Development of a tool to detect small airways dysfunction in asthma clinical practice.

BACKGROUND: Small airways dysfunction (SAD) in asthma is difficult to measure and a gold standard is lacking. The aim of this study was to develop a simple tool including items of the Small Airways Dysfunction Tool (SADT) questionnaire, basic patient characteristics and respiratory tests available depending on the clinical setting to predict SAD in asthma. METHODS: This study was based on the data of the multinational ATLANTIS (Assessment of Small Airways Involvement in Asthma) study including the earlier developed SADT questionnaire. Key SADT items together with clinical information were now used to build logistic regression models to predict SAD group (less likely or more likely to have SAD). Diagnostic ability of the models was expressed as area under the receiver operating characteristic curve (AUC) and positive likelihood ratio (LR+). RESULTS: SADT item 8, "I sometimes wheeze when I am sitting or lying quietly", and the patient characteristics age, age at asthma diagnosis and body mass index could reasonably well detect SAD (AUC 0.74, LR+ 2.3). The diagnostic ability increased by adding spirometry (percentage predicted forced expiratory volume in 1 s: AUC 0.87, LR+ 5.0) and oscillometry (resistance difference between 5 and 20 Hz and reactance area: AUC 0.96, LR+ 12.8). CONCLUSIONS: If access to respiratory tests is limited (e.g. primary care in many countries), patients with SAD could reasonably well be identified by asking about wheezing at rest and a few patient characteristics. In (advanced) hospital settings patients with SAD could be identified with considerably higher accuracy using spirometry and oscillometry.

Airway Elastin is increased in severe asthma and relates to proximal wall area: histological and computed tomography findings from the U-BIOPRED severe asthma study.

BACKGROUND: Airway remodelling, which may include goblet cell hyperplasia / hypertrophy, changes in epithelial integrity, accumulation of extracellular matrix components, smooth muscle hypertrophy and thickening of the lamina reticularis, is a feature of severe asthma and contributes to the clinical phenotype. OBJECTIVE: Within the U-BIOPRED severe asthma study, we have assessed histological elements of airway remodelling and their relationship to computed tomography (CT) measures of proximal airway dimensions. METHODS: Bronchial biopsies were collected from two severe asthma groups, one non-smoker (SAn, n = 28) and one current/ex-smoker (SAs/ex, n = 13), and a mild-moderate asthma group (MMA, n = 28) classified and treated according to GINA guidelines, plus a healthy control group (HC, n = 33). Movat's pentachrome technique was used to identify mucin, elastin and total collagen in these biopsies. The number of goblet cells (mucin+) was counted as a percentage of the total number of epithelial cells and the percentage mucin epithelial area measured. The percentage area of elastic fibres and total collagen within the submucosa was also measured, and the morphology of the elastic fibres classified. Participants in the asthma groups also had a CT scan to assess large airway morphometry. RESULTS: The submucosal tissue elastin percentage was higher in both severe asthma groups (16.1% SAn, 18.9% SAs/ex) compared with the HC (9.7%) but did not differ between asthma groups. There was a positive relationship between elastin and airway wall area measured by CT (n = 18-20, rho=0.544, p = 0.024), which also related to an increase in elastic fibres with a thickened lamellar morphological appearance. Mucin epithelial area and total collagen were not different between the four groups. Due to small numbers of suitable CT scans, it was not feasible to compare airway morphometry between the asthma groups. CONCLUSION: These findings identify a link between extent of elastin deposition and airway wall thickening in severe asthma.

Efficacy and safety of single-inhaler extrafine triple therapy versus inhaled corticosteroid plus long-acting beta2 agonist in eastern Asian patients with COPD: the TRIVERSYTI randomised controlled trial.

