SPP1 and COVID-19: The presence of any dyspnea, fatigue or muscular weakness was linked to female gender and BMI > 30, while severe post-COVID-19 exertional dyspnea with m-MRC > 1 was associated with high plasma OPN, female gender and the presence of severe exertional dyspnea (m-MRC > 1) before the onset of the acute disease (Table 3).