RESUMEN

In patients previously hospitalised for COVID-19, a 12-week high-intensity interval training (HIIT) intervention has previously been shown to increase left ventricular mass (LVM) immediately after the intervention. In the present study, we examined the effects of the same HIIT scheme on LVM, pulmonary diffusing capacity, symptom severity and functional capacity at 12-month follow-up. In this investigator-blinded, randomised controlled trial, 12 weeks of a supervised HIIT scheme (4 × 4 min, three times a week) was compared to standard care (control) in patients recently discharged from hospital due to COVID-19. At inclusion and at 12-month follow-up, LVM was assessed by cardiac magnetic resonance imaging (cMRI, primary outcome), while pulmonary diffusing capacity for carbon monoxide (DLCOc, secondary outcome) was examined by the single-breath method. Symptom severity and functional status were examined by the Post-COVID-19 Functional Scale (PCFS) and King's Brief Interstitial Lung Disease (KBILD) questionnaire score. Of the 28 patients assessed at baseline, 22 completed cMRI at 12-month follow-up (12.4 ± 0.6 months after inclusion). LVM was maintained in the HIIT but not the standard care group, with a mean between-group difference of 9.68 [95% CI: 1.72, 17.64] g (P = 0.0182). There was no differences in change from baseline to 12-month follow-up between groups in DLCOc % predicted (-2.45 [-11.25, 6.34]%; P = 0.578). PCFS and KBILD improved similarly in the two groups. In individuals previously hospitalised for COVID-19, a 12-week supervised HIIT scheme resulted in a preserved LVM at 12-month follow-up but did not affect pulmonary diffusing capacity or symptom severity.

RESUMEN

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) has traditionally been diagnosed based on the criterion of an FEV1/FVC <0.70. However, this definition has limitations as it may only detect patients with later-stage disease, when pathologic changes have become irreversible. Consequently, it potentially omits individuals with early-stage disease, in whom the pathologic changes could be delayed or reversed. AREAS COVERED: This narrative review summarizes recent evidence regarding early-stage COPD, which may not fulfill the spirometric criteria but nonetheless exhibits features of COPD or is at risk of future COPD progression. EXPERT OPINION: A comprehensive approach, including symptoms assessment, various physiologic tests, and radiologic features, is required to diagnose COPD. This approach is necessary to identify currently underdiagnosed patients and to halt disease progression in at- risk patients.

RESUMEN

INTRODUCTION: Dissolved-phase 129Xe MRI metrics suggest that gas diffusion may be more compromised at submaximal lung inflation compared to maximal inflation. We hypothesized that this diffusion deficit could be detected by comparing the carbon monoxide transfer coefficient (Kco) at submaximal lung inflation to that measured routinely at total lung capacity (TLC). METHODS: Asthma and COPD patients performed carbon monoxide diffusion tests, first at maximal lung inflation for routine Kco and alveolar volume VA and then, at a 30 % reduced inflation (redux; obtaining Kcoredux and VAredux). At both inflations mixing efficiency was determined as VA/TLC and VAredux/TLCredux to examine a potential effect on Kcoredux/Kco behavior. RESULTS: In normal subjects (n=36), median Kcoredux/Kco amounted to 130 [IQR:122-136]% as expected for normal Kco recruitment response. However, 60 % of asthma patients (49/83) and 80 % of COPD patients (44/55) showed reduced Kco recruitment at submaximal inflation (Kcoredux/Kco<122 %). In the asthma group, with otherwise normal routine Kco, Kcoredux/Kco was significantly correlated with RV/TLC ratio (r=-0.53;P<0.001), but not with VA/TLC. In COPD patients, all with abnormal routine Kco, abnormal Kcoredux/Kco response occurred in those patients with lower FEV1, higher RV/TLC and lower VA/TLC (P<0.01 for all). CONCLUSION: Sizeable portions of COPD and asthma patients showed a lack of normal Kco recruitment at submaximal lung inflation, related to high RV/TLC. In asthma, this was the case despite normal Kco at full lung inflation, suggesting that hyperinflation at lung volumes less than TLC affects the carbon monoxide diffusion rate constant by distorting pulmonary capillaries and alveolar-capillary membranes.

