung function impairment and significantly improved after monoclonal antibody treatment in the severe asthma group. The changes in VH correlated with change in post bronchodilator forced expiratory volume in 1 second (FEV1) %predicted (r = -0.503; P = .001) and post bronchodilator FEV1/FVC (forced vital capacity) (r = -0.415; P = .01).

CONCLUSIONS

The VH is clinically significant, measurable, and treatable, which establishes VH as a treatable trait in severe asthma.

Nutrition intake modifies the association between pulmonary function and cognitive performance among elderly Americans from NHANES 2011-2012

PURPOSE

Nutrition intake is one of the modifiable risk factors for cognitive decline. Whether energy and protein intakes alter the association between pulmonary function (PF) and cognition has not been studied.

METHODS

We made use of information from the U.S. National Health and Nutrition Examination Survey (NHANES) 2011-2012. PF measures, including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF), were calculated, whereas cognitive function was assessed through four tests: the Immediate Recall test (IRT), the Delayed Recall test (DRT), the Animal Fluency test (AFT) and the Digit Symbol Substitution test (DSST). Energy and protein intakes were measured using the 24-h dietary recall method. Weighted generalized linear regression was performed upon adjustment for covariates. Further interaction analyses were conducted to investigate the effect of energy and protein intakes on the association between PF and cognition.

RESULTS

We finally included 803 participants aged ≥ 60 years (54.4% female, weighted value). After adjusting for covariates, multiple measures (including FEV1, FVC, PEF, and composite PF) were all positively associated with better global cognition and the DSST score (P < 0.05). A stronger positive association between the DSST score and FEV1 (P for interaction = 0.001), FVC (P for interaction = 0.004), PEF (P for interaction = 0.003), and composite PF (P for interaction = 0.001) in lower energy intake. Similar results were observed in lower protein intake (all P for interaction < 0.05).

CONCLUSION

Higher PF was independently associated with improved specific components of cognitive function (i.e., the DSST score). The positive association between PF and the DSST score was stronger in individuals with lower energy and protein intakes.

Longitudinal changes in respiratory reactance in patients with COPD: associations with longitudinal change in air-trapping, exacerbations, and mortality

INTRODUCTION

Air-trapping affects clinical outcomes in patients with chronic obstructive pulmonary disease (COPD) and may be detected by reactance at 5 Hz (X5) on respiratory oscillometry because X5 sensitively reflects the elasticity of the chest wall, airway and lung. However, the longitudinal association between X5 and air-trapping remains to be explored. This study aimed to test whether longitudinal changes in X5 could be associated with air-trapping progression, exacerbations, and mortality in patients with COPD.

METHODS

In this prospective COPD observational study, the follow-up period consisted of the first 4 years to obtain longitudinal changes in X5 and residual volume (RV) and number of exacerbations and the remaining years (year 4 to 10) to test mortality. Patients were divided into large, middle, and small X5 decline groups based on the tertiles of longitudinal change in X5, and mortality after 4 years was compared between the groups.

RESULTS

Patients with COPD (n = 114) were enrolled. The large X5 decline group (n = 38) showed a greater longitudinal change in RV and more exacerbations compared with the small X5 decline group (n = 39) in multivariable models adjusted for age, sex, body mass index, and smoking history. Long-term mortality after the 4-year follow-up was higher in the large X5 decline group than in the small X5 decline group (hazard ratio [95 % confidence interval] = 8.37[1.01, 69.0]) in the multivariable Cox proportional hazard model.

CONCLUSION

Longitudinal changes in respiratory reactance could be associated with progressive air-trapping, exacerbation frequency, and increased mortality in patients with COPD.

Impact of biologics on lung hyperinflation in patients with severe asthma

BACKGROUND

In asthma, inflammation affects both the proximal and distal airways and can cause significant hyperinflation, which is thought to be a major cause of dyspnea.

METHODS

This is a retrospective observational study evaluating the effect of three months of treatment with different biologic drugs (benralizumab, dupilumab and omalizumab) on pulmonary hyperinflation in a cohort of patients with severe asthma already receiving regular triple inhaled therapy. Changes in RV, RV/TLC ratio, FRC and FRC/TLC ratio were the primary efficacy measures. Secondary outcomes included FEV1, FVC, FEV1/FVC ratio, IC, IC/TLC ratio, asthma control test, the percentage of eosinophils in the blood and fractional FENO.

