Obesity triples complications from Covid, studies show

Obesity is already recognized as a risk factor for Covid-19 and also for other viral infections. New studies, however, seek to better understand the impacts that excessive fat accumulation and associated diseases have on different age groups — and also the benefits that medical interventions for weight reduction would bring in reducing complications.

In Brazil, overweight already affects a large part of the population and has been growing over time. Data from the PNS (National Health Survey), carried out by the IBGE (Brazilian Institute of Geography and Statistics), show that, in 2019, obesity was recorded in about 26% of Brazilians over 20 years old. In comparison, in 2003, this percentage was 12%.

One such research was recently published in the scientific journal Jama Surgery. Signed by researchers at the Cleveland Clinic, in the United States, the study was composed of 2,958 people who had undergone weight reduction surgery and were followed up during the pandemic.

In addition to these, there was the control group, composed of more than 8,000 individuals who were obese and had not undergone surgery.

The intent of the research was to compare the two groups to understand whether surgical intervention for weight reduction could reduce the risks of coronavirus.

The researchers focused their analysis on four points: positive result for Covid-19, hospitalizations, need for supplemental oxygenation and serious situations with the disease (hospitalization in ICU, mechanical ventilation or death).

In the results, it was observed that the rate of positive tests for Covid was similar in the two groups, but the worsening by the disease was considerably greater in those who did not have weight reduction.

The most serious outcomes, such as ICU admission, need for mechanical ventilation or death, reached three times more than the control group. The need for supplemental oxygenation had a similar rate, while hospitalization recorded almost twice as many records in this group.

Made by Brazilian researchers and published in The Lancet Regional Health Americas, a second recent study deepened the findings on obesity and Covid, focusing on the division by age groups and also on the analysis of diseases associated with excessive weight accumulation.

The work compared obesity, cardiovascular disease and diabetes in three age groups. In this way, it was possible to understand the risks that a person with these comorbidities has of developing more critical cases of Covid, in contrast to those who, in the same age group, do not have them.

In the analyses, the researchers identified that young people with diabetes, cardiovascular complications and obesity were seven times more likely to die from contracting Covid-19 compared to people in the same age group who did not have these previous diseases.

For the elderly, these risks significantly lessened the chances of dying from the coronavirus, indicating that obesity and associated diseases have a greater impact on younger people.

“When looking at youth with comorbidities versus youth without comorbidities, [aqueles] are closely associated with an enormous risk of dying. Elderly people with and without comorbidity have almost no difference because the fact that they are elderly is already increasing [a chance de óbito]”, explains Helder Nakaya, a senior researcher at Einstein and one of the authors of the research.

By identifying this aspect, the authors defend the need to prioritize young people who have these comorbidities during vaccination campaigns, in order to reduce mortality caused by diseases such as Covid-19.

“This work may help guide public policies in the sense that it scientifically shows that this is a relevant risk group, which deserves to be prioritized in future vaccination campaigns”, says Nakaya.

The understanding that obesity worsens infections is already well established. According to Ricardo Cohen, coordinator of the Obesity and Diabetes Center at the Hospital Alemão Oswaldo Cruz, this perception probably dates back to the Spanish flu pandemic, which occurred in the early 20th century.

“Whoever had the most weight died,” says Cohen.

However, there is still a lack of studies that consolidate why the accumulation of fat contributes to these complications. According to Nakaya, a possible way to understand this pattern is because of the inflammatory process.

The researcher explains that “Obesity is considered an inflammatory disease, so if you get an obese person, you’re going to see increased baseline levels of inflammation.” By joining this already inflamed organism with another disease that increases the inflammatory process even more, such as Covid, “this can cause death, because the person inflames very quickly”.

Another possible explanation comes from a study, also signed by Nakaya, which consisted of analyzing the autopsy of 14 lungs of patients who had died from Covid-19 and had obesity, diabetes or hypertension. In addition to these, there were also four other lungs for a control group.

“People with obesity had gene changes in the lung that probably explained why they died,” he says, about a possible genetic explanation for why obesity makes Covid worse.

Even so, he points out, this finding is not necessarily indicative that it can be replicated for other individuals, as the study “was done with a much smaller number of people.”

For Cohen, it is important to understand that treatment for obesity — especially when it is associated with other diseases, such as diabetes and hypertension — is essential for the pandemic we are experiencing and for others that we may face.

“If I had control of diabesity [junção da diabetes e obesidade], we would certainly have gone through the Covid-19 pandemic and the next pandemics with much more tranquility”, he says.

He says that in 2019, there were 70,000 bariatric surgeries, but that only represents 2% of the population that should be operated on. The doctor also cites the emergence of drugs that treat obesity, but still with little adherence in the country.