BACKGROUND: A single-inhaler extrafine triple combination of beclometasone dipropionate (BDP), formoterol fumarate (FF) and glycopyrronium (G) has been developed for maintenance therapy of chronic obstructive pulmonary disease (COPD). This study evaluated the efficacy and safety of BDP/FF/G in patients in three eastern Asian areas: China, Republic of Korea and Taiwan. METHODS: TRIVERSYTI was a double-blind, randomised, active-controlled, parallel-group study in patients with COPD, post-bronchodilator forced expiratory volume in 1 s (FEV1) < 50% predicted, ≥ 1 exacerbation in the previous 12 months, and receiving inhaled maintenance medication. Patients received either extrafine BDP/FF/G 100/6/10 µg via pressurised metered-dose inhaler, or non-extrafine budesonide/formoterol (BUD/FF) 160/4.5 µg via dry-powder inhaler, both administered as two puffs twice-daily for 24 weeks. The co-primary objectives (analysed in the overall population) were to demonstrate superiority of BDP/FF/G over BUD/FF for change from baseline in pre-dose morning and 2-h post-dose FEV1 at Week 24 (these were analysed as key secondary objectives in the China subgroup). The rate of moderate/severe COPD exacerbations was a secondary endpoint. RESULTS: Of 708 patients randomised, 88.8% completed. BDP/FF/G was superior to BUD/FF for pre-dose and 2-h post-dose FEV1 at Week 24 [adjusted mean differences 62 (95% CI 38, 85) mL and 113 (87, 140) mL; both p < 0.001]. The annualised moderate/severe exacerbation rate was 43% lower with BDP/FF/G [rate ratio 0.57 (95% CI 0.42, 0.77); p < 0.001]. Adverse events were reported by 61.1% and 67.0% patients with BDP/FF/G and BUD/FF. Results were similar in the China subgroup. CONCLUSIONS: In patients with COPD, FEV1 < 50% and an exacerbation history despite maintenance therapy, treatment with extrafine BDP/FF/G improved bronchodilation, and was more effective at preventing moderate/severe COPD exacerbations than BUD/FF. Trial registration CFDA CTR20160507 (registered 7 Nov 2016, http://www.chinadrugtrials.org.cn/index.html ).

Relationship between lung function and quantitative computed tomographic parameters of airway remodeling, air trapping, and emphysema in patients with asthma and chronic obstructive pulmonary disease: A single-center study.

BACKGROUND: There is a paucity of studies comparing asthma and chronic obstructive pulmonary disease (COPD) based on thoracic quantitative computed tomographic (QCT) parameters. OBJECTIVES: We sought to compare QCT parameters of airway remodeling, air trapping, and emphysema between asthmatic patients and patients with COPD and explore their relationship with airflow limitation. METHODS: Asthmatic patients (n = 171), patients with COPD (n = 81), and healthy subjects (n = 49) recruited from a single center underwent QCT and clinical characterization. RESULTS: Proximal airway percentage wall area (%WA) was significantly increased in asthmatic patients (62.5% [SD, 2.2]) and patients with COPD (62.7% [SD, 2.3]) compared with that in healthy control subjects (60.3% [SD, 2.2], P < .001). Air trapping measured based on mean lung density expiratory/inspiratory ratio was significantly increased in patients with COPD (mean, 0.922 [SD, 0.037]) and asthmatic patients (mean, 0.852 [SD, 0.061]) compared with that in healthy subjects (mean, 0.816 [SD, 0.066], P < .001). Emphysema assessed based on lung density measured by using Hounsfield units below which 15% of the voxels lie (Perc15) was a feature of COPD only (patients with COPD: mean, -964 [SD, 19.62] vs asthmatic patients: mean, -937 [SD, 22.7] and healthy subjects: mean, -937 [SD, 17.1], P < .001). Multiple regression analyses showed that the strongest predictor of lung function impairment in asthmatic patients was %WA, whereas in the COPD and asthma subgrouped with postbronchodilator FEV1 percent predicted value of less than 80%, it was air trapping. Factor analysis of QCT parameters in asthmatic patients and patients with COPD combined determined 3 components, with %WA, air trapping, and Perc15 values being the highest loading factors. Cluster analysis identified 3 clusters with mild, moderate, or severe lung function impairment with corresponding decreased lung density (Perc15 values) and increased air trapping. CONCLUSIONS: In asthmatic patients and patients with COPD, lung function impairment is strongly associated with air trapping, with a contribution from proximal airway narrowing in asthmatic patients.