RESULTS

Benralizumab led to significant changes (p < 0.001) in RV, RV/TLC, FRC, and FRC/TLC. Dupilumab demonstrated a notable reduction in RV (p = 0.017) and RV/TLC (p = 0.002), but the decreases in FRC and FRC/TLC were merely numerical and not as pronounced as those induced by benralizumab. Omalizumab's positive impact on RV (p = 0.057) and RV/TLC (p = 0.085), as well as FRC (p = 0.202) and FRC/TLC (p = 0.096), was also predominantly numerical, with a tendency towards efficacy, albeit excluding the effect on FRC. Treatment with biologics resulted in improvements in all other lung function parameters assessed and a decrease in FENO levels.

CONCLUSION

This study, although limited by small sample size, lack of a placebo control, and unbalanced group sizes, suggests that biological agents are effective in reducing lung hyperinflation even after a relatively short treatment.

Childhood Asthma Control Test and spirometry values in school-age children

OBJECTIVE

To determine the relationship between child and parent reports of asthma control using the Childhood Asthma Control Test (C-ACT) and spirometry.

METHODS

This descriptive study included 648 children ages 5-11 years from a school-based asthma program. Not well-controlled asthma was defined as forced expiratory volume in 1 s (FEV1) and by FEV1/forced vital capacity (FVC) of 80% predicted or lower. Sensitivity and specificity of C-ACT scores for low FEV1 and FEV1/FVC levels were calculated. Logistic regression was used to obtain the area under the receiver operating characteristic curve (AUC) for C-ACT score categories by FEV1 level.

RESULTS

Mean child age was 8.2 years, mean C-ACT score was 20.3 (SD = 3.96), mean FEV1 was 94.3% (SD = 17.1), and mean FEV1/FVC was 81.3 (SD = 8.5). Children with an FEV1 of 80% or less had significantly lower C-ACT scores than those with an FEV1 > 80% (p = .023, t = -2.015, df = 167); 95% CI [. -1.79 to -0.018]). The sensitivity and specificity of a C-ACT score of 19 or less for an FEV1 of 80% predicted or lower were 44.9 and 66.4%. With a C-ACT score of 22 or less, sensitivity and specificity for low FEV1 were 67.7 and 30.9%. The AUC for a C-ACT score of 19 or less and FEV1 of 80% or lower was .444 while the AUC was higher at .507 for a CACT score of 22 or less.

CONCLUSION

The C-ACT is a useful screen but spirometry should be performed in children with persistent symptoms to assess current asthma control.

One-year follow-up of COVID-19 recoverees with impaired pulmonary function: A prospective cohort study

Decreased diffusion capacity for carbon monoxide (DLCO) is the most prevalent pulmonary testing abnormality among COVID-19 recoverees. We prospectively followed 51 individuals with impaired DLCO at an average of ∼3 months following COVID-19 and re-examined them at one year. At follow-up, mean DLCO increased from 68.0 % to 72.6 % (p = 0.002); while 33 % of the cohort experienced a clinically significant rise (>10 points) in DLCO, only 29 % normalized their values. While DLCO change did not correlate with symptoms, lack of improvement was more prevalent among individuals with obesity. Regardless of COVID-19 severity, a substantial proportion continued to exhibit DLCO impairment at 1-year.

Clinical characterization and outcomes of impulse oscillometry-defined bronchodilator response: an ECOPD cohort-based study

BACKGROUND

The clinical significance of the impulse oscillometry-defined small airway bronchodilator response (IOS-BDR) is not well-known. Accordingly, this study investigated the clinical characteristics of IOS-BDR and explored the association between lung function decline, acute respiratory exacerbations, and IOS-BDR.