Asunto(s)

RESUMEN

Background: Numerous studies have investigated methods of predicting postoperative pulmonary complications (PPCs) in lung cancer surgery, with chronic obstructive pulmonary disease (COPD) and low forced expiratory volume in 1 second (FEV1) being recognized as risk factors. However, predicting complications in COPD patients with preserved FEV1 poses challenges. This study considered various diffusing capacity of the lung for carbon monoxide (DLCO) parameters as predictors of pulmonary complication risks in mild COPD patients undergoing lung resection. Methods: From January 2011 to December 2019, 2,798 patients undergoing segmentectomy or lobectomy for non-small cell lung cancer (NSCLC) were evaluated. Focusing on 709 mild COPD patients, excluding no COPD and moderate/severe cases, 3 models incorporating DLCO, predicted postoperative DLCO (ppoDLCO), and DLCO divided by the alveolar volume (DLCO/VA) were created for logistic regression. The Akaike information criterion and Bayes information criterion were analyzed to assess model fit, with lower values considered more consistent with actual data. Results: Significantly higher proportions of men, current smokers, and patients who underwent an open approach were observed in the PPC group. In multivariable regression, male sex, an open approach, DLCO <80%, ppoDLCO <60%, and DLCO/VA <80% significantly influenced PPC occurrence. The model using DLCO/VA had the best fit. Conclusion: Different DLCO parameters can predict PPCs in mild COPD patients after lung resection for NSCLC. The assessment of these factors using a multivariable logistic regression model suggested DLCO/VA as the most valuable predictor.

Asunto(s)

RESUMEN

BACKGROUND: The Phase III slope from a single breath nitrogen washout test provides information about ventilation heterogeneity (VH) in the lungs. PURPOSE: To determine if the Phase III slope from the exhaled tracer gas concentration during a standard, single breath DLCO test using rapid gas analysis provides similar information about VH. BASIC PROCEDURES: Retrospective analysis of clinical pulmonary function laboratory data including spirometry, lung volumes, and DLCO. The normalized Phase III slope from the exhaled CH4 concentration (SnCH4) was compared among different patterns of physiologic abnormality and with VA/TLC as an indicator of VH. MAIN FINDINGS: SnCH4 was the steepest in the group with "Obstruction and Low DLCO", with significant differences between this group and the "Normal", "Obstruction with Normal DLCO", "Mixed Obstruction and Restriction" and "Isolated Low DLCO" groups. SnCH4 was steeper in current and former smokers compared to non-smokers. Among the entire study sample, SnCH4 correlated with VA/TLC (Spearman rho = -0.56, p < 0.01) and remained a significant determinant of VA/TLC by regression modeling. PRINCIPAL CONCLUSIONS: The SnCH4 derived from a standard, single breath DLCO test using rapid gas analysis varied among distinct patterns of physiologic abnormalities and was associated with VA/TLC as a measure of VH.

Asunto(s)

RESUMEN

PURPOSE: The present study aimed to investigate the clinical characteristics and lung function impairment in young people diagnosed with chronic obstructive pulmonary disease (COPD). PATIENTS AND METHODS: We retrospectively enrolled patients with COPD who underwent symptom assessment and comprehensive pulmonary function tests at the First Affiliated Hospital of Guangzhou Medical University between August 2017 and March 2022. The patients were categorized into two groups based on age: a young COPD group (aged 20-50 years) and an old COPD group (aged > 50 years). RESULTS: A total of 1282 patients with COPD were included in the study, with 76 young COPD patients and 1206 old COPD patients. Young COPD patients exhibited a higher likelihood of being asymptomatic, lower rates of smoking, and a lower smoking index compared to old COPD patients. Although young COPD patients had higher median post-bronchodilator forced expiratory volume in 1 s (post-BD FEV1) (1.4 vs.1.2 L, P = 0.019), diffusing capacity of the lung for carbon monoxide (DLCO) (7.2 vs. 4.6, P<0.001), and a lower median residual volume to total lung capacity ratio (RV/TLC) compared to their older counterparts, there were no differences observed in severity distribution by GOLD categories or the proportion of lung hyperinflation (RV/TLC%pred > 120%) between two groups. Surprisingly, the prevalence of reduced DLCO was found to be 71.1% in young COPD, although lower than in old COPD (85.2%). CONCLUSION: Young COPD showed fewer respiratory symptoms, yet displayed a similar severity distribution by GOLD categories. Furthermore, a majority of them demonstrated lung hyperinflation and reduced DLCO. These results underscore the importance of a comprehensive assessment of lung function in young COPD patients.

