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

Alterations in Circadian Rhythms, Sleep, and Physical Activity in COVID-19: Mechanisms, Interventions, and Lessons for the Future

Although the world is acquitting from the throes of COVID-19 and returning to the regularity of life, its effects on physical and mental health are prominently evident in the post-pandemic era. The pandemic subjected us to inadequate sleep and physical activities, stress, irregular eating patterns, and work hours beyond the regular rest-activity cycle. Thus, perturbing the synchrony of the regular circadian clock functions led to chronic psychiatric and neurological disorders and poor immunological response in several COVID-19 survivors. Understanding the links between the host immune system and viral replication machinery from a clock-infection biology perspective promises novel avenues of intervention. Behavioral improvements in our daily lifestyle can reduce the severity and expedite the convalescent stage of COVID-19 by maintaining consistent eating, sleep, and physical activity schedules. Including dietary supplements and nutraceuticals with prophylactic value aids in combating COVID-19, as their deficiency can lead to a higher risk of infection, vulnerability, and severity of COVID-19. Thus, besides developing therapeutic measures, perpetual healthy practices could also contribute to combating the upcoming pandemics. This review highlights the impact of the COVID-19 pandemic on biological rhythms, sleep-wake cycles, physical activities, and eating patterns and how those disruptions possibly contribute to the response, severity, and outcome of SARS-CoV-2 infection.

The Effect of Exercise on Immune Response in Population with Increased Risk Factors for Cardiovascular Disease: A Systematic Review

This systematic review aimed to provide information on existing interventional studies that evaluate the efficacy of exercise in populations with increased cardiovascular disease (CVD) risk factors through immune functional perspectives. A literature search was conducted in four databases: PubMed, Scopus, Taylor & Francis and ScienceDirect from January 2012 to February 2023. The articles were screened and evaluated for quality before data were extracted. The review protocol was registered at PROSPERO (CRD42022321704). In total, 18 studies were included for quality appraisal and synthesised evidence indicated that exercise contributes to enhancing the functioning of both innate and adaptive immune responses, potentially serving as an anti-immunosenescent response to exercise in individuals with elevated CVD risk factors. Furthermore, the review emphasised that exercise, irrespective of its type, intensity or mode, was well tolerated by individuals at increased risk for CVD and may have significant implications in generating anti-inflammatory effects.

Blood Profiling of Athletes after COVID-19: Differences in Blood Profiles of Post-COVID-19 Athletes Compared to Uninfected Athletic Individuals-An Exploratory Analysis

Blood profiling data in athletic populations and their respective responses to SARS-CoV-2 infection are lacking. Thus, this exploratory pilot study aimed to analyze and compare clinical blood markers in previously infected trained athletes (ATH; 30 m/29 f) and a not previously infected healthy athletic control group (HC; 12 m/19 f). The ATH group undertook a sports medical examination which included extended blood analyses. Blood profiles with a total of 74 variables were assessed (blood counts, pro-/inflammatory and immunological markers, and micronutrients), and the ATH group was compared to the age-matched, vaccinated HC group with comparable athletic back grounds, though without previous SARS-CoV-2-infections. The ATH group showed lower IgG, Troponin-T levels, and they had a lower complement/acute-phase protein activation. Furthermore, Vitamin D levels were lower and electrolyte/micronutrient concentrations were higher in ATH. Soluble transferrin receptor as a marker of erythrocyte turnover was decreased whereas PTT as a coagulation marker was increased. Subgroup analyses according to sex revealed more differences between the women of the ATH and HC groups (for 25 different variables) than between the men (for 5 different variables), especially for immunological and metabolic variables. In particular, the immune system and electrolyte/micronutrient status should be observed frequently and sex-specifically in this athletic cohort.

The molecular athlete: exercise physiology from mechanisms to medals

Human skeletal muscle demonstrates remarkable plasticity, adapting to numerous external stimuli including the habitual level of contractile loading. Accordingly, muscle function and exercise capacity encompass a broad spectrum, from inactive individuals with low levels of endurance and strength to elite athletes who produce prodigious performances underpinned by pleiotropic training-induced muscular adaptations. Our current understanding of the signal integration, interpretation, and output coordination of the cellular and molecular mechanisms that govern muscle plasticity across this continuum is incomplete. As such, training methods and their application to elite athletes largely rely on a "trial-and-error" approach, with the experience and practices of successful coaches and athletes often providing the bases for "post hoc" scientific enquiry and research. This review provides a synopsis of the morphological and functional changes along with the molecular mechanisms underlying exercise adaptation to endurance- and resistance-based training. These traits are placed in the context of innate genetic and interindividual differences in exercise capacity and performance, with special consideration given to aging athletes. Collectively, we provide a comprehensive overview of skeletal muscle plasticity in response to different modes of exercise and how such adaptations translate from "molecules to medals."

