The cytokine response to physical activity and training

Effect of physical activity on sleep in women experiencing vasomotor symptoms during menopause: a systematic review and meta-analysis

Hot flashes and night sweats, common vasomotor symptoms (VMS) during menopause, are strongly associated with poor sleep quality and disorders. Physical activity is proposed as a strategy to improve menopausal health and sleep outcomes. This systematic review and meta-analysis synthesizes and evaluates evidence on the relationship between physical activity and sleep parameters in women experiencing VMS. Comprehensive searches were conducted in October 2024 across multiple databases, including MEDLINE/PubMed, Cochrane Library, and EMBASE, alongside manual backward and forward searches. Randomized controlled trials (RCTs) investigating physical activity or exercise interventions and their effects on subjective and objective sleep outcomes in women with VMS were included. The risk of bias was assessed using the revised Cochrane RoB 2 tool, and data were pooled for meta-analysis. Nine studies with a total of 1579 participants were analyzed. Physical activity interventions did not significantly improve sleep quality (-0.03 [-1.23, 1.18]; P = 0.96; I2 = 78 %) or insomnia (-1.65 [-3.52, 0.21]; P = 0.08; I2 = 0 %) but produced minor improvements in sleep problems (-0.08 [-0.16, -0.00]; P = 0.04; I2 = 0 %). Despite concerns regarding bias, none of the studies were classified as high-risk, supporting result reliability. The findings suggest heterogeneity in the effects of physical activity on sleep, influenced by intervention-specific factors like type, frequency, intensity, timing, and duration. Environmental variables may also moderate these outcomes, highlighting the complexity of sleep regulation and the need for tailored approaches to improve sleep in menopausal women. Review protocol is registered in PROSPERO: CRD42024599593.

Enhancement of Interferon-γ Secretion by Lepidium meyenii Extract Supplementation After Exhaustive Endurance Exercise in Healthy Men: A Double-blind, Placebo-controlled Trial

Aim: To investigate the effects of 12-week Lepidium Meyenii extract supplementation on immune responses and inflammatory cytokines after exhaustive endurance exercise (EEE), emphasizing its novel focus on peripheral blood mononuclear cells (PBMCs) cytokine secretion and the implications of interferon-γ (IFN-γ) as a marker for immune modulation. Methods: Twenty healthy men were recruited and assigned into maca and placebo groups using a matched-pair design based on their maximal oxygen consumption (V̇O2max). All participants consumed 2.25 g of maca or placebo twice per day for 12 weeks, and they then performed EEE. Researchers collected blood samples before exercise, immediately after exercise, and at 2, 4, and 24 hours post-exercise to analyze immune functions and inflammatory markers. Results: No significant differences were observed in the variables between the two groups before supplementation. However, interferon-γ levels from peripheral blood mononuclear cells were significantly higher in the maca group than in the placebo group immediately and at 24 hours after exercise. Regarding the main time effect, the number of lymphocytes in all participants was significantly lower at 2 and 4 hours after exercise than before supplementation. The CD4+/CD8+ ratio in the groups was significantly lower immediately after exercise than before supplementation, and the ratio retuned to baseline levels at 2 hours after exercise. Conclusion: A 60-minute EEE session induces the open window phenomenon, characterized by immune suppression. Moreover, 12-week maca supplementation had positive effects only on interferon-γ levels from peripheral blood mononuclear cells.

Sexual dimorphism on the acute effect of exercise in the morning vs. evening: A randomized crossover study

BACKGROUND

Mammalian cells possess molecular clocks, the adequate functioning of which is decisive for metabolic health. Exercise is known to modulate these clocks, potentially having distinct effects on metabolism depending on the time of day. This study aimed to investigate the impact of morning vs. evening moderate-intensity aerobic exercise on glucose regulation and energy metabolism in healthy men and women. It also aimed to elucidate molecular mechanisms within skeletal muscle.

METHODS

Using a randomized crossover design, healthy men (n = 18) and women (n = 17) performed a 60-min bout of moderate-intensity aerobic exercise in the morning and evening. Glucose regulation was continuously monitored starting 24 h prior to the exercise day and continuing until 48 h post-exercise for each experimental condition. Energy expenditure and substrate oxidation were measured by indirect calorimetry during exercise and at rest before and after exercise for 30 min. Skeletal muscle biopsies were collected immediately before and after exercise to assess mitochondrial function, transcriptome, and mitochondrial proteome.

RESULTS

Results indicated similar systemic glucose, energy expenditure, and substrate oxidation during and after exercise in both sexes. Notably, transcriptional analysis, mitochondrial function, and mitochondrial proteomics revealed marked sexual dimorphism and time of day variations.

CONCLUSION

The sexual dimorphism and time of day variations observed in the skeletal muscle in response to exercise may translate into observable systemic effects with higher exercise-intensity or chronic exercise interventions. This study provides a foundational molecular framework for precise exercise prescription in the clinical setting.

Cross-sectional analysis of blood leukocyte responsiveness to interleukin-10 and interleukin-6 across age and physical activity level

Objectives

To determine how the anti-inflammatory actions of interleukin-10 (IL-10) and IL-6 differ across age and physical activity levels.

Methods

Using a cross-sectional design, fasted blood samples were obtained from younger physically inactive (YI: n=10, age: 22.7 ± 3.7 years, BMI: 24.8 ± 4.8 kg/m2, <150 min of weekly moderate-to-vigorous physical activity [MVPA]), younger highly active (YA: n=11 varsity cross country running athletes, 20.7 ± 2.7 years, 21.1 ± 1.8 kg/m2, >300 min of weekly MVPA), and older highly active (OA: 12, 56.0 ± 10.3 years, 22.8 ± 3.2 kg/m2, >300 min of weekly MVPA) individuals and analyzed for leukocyte counts, IL-10 and IL-6-related signaling, and cytokine secretion ex vivo.

Results

Total white blood cells and monocytes were similar between groups (p=0.8) but YA and OA had lower lymphocyte counts than YI (p<0.01). The ability of IL-10 (1 ng/mL) to phosphorylate signal transducer and activator of transcription 3 (STAT3) in CD14 monocytes was greater in YA vs. YI (p<0.03) despite YA having lower IL-10 receptor expression (p<0.01). IL-6 (10 ng/mL) mediated STAT3 phosphorylation in CD4 lymphocytes was higher in OA compared YI (p<0.01), with a similar tendency observed for YA vs. YI (p=0.08). Despite enhanced responsiveness of STAT3 to IL-10/6 in active individuals, the ability of IL-10/6 to inhibit tumor necrosis factor-alpha (TNF-⍺) secretion from lipopolysaccharide-stimulated whole-blood was similar between groups.

Conclusions

Highly active younger and older individuals demonstrate enhanced IL-10- and IL-6-mediated activation of immune cell STAT3. Although the ability of IL-10/6 to inhibit TNF-⍺ secretion appeared unimpacted by activity level, anti-inflammatory cytokine actions were preserved in older active individuals.

Causal association of circulating cytokines with sarcopenia-related traits: A Mendelian randomization study

BACKGROUND

Observational studies have reported that circulating cytokines are associated with sarcopenia. However, the causal relationship between circulating cytokines and sarcopenia has not been elucidated.

OBJECTIVES

This study aimed to investigate the causal relationship between circulating cytokines and sarcopenia with genetic data using Mendelian randomization (MR).

METHODS

Two-sample bidirectional MR analysis was performed to investigate the causal relationship in individuals of European ancestry. The publicly available genome-wide association study statistics were used to select the key eligible single nucleotide polymorphisms significantly associated with circulating cytokines. Multiple MR analysis approaches, including inverse variance weighted (IVW), MR-Egger, weighted median method (WMM), and MR-Pleiotropy residual Sum and Outlier (MR-PRESSO) methods, were used for the analysis. Sarcopenia-related traits were appendicular lean mass (ALM) and grip strength.

