Clinical and physiological variables in post-COVID-19 patients with and without fatigue

<bold>Introduction:</bold> Chronic fatigue exhibits multifactorial underlying mechanisms in long COVID-19; nevertheless, understanding of these symptoms remains limited. <bold>Objective:</bold> To assess clinical and physiological variables in post-COVID-19 patients. <bold>Methods:</bold> One year post-COVID-19 infection, participants were divided in G1-fatigue and G2-asymptomatic. Assessments included blood count, metabolic panel, spirometry, dyspnea, quality of life, anxiety, depression, physical capacity, muscle strength, comorbidities, and medications. <bold>Results:</bold> Seventy-seven patients (53% female, 55±12 years) were included. G1 had more women (68%, p=0.015) and autoimmune comorbidities (84%, p=0.010), with lower rates of hypertension (38%, p=0.001) and diabetes mellitus (13%, p=0.016). Table 1 shows significant between-group differences. <table-wrap><object-id>erj;64/suppl_68/PA300/TB1</object-id><object-id>T1</object-id><object-id>TB1</object-id><table><colgroup><col></col><col></col><col></col><col></col></colgroup><tbody><tr><td></td><td>G1(n=37)</td><td>G2(n=40)</td><td>p</td></tr><tr><td>FEV₁, L</td><td>2.4±0.5</td><td>2.7±0.6</td><td>0.022</td></tr><tr><td>Handgrip, kg</td><td>34(28-40)</td><td>40(30-46)</td><td>0.044</td></tr><tr><td>Maximal Inspiratory Pressure (MIP), cmH₂O</td><td>-81±31</td><td>-111±33</td><td><0.001</td></tr><tr><td>mMRC scale</td><td>1(1-2)</td><td>0(0-1)</td><td>0.002</td></tr><tr><td>BDI, score</td><td>7.5(6-9)</td><td>12(9-12)</td><td><0.001</td></tr><tr><td>HADS-A, score</td><td>8(5-9)</td><td>3(0.5-4)</td><td><0.001</td></tr><tr><td>SGRQ, total score (%)</td><td>35(25-48)</td><td>12(7-25)</td><td><0.001</td></tr></tbody></table></table-wrap> In the total sample, MIP showed significant correlations with FEV₁ (r=0.56, p<0.001), mMRC (r=-0.50, p<0.001), and SGRQ total score (r=-0.53, p<0.001). Handgrip correlated with FEV₁ (r=0.55, p<0.001) and total SGRQ (r=-0.53, p<0.001), while total SGRQ correlated with mMRC (r=0.73, p<0.001). No differences were noted in laboratory parameters, body composition, physical capacity, or medications. <bold>Conclusion:</bold> Post-COVID-19 fatigue patients exhibit more autoimmune comorbidities, dyspnea sensation, and anxiety, along with lower FEV₁, weakened muscle strength, and a significant impact on quality of life.