Pulmonary rehabilitation (PR), delivered as a supervised multidisciplinary program including exercise training, is one of the cornerstones in the chronic obstructive pulmonary disease (COPD) management. We performed a systematic review and meta-analysis to assess the effect on mortality of a supervised early PR program, initiated during or within 4 weeks after hospitalization with an acute exacerbation of COPD compared with usual post-exacerbation care or no PR program. Secondary outcomes were days in hospital, COPD related readmissions, health-related quality of life (HRQoL), exercise capacity (walking distance), activities of daily living (ADL), fall risk and drop-out rate. We identified randomized trials through a systematic search using MEDLINE, EMBASE and Cocharne Library and other sources through October 2017. Risk of bias was assessed regarding randomization, allocation sequence concealment, blinding, incomplete outcome data, selective outcome reporting, and other biases using the Cochrane Risk of Bias tool. We included 13 randomized trials (801 participants). Our meta-analyses showed a clinically relevant reduction in mortality after early PR (4 trials, 319 patients; RR = 0.58 (95% CI: [0.35 to 0.98])) and at the longest follow-up (3 trials, 127 patients; RR = 0.55 (95% CI: [0.12 to 2.57])). Early PR reduced number of days in hospital by 4.27 days (1 trial, 180 patients; 95% CI: [− 6.85 to − 1.69]) and hospital readmissions (6 trials, 319 patients; RR = 0.47 (95% CI: [0.29 to 0.75])). Moreover, early PR improved HRQoL and walking distance, and did not affect drop-out rate. Several of the trials had unclear risk of bias in regard to the randomization and blinding, for some outcome there was also a lack of power. Moderate quality of evidence showed reductions in mortality, number of days in hospital and number of readmissions after early PR in patients hospitalized with a COPD exacerbation. Long-term effects on mortality were not statistically significant, but improvements in HRQoL and exercise capacity appeared to be maintained for at least 12 months. Therefore, we recommend early supervised PR to patients with COPD-related exacerbations. PR should be initiated during hospital admission or within 4 weeks after hospital discharge.

Background: Different pathogens can cause community-acquired pneumonia (CAP); however, the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) has re-emphasized the vital role of respiratory viruses as a cause of CAP. The aim was to explore differences in metabolic profile, body composition, physical capacity, and inflammation between patients hospitalized with CAP caused by different etiology. Methods: A prospective study of Danish patients hospitalized with CAP caused by SARS-CoV-2, influenza, or bacteria. Fat (FM) and fat-free mass (FFM) were assessed with bioelectrical impedance analysis. Physical activity and capacity were assessed using questionnaires and handgrip strength. Plasma (p)-glucose, p-lipids, hemoglobin A1c (HbA1c), p-adiponectin, and cytokines were measured. Results: Among 164 patients with CAP, etiology did not affect admission levels of glucose, HbA1c, adiponectin, or lipids. Overall, 15.2% had known diabetes, 6.1% had undiagnosed diabetes, 51.3% had pre-diabetes, 81% had hyperglycemia, and 60% had low HDL-cholesterol, with no difference between groups. Body mass index, FM, and FFM were similar between groups, with 73% of the patients being characterized with abdominal obesity, although waist circumference was lower in patients with COVID-19. Physical capacity was similar between groups. More than 80% had low handgrip strength and low physical activity levels. Compared to patients with influenza, patients with COVID-19 had increased levels of interferon (IFN)-γ (mean difference (MD) 4.14; 95% CI 1.36–12.58; p = 0.008), interleukin (IL)-4 (MD 1.82; 95% CI 1.12–2.97; p = 0.012), IL-5 (MD 2.22; 95% CI 1.09–4.52; p = 0.024), and IL-6 (MD 2.41; 95% CI 1.02–5.68; p = 0.044) and increased IFN-γ (MD 6.10; 95% CI 2.53–14.71; p < 0.001) and IL-10 (MD 2.68; 95% CI 1.53–4.69; p < 0.001) compared to patients with bacterial CAP, but no difference in IL-1β, tumor necrosis factor-α, IL-8, IL-18, IL-12p70, C-reactive protein, and adiponectin. Conclusion: Despite higher inflammatory response in patients with COVID-19, metabolic profile, body composition, and physical capacity were similar to patients with influenza and bacterial CAP.

