The pandemic of COVID-19 has threatened the health and infrastructure of nations all over the world. Notably, the Center for Disease Control has warned that the COVID-19 infections are most severe in older adults and those who have underlying medical conditions such as heart disease, lung disease, or diabetes. Recently, severe obesity was added to the list of risk factors for severe illness.
Prior experience suggests that obesity is among the chronic diseases that predispose patients with respiratory viruses to more severe disease progression and higher rates of mortality. We can expect the same from COVID-19. For example, several reports from around the world identified obesity and severe obesity as risk factors for hospitalization and mechanical ventilation during the influenza H1N1 virus in 2009. Over half of adults with severe or fatal H1N1 in California were found to have obesity, with a quarter having severe obesity. Many of the H1N1 patients with obesity also had other chronic conditions, such as lung disease, heart disease, or diabetes.
The disproportionate impact that H1N1 had on patients with obesity and severe obesity may now be occurring in those with COVID-19, especially in cases with severe mixed infections. Observations in China, Italy, and the UK have documented a high prevalence of obesity and overweight in patients severely affected by COVID-19.
Factors that may play a role in the link between obesity and COVID-19 severity include inflammation, hypoventilation syndrome, and obesity-related comorbidities, such as hypertension, diabetes, cardiovascular disease, and cerebrovascular disease. Obesity is also associated with additional decreases in respiratory function that can contribute to an adverse outcome, including decreased expiratory reserve volume, functional capacity and respiratory system compliance. In light of these risks, the World Obesity Federation announced that “coronaviruses can cause more severe symptoms and complications in people with obesity-related conditions.”
Although the effects of COVID-19 on patients with obesity are still being explored, the lessons learned from the H1N1 pandemic should be taken seriously by those caring for patients with obesity, and particularly patients with severe obesity. The prevalence of adult obesity and severe obesity in 2017-2018 has increased since 2009-2010 and is now 42% and 9% respectively. These data indicate that a larger proportion of the American population is at risk for obesity-related complications in today’s pandemic than was at risk during the 2009 pandemic. These observations also emphasize the need for rapid assessment of patients with obesity who are suspected of having COVID-19 infections, and a heightened sensitivity to the increased risk of severe respiratory disease associated with their obesity.
Although this is a time of concern about infectious diseases, this pandemic reminds us that chronic diseases put our society at greater risk for poor health. Obesity is pandemic in its own right. Its treatment and prevention, and the prevention of the systemic inequities that contribute to it, must become priorities as we implement our response to the COVID-19 pandemic.