Angiotensin-(1-7) and Obesity: Role in Cardiorespiratory Fitness and COVID-19 Implications

Nutritional implications in the mechanistic link between the intestinal microbiome, renin-angiotensin system, and the development of obesity and metabolic syndrome

Obesity and metabolic disorders represent a significant global health problem and the gut microbiota plays an important role in modulating systemic homeostasis. Recent evidence shows that microbiota and its signaling pathways may affect the whole metabolism and the Renin-Angiotensin System (RAS), which in turn seems to modify microbiota. The present review aimed to investigate nutritional implications in the mechanistic link between the intestinal microbiome, renin-angiotensin system, and the development of obesity and metabolic syndrome components. A description of metabolic changes was obtained based on relevant scientific literature. The molecular and physiological mechanisms that impact the human microbiome were addressed, including the gut microbiota associated with obesity, diabetes, and hepatic steatosis. The RAS interaction signaling and modulation were analyzed. Strategies including the use of prebiotics, symbiotics, probiotics, and biotechnology may affect the gut microbiota and its impact on human health.

Potential Physiological and Cellular Mechanisms of Exercise That Decrease the Risk of Severe Complications and Mortality Following SARS-CoV-2 Infection

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has unmasked mankind's vulnerability to biological threats. Although higher age is a major risk factor for disease severity in COVID-19, several predisposing risk factors for mortality are related to low cardiorespiratory and metabolic fitness, including obesity, cardiovascular disease, diabetes, and hypertension. Reaching physical activity (PA) guideline goals contribute to protect against numerous immune and inflammatory disorders, in addition to multi-morbidities and mortality. Elevated levels of cardiorespiratory fitness, being non-obese, and regular PA improves immunological function, mitigating sustained low-grade systemic inflammation and age-related deterioration of the immune system, or immunosenescence. Regular PA and being non-obese also improve the antibody response to vaccination. In this review, we highlight potential physiological, cellular, and molecular mechanisms that are affected by regular PA, increase the host antiviral defense, and may determine the course and outcome of COVID-19. Not only are the immune system and regular PA in relation to COVID-19 discussed, but also the cardiovascular, respiratory, renal, and hormonal systems, as well as skeletal muscle, epigenetics, and mitochondrial function.

A Possible Preventive Role of Physically Active Lifestyle during the SARS-CoV-2 Pandemic; Might Regular Cold-Water Swimming and Exercise Reduce the Symptom Severity of COVID-19?

The objective of this study was to investigate the incidence and course of COVID-19 and the risk of an upper respiratory tract infection in a group of people with physically active lifestyles. Data were collected anonymously using an online survey platform during December 2020. The age of participants ranged from 18 to 65 years. Out of 2343 participants, 11.5% overcame COVID-19 infection. Relative to the control group (CTRL), physically active, cold-water swimmers (PACW) did not exhibit a lower risk of incidence for COVID-19 (RR 1.074, CI 95% (0.710–1.625). However, PACW had a higher chance of having an asymptomatic course of COVID-19 (RR 2.321, CI 95% (0.836–6.442); p < 0.05) and a higher chance of only having an acute respiratory infection once or less per year than CTRL (RR 1.923, CI 95% (1.1641–2.253); p < 0.01). Furthermore, PACW exhibited a lower incidence of acute respiratory infection occurring more than twice per year (RR 0.258, CI 95% (0.138–0.483); p < 0.01). Cold-water swimming and physical activity may not lessen the risk of COVID-19 in recreational athletes. However, a physically active lifestyle might have a positive effect on the rate of incidence of acute respiratory infection and on the severity of COVID-19 symptoms.

Dual role for angiotensin-converting enzyme 2 in Severe Acute Respiratory Syndrome Coronavirus 2 infection and cardiac fat

Angiotensin-converting enzyme 2 (ACE2) has been an increasingly prevalent target for investigation since its discovery 20 years ago. The finding that it serves a counterregulatory function within the traditional renin-angiotensin system, implicating it in cardiometabolic health, has increased its clinical relevance. Focus on ACE2's role in cardiometabolic health has largely centered on its apparent functions in the context of obesity. Interest in ACE2 has become even greater with the discovery that it serves as the cell receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), opening up numerous mechanisms for deleterious effects of infection. The proliferation of ACE2 within the literature coupled with its dual role in SARS-CoV-2 infection and obesity necessitates review of the current understanding of ACE2's physiological, pathophysiological, and potential therapeutic functions. This review highlights the roles of ACE2 in cardiac dysfunction and obesity, with focus on epicardial adipose tissue, to reconcile the data in the context of SARS-CoV-2 infection.