What is the problem and what is known about it so far?
Growing evidence suggests that a large proportion of patients hospitalized with coronavirus disease 2019 (COVID-19) are overweight or obese, and this group seems to do more poorly from COVID-19. Many chronic health conditions, such as diabetes and heart disease, are also associated with poor outcomes in COVID-19. It is unclear whether the higher risk associated with obesity is due to health conditions patients with obesity tend to have or whether obesity itself is a risk factor for poor clinical outcomes from COVID-19. Identifying obesity as an independent risk factor is important so that patients with obesity can take extra precautions and health care providers and public health officials can consider this when providing care and making public health decisions.
Why did the researchers do these particular studies?
To determine whether patients with COVID-19 do more poorly if they have higher body weight, regardless of whether they have risk factors for COVID-19.
Who was studied?
The study by Anderson and colleagues included 2466 adults admitted to the hospital with a diagnosis of COVID-19 between 10 March and 24 April 2020. The study by Tartof and colleagues included 6916 adults seen in the Kaiser Permanente Southern California integrated health care organization who had a diagnosis of COVID-19 between 13 February and 2 May 2020, including many ambulatory patients who were not hospitalized for COVID-19.
How were the studies done?
Investigators analyzed medical record information to determine patients' clinical outcomes. Anderson and colleagues looked to see which patients died or were intubated during their hospitalization for COVID-19 over a period of 45 days. Tartof and colleagues examined which patients died within 21 days of their COVID-19 diagnosis.
What did the researchers find?
Researchers in both studies found that those with a body weight that was lower or substantially higher than what is considered “normal” had poorer health outcomes, even after accounting for common medical conditions seen in many patients with obesity, in addition to smoking history, age, and sex. In Anderson and colleagues' study, the typical patient was hospitalized for 7 days: 22% were intubated, 25% died, 51% were discharged, and 2% were still hospitalized at the end of the study period. Patients in the highest weight group were 60% more likely to be intubated or die during the study period than those in the normal weight group, especially those under age 65. In Tartof and colleagues' study, patients in the highest weight group were 4 times as likely to die within 21 days of being diagnosed with COVID-19 as those in the normal weight group. Men and those younger than 60 years who had a high body weight were at particularly high risk for death.
What were the limitations of the studies?
More than a quarter of patients in Anderson and colleagues' study had missing body weight information. Deaths occurring outside the health care setting may not have been captured in Tartof and colleagues' study.
What are the implications of the studies?
High body weight is a risk factor for doing poorly with COVID-19. Adults who are overweight or obese should take extra care in managing their risk for exposure to COVID-19 even if they do not have other health conditions that put them at higher risk.
Footnotes
This article was published at Annals.org on 12 August 2020