METHODS

Participants were recruited from an Early Chronic Obstructive Pulmonary Disease (ECOPD) cohort subset and were followed up for two years with visits at baseline, 12 months, and 24 months. Chronic obstructive pulmonary disease (COPD) was defined as a post-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio < 0.70. IOS-BDR was defined as meeting any one of the following criteria: an absolute change in respiratory system resistance at 5 Hz ≤ - 0.137 kPa/L/s, an absolute change in respiratory system reactance at 5 Hz ≥ 0.055 kPa/L/s, or an absolute change in reactance area ≤ - 0.390 kPa/L. The association between IOS-BDR and a decline in lung function was explored with linear mixed-effects model. The association between IOS-BDR and the risk of acute respiratory exacerbations at the two-year follow-up was analyzed with the logistic regression model.

RESULTS

This study involved 466 participants (92 participants with IOS-BDR and 374 participants without IOS-BDR). Participants with IOS-BDR had higher COPD assessment test and modified Medical Research Council dyspnea scale scores, more severe emphysema, air trapping, and rapid decline in FVC than those without IOS-BDR over 2-year follow-up. IOS-BDR was not associated with the risk of acute respiratory exacerbations at the 2-year follow-up.

CONCLUSIONS

The participants with IOS-BDR had more respiratory symptoms, radiographic structural changes, and had an increase in decline in lung function than those without IOS-BDR.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1900024643. Registered on 19 July, 2019.

Implementation of an enhanced recovery protocol for lung volume reduction surgery: an observational cohort study

OBJECTIVES

Lung volume reduction surgery (LVRS) is an established therapeutic option for advanced emphysema. To improve patients' safety and reduce complications, an enhanced recovery protocol (ERP) was implemented. This study aims to describe and evaluate the short-term outcome of this ERP.

METHODS

This retrospective single-centre study included all consecutive LVRS patients (1 January 2017 until 15 September 2020). An ERP for LVRS was implemented and stepwise optimised from 1 August 2019, it consisted of changes in pre-, peri- and postoperative care pathways. Patients were compared before and after implementation of ERP. Primary outcome was incidence of postoperative complications (Clavien-Dindo), and secondary outcomes included chest tube duration, incidence of prolonged air leak (PAL), length of stay (LOS) and 90-day mortality. Lung function and exercise capacity were evaluated at 3 and 6 months post-LVRS.

RESULTS

Seventy-six LVRS patients were included (pre-ERP: n=41, ERP: n=35). The ERP cohort presented with lower incidence of postoperative complications (42% vs 83%, P=0.0002), shorter chest tube duration (4 vs 12 days, P<0.0001) with a lower incidence of PAL (21% vs 61%, P=0.0005) and shorter LOS (6 vs 14 days, P<0.0001). No in-hospital mortality occurred in the ERP cohort versus 4 pre-ERP. Postoperative forced expiratory volume in 1 s was higher in the ERP cohort compared to pre-ERP at 3 months (1.35 vs 1.02 l) and at 6 months (1.31 vs 1.01 l).

CONCLUSIONS

Implementation of ERP as part of a comprehensive reconceptualisation towards LVRS, demonstrated fewer postoperative complications, including PAL, resulting in reduced LOS. Improved short-term functional outcomes were observed at 3 and 6 months.

Analysis of Endocrine and Inflammatory Markers in Preserved Ratio Impaired Spirometry

Chronic Obstructive Pulmonary Disease (COPD) is a disease of the lungs characterized by chronic airflow obstruction. Individuals with preserved ratio impaired spirometry (PRISm) may be at risk for developing COPD. This study aimed to characterize PRISm and COPD patients in terms of their immune response and endocrine profile to identify differences extending beyond lung function. The participants performed the clinical assessment, pulmonary function test, and blood collection to determine serum hormone levels and concentrations of cytokine. Differences were observed in the nutritional status, lung function, and comorbidity. There were no differences in IL-6, IL-8, IL-10, IL-12, and TNF levels between PRISm and COPD groups. Both PRISm and COPD patients have lower dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) levels than controls. Correlation analysis of PRISm and COPD patients revealed positive correlations between serum levels of DHEA-S and DHEA, with forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC), which negatively correlated with IL-8 levels. The results indicated that despite differences in lung function parameters, the PRISm and COPD groups exhibited similarities in endocrine profile alterations. This study represents the first attempt to link endocrine with immune markers and lung function in individuals with PRISm.