Lung Deposition of Inhaled Extrafine Beclomethasone Dipropionate/Formoterol Fumarate/Glycopyrronium Bromide in Healthy Volunteers and Asthma: The STORM Study.

Background: An extrafine formulation triple therapy combination of beclomethasone dipropionate (BDP), formoterol fumarate (FF), and glycopyrronium bromide (GB) has been developed for the maintenance treatment of asthma and chronic obstructive pulmonary disease. This study used gamma scintigraphy to evaluate the intrapulmonary and extrapulmonary in vivo deposition of BDP/FF/GB, and the intrapulmonary regional distribution of the deposited formulation. Methods: This open-label uncontrolled nonrandomized single-dose study recruited 10 healthy volunteers and 9 patients with asthma. After a krypton-81m (81mKr) ventilation scan was conducted, subjects inhaled study drug (four inhalations of BDP/FF/GB 100/6/12.5 µg radiolabeled using technetium-99 m [99mTc]) through pressurized metered-dose inhaler, and a series of scintigraphic images were taken. The primary objective was to evaluate intrapulmonary drug deposition of BDP/FF/GB, determined as the percentage of nominal (i.e., metered) dose. Secondary endpoints included central/peripheral deposition ratio (C/P), and the standardized central/peripheral ratio (sC/P; 99mTc aerosol C/P/81mKr gas C/P). Results: All participants completed the study, with all scintigraphy procedures performed at one site. In patients with asthma, mean ± standard deviation intrapulmonary deposition was 25.50% ± 6.81%, not significantly different to that in healthy volunteers (22.74% ± 9.19%; p = 0.4715). Approximately half of the lung dose was deposited in the peripheral region of the lung (fraction deposited 0.52 ± 0.07 and 0.49 ± 0.06 in healthy volunteers and patients with asthma, respectively), resulting in C/P ratios of 0.94 ± 0.25 and 1.06 ± 0.25, respectively, with sC/P ratios of 1.80 ± 0.40 and 1.94 ± 0.38. Deposition patterns were similar in the two populations. BDP/FF/GB was well tolerated. Conclusions: This study confirmed that the extrafine particles delivered by BDP/FF/GB penetrate the peripheral areas of the lungs, with a similar proportion of particles deposited in the central and peripheral regions. Importantly, the deposition patterns were similar in healthy volunteers and patients with asthma, suggesting that disease characteristics are unlikely to impact drug deposition. Clinical Trial Registration number: NCT03795350.

Effect of stimulating waveform and of data processing on respiratory impedance measurement.

OBJECTIVE: Several commercial and custom-made forced oscillation technique (FOT) devices are used to assess respiratory system impedance. The impulse oscillometry system (IOS) is a widespread device, which yields similar but not identical results to those provided by other FOT systems. Differences may be related to the forcing waveform, the device hardware, or the data processing algorithms. We evaluated the agreement between resistance (R rs) and reactance (X rs) measurements while alternating between different forcing waveforms and data processing algorithms. APPROACH: We performed pre- and post-bronchodilator measurements in 20 patients with respiratory complaints. We generated pulse waveforms using an IOS, and sinusoidal oscillations by replacing the IOS loudspeaker with customized loudspeaker providing a 5 Hz sinusoidal pressure signal. Pressure and flow were measured using the IOS sensors and breathing circuit. We developed a data processing algorithm compatible to both forcing signals. We also applied commercial IOS software during pulse waveform and a least mean square (lms) algorithm during sinusoidal waveform. MAIN RESULTS: The median (5th, 95th percentile) differences between R rs and X rs were (1) -0.35 (-2.49, 1.23) and 0.16 (-1.63, 3.07 cmH2O*s l-1, when the same algorithm was used during pulse vs sinusoidal stimulus; (2) 0.34 (-2.33, 5.98) and 0.57 (-2.64, 6.09) cmH2O*s l-1, when our algorithm and the IOS software were used during pulse waveform; and (3) 0.33 (-1.20, 6.05) and 0.25 (-4.94, 4.28) cmH2O*s l-1 when the IOS software was used during pulse and the lms algorithm during sinusoidal waveforms. SIGNIFICANCE: Both forcing signal and data processing contribute to differences in impedance values measured by different FOT devices.