RESULTS

This study demonstrated the causal effect of genetically predicted circulating interleukin interleukin-16 (IL16) levels on both ALM [odds ratio (OR) = 0.990, 95% confidence interval (CI): 0.980-1.000, P = 0.049] and grip strength (OR = 0.971, 95% CI: 0.948-0.995, P = 0.020]. Additionally, C-X-C motif chemokine ligand 10 (CXCL10), interleukin-1beta (IL1B), and hepatocyte growth factor (HGF) were correlated with ALM, while vascular endothelial growth factor (VEGF), interleukin-12 (IL12), and interleukin-15 (IL15) were correlated with grip strength. The results of MR-Egger, weighted median, weighted mode, and simple mode methods were consistent with the IVW estimates. Sensitivity analysis revealed that horizontal pleiotropy did not bias the causal estimates.

CONCLUSION

These findings indicate that inflammatory cytokines exert a significant causal effect on sarcopenia and provide promising leads for the development of novel therapeutic targets for the disease. By evaluating the role of circulating cytokines in the pathologic condition via a genetic epidemiological approach, our study made contributions to a further investigation of underlying mechanisms of sarcopenia.

Deconstructing depression by machine learning: the POKAL-PSY study

Unipolar depression is a prevalent and disabling condition, often left untreated. In the outpatient setting, general practitioners fail to recognize depression in about 50% of cases mainly due to somatic comorbidities. Given the significant economic, social, and interpersonal impact of depression and its increasing prevalence, there is a need to improve its diagnosis and treatment in outpatient care. Various efforts have been made to isolate individual biological markers for depression to streamline diagnostic and therapeutic approaches. However, the intricate and dynamic interplay between neuroinflammation, metabolic abnormalities, and relevant neurobiological correlates of depression is not yet fully understood. To address this issue, we propose a naturalistic prospective study involving outpatients with unipolar depression, individuals without depression or comorbidities, and healthy controls. In addition to clinical assessments, cardiovascular parameters, metabolic factors, and inflammatory parameters are collected. For analysis we will use conventional statistics as well as machine learning algorithms. We aim to detect relevant participant subgroups by data-driven cluster algorithms and their impact on the subjects' long-term prognosis. The POKAL-PSY study is a subproject of the research network POKAL (Predictors and Clinical Outcomes in Depressive Disorders; GRK 2621).

Direct assessment of leukocyte signalling and cytokine secretion reveals exercise intensity-dependent reductions in anti-inflammatory cytokine action

Circulating interleukin (IL)-6 and IL-10 concentrations are widely used to evaluate the anti-inflammatory effects of exercise but do not capture cytokine action at the cellular level. Whether and how acute exercise impacts anti-inflammatory cytokine action in humans is unknown. To determine how exercise intensity and pattern impact IL-6 and IL-10 action in blood leukocytes, 16 active adults (eight males/eight females; age: 30 ± 3 years; body mass index: 22.8 ± 2.3 kg/m2;V ̇ O 2 peak ${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}{\mathrm{peak}}}}$ : 51 ± 6 mL/kg/min) completed a no-exercise control condition (CTL) or isocaloric bouts of cycling performed below (moderate continuous exercise; MCE) or above (heavy continuous or heavy intermittent exercise; HCE or HIE, respectively) lactate threshold. Venous blood (before, after, 30 min after and 90 min after exercise) was analysed for immune cell subpopulations, plasma cytokine concentrations, anti-inflammatory cytokine action and monocyte phenotype. Exercise induced rapid leukocytosis (P < 0.001) and increased plasma IL-6 (P < 0.001), IL-10 (P = 0.0145) and tumour necrosis factor-⍺ (TNF-⍺) (P = 0.0338) concentrations in an intensity-dependent manner (HCE and/or HIE vs. CTL). These systemic changes coincided with a diminished ability of IL-10/6 to phosphorylate STAT3 (P < 0.001) and inhibit TNF-⍺ secretion (P = 0.0238) in blood leukocytes following HCE and HIE. Monocyte polarization experiments revealed lower CD80 [MCE (P = 0.0933) and HIE (P = 0.0187) vs. CTL] and a tendency for higher CD163 expression (HCE vs. CTL, P = 0.0985), suggesting that hyporesponsiveness to anti-inflammatory cytokine action does not impede the ability of exercise to promote an anti-inflammatory monocyte phenotype. These findings provide novel insights into the immunomodulatory effects of exercise in humans and highlight the importance of directly measuring cellular cytokine action when evaluating the anti-inflammatory effects of exercise. KEY POINTS: Circulating cytokine concentrations are frequently used to evaluate the anti-inflammatory effects of exercise but may not capture changes in cytokine action occurring at the cellular level. We directly assessed anti-inflammatory cytokine action - measured using a combination of intracellular signalling and cytokine secretion ex vivo - in distinct immune cell subpopulations after acute calorie-matched exercise bouts differing in intensity and pattern. Anti-inflammatory cytokine action was blunted following higher intensity exercise despite corresponding increases in circulating cytokine concentrations and immune cell counts. Changes in cytokine action were not explained by changes in cytokine receptor expression on circulating immune cells. Our findings provide new insights into the immunomodulatory effects of exercise in humans and highlight the importance of directly measuring cellular cytokine action when evaluating the anti-inflammatory effects of exercise.

Immunology of Physical Exercise: Is Equus caballus an Appropriate Animal Model for Human Athletes?

Domestic horses routinely participate in vigorous and various athletic activities. This enables the horse to serve as a model for studying athletic physiology and immunology in other species, including humans. For instance, as a model of physical efforts, such as endurance rides (long-distance running/aerobic exercise) and races (anaerobic exercise), the horse can be useful in evaluating post-exercise response. Currently, there has been significant interest in finding biomarkers, which characterize the advancement of training and adaptation to physical exercise in the horse. The parallels in cellular responses to physical exercises, such as changes in receptor expression and blood cell activity, improve our understanding of the mechanisms involved in the body's response to intense physical activity. This study focuses on the changes in levels of the pro- and anti-inflammatory cytokines and cellular response in the context of post-exercise immune response. Both the direction of changes in cytokine levels and cellular responses of the body, such as proliferation and expression of surface markers on lymphocytes, monocytes and neutrophils, show cross-functional similarities. This review reveals that horses are robust research models for studying the immune response to physical exercise in human athletes.

Effect of Physical Activity during Pregnancy on the Risk of Hypertension Disorders and Gestational Diabetes: Evidence Generated by New RCTs and Systematic Reviews

Hypertensive disorders of pregnancy (HDP) and gestational diabetes mellitus (GDM) are the most common medical complications in pregnancy. Physical exercise is considered to be safe and beneficial during pregnancy. Moreover, pregnancy could be considered as an opportunity for healthcare providers to promote positive lifestyle behavior and optimize the well-being of pregnant women. Since there are few up-to-date reviews evaluating the role of exercise and the risks of developing obstetrical complications, we performed a review to investigate the effects of physical activity and exercise during pregnancy compared to a control group, focusing on the risk of development of HDP and GDM. We searched Medline and Web of Science, including only randomized controlled trials (RCTs) and systematic reviews. This review supports a beneficial effect of exercise and provides evidence that it significantly decreases the risk of HDP and GDM.

Exposure to parental depression in adolescence and proinflammatory phenotypes 20 years later

Although the biological embedding model of adversity proposes that stressful experiences in childhood create a durable proinflammatory phenotype in immune cells, research to date has relied on study designs that limit our ability to make conclusions about whether the phenotype is long-lasting. The present study leverages an ongoing 20-year investigation of African American youth to test research questions about the extent to which stressors measured in childhood forecast a proinflammatory phenotype in adulthood, as indicated by exaggerated cytokine responses to bacterial stimuli, monocyte insensitivity to inhibitory signals from hydrocortisone, and low-grade inflammation. Parents reported on their depressive symptoms and unsupportive parenting tendencies across youths' adolescence. At age 31, youth participants (now adults) completed a fasting blood draw. Samples were incubated with lipopolysaccharide and doses of hydrocortisone to evaluate proinflammatory processes. Additionally, blood samples were tested for indicators of low-grade inflammation, including IL-6, IL-8, IL-10, and TNF-α, and soluble urokinase plasminogen activator receptor. Analyses revealed that parental depression across youths' adolescence prospectively predicted indicators of proinflammatory phenotypes at age 31. Follow-up analyses suggested that unsupportive parenting mediated these associations. These findings suggest that exposure to parental depression in adolescence leaves an imprint on inflammatory activity that can be observed 20 years later.