Association of resistance training and moderate-to-vigorous physical activity with clinical outcomes in men with airflow limitation: a nationwide population-based study

Aerobic moderate-to-vigorous physical activity (MVPA) is recommended for individuals with chronic diseases. However, the association between resistance training (RT) in addition to moderate to vigorous physical activity (MVPA) and sleep duration, as well as respiratory symptoms, in patients with chronic obstructive pulmonary disease has not been thoroughly investigated. This population-based cross-sectional study used data from the Korea National Health and Nutrition Examination Survey between 2014 and 2019. A total of 61,754 individuals were identified and men with airflow limitation (FEV1/FVC < 0.7) who engaged in aerobic MVPA were selected (n = 794). Weighted percentages and odds ratio (OR) of sleep problems (≤ 5 or ≥ 9 h), chronic cough, and chronic sputum were estimated. A multivariate-adjusted complex sample logistic regression model was used to calculate ORs and 95% confidence intervals (CI). Subgroup analyses were conducted using the forced expiratory volume (FEV1) % of the predicted value (%pred) ≥ 80 vs. < 80. The percentages of sleep problems, chronic cough, and chronic sputum production were lower in men who underwent aerobic MVPA + RT than in those who underwent aerobic MVPA alone. The multivariable-adjusted OR of sleep problems was 0.44 (95% CI 0.25-0.77) in individuals undergoing aerobic MVPA + RT compared to aerobic MVPA alone. The ORs of chronic cough and sputum were 0.35 (95% CI 0.13-0.94) and 0.51 (95% CI 0.30-0.87), respectively. These associations were only significant in individuals with FEV1 < 80% pred. Compared with aerobic MVPA alone, aerobic MVPA + RT was associated with appropriate sleep duration and a decrease in chronic cough and sputum in male with airflow limitation. This was more pronounced in individuals with a FEV1 < 80% pred.

Type-2 inflammation and lung function decline in chronic airway disease in the general population

BACKGROUND

It is unclear if type-2 inflammation is associated with accelerated lung function decline in individuals with asthma and chronic obstructive pulmonary disease (COPD). We tested the hypothesis that type-2 inflammation indicated by elevated blood eosinophils (BE) and fraction of exhaled nitric oxide (FeNO) is associated with accelerated lung function decline in the general population.

METHODS

We included adults from the Copenhagen General Population Study with measurements of BE (N=15 605) and FeNO (N=2583) from a follow-up examination and assessed forced expiratory volume in 1 s (FEV1) decline in the preceding 10 years. Based on pre- and post-bronchodilator lung function, smoking history and asthma at follow-up examination, participants were assigned as not having airway disease, asthma with full reversibility (AR), asthma with persistent obstruction (APO), COPD, and not classifiable airflow limitation (NAL).

RESULTS

FEV1 decline in mL/year increased with 1.0 (95% CI 0.6 to 1.4, p<0.0001) per 100 cells/µL higher BE and with 3.2 (95% CI 2.0 to 4.5, p<0.0001) per 10 ppb higher FeNO. Adjusted FEV1 decline in mL/year was 18 (95% CI 17 to 20) in those with BE<300 cells/µL and FeNO<20 ppb, 22 (19-25) in BE≥300 cells/µL or FeNO≥20 ppb, and 27 (21-33) in those with BE≥300 cells/µL and FeNO≥20 ppb (p for trend<0.0001). Corresponding FEV1 declines were 24 (19-29), 33 (25-40) and 44 (31-56) in AR (0.002), 26 (14-37), 36 (12-60) and 56 (24-89) in APO (0.07), 32 (27-36), 31 (24-38) and 44 (24-65) in COPD (0.46), and 27 (21-33), 35 (26-45), and 37 (25-49) in NAL (0.10), respectively.

CONCLUSIONS

Type-2 inflammation indicated by elevated BE and FeNO is associated with accelerated FEV1 decline in individuals with chronic airway disease in the general population, and this association was most pronounced in an asthma-like phenotype.

[Correlation of nutritional status with clinical characteristics and lung function in children with cystic fibrosis]

OBJECTIVES

To investigate the nutritional status of children with cystic fibrosis (CF) and understand the correlation between malnutrition and clinical characteristics as well as lung function.

