What role does obesity play in severe Covid-19?

Obesity has been shown to be a strong independent predictor of not only Covid-19-related hospitalization but also critical illness requiring invasive mechanical ventilation (IMV) or ICU support (1-3).

A large New York City study involving over 4,000 Covid-19 patients found obesity ( BMI≥30 kg/m2) to be an independent risk factor for hospitalization; BMI 30-40 kg/m2 was associated with ~4-fold and >40 kg/m2 with ~6-fold increased risk. Obesity was also strongly associated with increased risk of critical illness, stronger than other common preexisting conditions such as heart disease, hypertension or diabetes (1, preprint).

Another New York City study found that among Covid-19 patients younger than 60 years of age, obese patients were twice as likely to be hospitalized or have critical illness (2). Similarly, a French study found severe obesity (BMI >35 kg/m2) to be strongly associated with IMV compared to those with BMI <25 kg/m2 (O.R. 7.4, 1.7-33) (3).

Many factors likely play a role in making obese patients particularly susceptive to severe Covid-19. Obesity is a well-recognized inflammatory state and is associated with abnormal secretion of cytokines and adipokines which may have an effect on lung parenchyma and bronchi (1,3,4). Somewhat paradoxically, obese patients may also have an impaired adaptive immune response to certain infections, including influenza (4). Abdominal obesity is also associated with impaired ventilation of the base of the lungs resulting in reduced oxygenation (1).



Bonus Pearl: Did you know among pre-existing conditions commonly found in the population (eg, hypertension, diabetes, COPD), obesity has been found to be the only condition independently associated with pulmonary embolism in Covid-19 (O.R. 2.7, 1.3-5.5) (5).

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

1. Petrilli CM, Jones SA, Yang J, et al. Factors associated with hospitalization and critical illness among 4, 103 patients with Covid-19 disease in New York City. MedRxiv preprint doi: https://doi.org/10.1101/2020.04.0820057794
2. Lighter J, Phillips M, Hochman S, et al. Obesity in patients younger than 60 years is a risk factor for COVID-19 hospital admission. Clin Infect Dis 2020. https://pubmed.ncbi.nlm.nih.gov/32271368/
3. Simonnet A, Chetboun M, Poissy J, et al. High prevalence of obesity in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) requiring invasive mechanical ventilation. https://pubmed.ncbi.nlm.nih.gov/32271993/
4. Sattar N, BcInnes IB, McMurray JJV. Obesity a risk factor for severe COVID-19 infection:multiple potential mechanisms. Circulation 2020. https://www.ahajournals.org/doi/pdf/10.1161/CIRCULATIONAHA.120.047659
5. Poyiadji N, Cormier P, Patel PY, et al. Acute pulmonary embolism and COVID-19. Radiology 2020; https://pubmed.ncbi.nlm.nih.gov/32407256/

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

What role does obesity play in severe Covid-19?

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.