A study conducted at the Universidade Estadual Paulista (Unesp) indicates that even mild to moderate infection with the new coronavirus can cause imbalances in the cardiovascular system of young adults without preexisting diseases.
The research also indicates that both obesity and a low level of physical activity are determining factors in the post-Covid period, which help to change the autonomic nervous system, responsible for vital functions of the body, such as blood pressure, heart and respiratory rates.
The work, which had the support of the Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp), followed individuals between 20 and 40 years before vaccination.
“These results give us elements to encourage people, even with mild symptoms of Covid, to seek a more thorough diagnosis after contamination. The baggage triggered by the virus can have consequences and the patient does not know”, evaluates the project coordinator, Fábio Santos de Lira, professor at the Department of Physical Education at the Faculty of Science and Technology at Unesp.
The findings were published in the International Journal of Environmental Research and Public Health.
The research is part of a broader project, FIT-COVID, which aims to investigate gaps in scientific knowledge about the disease with a specific focus on immunological, inflammatory and metabolic markers, exploring the effects of physical activity and body composition.
For the study, the researchers recruited patients infected with SARS-CoV-2 in Presidente Prudente, a municipality in the interior of São Paulo with about 231,000 inhabitants and which, by the end of February, had recorded 39,049 confirmed cases of Covid-19 and 982 deaths.
Subjects had a diagnosis confirmed by molecular diagnostic test (RT-PCR) and infection with mild to moderate symptoms. A group of healthy people was selected by age for comparison purposes. In total, 57 people were evaluated, 38 of which were considered in the final result.
The researchers measured the body mass index (BMI), a parameter used to assess overweight and obesity and which corresponds to the ratio between weight and height squared, and levels of physical activity, in addition to the assessment of the autonomic nervous system by through heart rate variability.
The main finding was that, even in mild and moderate infections, young adults infected with SARS-CoV-2 showed: greater sympathetic activity (a system that adjusts the body to withstand situations of danger, intense effort and stress); less parasympathetic activity (responsible for making the body calm down after a stressful situation); and global variability when compared to uninfected individuals.
Which points out that in the post-Covid group there was an increase in heart rate and less activity of the body to “stop” this frequency.
When comparing overweight and obese or physically inactive individuals, cardiac autonomic modulation showed worse rates. With this, the results provide new data on the role of BMI and physical activity in post-Covid-19 infection dysregulation that may contribute to the understanding of the pathophysiology and treatment of later acute symptoms.
“We did not expect such an altered cardiovascular system because they are young and without other diseases. Our work shows that people infected by Covid, even without severe symptoms, can present important functional changes. For example, this variation in heart rate may, in the future, become an arrhythmia”, says Luciele Guerra Minuzzi, a postdoctoral fellow at Unesp.
The reflection of these variations was recorded in the patients’ daily activities, such as the ability to exercise, climb stairs and even walk. They reported tiredness and fatigue. To detect the problem, you can do a simple test known as the six-minute walk test.
According to Luciele, the group had already shown metabolic deregulations – such as a higher concentration of lipids in the bloodstream and altered blood glucose – in patients with SARS-CoV-2 who had more severe conditions and were hospitalized.
Another study published in August last year by scientists at Appalachian State University in North Carolina, in the United States, found that young adults recovering from the disease had autonomic dysregulation. However, the work used an invasive method, while the Brazilian research adopted a simpler, cheaper and non-invasive form of evaluation.
At the time, the conclusion was that there was a prolonged physiological impact of SARS-CoV-2 infection, lasting two to three months, on resting heart rate, which may reflect autonomic dysfunction. The findings were attributed to the increased state of inflammation generated during infection.
Upcoming results
According to Lira, the researchers are now evaluating other results obtained in the analyses, which should be published soon. The project is multicentric and has the participation of scientists from the University of Coimbra and the Polytechnic Institute of Coimbra, Portugal.
In addition, the same patients continue to be followed up after being vaccinated. There has already been an evaluation six weeks after the vaccine and the next one will be at the 18th month post-immunization.
Basic care helps prevent Covid-19
Source: CNN Brasil