METHODS

A retrospective analysis was performed on clinical data of CF children admitted from January 2016 to June 2023. Clinical characteristics of CF children with different nutritional statuses were compared, and the correlation between malnutrition and lung function was analyzed.

RESULTS

A total of 52 CF children were included, comprising 25 boys (48%) and 27 girls (52%), aged between 7 months and 17 years. Respiratory symptoms were the predominant clinical manifestations (96%, 50/52). The prevalence of malnutrition was 65% (34/52), with moderate/severe malnutrition being the most common (65%, 22/34). The malnutrition group had a longer duration of illness, higher proportion of digestive system symptoms, and lower levels of serum albumin (P<0.05). Pulmonary function parameters, including forced expiratory volume in one second as a percentage of the predicted value, ratio of forced expiratory volume in one second to forced vital capacity, forced expiratory flow at 25% of forced vital capacity exhaled, forced expiratory flow at 50% of forced vital capacity exhaled, forced expiratory flow at 75% of forced vital capacity exhaled, and maximum mid-expiratory flow as a percentage of the predicted value, were lower in the malnutrition group compared to the normal nutrition group (P<0.05). Correlation analysis showed body mass index Z-score was positively correlated with the above six pulmonary function parameters (P<0.05).

CONCLUSIONS

The prevalence of malnutrition is high in CF children and is associated with decreased lung function. CF children with higher body mass index have better lung function. Therefore, screening and evaluation of nutritional status as well as appropriate nutritional intervention should be emphasized in CF children.

Pulmonary Function and Lung Fibrosis up to 12 Years After Breast Cancer Radiotherapy

PURPOSE

Breast cancer (BC) treatment may affect pulmonary function, but evidence of long-term pulmonary toxicity is scarce. This study aimed to evaluate pulmonary function, radiation fibrosis (RF), and patient-reported dyspnea up to 12 years after different BC treatment modalities.

METHODS AND MATERIALS

Two hundred fifty patients with BC referred to postoperative radiotherapy (RT) were included in this study. High-resolution computed tomography, pulmonary function tests (PFTs), clinical examinations, and patient-reported dyspnea were assessed before RT and at 3, 6, and 12 months and up to 12 years after RT.

RESULTS

Vital capacity (VC), forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and diffusion capacity of the lungs for carbon monoxide (DLCO) declined at 3 months after RT and remained low at long-term follow-up except for DLCO, which increased up to 12 years after RT. VC, FEV1, and FVC changes differed between patients treated with and without chemotherapy, and FEV1 differed between patients treated with locoregional and local RT. An early decline in VC, FEV1, and FVC predicted a late decline in PFT values up to 12 years after RT (P = .020, P = .004, and P = .020, respectively). RF, mainly grade 1, was observed in 91% of patients at long-term follow-up. Few patients reported severe dyspnea at long-term follow-up, and there was no statistically significant association with concurrent RF or decline in PFT values from baseline.

CONCLUSIONS

Chemotherapy and locoregional RT affected performance in PFTs up to 12 years after RT. Reduction in VC, FVC, and FEV1 3 months after RT predicted a decline in PFT values at long-term follow-up. However, a late decline in PFT values was not associated with long-term RF or patient-reported dyspnea.

Impact on Pulmonary Function in a Randomized Trial of Single-Fraction and Multifraction Stereotactic Body Radiation Therapy for Pulmonary Oligometastatic Disease: An Analysis of TROG 13.01 (SAFRON II)

PURPOSE

The TROG 13.01 (SAFRON II) trial was a phase 2 multicenter trial comparing single-fraction (SF) and multifraction (MF) stereotactic body radiation therapy. Patients with 1 to 3 peripheral pulmonary oligometastases were randomized 1:1 between 28 Gy in 1 fraction and 48 Gy in 4 fractions. There were no differences between arms in efficacy or toxicity. We performed an analysis to assess changes in pulmonary function tests (PFTs) between arms over time and assessed the effect of the number and total volume of targets on PFT change over time.

METHODS AND MATERIALS

A linear mixed model was used to describe the PFTs by treatment arm over time. The effect of number and volume of targets on PFTs at 6 and 12 months was assessed by a simple linear model.

