Reduced serum albumin levels in patients hospitalised with COVID-19 appears to be an independent risk factor for severe disease and mortality.
In systemic inflammatory conditions such as sepsis, low serum albumin levels are associated with an increased risk of death in patients with severe disease. However, whether serum albumin (SA) levels can used predictively to identify those at risk of both severe disease and mortality in COVID-19 remains unclear. This was the question addressed in a retrospective study by a team from the Emergency Department, Alto Adige, Italy. The team considered consecutive patients with COVID-19 seen at the emergency department (ED) of three hospitals during March to April 2020. Serum albumin levels were added to the panel of blood samples routinely performed on those with suspected COVID-19 upon arrival at the ED. The primary outcome of the study was the presence of severe COVID-19 infection. In addition, the team explored 30-day mortality after the initial ED assessment as a secondary outcome. The researchers categorised SA levels upon ED admission as < 3 g/dL, 3 – 3.49 g/dL and greater than 3.5 g/dL.
There were 296 patients with COVID-19 for whom the overall mean SA value was 3.7 g/dL. Serum albumin levels were higher for patients aged under 75 years of age (3.9 vs 3.4, under 75 years vs over 75 years, p < 0.001) although there were no gender differences. Most patients (59.8%) had SA levels above 3.5 g/dL with only 10.1% having levels below 3 g/dL. Nearly two thirds (63.2%) of patients had severe COVID-19 infection and 18.2% of all patients died within 30 days of their arrival at the ED.
In their analysis, the authors calculated that SA levels < 3.5 g/dL was an independent risk factor for both severe infection (adjusted odds ratio, aOR = 2.92, 95% CI 1.51 – 5.66) and 30-day mortality (aOR – 2.62, 95% CI 1.13 – 6.1).
In their conclusion, the authors stated that their preliminary data suggested that “serum albumin level in the ED may play a role in the assessment of the severity of SARS-CoV-2 infection and the risk of death at 30 days.” They also called for more prospective evaluations to confirm whether albumin levels was an important prognostic factor in patients with COVID-19.