Hypoalbuminemia is an indicator of prolonged recovery in the Omicron variant COVID-19

Introduction: The rate of severe cases of coronavirus disease 2019 (COVID-19) has decreased since the Omicron variant became epidemic. Although hypoalbuminemia has been reported to be a risk for disease severity and mortality in conventional variants, it is not clear whether hypoalbuminemia is associated with prolonged time to cure in the Omicron variants. In this study, we analyzed whether serum albumin levels are associated with prolonged time to resolution of symptoms in the Omicron variants. Methods: Participants in this study comprised patients ≥20 years old who had been admitted to our hospital between 1 January and 5 August 20222 and had a diagnosis of COVID-19 either on admission or during hospitalization. Serum albumin levels at the diagnosis of COVID-19 and other medical information were extracted from medical records. Endpoints were defined as resolution of fever, resolution of symptoms, and completion of oxygen administration. Results: A total of 226 patients were included in the study. The median serum albumin level was 3.7 g/dL, and 40.7% of patients had hypoalbuminemia of less than 3.5 g/dL. At admission or diagnosis, 140 patients had fever, 170 patients were symptomatic, and 54 patients required oxygen. Hypoalbuminemia group had a longer time to fever resolution and symptom resolution than non-hypoalbuminemia group (median 5 days vs. 3 days, p=0.0010; 9 days vs. 6 days, p=0.0002, respectively). Time to completion of oxygen administration did not differ between the two groups (median 8 days vs. 6 days, p=0.19). There was no difference in the rate of antiviral treatment between the two groups (20.1% vs. 15.2%, p=0.34). Discussion: Hypoalbuminemia can be caused by a combination of factors in infectious diseases. However, the Omicron variant tend to cause less severe infections, with symptoms and fever resolving within a few days, suggesting that factors other than inflammatory cytokines may be involved. The relationship between hypoalbuminemia and prolonged recovery in COVID-19 is speculated to be multifactorial, and further detailed analysis would be needed. Conclusion: Hypoalbuminemia was associated with prolonged symptom resolution in COVID-19 hospitalized patients during the Omicron variant epidemic and was independent of antiviral treatment. The results suggested that COVID-19 patients with hypoalbuminemia required prolonged observation for recovery.