RESULTS

Ninety patients were randomized; 87 were treated for 133 pulmonary oligometastases. Forty-four were randomized to the SF arm and 43 to the MF arm. There were no differences in absolute or relative PFT measures of forced expiratory volume in 1 second (FEV1), diffusing capacity of the lungs for carbon monoxide (DLCO), or forced vital capacity (FVC) between the 2 arms. At 12 months, there was a reduction in absolute DLCO from baseline (-1.7 mL/min/mm Hg [95% CI, -2.5 to -1.0]), relative DLCO (-5.5% [95% CI, -8.4% to -2.6%]), absolute FEV1 (-0.17 L [95% CI, -0.23 to -0.11]), and absolute FVC (-0.20 L [95% CI, -0.27 to -0.13]). In patients with multiple pulmonary targets, increase in target number (per lesion) was associated with a reduction in the absolute FEV1 at 6 months of -0.10 L (95% CI, -0.18 to -0.03; P = .007), FEV1 at 12 months of -0.10 L (95% CI, -0.20 to -0.01; P = .04), FVC at 6 months of -0.11 L (95% CI, -0.20 to -0.03; P = .014), and FVC at 24 months of -0.13 L (95% CI, -0.25 to -0.01; P = .036). Reduction in FEV1 was also seen per 10-mL increase in PTV at 12 months (-0.03 L [95% CI, -0.06 to -0.00], P = .036). The number of targets and PTV were not associated with DLCO.

CONCLUSIONS

Treating multiple targets resulted in increased loss of FEV1 and FVC but not DLCO. There were no significant differences in PFT decline between SF and MF stereotactic body radiation therapy.

Preserved Ratio Impaired Spirometry (PRISm): A Global Epidemiological Overview, Radiographic Characteristics, Comorbid Associations, and Differentiation from Chronic Obstructive Pulmonary Disease

Preserved Ratio Impaired Spirometry (PRISm) manifests notable epidemiological disparities across the globe, with its prevalence and influential factors showcasing pronounced diversities among various geographical territories and demographics. The prevalence of PRISm fluctuates considerably among regions such as Latin America, the United States, and Asian nations, potentially correlating with a myriad of determinants, including socioeconomic status, environmental factors, and lifestyle modalities. Concurrently, the link between PRISm and health risks and other disorders, especially its distinction and interrelation with chronic obstructive pulmonary disease (COPD), has become a pivotal subject of scientific enquiry. Radiographic anomalies, such as perturbations in the pulmonary parenchyma and structural alterations, are posited as salient characteristics of PRISm. Furthermore, PRISm unveils intricate associations with multiple comorbidities, inclusive of hypertension and type 2 diabetes, thereby amplifying the intricacy in comprehending and managing this condition. In this review, we aim to holistically elucidate the epidemiological peculiarities of PRISm, its potential aetiological contributors, its nexus with COPD, and its association with radiographic aberrations and other comorbidities. An integrative understanding of these dimensions will provide pivotal insights for the formulation of more precise and personalised preventative and therapeutic strategies.

Impulse oscillometry in patients with pulmonary arterial hypertension: an exploratory study

INTRODUCTION

Studies suggest peripheral airway abnormalities in Pulmonary Arterial Hypertension (PAH). Impulse Oscillometry (IOS) is a noninvasive and sensitive technique for assessing the small airways. It evaluates the impedance of the respiratory system ‒ Resistance (R) and reactance (X) ‒ to a pulse of sound waves sent to the lungs, in a range of frequencies (5‒20 Hz).

METHOD

Resistance variables: R5, R20, R5-R20 and reactance variables: AX (reactance area) and Fres (resonance frequency). The aim is to evaluate R and X in patients with idiopathic PAH (IPAH) and to investigate whether there is a correlation between IOS and spirometry.

