High BMI independently associated with mortality for COVID patients

In patients with COVID-19, a high body mass index (BMI) is associated with an increased risk of death and prolonged intensive care unit (ICU) stay, according to a study by Lovisa Sjögren and colleagues from the Sahlgrenska Academy at University of Gothenburg, Sweden.

Previous studies have shown that a high BMI is a risk factor for severe COVID-19. Obesity increases the risk of comorbidities such as type 2 diabetes and hypertension, and has been shown to increase the need for mechanical ventilation in association with other respiratory infectious diseases such as influenza and pneumonia.


In this study, ‘Impact of obesity on intensive care outcomes in patients with COVID-19 in Sweden—A cohort study’, published in PLoS ONE, Sjögren and colleagues analysed data on 1,649 COVID-19 patients from the Swedish Intensive Care Registry, a national quality registry which covers all ICUs in Sweden. The patients included in the study were admitted to ICUs during the first wave of the COVID-19 pandemic, between March and August 2020, 96% had a positive PCR test for the SARS-CoV-2 virus or a clinical diagnosis of COVID-19, were all over the age of 18, and had current weight and height data available.


A majority of the study cohort had a high BMI; 78.3% were overweight or were living with obesity. There was a significant association between increasing BMI and the composite outcome of death during intensive care, or an ICU stay of longer than 14 days in survivors (OR per SD increase: 1.29 95%CI 1.16–1.43 adjusted for age, and sex). Individuals with a BMI>35 kg/m2 were twice as likely to have one of the outcomes of death or prolonged ICU stay, adjusted for age and sex.


Moreover, this association remained after adjusting for the presence of cardiovascular disease, hypertension, diabetes mellitus, liver or kidney disease, as well as after adjusting for severity of illness at ICU admission (OR 2.02 [1.39-2.94] versus normal weight).


“The results establish obesity as an independent risk factor for severe outcome from intensive care in patients with COVID-19,” they concluded. “Based on our findings, we advocate that BMI is included in the severity scoring for patients with COVID-19 admitted to intensive care, and suggest that individuals with obesity should be more closely monitored when hospitalized for COVID-19.”


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