In chronic obstructive pulmonary disease (COPD), the progressive loss of lung tissue is widely considered irreversible. Thus, various treatment and rehabilitation schemes, including exercise-based pulmonary rehabilitation (PR) are thought to slow down but not reverse or halt the disease. Nonetheless, the adult lung conceals the intrinsic capacity for de novo lung tissue formation in the form of abundant progenitor/stem cell populations. In COPD, these maintain their differentiation potential but appear to be halted by a state of cellular senescence in the mesenchyme, which normally functions to support and coordinate their function. We propose that notably high-intensity interval training may improve pulmonary gas exchange during exercise in patients with COPD by interrupting mesenchymal senescence, thus reestablishing adaptive angiogenesis. By means of this, the downward spiral of dyspnea, poor quality of life, physical inactivity, and early death often observed in COPD may be interrupted. If this is the case, the perception of the regenerative capacity of the lungs will be fundamentally changed, which will warrant future clinical trials on various exercise schemes and other treatments targeting the formation of new lung tissue in COPD.

Background: Bed rest with limited physical activity is common during admission. The aim was to determine the association between daily step count and physical activity levels during and after admission with community-acquired pneumonia (CAP) and the risk of readmission and mortality. Methods: A prospective cohort study of 166 patients admitted with CAP. Step count and physical activity were assessed with accelerometers during and after admission and were categorised as sedentary, light, or moderate-vigorous physical activity. Linear regression was used to assess the association between step count and length of stay. Logistic regression was used to assess the association between step count, physical activity level, and risk of readmission and mortality. Results: Patients admitted with CAP were sedentary, light physically active, and moderate-to-vigorous physically active 96.4%, 2.6%, and 0.9% of their time, respectively, with 1356 steps/d. For every 500-step increase in daily step count on day 1, the length of stay was reduced by 6.6%. For every 500-step increase in daily step count during admission, in-hospital and 30-day mortality was reduced. Increased light and moderate-to-vigorous physical activity during admission were associated with reduced risk of in-hospital and 30-day mortality. After discharge, patients increased their daily step count to 2654 steps/d and spent more time performing light and moderate-to-vigorous physical activity. For every 500-step increase in daily step count after discharge, the risk of readmission was reduced. Higher moderate-to-vigorous physical activity after discharge was associated with a reduced risk of readmission. Conclusions: Increased physical activity during admission was associated with a reduced length of stay and risk of mortality, whereas increased physical activity after discharge was associated with a reduced risk of readmission in patients with CAP. Interventions focusing on increasing physical activity levels should be prioritised to improve the prognosis of patients admitted with CAP.

Background: Impaired functional status is a risk factor for hospitalization in patients with community-acquired pneumonia (CAP). The aim was to determine the influence of functional status and physical activity level on severe outcomes, including length of stay, admission to the intensive care unit (ICU), readmission, and mortality in patients with CAP. Methods: A prospective cohort study among patients hospitalized with CAP. Functional status was assessed with the Barthel index and grip strength, and physical activity level was assessed using the international physical activity questionnaire. Linear regression was used to assess the association with length of stay, and logistic regression was used to assess the risk of severe outcomes. Results: Among 355 patients admitted with CAP, 18% had a low Barthel index (<80), 45% had a low grip strength, and 75% had a low physical activity level. Low Barthel index was associated with increased risk of ICU admission (OR 3.6, 95% CI 1.2–10.9), longer length of stay (27.9%, 95% CI 2.3–59.7%), readmission within 30, 90, and 180 days (OR 2.1–2.4, p < 0.05), and mortality within 90 and 180 days (OR 4.2–5.0, p < 0.05). Low grip strength was associated with increased risk of 90 days readmission (OR 1.6, 95% CI 1.0–2.6, p < 0.05) and mortality within 30, 90, and 180 days (OR 2.6–3.2, p < 0.05). Low physical activity level was associated with increased risk of readmission within 90 and 180 days (OR 1.8–2.1, p < 0.05) and mortality within 30, 90, and 180 days (OR 3.3–5.5, p < 0.05). Conclusions: Impaired functional status and low physical activity level were associated with a longer length of stay and increased risk of ICU admission, readmission, and mortality in patients hospitalized with CAP. Routine assessment of functional status and physical activity level in clinical care could enable early identification of individuals with excess risk for a poor prognosis. Trial registration: ClinicalTrials.gov, NCT03795662.