Researchers in the US raise concerns about the impact of obesity on the effectiveness of a future Covid-19 vaccine.
A review of Covid-19 studies by researchers in the US has revealed a troubling connection between two health crises: Covid-19 and obesity.
A recently published study by researchers at the University of North Carolina at Chapel Hill found that people with obesity are 113% more likely to be admitted to hospital with Covid-19 and 74% more likely to need intensive care treatment.
People who are obese are at a higher risk of developing additional health complications including type 2 diabetes, hypertension and heart disease.
Researchers said their findings raised concerns about the impact of obesity on the effectiveness of any potential future Covid-19 vaccine.
In addition, people who were obese faced a difficult path to full recovery following being diagnosed with Covid-19.
Researchers looked at a number of published literature on individuals infected with the virus and found that people who were obese (having a body mass index (BMI) of more than 30) were at a much higher risk of hospitalisation (113%), more likely to be admitted to the intensive care unit (74%), and had a higher risk of death (48%) from the virus.
For the paper, researchers reviewed immunological and biomedical data to provide a detailed layout of the mechanisms and pathways that link obesity with increased risk of COVID-19 as well as an increased likelihood of developing more severe complications from the virus.
Metabolic changes caused by obesity — such as insulin resistance and inflammation – make it difficult for individuals with obesity to fight some infections, a trend that can be seen in other infectious diseases, such as influenza and hepatitis.
During times of infection, uncontrolled serum glucose, which is common in individuals with hyperglycaemia, can impair immune cell function.
Study co-author Melinda Beck, Professor of Nutrition at Gillings School of Global Public Health, said: “All of these factors can influence immune cell metabolism, which determines how bodies respond to pathogens, like the SARS-CoV-2 coronavirus.
“Individuals with obesity are also more likely to experience physical ailments that make fighting this disease harder, such as sleep apnea, which increases pulmonary hypertension, or a body mass index that increases difficulties in a hospital setting with intubation.”
Previous studies by Beck and colleagues found that the influenza vaccine is less effective in adults with obesity.
The same could be true for a future Covid-19 vaccine, according to Beck, who added: “However, we are not saying that the vaccine will be ineffective in populations with obesity, but rather that obesity should be considered as a modifying factor to be considered for vaccine testing. Even a less protective vaccine will still offer some level of immunity.”
It is estimated that around 40% of Americans are obese and the pandemic’s resulting lockdown has led to a number of conditions that make it harder for individuals to achieve or sustain a healthy weight.
Study lead author Barry Popkin, a Professor in the Department of Nutrition and member of the Carolina Population Center, said: “Working from home, limiting social visits and a reduction in everyday activities — all in an effort to stop the spread of the virus — means we’re moving less than ever.”
People have also been able to readily access healthy foods and economic hardships have put those who are already food insecure at further risk, making them more vulnerable to conditions that can arise from consuming unhealthy foods.
Professor Popkin added: “We’re not only at home more and experience more stress due to the pandemic, but we’re also not visiting the grocery store as often, which means the demand for highly processed junk foods and sugary beverages that are less expensive and more shelf-stable has increased.
“These cheap, highly processed foods are high in sugar, sodium and saturated fat and laden with highly refined carbohydrates, which all increase the risk of not only excess weight gain but also key noncommunicable diseases.”
Professor Popkin added that the findings highlight why governments must address the underlying dietary contributors to obesity and implement strong public health policies proven to reduce obesity at a population level.
For example, other countries, like Chile and Mexico, have adopted policies from taxing foods high in sugar to introducing warning labels on packaged foods that are high in sugar, fats and sodium and restricting the marketing of junk foods to children.
Professor Popkin said: “Given the significant threat Covid-19 represents to individuals with obesity, healthy food policies can play a supportive — and especially important — role in the mitigation of Covid-19 mortality and morbidity.”
The NHS recently announced that thousands of people at risk of serious complications from type 2 diabetes could improve their health through a weight loss plan
Find out more about the NHS Healthier You: NHS Diabetes Prevention Programme
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