RESULTS

Thirteen IPAH patients and 11 healthy subjects matched for sex and age underwent IOS and spirometry. IPAH patients had lower FVC and FEV1 values (p < 0.001), VEF1/CVF (p = 0.049) and FEF 25-75 (p = 0.006) than healthy patients. At IOS, IPAH patients showed lower tidal volumes and higher AX (p < 0.05) compared to healthy individuals, and 53.8 of patients had R5-R20 values ≥ 0.07 kPa/L/s. Correlation analysis: X5, AX, R5-R20 and Fres showed moderate correlation with FVC (p = 0.036 r = 0.585, p = 0.001 r = -0.687, p = 0.005 r = -0.726 and p = 0.027 r = -0.610); Fres (p = 0.012 r = -0.669) and AX (p = 0.006 r = -0.711) correlated with FEV1; [R5 and R20, (R5-R20)] also correlated with FEV1 (p < 0.001 r = -0.573, p = 0.020 r = -0.634 and p = 0.010 r = -0.683, respectively) in the IPAH group. There were also moderate correlations of FEF 25-75 % with Z5 (p = 0.041), R5 (p = 0.018), Fres (p = 0.043) and AX (p = 0.023).

DISCUSSION

Patients showed changes suggestive of increased resistance and reactance in the IOS compared to healthy individuals, and the IOS findings showed a good correlation with spirometry variables.

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 of high-sensitivity CRP and FEV1%pred: a study on non-pulmonary disease in a population in Beijing, China

BACKGROUND

No studies have investigated whether high-sensitivity C reactive protein (hsCRP) can be used to predict the forced expiratory volume in 1 s (FEV1)/estimated value of FEV1 (FEV1%pred). This study aimed to assess the association between hsCRP and FEV1%pred in middle-aged and elderly individuals without underlying lung disease.

METHODS

The data for this study were obtained from a prospective cohort study that included 1047 middle-aged and elderly citizens from Beijing aged 40-75 years without any evidence of underlying lung diseases with FEV1 >70% after receiving inhalational bronchodilators. The baseline analysis of the participants was performed from 30 May 2018 to 31 October 2018. Restricted cubic spline regression and multivariate linear regression models were used to assess the non-linear association and linear association between hsCRP and FEV1/FEV in 6 s (FEV6) and FEV1%pred, respectively.

RESULTS

The hsCRP values of 851 participants were recorded; the values were normal in 713 (83.8%) participants. The remaining 196 participants (18.7%) had missing data. A non-linear association was observed between normal hsCRP values and FEV1/FEV6. hsCRP was linearly and negatively correlated with FEV1%pred, and each 1 SD increase in hsCRP was significantly associated with a 2.4% lower in FEV1%pred. Significantly higher FEV1/FEV6 differences were observed in the female subgroup than those in the male subgroup (p=0.011 for interaction).

CONCLUSIONS

hsCRP had a non-linear association with FEV1/FEV6 and a linear negative association with FEV1%pred in individuals with normal hsCRP values. hsCRP can be used to predict FEV1%pred, which can be used to predict the development of chronic obstructive pulmonary disease. hsCRP has a stronger association with lung function in women than that in men.

TRIAL REGISTRATION NUMBER

NCT03532893.

Associations of a plant-centered diet and lung function across early to mid-adulthood: The CARDIA Lung Study

BACKGROUND

Lung function throughout adulthood predicts morbidity and mortality even among adults without chronic respiratory disease. Diet quality may represent a modifiable risk factor for lung function impairment later in life. We investigated associations between nutritionally-rich plant-centered diet and lung function across early and middle adulthood from the Coronary Artery Risk Development in Young Adults (CARDIA) Study.

METHODS

Diet was assessed at baseline and years 7 and 20 of follow-up using the validated CARDIA diet history questionnaire. Plant-centered diet quality was scored using the validated A Priori Diet Quality Score (APDQS), which weights food groups to measure adherence to a nutritionally-rich plant-centered diet for 20 beneficially rated foods and 13 adversely rated foods. Scores were cumulatively averaged over follow-up and categorized into quintiles. The primary outcome was lung function decline, including forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), measured at years 0, 2, 5, 10, 20, and 30. We estimated the association of APDQS with annual pulmonary function changes and cross-sectional differences in a repeated measures regression model, adjusting for clinically relevant covariates.