Extrafine Beclometasone Dipropionate/Formoterol Fumarate vs Double Bronchodilation Therapy in Patients with COPD: A Historical Real-World Non-Inferiority Study.

Purpose: This study aimed to evaluate the non-inferiority of initiating extrafine beclometasone dipropionate/formoterol fumarate (BDP/FF) versus double bronchodilation (long-acting beta-agonists [LABA]/long-acting muscarinic antagonists [LAMA]) among patients with a history of chronic obstructive pulmonary disease (COPD) exacerbations. Patients and Methods: A historical cohort study was conducted using data from the UK's Optimum Patient Care Research Database. Patients with COPD ≥40 years at diagnosis were included if they initiated extrafine BDP/FF or any LABA/LAMA double therapy as a step-up from no maintenance therapy or monotherapy with inhaled corticosteroids (ICS), LAMA, or LABA and a history of ≥2 moderate/severe exacerbations in the previous two years. The primary outcome was exacerbation rate from therapy initiation until a relevant therapy change or end of follow-up. Secondary outcomes included rate of acute respiratory events, acute oral corticosteroids (OCS) courses, and antibiotic prescriptions with lower respiratory indication, modified Medical Research Council score (mMRC) ≥2, and time to first pneumonia diagnosis. The non-inferiority boundary was set at a relative difference of 15% on the ratio scale. Five potential treatment effect modifiers were investigated. Results: A total of 1735 patients initiated extrafine BDP/FF and 2450 patients initiated LABA/LAMA. The mean age was 70 years, 51% were male, 41% current smokers, and 85% had FEV1 <80% predicted. Extrafine BDP/FF showed non-inferiority to LABA/LAMA for rate of exacerbations (incidence rate ratio [IRR] = 1.01 [95% CI 0.94-1.09]), acute respiratory events (IRR = 0.98 [0.92-1.04]), acute OCS courses (IRR = 1.01 [0.91-1.11]), and antibiotic prescriptions (IRR = 0.99 [0.90-1.09]), but not for mMRC (OR = 0.93 [0.69-1.27]) or risk of pneumonia (HR = 0.50 [0.14-1.73]). None of the a priori defined effect modifier candidates affected the comparative effectiveness. Conclusion: This study found that stepping up to extrafine BDP/FF from no maintenance or monotherapy was not inferior to stepping up to double bronchodilation therapy in patients with a history of exacerbations.

Exploring the relevance and extent of small airways dysfunction in asthma (ATLANTIS): baseline data from a prospective cohort study.

