Pulmonary Rehabilitation in Post-Covid-19 Patients Improves Lung Function and Mechanics and Skeletal Muscle, and Immune Response

ABSTRACT

The COVID-19 let sequelae not only in the respiratory system but also in several other systems, for instance in the skeletal muscle and in the immune response. This study evaluated the effects of 12 weeks of pulmonary rehabilitation (PR), constituted by aerobic (30 minutes of treadmill training at 75% of maximum heart rate) and resistance training (30 minutes at 75% of 1 maximum repetition) on 33 moderate and severe post-COVID-19 patients. The results demonstrated that PR effectively improved lung function, denoted by improved FVC (p<0.02), FEV1 (p<0.02), FEV1/FVC (p<0.01), MEF25% (p<0.006), MEF50% (p<0.03), and MEF75% (p<0.02). PR also improved lung mechanics, denoted by improved respiratory impedance (Z5hz, p<0.03);respiratory reactance (X5Hz, p<0.01), resistance of the whole respiratory systems (R5Hz, p<0.03), central airway resistance (RCentral, p<0.03), and peripheral airway resistance (RPeripheral, p<0.02). In addition, PR improved peripheral muscle strength denoted by increased right (p<0.02) and left (p<0.01) hand grip strength and the respiratory muscle strength, denoted by increased maximum inspiratory pressure (p<0.02) and maximum expiratory pressure (p<0.03). Of note, PR reduced pulmonary (breath condensate) inflammation, as observed by reduced levels of the pro-inflammatory cytokine IL-1beta (p<0.0001), IL-6 (p<0.0001), while increased the levels of the anti-inflammatory cytokine IL- 1RA (p<0.0004) and IL-10 (p<0.003), beyond to increase the levels of the cytokines with anti-viral properties, IFN-gamma (p<0.0002) and IFN-beta (p<0.008). Such response was also observed in the serum, as denoted by reduced levels of pro-inflammatory IL-1beta (p<0.006), and IL-6 (p<0.01), while increased the levels of anti-inflammatory cytokine IL-1RA (p<0.0001), and IL-10 (p<0.0001). PR also increased the serum levels of the cytokines with anti-viral properties, IFN-gamma (p<0.02) and IFN-beta (p<0.001). In conclusion, PR reveals to be beneficial for post-COVID-19 patients, mitigating the sequelae observed in the respiratory system, skeletal muscle and in the immune response.