Body Mass Index and Risk for Intubation or Death in SARS-CoV-2 Infection : A Retrospective Cohort Study

Ann Intern Med. 2020 Nov 17;173(10):782-790. doi: 10.7326/M20-3214. Epub 2020 Jul 29.


Background: Obesity is a risk factor for pneumonia and acute respiratory distress syndrome.

Objective: To determine whether obesity is associated with intubation or death, inflammation, cardiac injury, or fibrinolysis in coronavirus disease 2019 (COVID-19).

Design: Retrospective cohort study.

Setting: A quaternary academic medical center and community hospital in New York City.

Participants: 2466 adults hospitalized with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection over a 45-day period with at least 47 days of in-hospital observation.

Measurements: Body mass index (BMI), admission biomarkers of inflammation (C-reactive protein [CRP] level and erythrocyte sedimentation rate [ESR]), cardiac injury (troponin level), and fibrinolysis (D-dimer level). The primary end point was a composite of intubation or death in time-to-event analysis.

Results: Over a median hospital length of stay of 7 days (interquartile range, 3 to 14 days), 533 patients (22%) were intubated, 627 (25%) died, and 59 (2%) remained hospitalized. Compared with overweight patients, patients with obesity had higher risk for intubation or death, with the highest risk among those with class 3 obesity (hazard ratio, 1.6 [95% CI, 1.1 to 2.1]). This association was primarily observed among patients younger than 65 years and not in older patients (P for interaction by age = 0.042). Body mass index was not associated with admission levels of biomarkers of inflammation, cardiac injury, or fibrinolysis.

Limitations: Body mass index was missing for 28% of patients. The primary analyses were conducted with multiple imputation for missing BMI. Upper bounding factor analysis suggested that the results are robust to possible selection bias.

Conclusion: Obesity is associated with increased risk for intubation or death from COVID-19 in adults younger than 65 years, but not in adults aged 65 years or older.

Primary funding source: National Institutes of Health.

MeSH terms

  • Academic Medical Centers
  • Age Factors
  • Aged
  • Betacoronavirus*
  • Biomarkers / blood
  • Blood Sedimentation
  • Body Mass Index*
  • C-Reactive Protein / analysis
  • COVID-19
  • Cohort Studies
  • Coronavirus Infections / epidemiology*
  • Female
  • Fibrin Fibrinogen Degradation Products / analysis
  • Hospitalization
  • Hospitals, Community
  • Humans
  • Intubation, Intratracheal / statistics & numerical data*
  • Length of Stay / statistics & numerical data
  • Male
  • Middle Aged
  • New York City / epidemiology
  • Obesity / epidemiology*
  • Pandemics
  • Pneumonia, Viral / epidemiology*
  • Proportional Hazards Models
  • Retrospective Studies
  • SARS-CoV-2
  • Troponin / blood


  • Biomarkers
  • Fibrin Fibrinogen Degradation Products
  • Troponin
  • fibrin fragment D
  • C-Reactive Protein