BACKGROUND: Small airways dysfunction (SAD) is well recognised in asthma, yet its role in the severity and control of asthma is unclear. This study aimed to assess which combination of biomarkers, physiological tests, and imaging markers best measure the presence and extent of SAD in patients with asthma. METHODS: In this baseline assessment of a multinational prospective cohort study (the Assessment of Small Airways Involvement in Asthma [ATLANTIS] study), we recruited participants with and without asthma (defined as Global Initiative for Asthma severity stages 1-5) from general practices, the databases of chest physicians, and advertisements at 29 centres across nine countries (Brazil, China, Germany, Italy, Spain, the Netherlands, the UK, the USA, and Canada). All participants were aged 18-65 years, and participants with asthma had received a clinical diagnosis of asthma more than 6 months ago that had been confirmed by a chest physician. This diagnosis required support by objective evidence at baseline or during the past 5 years, which could be: positive airway hyperresponsiveness to methacholine, positive reversibility (a change in FEV1 ≥12% and ≥200 mL within 30 min) after treatment with 400 µg of salbutamol in a metered-dose inhaler with or without a spacer, variability in peak expiratory flow of more than 20% (measured over 7 days), or documented reversibility after a cycle (eg, 4 weeks) of maintenance anti-asthma treatment. The inclusion criteria also required that patients had stable asthma on any previous regular asthma treatment (including so-called rescue ß2-agonists alone) at a stable dose for more than 8 weeks before baseline and had smoked for a maximum of 10 pack-years in their lifetime. Control group participants were recruited by advertisements; these participants were aged 18-65 years, had no respiratory symptoms compatible with asthma or chronic obstructive pulmonary disease, normal spirometry, and normal airways responsiveness, and had smoked for a maximum of 10 pack-years. We assessed all participants with spirometry, body plethysmography, impulse oscillometry, multiple breath nitrogen washout, CT (in selected participants), and questionnaires about asthma control, asthma-related quality of life (both in participants with asthma only), and health status. We applied structural equation modelling in participants with asthma to assess the contribution of all physiological and CT variables to SAD, from which we defined clinical SAD and CT SAD scores. We then classified patients with asthma into SAD groups with model-based clustering, and we compared asthma severity, control, and health-care use during the past year by SAD score and by SAD group. This trial is registered with ClinicalTrials.gov, number NCT02123667. FINDINGS: Between June 30, 2014, and March 3, 2017, we recruited and evaluated 773 participants with asthma and 99 control participants. All physiological measures contributed to the clinical SAD model with the structural equation modelling analysis. The prevalence of SAD in asthma was dependent on the measure used; we found the lowest prevalence of SAD associated with acinar airway ventilation heterogeneity (Sacin), an outcome determined by multiple breath nitrogen washout that reflects ventilation heterogeneity in the most peripheral, pre-acinar or acinar airways. Impulse oscillometry and spirometry results, which were used to assess dysfunction of small-sized to mid-sized airways, contributed most to the clinical SAD score and differed between the two SAD groups. Participants in clinical SAD group 1 (n=452) had milder SAD than group 2 and comparable multiple breath nitrogen washout Sacin to control participants. Participants in clinical SAD group 2 (n=312) had abnormal physiological SAD results relative to group 1, particularly their impulse oscillometry and spirometry measurements, and group 2 participants also had more severe asthma (with regard to asthma control, treatments, exacerbations, and quality of life) than group 1. Clinical SAD scores were higher (indicating more severe SAD) in group 2 than group 1, and we found that these scores were related to asthma control, severity, and exacerbations. We found no correlation between clinical SAD and CT SAD scores. INTERPRETATION: SAD is a complex and silent signature of asthma that is likely to be directly or indirectly captured by combinations of physiological tests, such as spirometry, body plethysmography, impulse oscillometry, and multiple breath nitrogen washout. SAD is present across patients with all severities of asthma, but it is particularly prevalent in severe disease. The clinical classification of SAD into two groups (a milder and a more severe group) by use of impulse oscillometry and spirometry, which are easy to use, is meaningful given its association with GINA severity stages, asthma control, quality of life, and exacerbations. FUNDING: Chiesi Farmaceutici SpA.

Novel imaging approaches in adult asthma and their clinical potential.

Currently, imaging in asthma is confined to chest radiography and CT. The emergence of new imaging techniques and tremendous improvement of existing imaging methods, primarily due to technological advancement, has completely changed its research and clinical prospects. In research, imaging in asthma is now being employed to provide quantitative assessment of morphology, function and pathogenic processes at the molecular level. The unique ability of imaging for non-invasive, repeated, quantitative, and in vivo assessment of structure and function in asthma could lead to identification of 'imaging biomarkers' with potential as outcome measures in future clinical trials. Emerging imaging techniques and their utility in the research and clinical setting is discussed in this review.

Medicinal clays improve the endurance of loaded inspiratory muscles in COPD: a randomized clinical trial of nonpharmacological treatment.