Moderate Exercise Modulates Inflammatory Responses and Improves Survival in a Murine Model of Acute Pneumonia

OBJECTIVES

An association between physical inactivity and worse outcome during infectious disease has been reported. The effect of moderate exercise preconditioning on the immune response during an acute pneumonia in a murine model was evaluated.

SETTING

Laboratory experiments.

SUBJECTS

C57BL6/j male mice.

INTERVENTIONS

Six-week-old C57BL/6J mice were divided in two groups: an exercise group and a control group. In the exercise group, a moderate, progressive, and standardized physical exercise was applied for 8 weeks. It consisted in a daily treadmill training lasting 60 minutes and with an intensity of 65% of the maximal theoretical oxygen uptake. Usual housing recommendation were applied in the control group during the same period. After 8 weeks, pneumonia was induced in both groups by intratracheal instillation of a fixed concentration of a Klebsiella pneumoniae (5 × 103 colony-forming unit) solution.

MEASUREMENTS AND MAIN RESULTS

Mice preconditioned by physical exercise had a less sever onset of pneumonia as shown by a significant decrease of the Mouse Clinical Assessment Severity Score and had a significantly lower mortality compared with the control group (27% vs. 83%; p = 0.019). In the exercise group, we observed a significantly earlier but transient recruitment of inflammatory immune cells with a significant increase of neutrophils, CD4+ cells and interstitial macrophages counts compared with control group. Lung tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and IL-10 were significantly decreased at 48 hours after pneumonia induction in the exercise group compared with the control group.

CONCLUSIONS

In our model, preconditioning by moderate physical exercise improves outcome by reducing the severity of acute pneumonia with an increased but transient activation of the innate immune response.

Association between Circulating Levels of CXCL9 and CXCL10 and Physical Frailty in Older Adults

INTRODUCTION

Dysregulation of pro-inflammatory chemokines is considered a potential mechanism for the development of age-related medical conditions such as frailty. However, evidence linking circulating chemokines with frailty remains lacking.

MATERIALS AND METHODS

We performed a case-control study including 48 cases and 48 controls aged 65-90 years, using the National Center for Geriatrics and Gerontology outpatient registry data. Cases were outpatients with physical frailty and low habitual daily activity. Controls were robust outpatients who performed habitual daily activities. The Japanese version of the Cardiovascular Health Study criteria was used to diagnose physical frailty, and the modified Baecke questionnaire was used to evaluate habitual daily activities. Serum CXCL9 and CXCL10 levels were measured using enzyme-linked immunosorbent assay.

RESULTS

The median age (interquartile range) in cases and controls was 78 (73-83) and 76 (72-80) years, with the proportions of men were 47.9% and 43.8%, respectively. In the logistic regression model with adjustment for age, sex, and other confounding factors, the multivariable odds ratios (95% confidence intervals) for the highest versus lowest tertile of CXCL9 and CXCL10 levels were 7.90 (1.61-49.80) and 1.61 (0.42-6.30), respectively. However, we did not observe a linear association between CXCL9 levels and physical frailty components.

DISCUSSION/CONCLUSION

Our preliminary data exhibit that circulating CXCL9 levels were positively associated with the odds of physical frailty. However, these findings lack evidence of a dose-response relationship between CXCL9 levels and physical frailty components. Further research with a larger sample size is required to confirm these findings.

Impacts of different triathlon races on systemic cytokine profile and metabolic parameters in healthy individuals: a systematic review

The present systematic review aimed to discuss the impacts of different triathlon protocols on the level of pro and anti-inflammatory cytokines, as well as biomarkers related to the performance of healthy individuals. Four databases [PubMed (28 articles), Scopus (24 articles), Science Direct (200 articles), and SPORT Discus (1101 articles) were assessed. The eligibility criteria were applied, and the selected articles were used in the peer review, independently, as they were identified by March 2022. Of the 1359 articles found, 10 were included in this systematic review. Despite the difference in triathlon protocols, it was observed an increase in pro and anti-inflammatory cytokines including IL-4 and IL-10, and chemokines, such as IL-8 and MCP-1. Moreover, the anti-inflammatory serum levels increase after triathlon. Overall, the studies also reported enhancement in the serum levels of cortisol, creatine kinase, C reactive protein, Endothelial Growth Factor, Vascular Endothelial Growth Factor, Myostatin, Lactate dehydrogenase, free fatty acids, and lactate dehydrogenase in triathlon athletes. This systematic review indicates that different triathlon race promotes an acute elevation of circulating cytokines and chemokines levels which return to standard levels after triathlon races. The findings of this systematic review demonstrate that the modulation of inflammatory parameters may be associated with an increase in metabolic indicators (CK, Cortisol, and LDH) after the end of different types of triathlon races.

A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 1: Foundational principles and theories of regulation

This contribution is the first of a four-part, historical series encompassing foundational principles, mechanistic hypotheses and supported facts concerning human thermoregulation during athletic and occupational pursuits, as understood 100 years ago and now. Herein, the emphasis is upon the physical and physiological principles underlying thermoregulation, the goal of which is thermal homeostasis (homeothermy). As one of many homeostatic processes affected by exercise, thermoregulation shares, and competes for, physiological resources. The impact of that sharing is revealed through the physiological measurements that we take (Part 2), in the physiological responses to the thermal stresses to which we are exposed (Part 3) and in the adaptations that increase our tolerance to those stresses (Part 4). Exercising muscles impose our most-powerful heat stress, and the physiological avenues for redistributing heat, and for balancing heat exchange with the environment, must adhere to the laws of physics. The first principles of internal and external heat exchange were established before 1900, yet their full significance is not always recognised. Those physiological processes are governed by a thermoregulatory centre, which employs feedback and feedforward control, and which functions as far more than a thermostat with a set-point, as once was thought. The hypothalamus, today established firmly as the neural seat of thermoregulation, does not regulate deep-body temperature alone, but an integrated temperature to which thermoreceptors from all over the body contribute, including the skin and probably the muscles. No work factor needs to be invoked to explain how body temperature is stabilised during exercise.

Impact of Chlorogenic Acid on Peripheral Blood Mononuclear Cell Proliferation, Oxidative Stress, and Inflammatory Responses in Racehorses during Exercise

Green coffee extract is currently of great interest to researchers due to its high concentration of chlorogenic acid (CGA) and its potential health benefits. CGA constitutes 6 to 10% of the dry weight of the extract and, due to its anti-inflammatory properties, is a promising natural supplement and agent with therapeutic applications. The purpose of our study was to discover the effects of CGA on peripheral blood mononuclear cell proliferation, and the production of pro- and anti-inflammatory cytokines as well as reactive oxidative species (ROS) in horses during exercise. According to the findings, CGA can affect the proliferation of T helper cells. In addition, at a dose of 50 g/mL, CGA increased the activation of CD4+FoxP3+ and CD8+FoxP3+ regulatory cells. Physical activity decreases ROS production in CD5+ monocytes, but this effect depends on the concentration of CGA, and the effect of exercise on oxidative stress was lower in CD14+ than in CD5+ cells. Regardless of CGA content, CGA significantly increased the release of the anti-inflammatory cytokine IL-10. Moreover, the production of IL-17 was greater in cells treated with 50 g/mL of CGA from beginners compared to the control and advanced groups of horses. Our findings suggest that CGA may have immune-enhancing properties. This opens new avenues of research into the mechanisms of action of CGA and possible applications in prevention and health promotion in sport animals.