Asunto(s)

RESUMEN

BACKGROUND: The 2022 European Society of Cardiology/European Respiratory Society guidelines define pulmonary hypertension (PH) as a resting mean pulmonary artery pressure (mPAP) > 20 mm Hg at right heart catheterization (RHC). Previously, patients with an mPAP between 21 and 24 mm Hg were classified in a "gray zone" of unclear clinical significance. RESEARCH QUESTION: What is the diagnostic performance of the main parameters used for PH screening in detecting patients with systemic sclerosis (SSc) with an mPAP of 21 to 24 mm Hg at RHC? STUDY DESIGN AND METHODS: Patients with SSc from the European Scleroderma Trials and Research (EUSTAR) database with available tricuspid annular plane systolic excursion (TAPSE), systolic PAP (sPAP), and mPAP data were included. Patients with mPAP 21 to 24 mm Hg and patients with mPAP ≤ 20 mm Hg were considered for the analysis. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. RESULTS: TAPSE/sPAP was lower in the group of patients with SSc with mPAP 21 to 24 mm Hg than in the non-PH group (0.58 [0.46-0.72] vs 0.69 [0.57-0.81] mm/mm Hg, respectively; P < .01). No difference was found in other parameters between the two groups. Diffusing capacity of the lungs for carbon monoxide < 80% of the predicted value had the highest sensitivity (88.9%) and NPV (80%), but the lowest specificity (18.2%) and PPV (30.8%) in detecting patients with SSc with mPAP 21 to 24 mm Hg. TAPSE/sPAP < 0.55 mm/mm Hg had the highest specificity (78.9%), PPV (50%), and accuracy (68.1%); its NPV was 75.4%, and its sensitivity was 45.1%. INTERPRETATION: In this study, diffusing capacity of the lungs for carbon monoxide < 80% of the predicted value was the parameter with the highest sensitivity and NPV in detecting patients with SSc with mPAP 21 to 24 mm Hg. TAPSE/sPAP < 0.55 mm/mm Hg had the highest specificity, PPV, and accuracy and, therefore, can be a useful additional parameter to decrease the number of unnecessary RHCs.

RESUMEN

BACKGROUND: The US Department of Labor (DOL) does not fund diffusing capacity (DLCO) or metabolic measurements from cardiopulmonary exercise testing (CPET) for coal miners' disability evaluations. Although exercise arterial blood gas testing is covered, many miners are unable to perform maximal tests, and sampling at peak exercise can be challenging. We explored the relationship between resting DLCO, radiographic disease severity, and CPET abnormalities in former US coal miners. METHODS: We analyzed data from miners evaluated between 2005 and 2015. Multivariable linear and logistic regression analyses were used to examine relationships between percent predicted (pp) forced expiratory volume in 1 s (FEV1pp), DLCOpp, VO2maxpp, A-a oxygen gradient (A-a)pp, dead space fraction (Vd/Vt), disabling oxygen tension (PO2), and radiographic findings of pneumoconiosis. RESULTS: Data from 2015 male coal miners was analyzed. Mean tenure was 28 years (SD 8.6). Thirty-twopercent had an abnormal A-a gradient (>150 pp), 20% had elevated Vd/Vt (>0.33), and 34% a VO2max < 60 pp. DLCOpp strongly predicted a disabling PO2, with an odds ratio (OR) of 2.33 [2.09-2.60], compared to 1.18 [1.08-1.29] for FEV1. Each increase in subcategory of small opacity (simple) pneumoconiosis increased the odds of a disabling PO2 by 42% [1.29-1.57], controlling for age, body mass index, pack-years of tobacco smoke exposure, and years of coal mine employment. CONCLUSIONS: DLCO is the best resting pulmonary function test predictor of CPET abnormalities. Radiographic severity of pneumoconiosis was also associated with CPET abnormalities. These findings support funding DLCO testing for impairment and suggest the term "small opacity" should replace "simple" pneumoconiosis to reflect significant associations with impairment.