BACKGROUND: Inspiratory resistive breathing (IRB) challenges affect respiratory muscle endurance in healthy individuals, which is considered to be an interleukin 6 (IL-6)-dependent mechanism. Whether nonpharmacological thermal therapies promote the endurance of loaded inspiratory muscles in chronic obstructive pulmonary disease (COPD) is unclear. The objectives of this study were to compare the effects of two thermal interventions on endurance time (ET) and plasma IL-6 concentration following an IRB challenge. METHODS: This study was a randomized, parallel-group, unblinded clinical trial in a single-center setting. Forty-two patients (aged 42-76 years) suffering from mild to severe COPD participated in this study. Both groups completed 12 sessions of the mud bath therapy (MBT) (n=22) or leisure thermal activity (LTA) (n=19) in a thermal spa center in Italy. Pre- and postintervention spirometry, maximum inspiratory pressure, and plasma mediators were obtained and ET and endurance oxygen expenditure (VO2Endur) were measured following IRB challenge at 40% of maximum inspiratory pressure. RESULTS: There was no difference in ΔIL-6 between the intervention groups. But, IRB challenge increased cytokine IL-6 plasma levels systematically. The effect size was small. A statistically significant treatment by IRB challenge effect existed in ET, which significantly increased in the MBT group (P=0.003). In analysis of covariance treatment by IRB challenge analysis with LnVO2Endur as the dependent variable, ΔIL-6 after intervention predicted LnVO2Endur in the MBT group, but not in the LTA group. Adverse events occurred in two individuals in the MBT group, but they were mainly transient. One patient in the LTA group dropped out. CONCLUSION: MBT model improves ET upon a moderate IRB challenge, indicating the occurrence of a training effect. The LnVO2Endur/ΔIL-6 suggests a physiologic adaptive mechanism in respiratory muscles of COPD patients allocated to treatment. Both thermal interventions are safe.

Pediatric bronchiectasis: correlation of HRCT, ventilation and perfusion scintigraphy, and pulmonary function testing.

Bronchiectasis in children, although occurring with diminished frequency, continues as a major challenge for the pediatric pulmonologist. The method of choice for the diagnosis of the condition is high-resolution computed tomography (HRCT). The aim of the present study was to correlate the relationship(s) of HRCT, lung function, ventilation lung scintigraphy (VLS), and perfusion lung scintigraphy (PLS) in children with bronchiectasis. Sixteen children ranging in age from 4-18 years with clinical and chest X-ray evidence of bronchiectasis were enrolled in the study. The degree of bronchiectasis was assessed by HRCT scores, decrease in attenuation on expiratory scans, VLS, and PLS. HRCT scores for bronchiectasis and decreased lung attenuation showed a strong correlation with PLS (rho = 0.82; P < 0.001) and with VLS (rho = 0.72; P < 0.01). There was a moderate negative correlation between FEV(1) and HRCT bronchiectasis scores (rho = -0.53; P = 0.02), decreased lung attenuation score (rho = -0.64; P = 0.007), and atelectasis score (rho = -0.54; P = 0.03). In conclusion, HRCT provides a complete and precise assessment of children with bronchiectasis. Ventilation/perfusion scans and lung functions are additive tools to understand the complexity of the disease process and to improve diagnosis and therapeutic strategies.

The mediating role of cytokine IL-6 on the relationship of FEV1 upon 6-minute walk distance in chronic obstructive pulmonary disease.

