An Australian-led international study has found that Covid-19 patients who are overweight or obese are at increased risk of experiencing more severe infection and are more likely to require oxygen and invasive mechanical ventilation.
Published in Diabetes Care, the research was led by the Murdoch Children’s Research Institute (MCRI) and The University of Queensland, and also found that diabetes was associated with more severe infection (but not death); however, the combination of obesity in those with diabetes did not increase the risk further.
The study looked at hospitalised SARS-CoV-2 patients from 18 hospitals in 11 countries including China, America, Italy, South Africa and The Netherlands.
Among the 7244 patients aged 18 years and over, 34.8% were overweight and 30.8% were obese.
The researchers found that Covid-19 patients with obesity were more likely to require oxygen and had a 73% greater chance of needing invasive mechanical ventilation. Similar but more modest results were seen in overweight patients.
Reportedly, no link was found between being overweight or obese and dying in hospital from Covid-19.
The study also found that cardiovascular and pre-existing respiratory diseases were associated with increased odds of in-hospital deaths but not a greater risk for needing oxygen and mechanical ventilation.
For patients with pre-existing diabetes, there was increased odds of needing invasive respiratory support, but no additional increase in risk in those with obesity and diabetes.
Men were at an increased risk of severe Covid-19 outcomes and needing invasive mechanical ventilation. In those aged over 65 years, there was an increased chance of requiring oxygen and higher rates of in-hospital deaths.
MCRI researcher Dr Danielle Longmore says that the findings point to the urgent need to “introduce strategies to address the complex socio-economic drivers of obesity, and public policy measures such as restrictions on junk food advertising”.
“Although taking steps to address obesity in the short-term is unlikely to have an immediate impact in the Covid-19 pandemic, it will likely reduce the disease burden in future viral pandemics and reduce risks of complications like heart disease and stroke,” says Dr Longmore.
“Obesity is associated with numerous poor health outcomes,” adds The University of Queensland’s Dr Kirsty Short, who co-led the research, “including increased risk of cardiometabolic and respiratory disease and more severe viral disease, including influenza, dengue and SARS-CoV-1.”
Dr Short says that while previous reports indicated that obesity was an important risk factor in the severity of Covid-19, almost all this data had been collected from single sites and many regions were not represented. Moreover, there was a limited amount of evidence available about the effects of being overweight or obese on Covid-19 severity.
“Given the large scale of this study we have conclusively shown that being overweight or obese are independent risk factors for worse outcomes in adults hospitalised with Covid-19,” says Dr Short.
MCRI Professor David Burgner, who also co-led the research, adds that the data should help inform immunisation prioritisation for higher-risk groups.
“At the moment, the World Health Organisation has not had enough high-quality data to include being overweight or obese as a risk factor for severe Covid-19 disease.
“Our study should help inform decisions about which higher-risk groups should be vaccinated as a priority,” he says.
To read the research paper, visit: care.diabetesjournals.org/content/early/2021/04/12/dc20-2676