The Effect of Moderate-Intensity Physical Exercise on Some Serum Inflammation Markers and the Immune System in Rats Fed Intermittent Fasting with a High-Fat Diet

Background and Objectives: This study aimed to investigate the impact of moderate-intensity physical exercise on serum inflammation markers and the immune system in rats that were fed a high-fat diet (HFD) with intermittent fasting. Materials and Methods: A total of 48 Wistar albino male rats were included in the study and divided into eight groups, each consisting of six rats. Group 1 served as the control group (CG), receiving a standard diet. Group 2 followed the standard nutrition program with intermittent fasting (CG + IF). Group 3 underwent exercise with a standard diet (CG + E). Group 4 underwent both a standard diet with intermittent fasting and exercise (CG + IF + E). Group 5 was fed a high-fat diet (HFD). Group 6 received a high-fat diet with intermittent fasting (HFD + IF). Group 7 followed a high-fat diet with exercise (HFD + E). Group 8 underwent both a high-fat diet with intermittent fasting and exercise (HFD + IF + E). The study lasted for 8 weeks. Results: The results of the analysis show that lymphocyte cell levels in groups HFD + IF, HFD + IF, and HFD + IF + E were higher compared to groups CG-HFD (p < 0.05). Additionally, B lymphocyte and monocyte cell levels were higher in group HFD + IF + E compared to groups CG, CG + IF, and CG + IF + E, as well as CG, CG + IF, and CG + E, respectively. TNF-α levels were significantly higher in group HFD compared to the other groups. Furthermore, IL 10 levels were higher in group HFD + IF + E compared to the other groups. Conclusions: These findings indicate that moderate exercise and intermittent fasting, particularly in groups fed a high-fat diet, increased anti-inflammatory cytokine levels, and certain immune system cell counts, while decreasing pro-inflammatory cytokine levels.

Eccentric exercise 24 h prior to hypobaric decompression increases decompression strain

PURPOSE

Animal studies have shown that recent musculoskeletal injuries increase the risk of decompression sickness (DCS). However, to date no similar experimental study has been performed in humans. The aim was to investigate if exercise-induced muscle damage (EIMD)-as provoked by eccentric work and characterized by reduced strength and delayed-onset muscle soreness (DOMS)-leads to increased formation of venous gas emboli (VGE) during subsequent hypobaric exposure.

METHODS

Each subject (n = 13) was on two occasions exposed to a simulated altitude of 24,000 ft for 90 min, whilst breathing oxygen. Twenty-four hours prior to one of the altitude exposures, each subject performed 15 min of eccentric arm-crank exercise. Markers of EIMD were reduction in isometric m. biceps brachii strength and DOMS as assessed on the Borg CR10 pain scale. The presence of VGE was measured in the right cardiac ventricle using ultrasound, with measurements performed at rest and after three leg kicks and three arm flexions. The degree of VGE was evaluated using the six-graded Eftedal-Brubakk scale and the Kisman integrated severity score (KISS).

RESULTS

Eccentric exercise induced DOMS (median 6.5), reduced the biceps brachii strength (from 230 ± 62 N to 151 ± 8.8 N) and increased the mean KISS at 24,000 ft, both at rest (from 1.2 ± 2.3 to 6.9 ± 9.2, p = 0.01) and after arm flexions (from 3.8 ± 6.2 to 15.5 ± 17.3, p = 0.029).

CONCLUSION

EIMD, induced by eccentric work, provokes release of VGE in response to acute decompression.

Cytokines as Biomarkers for Evaluating Physical Exercise in Trained and Non-Trained Individuals: A Narrative Review

Physical activity and exercise training have numerous health benefits, including the prevention and management of chronic diseases, improvement of cardiovascular health, and enhancement of mental well-being. However, the effectiveness of training programs can vary widely among individuals due to various factors, such as genetics, lifestyle, and environment. Thus, identifying reliable biomarkers to evaluate physical training effectiveness and personalize training programs is crucial. Cytokines are signaling molecules produced by immune cells that play a vital role in inflammation and tissue repair. In recent years, there has been increasing interest in the potential use of cytokines as biomarkers for evaluating training effectiveness. This review article aims to provide an overview of cytokines, their potential as biomarkers, methods for measuring cytokine levels, and factors that can affect cytokine levels. The article also discusses the potential benefits of using cytokines as biomarkers, such as monitoring muscle damage and inflammation, and the potential for personalized training programs based on cytokine responses. We believe that the use of cytokines as biomarkers holds great promise for optimizing training programs and improving overall health outcomes.

Exercise-Induced Alternations of Adiponectin, Interleukin-8 and Indicators of Carbohydrate Metabolism in Males with Metabolic Syndrome

Adiponectin (ADIPO) and interleukin-8 (IL-8) are proteins that play a significant, albeit opposing, role in metabolic syndrome (MetS). The reported data on the effect of physical activity on the levels of these hormones in the population of people with MetS are conflicting. The aim of the study was to evaluate the changes in hormone concentrations, insulin-resistance indices and body composition after two types of training. The study included 62 men with MetS (age 36.6 ± 6.9 years, body fat [BF] = 37.53 ± 4.5%), randomly assigned to: an experimental group EG1 (n = 21) with aerobic exercise intervention, an experimental group EG2 (n = 21) with combined aerobic and resistance exercise intervention, both for 12 weeks, and a control group CG (n = 20) without interventions. Anthropometric measurements and body composition (fat-free mass [FFM], gynoid body fat [GYNOID]), as well as a biochemical blood analysis (adiponectin [ADIPO], interleukin-8 [IL-8], homeostatic model assessment-adiponectin (HOMA-AD) and homeostatic model assessment-triglycerides (HOMA-TG) were performed at baseline, and at 6 and 12 weeks of intervention and 4 weeks after the intervention (follow-up). Intergroup (between groups) and intragroup (within each group) changes were statistically evaluated. In the experimental groups EG1 and EG2, no significant changes were observed in the ADIPO concentration, but a decrease of GYNOID and insulin-resistance indices was confirmed. The aerobic training led to favorable changes in IL-8 concentration. The use of combined resistance and aerobic training led to improved body composition, decreased waist circumference and better insulin-resistance indices in men with MetS.

Unlocking the Therapeutic Potential of Irisin: Harnessing Its Function in Degenerative Disorders and Tissue Regeneration

Physical activity is well-established as an important protective factor against degenerative conditions and a promoter of tissue growth and renewal. The discovery of Fibronectin domain-containing protein 5 (FNDC5) as the precursor of Irisin in 2012 sparked significant interest in its potential as a diagnostic biomarker and a therapeutic agent for various diseases. Clinical studies have examined the correlation between plasma Irisin levels and pathological conditions using a range of assays, but the lack of reliable measurements for endogenous Irisin has led to uncertainty about its prognostic/diagnostic potential as an exercise surrogate. Animal and tissue-engineering models have shown the protective effects of Irisin treatment in reversing functional impairment and potentially permanent damage, but dosage ambiguities remain unresolved. This review provides a comprehensive examination of the clinical and basic studies of Irisin in the context of degenerative conditions and explores its potential as a therapeutic approach in the physiological processes involved in tissue repair/regeneration.

Irisin: An anti-inflammatory exerkine in aging and redox-mediated comorbidities

Human beings lead largely sedentary lives. From an evolutionary perspective, such lifestyle is not beneficial to health. Exercise can promote many enabling pathways, particularly through circulating exerkines, to optimize individual health and quality of life. Such benefits might explain the protective effects of exercise against aging and noncommunicable diseases. Nevertheless, the miRNA-mediated molecular mechanisms and exerkine interorgan crosstalk that underlie the beneficial effects of exercise remain poorly understood. In this mini review, we focused on the exerkine, irisin, mainly produced by muscle contraction during adaptation to exercise and its beneficial effects on body homeostasis. Herein, the complex role of irisin in metabolism and inflammation is described, including its subsequent effects on thermogenesis through browning to control obesity and improve glycemic regulation for diabetes mellitus control, its potential to improve cognitive function (via brain derived neurotrophic factor), and its pathways of action and role in aging.

Mild Hyperbaric Oxygen Exposure Enhances Peripheral Circulatory Natural Killer Cells in Healthy Young Women

Mild hyperbaric oxygen (HBO) enhances oxygen absorption in blood, relieving fatigue without causing oxidative stress. The benefits of mild HBO have been recognized in the treatment of lifestyle-related diseases and hypertension, but no research has been conducted on its effects on immunity. The aim of the present study is to investigate the effect of mild HBO on natural killer (NK) cells and cytokines in healthy young women. This crossover randomized control trial was conducted with 16 healthy young women. Participants were randomly exposed to normobaric oxygen (NBO; 1.0 atmospheres absolute (ATA), 20.8% oxygen) and mild HBO conditions (1.4 ATA, 35-40% oxygen, injected 18L oxygen per minute) in a hyperbaric oxygen chamber for 70 min. Heart rate, parasympathetic activity, NK cell count, interleukin (IL)-6, IL-12p70 and derivatives of reactive oxygen metabolites (d-ROMs) were measured before and after both exposures. In the NBO condition, parasympathetic activity remained unchanged, whereas after mild HBO exposure, parasympathetic activity was significantly increased. NK cells remained unchanged after NBO exposure, while NK cells were increased after exposure to mild HBO. Exposure to mild HBO did not increase d-ROM values, IL-6 and IL-12p70 protein levels. These findings suggest that exposure to mild HBO can be a useful protocol to increase NK cells by regulating parasympathetic activity via increasing oxygen delivery.