OBJECTIVES: To explore the mediating role of protein interleukin-6 (IL-6) on the relationship between forced expiratory volume in 1 second (FEV1) and 6-minute walk distance (6MWD) and, further, to determine whether status variables (such as age, sex, and body mass index [BMI]) operate as moderators of this mediation relationship. DESIGN: Moderated mediation model. SETTING: An inpatient pulmonary rehabilitation center in Italy. PARTICIPANTS: All 153 patients involved in the screening of a randomized controlled clinical trial (ClinicalTrials.gov identifier: NCT01253941) were included in this study. All patients were Global initiative for chronic Obstructive Lung Disease (GOLD) stages I-IV and were aged 70.1±9.1 years. MEASUREMENTS: At run-in phase of the protocol, clinical and functional screening included BMI, fasting plasma levels of protein (IL-6), spirometry, and standardized 6-minute walking test, measured at the start of the respiratory rehabilitation program. METHODS: The size of the indirect effect of the initial variable (FEV1) upon the outcome variable (6MWD) through the intervening variable (IL-6) was computed and tested for statistical significance. Moderated mediation analyses were subsequently conducted with age, sex, and BMI. RESULTS: FEV1 averaged 53.4%±21.2%, and 6MWD 66.4%±41.3% of predicted. Median protein IL-6 was 6.68 pg/mL (interquartile range: 5.96). A bootstrapped mediation test supported the predicted indirect pathway (P=0.003). The indirect effect through IL-6 log units accounted for 17% of the total effect between FEV1 and 6MWD. Age functioned as a significant moderator of the mediational pattern. For individuals aged <70 years, the standardized indirect effect was significant (0.122, 95% confidence interval [CI]: 0.044-0.254, P=0.004), and for individuals >70 years it was not significant (0.04, 95% CI: -0.010 to 0.142, P=0.10). CONCLUSION: This moderated mediation result based on concurrent data suggests, but does not prove, a causal role of systemic inflammatory syndrome on progression from functional impairment to "frailty" status and substantial disability in aging chronic obstructive pulmonary disease.

Fat-free mass change after nutritional rehabilitation in weight losing COPD: role of insulin, C-reactive protein and tissue hypoxia.

BACKGROUND: Fat-free mass (FFM) depletion marks the imbalance between tissue protein synthesis and breakdown in chronic obstructive pulmonary disease (COPD). To date, the role of essential amino acid supplementation (EAAs) in FFM repletion has not been fully acknowledged. A pilot study was undertaken in patients attending pulmonary rehabilitation. METHODS: 28 COPD patients with dynamic weight loss > 5% over the last 6 months were randomized to receive EAAs embedded in a 12-week rehabilitation program (EAAs group n = 14), or to the same program without supplementation (C group n = 14). Primary outcome measures were changes in body weight and FFM, using dual X-ray absorptiometry (DEXA). RESULTS: At the 12th week, a body weight increment occurred in 92% and 15% of patients in the EAAs and C group, respectively, with an average increase of 3.8 +/- 2.6 kg (P = 0.0002) and -0.1 +/- 1.1 kg (P = 0.81), respectively. A FFM increment occurred in 69% and 15% of EAAs and C patients, respectively, with an average increase of 1.5 +/- 2.6 kg (P = 0.05) and -0.1 +/- 2.3 kg (P = 0.94), respectively. In the EAAs group, FFM change was significantly related to fasting insulin (r(2) 0.68, P < 0.0005), C-reactive protein (C-RP) (r(2) = 0.46, P < 0.01), and oxygen extraction tension (PaO(2x)) (r(2) = 0.46, P < 0.01) at end of treatment. These three variables were highly correlated in both groups (r > 0.7, P < 0.005 in all tests). CONCLUSIONS: Changes in FFM promoted by EAAs are related to cellular energy and tissue oxygen availability in depleted COPD. Insulin, C-RP, and PaO(2x) must be regarded as clinical markers of an amino acid-stimulated signaling to FFM accretion.

Airway distensibility and volume recruitment with lung inflation in COPD.