Asunto(s)

RESUMEN

Objective: While the coronavirus disease-2019 (COVID-19) pandemic has generally resulted in milder illness among children than adults, persistent respiratory symptoms have been increasingly reported in this population. Methods: We conducted a prospective, single-center cohort study focusing on children experiencing prolonged respiratory symptoms after contracting COVID-19. Spirometry, 6- minute walk tests (6MWTs), and tests of lung volume, the diffusing capacity of the lungs for carbon monoxide (DLCO), and fractional exhaled nitric oxide (FeNO) were performed on COVID-19 survivors at least 4 weeks after infection and a group of healthy control subjects. Results: Fifty-five children with long-term COVID and 55 healthy control subjects were recruited. The weight, height, and body mass index Z-scores were similar in the groups. Within a median duration of 85 days (minimummaximum: 35-194) following COVID-19 infection, a restrictive pattern was observed to be more common in the study group (p=0.021). In children with long COVID, 6MWT distances, DLCO Z-scores, and the predicted values of spirometry and lung volume tests were found to be significantly lower but in the normal range. The average predicted values for DLCO, FeNO, and 6MWT were similar in the two groups. Conclusions: Prolonged respiratory symptoms often persist long after COVID-19 infection, necessitating comprehensive evaluation of affected children. Close monitoring, including spirometry and lung volume assessments, is crucial for children with abnormalities in lung imaging. However, FeNO measurements were found to be ineffective in monitoring long COVID.

RESUMEN

Hepatitis C virus (HCV) infection is associated with extrahepatic effects, including reduced diffusing capacity of the lungs. It is unknown whether clearance of HCV infection is associated with improved diffusing capacity. In this sample of women with and without human immunodeficiency virus, there was no association between HCV clearance and diffusing capacity.

RESUMEN

Reduced pulmonary diffusing capacity for carbon monoxide (DLCO) can be observed in pulmonary arterial hypertension (PAH) and associates with increased mortality. However, the prognostic value of DLCO when corrected for haemoglobin (DLCOc), an independent modifier of DLCO, remains understudied. Additionally, the prognostic role of ventilation (V)-perfusion (Q) emission computed tomography (V/Q SPECT) findings in patients with PAH, which may concurrently be performed to rule out chronic thromboembolic pulmonary hypertension, is uncertain. A retrospective cohort study was conducted on 152 patients with PAH referred to a tertiary hospital for evaluation from January 2011 to January 2020. Lung function tests, clinical data and V/Q SPECT were ascertained. Cox regression analysis was performed to evaluate the association between DLCOc, DLCO and V/Q SPECT defects at referral with all-cause mortality. In equally adjusted Cox regression analysis, each percentage increase in DLCOc % predicted (%pred) (hazard ratio (HR) 0.97; 95% CI: 0.94-0.99) and DLCO%pred (HR 0.97; 95% CI: 0.94-0.99) was similarly associated with all-cause mortality. There was no detectable difference in area under the curve for prediction of all-cause mortality by DLCOc%pred and DLCO%pred (C-index 0.71 and 0.72, respectively, P = 0.85 for difference). None of the defects noted on V/Q SPECT were significantly associated with mortality, but mismatched defects were associated with lower values of DLCOc%pred and DLCO%pred. DLCOc%pred and DLCO%pred perform equally as prognostic markers in PAH, supporting the use of either metric when available for prognostic stratification.

Asunto(s)

RESUMEN

Background: Few studies consider both radiological and functional outcomes in COVID-19 survivors treated in the intensive care unit (ICU). We investigated clinical findings and pulmonary abnormalities on chest computed tomography (CT) and compared outcomes of severe versus mild-moderate acute respiratory distress syndrome (ARDS) on long-term follow-up. Methods: This longitudinal cohort study included 118 COVID-19 patients (median age, 58 years; 79% men). Thoracic CT scans were performed 4, 10, and 22 months after hospital discharge. Two independent blinded radiologists analyzed the 10 months scans and scored the radiology findings semi-quantitatively, as no/minor versus widespread opacities [low-radiology opacity grade (ROG) versus high-ROG]. ARDS severity was based on the PaO2/FiO2 ratio. The 6 min walk test (6MWT) was performed after 3 and 9 months, and lung diffusion capacity for carbon monoxide (DLCO) and lung volume measurement after 9 and 15 months. Dynamic spirometry was done at all time points. Residual symptoms and health-related quality-of-life (HRQL) were evaluated using validated questionnaires. Results: At 10 months, most patients (81/118; 69%) were classified as high-ROG, of which 70% had severe ARDS during hospitalisation; 69% of those with mild-moderate ARDS also had high-ROG. Patients with high-ROG had longer ICU stay and lower PaO2/FiO2 during hospitalisation (p < 0.01). At 9 months follow-up, patients with high-ROG had smaller lung volumes as % of predicted values [mean (±CI): 80 (77-84) vs. 93 (88-98) (p < 0.001)], lower DLCO as % of predicted values [74 (70-78) vs. 87 (82-92) (p < 0.001)], lower oxygen saturation during 6MWT (p = 0.02), and a tendency to more severe dyspnoea (p = 0.07), but no difference was found in HRQL compared with no/minor ROG (p = 0.92). A higher opacity score was related to lower DLCO at follow-up (r = -0.48, p < 0.001, Spearman rank test). Severe ARDS patients had slightly more severe fatigue at 9 months compared to mild-moderate, but no differences in dyspnoea or lung function at follow-up. Fibrotic-like changes were found in 93% of patients examined with CT scans at 2 years (55/118; 47%). Severe ARDS could predict widespread opacities (ROG > 25%) in most patients at follow-up at 10 months (AUC 0.74). Conclusion: Residual radiological abnormalities in ICU-treated COVID-19 patients, evaluated for up to 2 years, relate to persisting symptoms and impaired lung function, demanding careful follow-up regardless of ARDS severity at hospitalisation.

