Factors associated with COVID-19: is obesity associated with a higher risk of adverse outcomes?
Vanessa Jordan
1 *
1 Department Obstetrics and Gynaecology, Grafton Campus, University of Auckland, Auckland, New Zealand.
Journal of Primary Health Care 15(2) 190-191 https://doi.org/10.1071/HC23061
Published: 19 June 2023
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the Royal New Zealand College of General Practitioners. This is an open access article distributed under the Creative Commons Attribution 4.0 International License (CC BY).
Tadayon Najafabadi B, Rayner DG, Shokraee K, Shokraie K, Panahi P, et al. Obesity as an independent risk factor for COVID-19 severity and mortality. Cochrane Database of Systematic Reviews 2023, Issue 5. Art. No. CD015201. doi: 10.1002/14651858.CD015201.1
Background
On 11 March 2020 the World Health Organization (WHO) declared the novel coronavirus (COVID-19) outbreak a global pandemic.2 As of May 2023, the WHO declared that COVID-19 no longer constitutes a public health emergency of international concern.3 Instead, it is time to transition to longer term management of this illness. The burden that COVID-19 places on the healthcare system has been felt globally both financially, psychologically (by those working in the system) and by delays in providing care for those with other health needs.4,5
It is important that health professionals can identify individuals that are at highest risk of COVID-19 complications in order to allocate the limited resources that exist within the healthcare setting. Obesity has been identified as a factor that maybe used to recognise those at high risk of adverse outcomes. The systematic review summarised here assessed if this was indeed the case.
Clinical bottom line
Obesity in those with BMI <40 kg/m2 does not appear to be associated with an increase in mortality, but as the level of obesity increases the association does emerge and for those with a BMI >40 kg/m2 there is an increased risk of mortality associated with COVID-19 infection. As obesity increases there appears to be a dose-response relationship which does not reach significance until higher levels of obesity. The authors of this review suggest that ‘every five units of BMI increase inflates mortality risk by more than 2%’.1 A similar narrative can be seen with hospitalisation with no association shown for those with obesity class I and II but an association appearing for those with obesity class III (BMI > 40 kg/m2). The risk of having to have assisted mechanical ventilation is increased for all obesity groups with a dose-response relationship again evident. This evidence indicates that obesity, particularly obesity class III (morbid obesity), is indeed an important risk factor for the development of adverse outcomes following COVID-19 infection (Table 1).
| Outcome measured | Success | Evidence | |
|---|---|---|---|
| Mortality (in hospital) | Obesity class I (30 kg/m2 ≤ BMI < 35 kg/m2) | Obesity class I makes little or no difference in Mortality | This evidence is of high quality and is based on 335 209 participants from 15 studies. |
| Obesity class II (35 kg/m2 ≤ BMI < 40 kg/m2) | Obesity class II makes little or no difference in Mortality | This evidence is of high quality and is based on 317 925 participants from 11 studies. | |
| Obesity class III (BMI ≥ 40 kg/m2) | Obesity class III may increase mortality | This evidence is of low quality and is based on 354 967 participants from 19 studies. | |
| Mechanical ventilation | Obesity class I (30 kg/m2 ≤ BMI < 35 kg/m2) | Obesity class I probably increases the risk of mechanical ventilation | This evidence is of moderate quality and is based on 187 895 participants from 10 studies. |
| Obesity class II (35 kg/m2 ≤ BMI < 40 kg/m2) | Obesity class II increases the risk of mechanical ventilation | This evidence is of high quality and is based on 171 149 participants from six studies. | |
| Obesity class III (BMI ≥ 40 kg/m2) | Obesity class III increases the risk of mechanical ventilation | This evidence is of high quality and is based on 174 520 participants from 11 studies. | |
| Hospitalisation | Obesity class I (30 kg/m2 ≤ BMI < 35 kg/m2) | Obesity class I probably makes little to no difference in the risk of hospitalisation | This evidence is of moderate quality and is based on 515 155 participants from five studies. |
| Obesity class II (35 kg/m2 ≤ BMI < 40 kg/m2) | Obesity class I probably makes little to no difference in the risk of hospitalisation | This evidence is of moderate quality and is based on 293 707 participants from three studies. | |
| Obesity class III (BMI ≥ 40 kg/m2) | Obesity class III may increase the risk of hospitalisation | This evidence is of low quality and is based on 747 176 participants from seven studies. | |
References
1 Tadayon Najafabadi B, Rayner DG, Shokraee K, et al. Obesity as an independent risk factor for COVID‐19 severity and mortality. Cochrane Database Syst Rev [5] 2023; CD015201.
| Crossref | Google Scholar |
2 World Health Organization. WHO Director-General’s opening remarks at the media briefing on COVID-19 11 March 2020. 2020. Available at https://www.who.int/director-general/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19---11-march-2020
3 World Health Organization. Statement on the fifteenth meeting of the IHR (2005) Emergency Committee on the COVID-19 pandemic. 2023. Available at https://www.who.int/news/item/05-05-2023-statement-on-the-fifteenth-meeting-of-the-international-health-regulations-(2005)-emergency-committee-regarding-the-coronavirus-disease-(covid-19)-pandemic
4 Chavez-MacGregor M, Lei X, Zhao H, et al. Evaluation of COVID-19 mortality and adverse outcomes in US patients with or without cancer. JAMA Oncol 2022; 8(1): 69-78.
| Crossref | Google Scholar |
5 Schneider M, Altersberger M, Binder C, et al. The COVID-19 burden for health care professionals: results of a global survey. Eur J Intern Med 2021; 83: 96-98.
| Crossref | Google Scholar |