The Contribution of Tumor Derived Exosomes to Cancer Cachexia

Cancer cachexia is defined as unintentional weight loss secondary to neoplasia and is associated with poor prognosis and outcomes. Cancer cachexia associated weight loss affects both lean tissue (i.e., skeletal muscle) and adipose tissue. Exosomes are extracellular vesicles that originate from multivesicular bodies that contain intentionally loaded biomolecular cargo. Exosome cargo includes proteins, lipids, mitochondrial components, and nucleic acids. The cargo carried in exosomes is thought to alter cell signaling when it enters into recipient cells. Virtually every cell type secretes exosomes and exosomes are known to be present in nearly every biofluid. Exosomes alter muscle and adipose tissue metabolism and biological processes, including macrophage polarization and apoptosis which contribute to the development of the cachexia phenotype. This has led to an interest in the role of tumor cell derived exosomes and their potential role as biomarkers of cancer cell development as well as their contribution to cachexia and disease progression. In this review, we highlight published findings that have studied the effects of tumor derived exosomes (and extracellular vesicles) and their cargo on the progression of cancer cachexia. We will focus on the direct effects of tumor derived exosomes and their cellular cross talk on skeletal muscle and adipose tissue, the primary sites of weight loss due to cancer cachexia.

The effect of Tabata-style functional high-intensity interval training on cardiometabolic health and physical activity in female university students

Introduction: The increasing prevalence of metabolic syndrome and physical inactivity enhances exposure to cardiometabolic risk factors in university students. High-intensity interval training (HIIT) improved cardiometabolic health in clinical adults but the evidence in the university setting is limited. Furthermore, few studies examined the effect of low-volume HIIT on habitual physical activity (PA). Therefore, the primary aim of this study was to evaluate the efficacy of 12-week Tabata-style functional HIIT for improving multiple cardiometabolic health outcomes and habitual PA. We also investigated whether changes in habitual PA over the intervention period had an impact on exercise-induced health outcomes. Methods: 122 female freshmen were randomized into the Tabata group (n = 60) and the control (n = 62). The Tabata training protocol involved 8 × 20 s maximal repeated functional exercises followed by 10 s rest with a frequency of 3 times per week for 12 weeks. Body composition, maximal oxygen uptake (VO_2max), blood pressure (BP), blood lipids, fasting glucose and insulin, C-reactive protein and PA were objectively measured using standardized methods. Dietary intake was measured using a valid food frequency questionnaire. All variables were measured pre- and post-intervention. Results: Mixed linear modelling results showed that there were large intervention effects on VO_2max (p < 0.001, d = 2.53, 95% CI: 2.03 to 3.00 for relative VO_2max; p < 0.001, d = 2.24, 95% CI: 1.76 to 2.68 for absolute VO_2max), resting heart rate (p < 0.001, d = -1.82, 95% CI: -2.23 to -1.37), systolic BP (p < 0.001, d = -1.24, 95% CI: -1.63 to -0.84), moderate-to-vigorous intensity physical activity (MVPA) (p < 0.001, d = 2.31, 95% CI: 1.83 to 2.77), total PA (p < 0.001, d = 1.98, 95% CI: 1.53 to 2.41); moderate effects on %BF (p < 0.001, d = -1.15, 95% CI: -1.53 to -0.75), FM (p < 0.001, d = -1.08, 95% CI: -1.46 to -0.69), high-density lipoprotein (HDL) (p < 0.001, d = 1.04, 95% CI: 0.65 to 1.42), total cholesterol (p = 0.001, d = -0.64, 95% CI: -1.00 to -0.26); small effects on BMI (p = 0.011, d = -0.48, 95% CI: -0.84 to 0.11), WC (p = 0.043, d = -0.37, 95% CI: -0.74 to -0.01), low-density lipoprotein (p = 0.003, d = -0.57, 95% CI: -0.93 to -0.19), HOMA-IR (p = 0.026, d = -0.42, 95% CI: -0.78 to -0.05) and fasting insulin (p = 0.035, d = -0.40, 95% CI: -0.76 to -0.03). Regression analysis showed that only the percentage change of HDL was associated with the change of MVPA (b = 0.326, p = 0.015) and TPA (b = 0.480, p = 0.001). Conclusion: From the findings of the study we can conclude that 12-week low-volume Tabata-style functional HIIT was highly effective for university female students to improve cardiorespiratory fitness, body fat, some cardiometabolic health outcomes and habitual PA.

No dynamic changes in the expression of genes related to the epigenetic mechanism during acute exercise

Physical exercise results in structural remodeling in tissues and modifies cellular metabolism. Changes in gene expression lie at the root of these adaptations. Epigenetic changes are one of the factors responsible for such exercise-related alterations. One-hour acute exercise will change DNMT1, HDAC1, and JHDM1D transcriptions in PBMC. This study examined changes in the expression of genes responsible for epigenetic modifications (HDAC1, DNMT1, and JHDM1D) during and after an incremental exercise test on a treadmill and a 30-min recovery. Blood samples from 9 highly trained triathletes were tested. Examination of the transcripts showed no significant changes. Correlations between transcript results and biochemical indices revealed a significant (p = 0.007) relationship between JHDM1D mRNA and the number of monocytes at peak exercise intensity (exhaustion), while there was no significant (p = 0.053) correlation at rest. There are no rapid changes in the mRNA levels of the genes studied in blood cells in competitive athletes during acute exercise and recovery. Due to the small group of subjects studied, more extensive research is needed to verify correlations between transcription and biochemical variables.

Influence of routine exercise on the peripheral immune system to prevent and alleviate pain

Routine physical activity reduces the onset of pain and exercise is a first line treatment for individuals who develop chronic pain. In both preclinical and clinical research regular exercise (routine exercise sessions) produces pain relief through multiple mechanisms such as alterations in the central and peripheral nervous system. More recently, it has been appreciated that exercise can also alter the peripheral immune system to prevent or reduce pain. In animal models, exercise can alter the immune system at the site of injury or pain model induction, in the dorsal root ganglia, and systemically throughout the body to produce analgesia. Most notably exercise shows the ability to dampen the presence of pro-inflammatory immune cells and cytokines at these locations. Exercise decreases M1 macrophages and the cytokines IL-6, IL-1β, and TFNα, while increasing M2 macrophages and the cytokines IL-10, IL-4, and IL-1ra. In clinical research, a single bout of exercise produces an acute inflammatory response, however repeated training can lead to an anti-inflammatory immune profile leading to symptom relief. Despite the clinical and immune benefits of routine exercise, the direct effect of exercise on immune function in clinical pain populations remains unexplored. This review will discuss in more detail the preclinical and clinical research which demonstrates the numerous ways through which multiple types of exercise alter the peripheral immune system. This review closes with the clinical implications of these findings along with suggestions for future research directions.

Efficacy of Therapeutic Exercise in Reversing Decreased Strength, Impaired Respiratory Function, Decreased Physical Fitness, and Decreased Quality of Life Caused by the Post-COVID-19 Syndrome

In the current global scenario, many COVID-19 survivors present a severe deterioration in physical strength, respiratory function, and quality of life due to persistent symptoms and post-acute consequences of SARS-CoV-2 infection. These alterations are known as post-COVID-19 syndrome for which there is no specific and effective treatment for their management. Currently, therapeutic exercise strategies (ThEx) are effective in many diseases by reducing the appearance of complications and side effects linked to treatment, and are consequently of great relevance. In this study, we review the effect of ThEX in reversing decreased strength, impaired respiratory function, decreased physical fitness, and decreased quality of life (QoL) caused by post-COVID-19 syndrome. A literature search was conducted through the electronic databases, Medline (PubMed), SciELO and Cochrane Library Plus for this structured narrative review for studies published from database retrieval up till 12 December 2022. A total of 433 patients with post-COVID-19 syndrome condition (60% women) were included in the nine studies which met the inclusion/exclusion criteria. Overall, post-COVID-19 syndrome patients who followed a ThEx intervention showed improvements in strength, respiratory function, physical fitness and QoL, with no exercise-derived side effects. Thus, ThEx based on strength, aerobic and respiratory training could be an adjuvant non-pharmacological tool in the modulation of post-COVID-19 syndrome.