RESUMEN

The progression of idiopathic pulmonary fibrosis (IPF) is assessed through serial monitoring of forced vital capacity (FVC). Currently, data regarding the clinical significance of longitudinal changes in diffusing capacity for carbon monoxide (DLCO) is lacking. We investigated the prognostic implications of a 1-year decline in DLCO in 319 patients newly diagnosed with IPF at a tertiary hospital between January 2010 and December 2020. Changes in FVC and DLCO over the first year after the initial diagnosis were reviewed; a decline in FVC ≥ 5% and DLCO ≥ 10% predicted were considered significant changes. During the first year after diagnosis, a significant decline in FVC and DLCO was observed in 101 (31.7%) and 64 (20.1%) patients, respectively. Multivariable analysis showed that a 1-year decline in FVC ≥ 5% predicted (aHR 2.74, 95% CI 1.88-4.00) and 1-year decline in DLCO ≥ 10% predicted (aHR 2.31, 95% CI 1.47-3.62) were independently associated with a higher risk of subsequent mortality. The prognostic impact of a decline in DLCO remained significant regardless of changes in FVC, presence of emphysema, or radiographic indications of pulmonary hypertension. Therefore, serial monitoring of DLCO should be recommended because it may offer additional prognostic information compared with monitoring of FVC alone.

Asunto(s)

RESUMEN

BACKGROUND: Observational studies have shown that smoking is related to the diffusing capacity of the lungs for carbon monoxide (DLCO) in individuals with idiopathic pulmonary fibrosis (IPF). Nevertheless, further investigation is needed to determine the causal effect between these two variables. Therefore, we conducted a study to investigate the causal relationship between smoking and DLCO in IPF patients using two-sample Mendelian randomization (MR) analysis. METHODS: Large-scale genome-wide association study (GWAS) datasets from individuals of European descent were analysed. These datasets included published lifetime smoking index (LSI) data for 462,690 participants and DLCO data for 975 IPF patients. The inverse-variance weighting (IVW) method was the main method used in our analysis. Sensitivity analyses were performed by MR‒Egger regression, Cochran's Q test, the leave-one-out test and the MR-PRESSO global test. RESULTS: A genetically predicted increase in LSI was associated with a decrease in DLCO in IPF patients [ORIVW = 0.54; 95% CI 0.32-0.93; P = 0.02]. CONCLUSIONS: Our study suggested that smoking is associated with a decrease in DLCO. Patients diagnosed with IPF should adopt an active and healthy lifestyle, especially by quitting smoking, which may be effective at slowing the progression of IPF.

