A Swedish cohort study determined that obese patients, (BMI >35 kg/m2), were twice as likely to experience a prolonged ICU stay or die, according to a study in PLOS ONE by researchers 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 the study, Lovisa 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 6 March and 30 August 2020; 96% had a positive PCR test for the SARS-CoV-2 virus or a clinical diagnosis of COVID-19, were all over 18 years old, and had current weight and height data available.
Most of the study cohort had a high BMI; 78.3% were overweight or had 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.
Individuals with a BMI of 35 kg/m2 or more 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 versus normal weight).
The authors conclude that obesity is an independent risk factor for severe outcome from intensive care in patients with COVID-19 and suggest that BMI be included in the severity scoring for COVID-19 ICU patients.
They added: “A high BMI was associated with increasing risk of death and prolonged length of stay in the ICU. Based on our findings, we suggest that individuals with obesity should be more closely monitored when hospitalised for COVID-19.”
Study details
Impact of obesity on intensive care outcomes in patients with COVID-19 in Sweden—A cohort study
Lovisa Sjögren, Erik Stenberg, Meena Thuccani, Jari Martikainen, Christian Rylander, Ville Wallenius, Torsten Olbers, Jenny M. Kindblom,
Published in PLOS ONE on 13 October 2021
Abstract
Background
Previous studies have shown that a high body mass index (BMI) is a risk factor for severe COVID-19. The aim of the present study was to assess whether a high BMI affects the risk of death or prolonged length of stay (LOS) in patients with COVID-19 during intensive care in Sweden.
Methods and findings
In this observational, register-based study, we included patients with COVID-19 from the Swedish Intensive Care Registry admitted to intensive care units (ICUs) in Sweden. Out- comes assessed were death during intensive care and ICU LOS 14 days. We used logistic regression models to evaluate the association (odds ratio [OR] and 95% confidence interval [CI]) between BMI and the outcomes.
Valid weight and height information could be retrieved in 1,649 patients (1,227 (74.4%) males) with COVID-19. We found a significant association between BMI and the risk of the composite outcome death or LOS 14 days in survivors (OR per standard deviation [SD] increase 1.30, 95%CI 1.16–1.44, adjusted for sex, age and comorbidities), and this association remained after further adjustment for severity of illness (simplified acute physiology score; SAPS3) at ICU admission (OR 1.30 per SD, 95%CI 1.17–1.45). Individuals with a BMI 35 kg/m2 had a doubled risk of the composite outcome. A high BMI was also associated with death during intensive care and a prolonged LOS in survivors assessed as separate outcomes.
The main limitations were the restriction to the first wave of the pandemic, and the lack of information on socioeconomic status as well as smoking.
Conclusions
In this large cohort of Swedish ICU patients with COVID-19, a high BMI was associated with increasing risk of death and prolonged length of stay in the ICU. Based on our findings, we suggest that individuals with obesity should be more closely monitored when hospitalised for COVID-19.
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