Effects of Probiotic Supplementation on Immune and Inflammatory Markers in Athletes: A Meta-Analysis of Randomized Clinical Trials

Background and Objectives: Probiotic supplementation can prevent and alleviate gastrointestinal and respiratory tract infections in healthy individuals. Markers released from the site of inflammation are involved in the response to infection or tissue injury. Therefore, we measured the pre-exercise and postexercise levels of inflammation-related markers-tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8, IL-10, interferon (IFN)-γ, salivary immunoglobulin A (IgA), IL-1β, IL-2, IL-4, and C-reactive protein (CRP)-in probiotic versus placebo groups to investigate the effects of probiotics on these markers in athletes. Probiotics contained multiple species (e.g., Bacillus subtilis, Bifidobacterium bifidum, etc.). Materials and Methods: We performed a systematic search for studies published until May 2022 and included nine randomized clinical trials. Reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline. Fixed-effects meta-analyses and sensitivity analyses were performed. Subgroup analyses were conducted on the basis of the period of probiotic intervention and timing of postassessment blood sampling. Results: The levels of IFN-γ and salivary IgA exhibited a significant positive change, whereas those of TNF-α and IL-10 demonstrated a negative change in the probiotic group. The subgroup analysis revealed that the probiotic group exhibited significant negative changes in TNF-α and IL-10 levels in the shorter intervention period. For the subgroup based on the timing of postassessment blood sampling, the subgroup whose blood sample collection was delayed to at least the next day of exercise exhibited significant negative changes in their TNF-α and IL-10 levels. The subgroups whose blood samples were collected immediately after exercise demonstrated negative changes in their TNF-α, IL-8, and IL-10 levels. Conclusions: Probiotic supplementation resulted in significant positive changes in the IFN-γ and salivary IgA levels and negative changes in the IL-10 and TNF-α levels. No significant changes in the IL-1β, IL-2, IL-4, IL-6, IL-8, or CRP levels were observed after probiotic use in athletes.

A Randomized Trial of the Effects of Dietary n3-PUFAs on Skeletal Muscle Function and Acute Exercise Response in Healthy Older Adults

Skeletal muscle is critical for maintaining mobility, independence, and metabolic health in older adults. However, a common feature of aging is the progressive loss of skeletal muscle mass and function, which is often accompanied by mitochondrial impairments, oxidative stress, and insulin resistance. Exercise improves muscle strength, mitochondrial health, and cardiorespiratory fitness, but older adults often exhibit attenuated anabolic responses to acute exercise. Chronic inflammation associated with aging may contribute to this "anabolic resistance" and therapeutic interventions that target inflammation may improve exercise responsiveness. To this end, we conducted a randomized controlled trial to determine the effect of 6 months of dietary omega-3 polyunsaturated fatty acids (n3-PUFA) supplementation on skeletal muscle function (mass, strength), mitochondrial physiology (respiration, ATP production, ROS generation), and acute exercise responsiveness at the level of the muscle (fractional synthesis rate) and the whole-body (amino acid kinetics) in healthy older adults. When compared with a corn oil placebo (n = 33; 71.5 ± 4.8 years), older adults treated with 4 g/day n3-PUFA (n = 30; 71.4 ± 4.5 years) exhibited modest but significant increases in muscle strength (3.1 ± 14.7% increase in placebo vs. 7.5 ± 14.1% increase in n3-PUFA; p = 0.039). These improvements in muscle strength with n3-PUFA supplementation occurred in the absence of any effects on mitochondrial function and a minor attenuation of the acute response to exercise compared to placebo. Together, these data suggest modest benefits of dietary n3-PUFAs to muscle function in healthy older adults. Future studies may elucidate whether n3-PUFA supplementation improves the exercise response in elderly individuals with co-morbidities, such as chronic inflammatory disease or sarcopenia.

Monocyte Phenotypes and Physical Activity in Patients with Carotid Atherosclerosis

Atherosclerosis is associated with low-grade inflammation involving circulating monocytes. It has been shown that the levels of intermediate pro-inflammatory monocytes are associated with cardiovascular mortality and risk of ischemic stroke. It also has been shown that physical activity (PA) decreases inflammation markers, incidence of strokes, and mortality. In this cross-sectional study, we tested the effect of PA on circulating monocytes phenotype rate. A total of 29 patients with a carotid stenosis > 50% were recruited. Levels of physical activity (MET.min/week) were measured by the GPAQ questionnaire, arterial samples of blood were collected to analyze monocyte phenotype (classical, intermediate and non-classical) assessed by flow cytometry, and venous blood samples were used to dose antioxidant activity and oxidative damage. Antioxidant capacity was reduced and oxidative damage increased in patients. There was a significant decrease in the percentage of classical and intermediate monocytes in moderately active patients as compared with non-active and highly active patients. Inversely, the rate of non-classical monocytes increased in moderately active patients. Intense PA appears to blunt the beneficial effects of moderate PA. Our study also suggests that PA could be beneficial in such patients by reducing the rate of intermediate monocytes known to predict the risk of ischemic stroke and by increasing the non-classical monocytes involved in lesions’ healing. Nevertheless, a longitudinal study would be necessary to confirm this hypothesis.

Changes in Cytokines Concentration Following Long-Distance Running: A Systematic Review and Meta-Analysis

Long-distance running is an exhausting effort for the whole organism. Prolonged aerobic exercise induces changes in inflammatory markers. However, predicting muscle damage in response has limitations in terms of selecting biomarkers used to measure inflammatory status. The present study conducts a systematic review and meta-analysis of articles focusing in ultra-marathon, marathon, and half-marathon and levels of cytokines. The search was conducted in PubMed, Web of Science, and Scopus databases, resulting in the inclusion of 76 articles. IL-6 was highlighted, evaluated in 62 studies and show increase in the standard mean difference (SMD): half-marathon (SMD −1.36; IC 95%: −1.82, −0.89, Ch²:0.58; tau²:0.00; p < 0.0001), marathon (SMD −6.81; IC 95%: −9.26, −4.37; Ch²:481.37 tau²:11.88; p < 0.0001) and ultra-marathon (SMD −8.00 IC 95%: −10.47, −5.53; Ch²:328.40; tau²:14.19; p < 0.0001). In contrast meta-regression analysis did not show relationship to the running distance (p = 0.864). The meta-analysis evidenced increase in the concentration of IL-1ra (p < 0.0001), IL-1B (p < 0.0001), IL-8 (p < 0.0001), IL-10 (p < 0.0001) and TNF-α (p < 0.0001). Reduction in IL-2 (p < 0.0001) and INF-y (p < 0.03) and no change in the IL-4 (p < 0.56). The number of studies evaluating the effect of adipokines was limited, however Leptin and Resistin were recurrent. The effects of an acute bout of prolonged aerobic exercise will protect against chronic systemic inflammation. The time to return to baseline values showed a substantial and dose-dependent relationship with run volume. The concentration of IL-6 was robustly studied and the marathon running was the most explored. Network of endocrine interactions in which circulating factors, released in extreme exercises, interplay through inter-organ crosstalk and physiologic changes were expressed. The running volume variability was able to modulate compounds that play a fundamental role in the maintenance of homeostasis and cell signaling.

