The Centre for Disease Control has added obesity to the list of conditions that cause increased risk of severe illness with coronavirus.
Studies from around the world are reporting that excess weight is associated with increased risk of: testing positive, hospitalisation, admission to ICU and mortality. The risk seems to increase progressively with increasing BMI above the healthy weight range1. A large New York study showed that people with BMI>30 were 4-6 times more likely to be hospitalised than non-obese patients2. We do not yet have the complete picture as most studies are from hospitalised patients only, the number of people living with obesity who experience asymptomatic infection remains unknown.
Although there are no studies investigating the mechanisms behind the link between obesity and Covid-19, many specialists believe the main issue is impaired lung function. A heavy, thick chest wall prevents the lung from expanding to its full capacity and when lying flat the diaphragm is prevented from moving downwards as abdominal fat pushes back on it. This is not a problem for day to day life but does become an issue when coupled with copious airway secretions and severe inflammation from Covid-19. The combination leads to poor oxygenation of the blood and all organs start to perform poorly.
Individuals living with obesity are at high risk of other diseases associated with worse Covid-19 outcomes including diabetes, hypertension, dyslipidaemia and liver disease. Other potential mechanisms that are under investigation are: obesity causing an altered immune response, an increased risk of thrombosis (blood clot formation), and that fat cells have many more ACE-2 receptors on their surface than other tissues (Covid-19 latches onto this so it can gain access to cells).
Covid-19 has changed human lives and the function of society in a way we have never seen before. While obesity is associated with more severe infection, the rates of obesity are predicted to rise as stay at home orders and social distancing lead to increased consumption of high calorie foods and reduced physical activity. Eating habits developed during this time of prolonged stress are a major health risk moving into the future as processed food and drink become part of household routines.
The good news is that excess weight is one of the risk factors that can be improved so that a person may survive the duration of the pandemic in good health. If you are obese, the best thing you can do right now is invest in your own health, it’s a good time to begin a conversation with your GP or specialist about strategies to move towards a healthier weight range.
- Public Health England Report- Excess Weight and COVID-19. July 2020.
- Petrilli et al. 2020. Factors associated with hospitalization and critical illness among 4,103 patients with COVID-19 disease in New York City. medRxiv 2020.04.08.20057794.