Asunto(s)

RESUMEN

OBJECTIVES: Evaluating the diffusing capacity for carbon monoxide (DLco) is crucial for patients with lung cancer and interstitial lung disease. However, the clinical significance of assessing exercise oxygen desaturation (EOD) remains unclear. METHODS: We retrospectively analysed 186 consecutive patients with interstitial lung disease who underwent lobectomy for non-small-cell lung cancer. EOD was assessed using the two-flight test (TFT), with TFT positivity defined as ≥5% SpO2 reduction. We investigated the impact of EOD and predicted postoperative (ppo)%DLco on postoperative complications and prognosis. RESULTS: A total of 106 (57%) patients were identified as TFT-positive, and 58 (31%) patients had ppo% DLco < 30%. Pulmonary complications were significantly more prevalent in TFT-positive patients than in TFT-negative patients (52% vs 19%, P < 0.001), and multivariable analysis revealed that TFT-positivity was an independent risk factor (odds ratio 3.46, 95% confidence interval 1.70-7.07, P < 0.001), whereas ppo%DLco was not (P = 0.09). In terms of long-term outcomes, both TFT positivity and ppo%DLco < 30% independently predicted overall survival. We divided the patients into 4 groups based on TFT positivity and ppo%DLco status. TFT-positive patients with ppo%DLco < 30% exhibited the significantly lowest 5-year overall survival among the 4 groups: ppo%DLco ≥ 30% and TFT-negative, 54.2%; ppo%DLco < 30% and TFT-negative, 68.8%; ppo%DLco ≥ 30% and TFT-positive, 38.1%; and ppo%DLco < 30% and TFT-positive, 16.7% (P = 0.001). CONCLUSIONS: Incorporating EOD evaluation was useful for predicting postoperative complications and survival outcomes in patients with lung cancer and interstitial lung disease.

Asunto(s)

RESUMEN

BACKGROUND: The 2017 ATS/ERS technical standard for measuring the single-breath diffusing capacity (DLCO) proposed the "rapid-gas-analyzer" (RGA) or, equivalently, "total-breath" (TB) method for the determination of total lung capacity (TLC). In this study, we compared DLCO and TLC values estimated using the TB and conventional method, and how estimated TLC using these two methods compared to that determined by body plethysmography. METHOD: A total of 95 people with COPD (GOLD grades 1-4) and 23 healthy subjects were studied using the EasyOne Pro (ndd Medical Technologies, Switzerland) and Master Screen Body (Vyaire Medical, Höchberg, Germany). RESULTS: On average the TB method resulted in higher values of DLCO (mean ± SD Δ = 0.469 ± 0.267; 95%CI: 0.420; 0.517 mmol*min-1*kPa-1) and TLC (Δ = 0.495 ± 0.371; 95%CI: 0.427; 0.562 L) compared with the conventional method. In healthy subjects the ratio between TB and conventional DLCO was close to one. TLC estimated using both methods was lower than that determined by plethysmography. The difference was smaller for the TB method (Δ = 1.064 ± 0.740; 95%CI: 0.929; 1.199 L) compared with the conventional method (Δ = 1.558 ± 0.940; 95%CI: 1.387; 1.739 L). TLC from body plethysmography could be estimated as a function of TB TLC and FEV1 Z-Score with an accuracy (normalized root mean square difference) of 9.1%. CONCLUSION: The total-breath method yielded higher values of DLCO and TLC than the conventional analysis, especially in subjects with COPD. TLC from the total-breath method can also be used to estimate plethysmographic TLC with better accuracy than the conventional method. The study is registered under clinicaltrial.gov NCT04531293.

Asunto(s)

RESUMEN

Rationale: Nocturnal hypoxemia is common in sleep-disordered breathing (SDB) and is associated with increased morbidity and mortality. Although impaired diffusing capacity of the lung for carbon monoxide (DlCO) is associated with daytime hypoxemia, its influence on SDB-related nocturnal hypoxemia is not known. Objectives: To characterize the effects of DlCO impairment on SDB-related nocturnal hypoxemia and associated health outcomes. Methods: Data from a multicenter cohort of men with and without human immunodeficiency virus (HIV) infection, with concomitant measures of DlCO and home-based polysomnography (n = 544), were analyzed. Multivariable quantile regression models characterized associations between DlCO and several measures of SDB-related hypoxemia (e.g., total sleep time with oxygen saturation as measured by pulse oximetry [SpO2] < 90% [T90]). Structural equation models were used to assess associations of impaired DlCO and SDB-related hypoxemia measures with prevalent hypertension and type 2 diabetes. Results: DlCO impairment (<80% predicted) was associated with sleep-related hypoxemia. Participants with severe SDB (apnea-hypopnea index ⩾ 30 events/h) and impaired DlCO had higher T90 (median difference, 15.0% [95% confidence interval (CI), 10.3% to 19.7%]) and average SDB-related desaturation (median difference, 1.0 [95% CI, 0.5 to 1.5]) and lower nadir SpO2 (median difference, -8.2% [95% CI, -11.4% to -4.9%]) and average SpO2 during sleep (median difference, -1.1% [95% CI, -2.1% to -0.01%]) than those with severe SDB and preserved DlCO. Higher T90 was associated with higher adjusted odds of prevalent hypertension (odds ratio, 1.39 [95% CI, 1.14 to 1.70]) and type 2 diabetes (odds ratio, 1.25 [95% CI, 1.07 to 1.46]). Conclusions: DlCO impairment in severe SDB was associated with sleep-related hypoxemia, prevalent hypertension, and type 2 diabetes. Assessment of SDB should be considered in those with impaired DlCO to guide testing and risk stratification strategies.