Effects of Exercise Training on the Autonomic Nervous System with a Focus on Anti-Inflammatory and Antioxidants Effects

Studies show that the autonomic nervous system (ANS) has an important impact on health in general. In response to environmental demands, homeostatic processes are often compromised, therefore determining an increase in the sympathetic nervous system (SNS)’s functions and a decrease in the parasympathetic nervous system (PNS)’s functions. In modern societies, chronic stress associated with an unhealthy lifestyle contributes to ANS dysfunction. In this review, we provide a brief introduction to the ANS network, its connections to the HPA axis and its stress responses and give an overview of the critical implications of ANS in health and disease—focused specifically on the immune system, cardiovascular, oxidative stress and metabolic dysregulation. The hypothalamic–pituitary–adrenal axis (HPA), the SNS and more recently the PNS have been identified as regulating the immune system. The HPA axis and PNS have anti-inflammatory effects and the SNS has been shown to have both pro- and anti-inflammatory effects. The positive impact of physical exercise (PE) is well known and has been studied by many researchers, but its negative impact has been less studied. Depending on the type, duration and individual characteristics of the person doing the exercise (age, gender, disease status, etc.), PE can be considered a physiological stressor. The negative impact of PE seems to be connected with the oxidative stress induced by effort.

The effect of exercise on cytokines: implications for musculoskeletal health: a narrative review

The physiological effects of physical exercise are ubiquitously reported as beneficial to the cardiovascular and musculoskeletal systems. Exercise is widely promoted by medical professionals to aid both physical and emotional wellbeing; however, mechanisms through which this is achieved are less well understood. Despite numerous beneficial attributes, certain types of exercise can inflict significant significant physiological stress. Several studies document a key relationship between exercise and immune activation. Activation of the innate immune system occurs in response to exercise and it is proposed this is largely mediated by cytokine signalling. Cytokines are typically classified according to their inflammatory properties and evidence has shown that cytokines expressed in response to exercise are diverse and may act to propagate, modulate or mitigate inflammation in musculoskeletal health. The review summarizes the existing literature on the relationship between exercise and the immune system with emphasis on how exercise-induced cytokine expression modulates inflammation and the immune response.

Iron Status and Homeostasis Across 2 Competitive Seasons in NCAA Division I Collegiate Cross-Country Runners Residing at Low Altitude

Purpose: Inflammatory cytokines including interleukin-6 can upregulate hepcidin and decrease iron absorption. Endurance exercise is associated with transient increases in cytokines, which may alter the risk of iron deficiency (ID). This study examined whether chronic elevations in basal levels of cytokines and hepcidin were associated with ID in highly trained runners. Methods: Fifty-four collegiate runners (26 males and 28 females) living at ∼1625 m were recruited from an NCAA Division I cross-country team for this prospective cohort study. Over 2 seasons, fasted, preexercise blood draws were performed in the morning 4 times per season and were analyzed for hemoglobin concentration, ferritin, soluble transferrin receptor (sTfR), hepcidin, and 10 cytokines. Stages of ID were defined using ferritin, sTfR, and hemoglobin concentration. During the study, a registered dietician provided all runners with iron supplements using athletic department–created guidelines. Results: Fifty-seven percent of females and 35% of males exhibited stage 2 ID (ferritin <20 ng/mL or sTfR >29.5 nmol/L) at least once. Cytokines, ferritin, and sTfR exhibited changes through the 2 years, but changes in cytokines were not associated with alterations in hepcidin, ferritin, or sTfR. In males and females, lower ferritin was associated with lower hepcidin (both P < .0001). One female exhibited higher hepcidin and lower iron stores compared with other individuals, suggesting a different etiology of ID. Conclusion: ID is common in highly trained collegiate runners. In general, the high prevalence of ID in this population is not associated with alterations in basal hepcidin or cytokine levels.

Inflammation in the Pathogenesis of Arrhythmogenic Cardiomyopathy: Secondary Event or Active Driver?

Arrhythmogenic cardiomyopathy (ACM) is a rare inherited cardiac disease characterized by arrhythmia and progressive fibro-fatty replacement of the myocardium, which leads to heart failure and sudden cardiac death. Inflammation contributes to disease progression, and it is characterized by inflammatory cell infiltrates in the damaged myocardium and inflammatory mediators in the blood of ACM patients. However, the molecular basis of inflammatory process in ACM remains under investigated and it is unclear whether inflammation is a primary event leading to arrhythmia and myocardial damage or it is a secondary response triggered by cardiomyocyte death. Here, we provide an overview of the proposed players and triggers involved in inflammation in ACM, focusing on those studied using in vivo and in vitro models. Deepening current knowledge of inflammation-related mechanisms in ACM could help identifying novel therapeutic perspectives, such as anti-inflammatory therapy.

A prescription for exercise in systemic lupus erythematosus

Patients with systemic lupus erythematosus (SLE) have increased cardiovascular risk, and fatigue is a major subjective complaint. Sedentary lifestyle has been shown to have negative health impacts in cardiovascular and rheumatic disease, though exercise has not traditionally been incorporated into routine therapy recommendations. Regular exercise in SLE may improve difficult to treat Type 2 symptoms, such as fatigue, depression, stress, and quality of life. Insufficient counseling on exercise by physicians is a notable barrier for SLE patients to engage in physical activity. Aerobic exercise regimens are more commonly studied, and have been shown to improve cardiovascular health in SLE. Exercise may improve some inflammatory markers, though does not definitively affect SLE clinical disease activity. Physical activity should be recommended to improve quality of life and cardiovascular health in patients with SLE. Developing clearer guidelines for exercise regimens in a patient-centered manner is warranted, especially given diverse phenotypes of SLE patients and varying degrees of physical limitations.

The Immunomodulatory Function of Vitamin D, with Particular Reference to SARS-CoV-2

Vaccines are the only way to reduce the morbidity associated to SARS-CoV-2 infection. The appearance of new mutations urges us to increase the effectiveness of vaccines as a complementary alternative. In this context, the use of adjuvant strategies has improved the effectiveness of different vaccines against virus infections such as dengue, influenza, and common cold. Recent reports on patients infected by COVID-19 reveal that low levels of circulating vitamin D correlate with a severe respiratory insufficiency. The immunomodulatory activity of this micronutrient attenuates the synthesis of pro-inflammatory cytokines and at the same time, increases antibody production. Therefore, the present review proposes the use of vitamin D as adjuvant micronutrient to increase the efficacy of vaccines against SARS-CoV-2 infection.

Physical activity and adipokine levels in individuals with type 2 diabetes: A literature review and practical applications

We review the effects of acute and long-term physical activity on adipokine levels in individuals with type 2 diabetes (T2D). Three electronic databases were searched. Studies made in animal models were excluded, while studies based on participants with and without T2D, and also studies with type 1 diabetes were included. Of the 2,450 citations, 63 trials, including randomised control trials, cross-sectional and longitudinal studies, met our inclusion criteria. Seventy and five percent of studies reported the effects of physical activity on tumor necrosis factor-alpha (TNFα), interleukin 6 (IL-6), adiponectin, visfatin, omentin-1, and leptin levels. There are no robust results due to variations in exercise modality, intensity, duration, and also differences in cohort characteristics in the literature. Only four studies described the effects of an acute session of physical activity on adipokine levels. Overall, physical activity improves diabetes status by regulating adipokine levels. However, long-term aerobic + resistance training combined with dietary modifications is likely to be a more effective strategy for improving adipokines profiles in patients with type 2 diabetes.

Interpreting 'anti-inflammatory' cytokine responses to exercise: focus on interleukin-10

Circulating concentrations of canonically pro- and anti-inflammatory cytokines are commonly measured when evaluating the anti-inflammatory effects of exercise. An important caveat to interpreting systemic cytokine concentrations as evidence for the anti-inflammatory effects of exercise is the observed dissociation between circulating cytokine concentrations and cytokine function at the tissue/cellular level. The dichotomization of cytokines as pro- or anti-inflammatory also overlooks the context dependence of cytokine function, which can vary depending on the physiological state being studied, the cytokine's cellular source/target, and magnitude of cytokine responses. We re-evaluate our current understanding of anti-inflammatory cytokine responses to exercise by highlighting nuances surrounding the interpretation of altered systemic cytokine concentrations as evidence for changes in inflammatory processes occurring at the tissue/cellular level. We highlight the lesser known pro-inflammatory and immunostimulatory actions of the prototypical anti-inflammatory cytokine, interleukin (IL)-10, including the potentiation of interferon gamma production during endotoxaemia, CD8⁺ T cell activation in tumour bearing rodents and cancer patients in vivo, and CD8⁺ T lymphocyte and natural killer cell activation in vitro. IL-10's more well-established anti-inflammatory actions can also be blunted following exercise training and under chronic inflammatory states such as type 2 diabetes (T2D) independently of circulating IL-10 concentrations. The resistance to IL-10's anti-inflammatory action in T2D coincides with blunted STAT3 phosphorylation and can be restored with small-molecule activators of IL-10 signalling, highlighting potential therapeutic avenues for restoring IL-10 action. We posit that inferences based on altered circulating cytokine concentrations alone can miss important functional changes in cytokine action occurring at the tissue/cellular level.

