- A study of young Brazilian adults finds that even a mild-to-moderate case of COVID-19 can unbalance the autonomic nervous system, potentially leading to cardiovascular issues that become evident later in life.
- COVID-19’s effect on the autonomic nervous system makes sense considering how many organs and systems it seems to affect.
- Keeping a healthy body mass index (BMI) and maintaining a physically active lifestyle may reduce the imbalance.
A new study from São Paulo State University (UNESP) in Brazil, which worked with a cohort of young adults, found that COVID-19, even in mild-to-moderate cases, can disrupt the autonomous nervous system’s critical balancing act.
COVID-19 may thus quietly trigger cardiovascular problems that do not make themselves known until later in life.
COVID-19 has shown a perplexing ability to affect multiple organ systems, and the means by which this occurs is not yet fully understood. If the virus damages the effectiveness of the ANS, which is involved in the management of multiple systems, at least a partial explanation may be at hand.
Study co-author Prof. Fábio Santos de Lira of UNESP explained for Medical News Today:
“The autonomic nervous system controls the heart rate — the sympathetic nervous system activity maintains a higher heart rate, and parasympathetic activity reduces heart rate. This condition can favor, later, a heart dysfunction, [such] as
The sympathetic nervous system is responsible for the body’s response to stress, danger, and intense effort. In the case of the heart, it pushes the heart rate upwards. This increase is held down to acceptable boundaries by the parasympathetic nervous system that manages everyday bodily functions, such as digestion, resting, recharging.
The study also found that maintaining a healthy BMI and a physically active lifestyle appears to help keep the ANS in proper balance, suggesting that further research should look into mitigating the lasting worrying effects of COVID-19.
The new study appears in MDPI.
The cross-sectional, observational study took place in the town of Presidente Prudent, a community with some 232,000 inhabitants, which had 39,049 cases of COVID-19 by February 2022, and 982 deaths.
The researchers recruited male and female participants aged 20 to 40 who had tested positive for COVID-19 through a PCR test within 15 to 180 days before the analysis began.
After excluding individuals with chronic non-communicable diseases, a history of smoking, drug use, and taking anti-inflammatory drugs or antibiotics known to affect the ANS, the final cohort consisted of nine women and 11 men.
To assess the functioning of their ANS, researchers measured the participants’ heart rate variability (HRV), a measurement of the variation of time between each heartbeat.
Professor de Lira explained that the “simplest form of evaluating this circuit is by heart rate variability, where the watch captures the information and we can observe it in software.”
If the HRV is too high, the ANS is not operating smoothly, with the sympathetic and parasympathetic sides at odds with each other.
The researchers found that even with mild-to-moderate bouts of COVID-19, sympathetic activity increased while parasympathetic activity diminished.
The reduction of parasympathetic activity was especially pronounced in individuals with overweight or obesity.
The data also implied that leading a physically active lifestyle left an individual’s ANS in better balance. However, the study authors suggest that exercise may actually be a confounding factor because “the differences observed in HRV might be primarily modulated by levels of physical activity and not by the presence of post-COVID-19.”
In the study paper, the authors go on to caution that: “It is known that exercise promotes positive adaptations in HRV parameters in both control subjects and patients suffering from a variety of diseases. Similarly, both exercise training and physical activity habits improve heart rate variability parameters, the autonomic profile, and arterial compliance, as well as the baroreflex sensitivity in HIV+ patients, highlighting the impact of lifestyle habits to modulate ANS in viral conditions.”
Prof. de Lira recommended committing to a healthy lifestyle to offset the impact of COVID-19.
“Excess adipose tissue is related to several diseases, in addition to obesity, such as type 2 diabetes, dyslipidemia, fatty liver, cancer, kidney failure, among others,” he explained. “In the same sense, the sedentary lifestyle favors the gain of body fat, which will trigger or worsen obesity.“
“Thus, it is extremely important to maintain body weight, especially low body fat — nothing too athletic — [with] BMI ranges between 18-24.99, as well as maintaining a physical activity routine, such as walking, cycling, swimming, running, go walking to the bakery. This lifestyle will add protection against the consequences of COVID-19,” he advised.
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