Physical Activity Modifies the Severity of COVID-19 in Hospitalized Patients-Observational Study

BACKGROUND AND AIM

Physical activity (PA) can modulate the immune response, but its impact on infectious disease severity is unknown. We assess if the PA level impacts the severity of COVID-19.

METHODS

Prospective, cohort study for adults hospitalized due to COVID-19, who filled out the International Physical Activity Questionnaire (IPAQ). Disease severity was expressed as death, transfer to intensive care unit (ICU), oxygen therapy (OxTh), hospitalization length, complications, C-reactive protein, and procalcitonin level.

RESULTS

Out of 326 individuals, 131 (57; 43.51% women) were analyzed: age: median-70; range: 20-95; BMI: mean-27.18 kg/m²; and SD: ±4.77. During hospitalization: 117 (83.31%) individuals recovered, nine (6.87%) were transferred to ICU, five (3.82%) died, and 83 (63.36%) needed OxTh. The median for the hospital stay was 11 (range: 3-49) for discharged patients, and mean hospitalization length was 14 (SD: ±5.8312) for deaths and 14.22 days (SD: ±6.92) for ICU-transferred patients. The median for MET-min/week was 660 (range: 0-19,200). Sufficient or high PA was found in recovered patients but insufficient PA was observed in dead or ICU-transferred patients (p = 0.03). The individuals with poor PA had a higher risk of death (HR = 2.63; ±95%CI 0.58-11.93; p = 0.037). OxTh was used more often in the less active individuals (p = 0.03). The principal component analysis confirmed a relationship between insufficient PA and an unfavorable course of the disease.

CONCLUSION

A higher level of PA is associated with a milder course of COVID-19.

Age-related differences in symptoms in older emergency department patients with COVID-19: Prevalence and outcomes in a multicenter cohort

BACKGROUND

Older adults represent a disproportionate share of severe COVID-19 presentations and fatalities, but we have limited understanding of the differences in presentation by age and the association between less typical emergency department (ED) presentations and clinical outcomes.

METHODS

This retrospective cohort study used the RECOVER Network registry, a research collaboration of 86 EDs in 27 U.S. states. We focused on encounters with a positive nasopharyngeal swab for SARS-CoV-2, and described their demographics, clinical presentation, and outcomes. Sequential multivariable logistic regressions examined the strength of association between age cohort and outcomes.

RESULTS

Of 4536 encounters, median patient age was 55 years, 49% were women, and 34% were non-Hispanic Black persons. Cough was the most common presenting complaint across age groups (18-64, 65-74, and 75+): 71%, 67%, and 59%, respectively (p < 0.001). Neurological symptoms, particularly altered mental status, were more common in older adults (2%, 11%, 26%; p < 0.001). Patients 75+ had the greatest odds of ED index visit admission of all age groups (adjusted odds ratio [aOR] 6.66; 95% CI 5.23-8.56), 30-day hospitalization (aOR 7.44; 95% CI 5.63-9.99), and severe COVID-19 (aOR 4.26; 95% CI 3.45-5.27). Compared to individuals with alternate presentations and adjusting for age, patients with typical symptoms (fever, cough and/or shortness of breath) had similar odds of ED index visit admission (aOR 1.01; 95% CI 0.81-1.24), potentially higher odds of 30-day hospitalization (aOR 1.23; 95% CI 1.00-1.53), and greater odds of severe COVID-19 (aOR 1.46; 95% CI 1.12-1.90).

CONCLUSIONS

Older patients with COVID-19 are more likely to have presentations without the most common symptoms. However, alternate presentations of COVID-19 in older ED patients are not associated with greater odds of mechanical ventilation and/or death. Our data highlights the importance of a liberal COVID-19 testing strategy among older ED patients to facilitate accurate diagnoses and timely treatment and prophylaxis.