The effects of full lung inflation on respiratory conductance (Grs) and reactance (Xrs) were measured in 15 subjects with moderate to severe chronic obstructive pulmonary disease (COPD) and 11 matched healthy control subjects. Airway distensibility was estimated from the ratio of the difference of Grs between functional residual capacity and total lung capacity to the relevant changes in lung volume (ΔGrs/ΔVl) or transpulmonary pressure (ΔGrs/ΔPtp). Similar analysis was applied to Xrs to estimate lung volume recruitment (ΔXrs/ΔVl or ΔXrs/ΔPtp). The extent of emphysema in COPD subjects was estimated from the percentage of low attenuation area (LAA) at high-resolution computed tomography. At baseline, ΔGrs/ΔVl and ΔXrs/ΔVl were significantly less in COPD than control subjects, indicating less distensibility and volume recruitment in the former. In COPD, ΔGrs/ΔPtp and ΔXrs/ΔPtp were uncorrelated with LAA but correlated with 1-s forced expiratory volume and with each other. After albuterol, both ΔGrs/ΔPtp and ΔGrs/ΔVl became significantly and negatively correlated with LAA, while ΔXrs/ΔPtp and ΔXrs/ΔVl decreased significantly independently of LAA. Moreover, ΔGrs/ΔPtp and ΔXrs/ΔPtp with lung inflation were no longer correlated with each other, suggesting that airway distensibility and volume recruitment were affected differently by airway smooth muscle tone. Assuming that Grs mainly reflects airway caliber and Xrs the number of ventilated lung units, we conclude that airway smooth muscle contributes to airway stiffness and ventilation inhomogeneities in COPD subjects with prevailing bronchitis but only to the latter in those with more emphysema. We suggest that changes of airway distensibility and volume recruitment with a bronchodilator may be useful for disease phenotyping.

C-reactive protein correlates with tissue oxygen availability in patients with stable COPD.

BACKGROUND: Arterial oxygen tension, oxygen delivery to tissue, and systemic inflammation are recognized as pivotal factors in the progression of chronic obstructive pulmonary disease (COPD). However, interconnections between systemic inflammation and tissue oxygen availability are scantly investigated. Tissue oxygen availability depends on arterial PaO2, oxygen concentration, hemoglobin oxygen affinity (P50), and hemoglobin oxygen binding capacity (ceHb). As the integrated changes of those indices are summarized by oxygen extraction tension (PaO2x), the objective of this study was to explore the association between C-reactive protein (CRP) blood levels and either PaO2x or each of its determinants, in stable COPD. MATERIALS AND METHODS: Blood CRP and oxygen status of arterial blood were measured at rest while breathing room air in 44 moderate to severe stable COPD patients. PaO2x was calculated along the shape of oxygen binding curve as the oxygen tension resulting from removal of 2.3 mmol of oxygen per liter of blood. Multiple linear regression analysis was performed with PaO2, ceHb, and P50 as independent variables, and CRP as the dependent variable, adjusting for age and sex. The analysis was repeated using PaO2x as a sole independent variable. RESULTS: Multiple linear regression analysis indicated that ceHb, PaO2, and P50, were significant and independent predictors of CRP (R2 = 0.52, p < 0.0001). PaO2x alone was an even stronger predictor of CRP (R2 = 0.62, p < 0.0001). CONCLUSIONS: These findings indicate that physiological determinants of tissue oxygen availability are independently associated with CRP blood levels. Thus, improvement of tissue oxygen availability is a central therapeutic option to modulate the severity of systemic inflammatory processes in patients with COPD.

Effect of bronchodilatation on single breath pulmonary uptake of carbon monoxide in chronic obstructive pulmonary disease.

We studied 21 COPD patients in stable clinical conditions to evaluate whether changes in lung function induced by cumulative doses of salbutamol alter diffusing capacity for carbon monoxide (DL(CO)), and whether this relates to the extent of emphysema as assessed by high resolution computed tomography (HRCT) quantitative analysis. Spirometry and DL(CO) were measured before and after cumulative doses of inhaled salbutamol (from 200 microg to 1000 microg). Salbutamol caused significant increments of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and flows at 30% of control FVC taken from both partial and maximal forced expiratory maneuvers. Functional residual capacity and residual volume were reduced, while total lung capacity did not change significantly. DL(CO) increased progressively with the incremental doses of salbutamol, but this became significant only at the highest dose (1000 microg) and was independent of the extent of emphysema, as assessed by radiological parameters. No significant changes were observed in CO transfer factor (DLCO/VA) and alveolar volume (VA). The results suggest that changes in lung function induced by cumulative doses of inhaled salbutamol are associated with a slight but significant increase in DL(CO) irrespective of the presence and extent of emphysema.