RESULTS

The study included 3,787 Black and White men and women aged 18-30 in 1985-86 and followed for 30 years. In multivariable repeated measures regression models, individuals in the lowest APDQS quintile (poorest diet) had declines in FEV1 that were 1.6 ml/year greater than individuals in the highest quintile (35.0 vs. 33.4 ml/year, ß ± SE per 1 SD change APDQS 0.94 ± 0.36, p = 0.009). Additionally, declines in FVC were 2.4 ml/year greater in the lowest APDQS quintile than those in the highest quintile (37.0 vs 34.6 ml/year, ß ± SE per 1 SD change APDQS 1.71 ± 0.46, p < 0.001). The association was not different between never and ever smokers (pint = 0.07 for FVC and 0.32 for FEV1). In sensitivity analyses where current asthma diagnosis and cardiorespiratory fitness were further adjusted, results remained similar. Cross-sectional analysis at each exam year also showed significant differences in lung function according to diet after covariate adjustment.

CONCLUSIONS

In this 30-year longitudinal cohort study, long-term adherence to a nutritionally-rich plant-centered diet was associated with cross-sectional differences in lung function as well as slower decline in lung function, highlighting diet quality as a potential treatable trait supporting long-term lung health.

Respiratory Oscillometry and Functional Performance in Different COPD Phenotypes

Purpose

Chronic obstructive pulmonary disease (COPD) phenotypes may introduce different characteristics that need to be known to improve treatment. Respiratory oscillometry provides a detailed analysis and may offer insight into the pathophysiology of COPD. In this paper, we used this method to evaluate the differences in respiratory mechanics of COPD phenotypes.

Patients and Methods

This study investigated a sample of 83 volunteers, being divided into control group (CG = 20), emphysema (n = 23), CB (n = 20) and asthma-COPD overlap syndrome (ACOS, n = 20). These analyses were performed before and after bronchodilator (BD) use. Functional capacity was evaluated using the Glittre‑ADL test, handgrip strength and respiratory pressures.

Results

Initially it was observed that oscillometry provided a detailed description of the COPD phenotypes, which was consistent with the involved pathophysiology. A correlation between oscillometry and functional capacity was observed (r=-0.541; p = 0.0001), particularly in the emphysema phenotype (r = -0.496, p = 0.031). BD response was different among the studied phenotypes. This resulted in an accurate discrimination of ACOS from CB [area under the receiver operating curve (AUC) = 0.84] and emphysema (AUC = 0.82).

Conclusion

These results offer evidence that oscillatory indices may enhance the comprehension and identification of COPD phenotypes, thereby potentially improving the support provided to these patients.

Roles of gender and smoking in the associations between urinary phytoestrogens and asthma/wheeze and lung function: evidence from a cross-sectional study

BACKGROUND

The role of phytoestrogens in asthma/wheeze and lung function remains controversial. Thus, we aimed to examine whether phytoestrogens have beneficial effects on asthma/wheeze, lung function for subgroups and mortality.

METHODS

Participants in this study were individuals aged 20 years or older from the National Health and Nutrition Examination Survey. Multivariate logistic regression models were fitted to examine the associations of urinary phytoestrogens with the risk of asthma/wheeze and lung function in individuals with and without asthma/wheeze. Cox proportional hazards regression was used to examine the relationship between urinary phytoestrogens and all-cause mortality. Stratified analyses were conducted based on gender and smoking status.

RESULTS

We included 2465 individuals in this study. Enterolactone levels in the highest quartile were associated with a lower risk of asthma than those in the lowest quartile. As compared with the lowest quartile, the highest quartile of enterodiol and enterolactone was associated with a lower risk of wheeze. Significant associations were observed between subtypes of phytoestrogens (equol and enterolactone) and lung function (forced vital capacity (FVC) and forced expiratory volume in 1 s). Besides, FVC was higher in individuals with higher levels of enterodiol. The results were consistent in subpopulations without asthma/wheeze, while the significant difference was not observed in individuals with asthma/wheeze. The stratified analyses revealed that the associations between phytoestrogens and lung function differed by gender and smoking status among subgroups. No significant association was found between urinary phytoestrogens and all-cause mortality.

CONCLUSION

In summary, subtypes of phytoestrogens were associated with lower risk of asthma/wheeze and beneficial for lung function improvement in individuals without asthma/wheeze. Furthermore, gender and smoking may interact in the relationship between phytoestrogens and asthma/wheeze, and lung function. Further researches are needed to confirm these associations and explain the results of stratified analyses.