A new meta-analysis shows that, contrary to some previous research, being male and increasing body mass index (BMI) are not associated with increased mortality in COVID patients in intensive care units (ICU).
However, the study by Dr Bruce Biccard (Groote Schuur Hospital and University of Cape Town) and colleagues found that there were a wide range of factors linked to death from COVID in ICU. An August 2020 study of ICU COVID patients in Europe showed an association for age but not male sex.
The meta-analysis, which includes 58 studies and 44 305 patients published in the journal Anaesthesia, showed that, compared to patients without these risk factors, ICU COVID patients had a 40% greater mortality risk with smoking history, 54% higher with hypertension, 41% higher with diabetes, 75% higher with respiratory disease, around twice as high with cardiovascular disease or cancer, and 2.4 times higher with kidney disease. Other factors associated with an increased risk of death were the severity of organ failure, needing mechanical ventilation (a factor of 2.5 over non-ICU), as well as increased white blood cell counts and other inflammation markers.
The authors believe that age may effectively represent frailty in COVID patients which impacts on a person’s physiological reserve to overcome a critical illness. Hypertension, smoking and respiratory disease may be linked by their association with angiotensin-converting enzyme (ACE) receptors in the body, since there is increased expression of ACE-2 receptors amongst smokers and patients with chronic obstructive pulmonary disease. The link between hypertension and cardiovascular disease and increased mortality may be associated with the risk of cardiac injury which occurs with the systemic inflammatory response to COVID infection.
The authors said: “The findings confirm the association between diabetes, cardiovascular and respiratory comorbidities with mortality in COVID patients. However, the reported associations between male sex and increasing BMI worsening outcomes are not supported by this meta-analysis of patients admitted to ICU. This meta-analysis provides a large sample size with respect to these risk factors and is a robust estimate of risk associated with male sex and BMI.”
Source: EurekAlert!
Journal information: Anaesthesia, doi.org/10.1111/anae.15532