Asunto(s)

RESUMEN

INTRODUCTION: Exacerbations are common in individuals with alpha-1 antitrypsin deficiency (AATD)-related lung disease. This study intended to identify independent predictive factors for exacerbations in AATD using the Portuguese European Alpha-1 Research Collaboration (EARCO) registry. METHODS: This study includes patients from the Portuguese EARCO registry, a prospective multicenter cohort (NCT04180319). From October 2020 to April 2023, this registry enrolled 137 patients, 14 of whom were excluded for analysis for either missing 12 months of follow-up or baseline pulmonary function. RESULTS: Among the 123 AATD patients, 27 (22.0%) had at least one exacerbation in the last 12 months of follow-up. Patients with Pi*ZZ phenotype were three times more likely than the rest of the population to experience any exacerbation (32.7 vs. 14.1%, p = 0.014; OR 3.0). BODE index was significantly higher in exacerbators than in non-exacerbators (3.9 ± 2.4 vs. 1.3 ± 1.2; p < 0.001), including on multivariate analysis (p = 0.002). Similar results were found for BODEx (multivariate p < 0.001). DLCO was the only functional parameter independently associated with exacerbations (p = 0.024). CONCLUSIONS: DLCO, BODE, and BODEx were independent predictors of exacerbations at 12 months in AATD patients. Understanding these risk factors can aid decision-making on AATD-related lung disease management and improve patient outcomes.

Asunto(s)

RESUMEN

BACKGROUND: Fighter aircraft pilots are regularly exposed to physiological challenges from high acceleration (Gz) forces, as well as increased breathing pressure and oxygen supply in the support systems. We studied whether effects on the lung and systemic oxidative stress were detectable after real training flights comprising of a wide variety of exposure conditions, and their combinations. METHODS: Thirty-five pilots of the German Air Force performed 145 flights with the Eurofighter Typhoon. Prior to and after flight lung diffusing capacity for carbon monoxide (DLCO) and nitric oxide (DLNO), alveolar volume (VA), and diffusing capacities per volume (KCO, KNO) were assessed. In addition, the fractional concentration of exhaled nitric oxide (FeNO) was determined, and urine samples for the analysis of molecular species related to 8-hydroxy-2'-deoxyguanosine (8-OHdG) were taken. For statistical analysis, mixed ANOVA models were used. RESULTS: DLNO, DLCO, KNO, KCO and VA were reduced (p < 0.001) after flights, mean ± SD changes being 2.9 ± 5.0, 3.2 ± 5.2, 1.5 ± 3.7, 1.9 ± 3.7 and 1.4 ± 3.1%, respectively, while FeNO decreased by 11.1% and the ratio of 8-OHdG to creatinine increased by 15.7 ± 37.8%. The reductions of DLNO (DLCO) were smaller (p < 0.001) than those of KNO (KCO). In repeated flights on different days, baseline values were restored. Amongst various flight parameters comprising Gz-forces and/or being indicative of positive pressure breathing and oxygenation support, the combination of long flight duration and high altitude appeared to be linked to greater changes in DLNO and DLCO. CONCLUSIONS: The pattern of reductions in diffusing capacities suggests effects arising from atelectasis and increased diffusion barrier, without changes in capillary blood volume. The decrease in exhaled endogenous NO suggests bronchial mucosal irritation and/or local oxidative stress, and the increase in urinary oxidized guanosine species suggests systemic oxidative stress. Although changes were small and not clinically relevant, their presence demonstrated physiological effects of real training flights in a modern 4th generation fighter jet.

Asunto(s)