The effect of aerobic exercise on immune biomarkers and symptoms severity and progression in patients with COVID-19: A randomized control trial

BACKGROUND

The World Health Organization in March 2020 has announced that COVID-19 is a world pandemic because the number of infected cases increases rapidly. however, there are several available vaccines, their protection is limited to a certain period. Thus, the role of modalities that improve immune functions should be performed to counter COVID-19 viral load and decrease mortality rates.

OBJECTIVE

To investigate the effect of aerobic exercise on immune biomarkers, disease severity, and progression in patients with COVID-19.

DESIGN

A randomized controlled study.

PARTICIPANTS

Thirty patients with COVID-19 participated in this study. Participants' age ranged from 24 to 45 years old. Participants had a mild or moderate COVID-19. Participants were assigned randomly into two groups, exercise and control groups. There were two main dependent variables including blood immune markers and severity of respiratory symptoms.

INTERVENTIONS

All participants performed 2 weeks of moderate-intensity aerobic exercise for 40 min/session, 3 sessions/week. The measurements were performed at baseline, and after 2-weeks.

RESULTS

At baseline measurements, there were non-significant differences between both groups in the Wisconsin scale total score, Leucocytes, Lymphocytes, Interleukin-6, Interleukin-10, Immunoglobulin-A, and TNF-α (P > .05). After the intervention, the Wisconsin scale (patient-oriented illness-specific quality-of-life) total score significantly decreased in the intervention group (P < .05); while, Leucocytes, Lymphocytes, and Immunoglobulin-A significantly increased in the intervention group (P < .05).

CONCLUSION

The current study indicated that 2 weeks of moderate-intensity aerobic exercise decreased the severity and progression of COVID-19 associated disorders and quality of life. Also, a 2-weeks of aerobic exercise positively affected immune function by increasing the amounts of Leucocytes, Lymphocytes, Immunoglobulin A.

Role of Protein Arginine Methyltransferases and Inflammation in Muscle Pathophysiology

Arginine methylation mediated by protein arginine methyltransferases (PRMTs) is a post-translational modification of both histone and non-histone substrates related to diverse biological processes. PRMTs appear to be critical regulators in skeletal muscle physiology, including regeneration, metabolic homeostasis, and plasticity. Chronic inflammation is commonly associated with the decline of skeletal muscle mass and strength related to aging or chronic diseases, defined as sarcopenia. In turn, declined skeletal muscle mass and strength can exacerbate chronic inflammation. Thus, understanding the molecular regulatory pathway underlying the crosstalk between skeletal muscle function and inflammation might be essential for the intervention of muscle pathophysiology. In this review, we will address the current knowledge on the role of PRMTs in skeletal muscle physiology and pathophysiology with a specific emphasis on its relationship with inflammation.

Potential of Point-of-Care and At-Home Assessment of Immune Status via Rapid Cytokine Detection and Questionnaire-Based Anamnesis

Monitoring the immune system's status has emerged as an urgent demand in critical health conditions. The circulating cytokine levels in the blood reflect a thorough insight into the immune system status. Indeed, measuring one cytokine may deliver more information equivalent to detecting multiple diseases at a time. However, if the reported cytokine levels are interpreted with considering lifestyle and any comorbid health conditions for the individual, this will promote a more precise assessment of the immune status. Therefore, this study addresses the most recent advanced assays that deliver rapid, accurate measuring of the cytokine levels in human blood, focusing on add-on potentials for point-of-care (PoC) or personal at-home usage, and investigates existing health questionnaires as supportive assessment tools that collect all necessary information for the concrete analysis of the measured cytokine levels. We introduced a ten-dimensional featuring of cytokine measurement assays. We found 15 rapid cytokine assays with assay time less than 1 h; some could operate on unprocessed blood samples, while others are mature commercial products available in the market. In addition, we retrieved several health questionnaires that addressed various health conditions such as chronic diseases and psychological issues. Then, we present a machine learning-based solution to determine what makes the immune system fit. To this end, we discuss how to employ topic modeling for deriving the definition of immune fitness automatically from literature. Finally, we propose a prototype model to assess the fitness of the immune system through leveraging the derived definition of the immune fitness, the cytokine measurements delivered by a rapid PoC immunoassay, and the complementary information collected by the health questionnaire about other health factors. In conclusion, we discovered various advanced rapid cytokine detection technologies that are promising candidates for point-of-care or at-home usage; if paired with a health status questionnaire, the assessment of the immune system status becomes solid and we demonstrated potentials for promoting the assessment tool with data mining techniques.

Exercising immune cells: The immunomodulatory role of exercise on atrial fibrillation

Exercise training is generally beneficial for cardiovascular health, improving stroke volume, cardiac output, and aerobic capacity. Despite these benefits, some evidence indicates that endurance training may increase the risk of atrial fibrillation (AF), particularly in highly trained individuals. Among multiple mechanisms, autonomic tone changes and atrial remodeling have been proposed as main contributors for exercise-induced AF. However, the contribution of local and systemic immunity is poorly understood in the development of atrial arrhythmogenic substrates. Here we aim to update the field of immunomodulation in the context of exercise and AF by compiling and reconciling the most recent evidence from preclinical and human studies and rationalize the applicability of "lone" AF terminology in athletes.

Vitamin D, Its Role in Recovery after Muscular Damage Following Exercise

Aside from its role in bone metabolism, vitamin D is a key immunomodulatory micronutrient. The active form of vitamin D (1,25(OH)D) seems to modulate the innate immune system through different mechanisms. The vitamin is involved in the differentiation of monocytes into macrophages, increasing the phagocytic and chemotactic functions of these cells. At the same time, vitamin D enables efferocytosis and prevents immunopathology. In addition, vitamin D is involved in other processes related to immune function, such as inflammation. Regarding muscle tissue, vitamin D plays an active role in muscle inflammatory response, protein synthesis, and regulation of skeletal muscle function. Two mechanisms have been proposed: A direct role of 1,25(OH)D binding to vitamin D receptors (VDRs) in muscle cells and the modulation of calcium transport in the sarcoplasmic reticulum. This second mechanism needs additional investigation. In conclusion, vitamin D seems to be effective in cases of deficiency and/or if there is a great muscular commitment, such as in high intensity exercises.

Does the Interaction between Local and Systemic Inflammation Provide a Link from Psychology and Lifestyle to Tissue Health in Musculoskeletal Conditions?

Musculoskeletal conditions are known to involve biological, psychological, social and, often, lifestyle elements. However, these domains are generally considered in isolation from each other. This siloed approach is unlikely to be adequate to understand the complexity of these conditions and likely explains a major component of the disappointing effects of treatment. This paper presents a hypothesis that aims to provide a foundation to understand the interaction and integration between these domains. We propose a hypothesis that provides a plausible link between psychology and lifestyle factors with tissue level effects (such as connective tissue dysregulation/accumulation) in musculoskeletal conditions that is founded on understanding the molecular basis for interaction between systemic and local inflammation. The hypothesis provides plausible and testable links between mind and body, for which empirical evidence can be found for many aspects. We present this hypothesis from the perspective of connective tissue biology and pathology (fibrosis), the role of inflammation locally (tissue level), and how this inflammation is shaped by systemic inflammation through bidirectional pathways, and various psychological and lifestyle factors via their influence on systemic inflammation. This hypothesis provides a foundation for new consideration of the development and refinement of personalized multidimensional treatments for individuals with musculoskeletal conditions.