New research was presented at ERS 2021, the virtual European Respiratory Society International Congress, from September 5-8. The features below highlight some of the studies presented via the online conference.
Physical Training Outcomes in Women With Overweight, Obesity
Because they are often impaired in females with overweight or obesity, researchers investigated the impact of combined physical exercise (CPE) on lung function and mechanics and immune response in this patient population. The study team evaluated the effects of 12 weeks of CPE (20 min/session aerobic treadmill + 40 min/session resistance training [75% 1 max rep]) three times per week in women with eutrophy, overweight, and obesity grade I. CPE improved forced vital capacity percentage and peak expiration flow percentage in patients with obesity. In addition, CPE improved the resistance of the respiratory system (R5Hz) in patients with eutrophy, overweight, and obesity; the resistance of proximal airways (R20Hz) in eutrophy, overweight, and obesity; the resistance of distal airways (R5Hz-R20Hz) in eutrophy, overweight, and obesity; the reactance of the respiratory system (X5Hz) in eutrophy, overweight, and obesity; the impedance of respiratory system (Z5Hz) in eutrophy, overweight, and obesity; the central resistance (RCentral) in eutrophy, overweight, and obesity; and in peripheral resistance (RPeripheral) in eutrophy, overweight, and obesity. CPE also reduced the IGF-1 levels in body composition (BC) in patients with overweight and obesity but increased Klotho levels in BC in those with obesity. CPE reduced the levels of exhaled nitric oxide in patients with overweight and obesity. “We found that CPE improves lung function, mechanics, and pulmonary immune response in women with overweight and obesity by increasing anti-fibrotic protein Klotho and reducing pro-fibrotic IGF-1,” the study authors wrote.
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Sequential Cardiopulmonary Exercise Tests Post-COVID-19
Researchers performed sequential cardiopulmonary exercise testing (CPET) to determine the reduced exercise capacity (EC) in patients following COVID-19 infection and to evaluate for pathologic limitations. At first presentation after COVID-19, patients with subjective limitation of EC performed CPET at an outpatient clinic. If objectively limited, the study team offered follow-up CPET. Time from COVID-19 to first CPET was 129 (±57) days. Limited relative EC (<100% of nominal value) was detected in 37% of patients. Limitation correlated with reduced relative O2 uptake (VO2/kg max; 75% [±7] vs 104% [±15]). Reduced relative VO2/kg max was found in 60% of patients. Patients with reduced EC widely presented an impaired maximum O2 pulse (76% [±6] vs 107% [±14]). Abnormal gas exchange was absent in patients with limited EC. Moreover, no patients showed signs of reduced pulmonary perfusion. Cardiac MRI ruled out diminished biventricular ejection fraction in 53% of patients as a possible cause for reduced O2 pulse. Follow-up CPET did not reveal any exercise improvements. “Following COVID-19, patients often present with ongoing symptoms such as chronic fatigue and persistent subjective deterioration of EC,” the authors wrote. “We found that deterioration of EC was not associated with ventilatory, pulmonary, vascular, or cardiocirculatory limitation. Exercise limitation was connected, however, with both reduced O2 pulse and VO2/kg max, which did not correlate to initial severity of COVID-19.”
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COVID-19-Associated Pneumonia Lung Function Compared With COPD, ILD & EID
Researchers aimed to evaluate lung function, exercise capacity, and symptoms in survivors of COVID-19-associated pneumonia compared with those of patients with COPD and interstitial lung disease (ILD), as well as exercise-induced desaturation (EID). Survivors of COVID-19-associated pneumonia (study patients), normoxic at rest with EID, underwent assessment of dyspnea, dynamic lung volumes, carbon monoxide diffusion capacity, and the 6-minute walk test. Data of patients with COPD or ILD and EID were also retrospectively analyzed. The study team found that forced vital capacity was lower in the study patients and patients with ILD than in patients with COPD. As a group, study patients performed like patients with ILD but walked significantly less, showed more severe leg fatigue and dyspnea during exercise, and deeper EID than patients with COPD. “We found that survivors of COVID-19-associated pneumonia, normoxic at rest, with EID may suffer from alterations in lung function, exercise capacity, and symptoms similar to those of patients with ILD, but more severe than patients with COPD and EID,” the study authors wrote.
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Asthma Onset, Persistence & Adult Lung Function by Sex
With data lacking on whether age at asthma onset affects adult lung function depending on patient sex, researchers studied the association between asthma onset, asthma persistence, and airflow obstruction at age 24 in males and females based on data from examinations at aged 4, 8, 12, 16, and 24. Participants with asthma in remission (no asthma at age 24), incident asthma (onset after age 8), and persistent asthma (asthma from age 8 or younger through age 24) were compared with non-asthmatics (no asthma from ages 8-24) regarding FEV1/FVC post bronchodilation at age 24, expressed as a Z-score. Incident asthma was associated with a lower FEV1/FVC Z-score at age 24 in females, after adjustment for BMI, atopy, and both active and passive smoking (-0.22), compared with non-asthmatics. In males, incident lower Z-scores were associated with incident (-0.41), persistent (-0.52), and asthma in remission (-0.24) when compared with non-asthmatics. Among those with persistent asthma, males had a lower FEV1/FVC ratio than females. “In males, persistent asthma with an onset before 8 years of age is associated with more pronounced irreversible airflow obstruction at 24 years,” wrote the study authors. “This group of patients may require specific healthcare attention.”
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Functional Respiratory Imaging Valid in Patients With CF
Although research supports the value of functional respiratory imaging (FRI) combining high-resolution CT scans with computation fluid dynamics in pulmonary diseases like COPD and asthma, data are limited on its use in patients with cystic fibrosis (CF). To clinically validate FRI use in patients with CF, investigators compared FRI outcomes with those of conventional outcome measures (CT scans, spirometry, 6-minute walking test [6MWT]) among patients with CF aged 5 or older who were scheduled for a chest CT. Total CF-CT scores per lung lobe showed significant low-to-moderate correlations with FRI parameters: air trapping (correlation coefficient [r], 0.43), airway volume (r, 0.35), airway wall volume (r, 0.30), and airway resistance (r, -0.15). FRI-determined air trapping was significantly associated with standard spirometry parameters, distance covered during 6MWT, and post-6MWT oxygen saturation. “Multiple FRI parameters were associated with structural abnormalities determined by CF-CT score,” wrote the study authors. “Air trapping appears to be the most clinically relevant FRI parameter for CF patients due to its association with classical outcome measures.”
