Pulmonary rehabilitation restores limb muscle mitochondria and improves the intramuscular metabolic profile

Background: Exercise, as the cornerstone of pulmonary rehabilitation, is recommended to chronic obstructive pulmonary disease (COPD) patients. The underlying molecular basis and metabolic process were not fully elucidated. Methods: Sprague-Dawley rats were classified into five groups: non-COPD/rest ( n = 8), non-COPD/exercise ( n = 7), COPD/rest ( n = 7), COPD/medium exercise ( n = 10), and COPD/intensive exercise ( n = 10). COPD animals were exposed to cigarette smoke and lipopolysaccharide instillation for 90 days, while the non-COPD control animals were exposed to room air. Non-COPD/exercise and COPD/medium exercise animals were trained on a treadmill at a decline of 5° and a speed of 15 m/min while animals in the COPD/intensive exercise group were trained at a decline of 5° and a speed of 18 m/min. After eight weeks of exercise/rest, we used ultrasonography, immunohistochemistry, transmission electron microscopy, oxidative capacity of mitochondria, airflow-assisted desorption electrospray ionization-mass spectrometry imaging (AFADESI-MSI), and transcriptomics analyses to assess rectal femoris (RF). Results: At the end of 90 days, COPD rats’ weight gain was smaller than control by 59.48 ± 15.33 g ( P = 0.0005). The oxidative muscle fibers proportion was lower ( P < 0.0001). At the end of additional eight weeks of exercise/rest, compared to COPD/rest, COPD/medium exercise group showed advantages in weight gain, femoral artery peak flow velocity (Δ58.22 mm/s, 95% CI: 13.85-102.60 mm/s, P = 0.0104), RF diameters (Δ0.16 mm, 95% CI: 0.04-0.28 mm, P = 0.0093), myofibrils diameter (Δ0.06 μm, 95% CI: 0.02-0.10 μm, P = 0.006), oxidative muscle fiber percentage (Δ4.84%, 95% CI: 0.15-9.53%, P = 0.0434), mitochondria oxidative phosphorylate capacity ( P < 0.0001). Biomolecules spatial distribution in situ and bioinformatic analyses of transcriptomics suggested COPD-related alteration in metabolites and gene expression, which can be impacted by exercise. Conclusion: COPD rat model had multi-level structure and function impairment, which can be mitigated by exercise.

Development of a prediction model to identify undiagnosed chronic obstructive pulmonary disease patients in primary care settings in China

Background:At present,a large number of chronic obstructive pulmonary disease(COPD)patients are undiagnosed in China.Thus,this study aimed to develop a simple prediction model as a screening tool to identify patients at risk for COPD.Methods:The study was based on the data of 22,943 subjects aged 30 to 79 years and enrolled in the second resurvey of China Kadoorie Biobank during 2012 and 2013 in China.We stepwisely selected the predictors using logistic regression model.Then we tested the model validity through P-P graph,area under the receiver operating characteristic curve(AUROC),ten-fold cross validation and an external validation in a sample of 3492 individuals from the Enjoying Breathing Program in China.Results:The final prediction model involved 14 independent variables,including age,sex,location(urban/rural),region,educational background,smoking status,smoking amount(pack-years),years of exposure to air pollution by cooking fuel,family history of COPD,history of tuberculosis,body mass index,shortness of breath,sputum and wheeze.The model showed an area under curve(AUC)of 0.72(95%confidence interval[CI]:0.72-0.73)for detecting undiagnosed COPD patients,with the cutoff of predicted probability of COPD=0.22,presenting a sensitivity of 70.13%and a specificity of 62.25%.The AUROC value for screening undiagnosed patients with clinically significant COPD was 0.68(95%CI:0.66-0.69).Moreover,the ten-fold cross validation reported an AUC of 0.72(95%CI:0.71-0.73),and the external validation presented an AUC of 0.69(95%CI:0.68-0.71).Conclusion:This prediction model can serve as a first-stage screening tool for undiagnosed COPD patients in primary care settings.

Exposure Response Relationship of Acute Effects of Air Pollution on Respiratory Diseases-China,2013−2018

Summary What is already known about this topic?Short-term exposure to air pollutants has been associated with chronic obstructive pulmonary disease(COPD)and asthma,which needs continuous observation.What is added by this report?This study uses the longest time series data so far from 2013 to 2018 and adds additional data analysis for ozone(O_(3))to existing studies.