Clinical implications of exercise immunology

Impact of exercise on markers of B cell-related immunity: A systematic review

BACKGROUND

B cells represent a crucial component of adaptive immunity that ensures long-term protection from infection by generating pathogen-specific immunoglobulins. Exercise alters B cell counts and immunoglobulin levels, but evidence-based conclusions on potential benefits for adaptive immunity are lacking. This systematic review assessed current literatures on the impact of acute exercise and exercise training on B cells, immunoglobulins, and markers of secretory immunity in human biofluids.

METHODS

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, MEDLINE, Web of Science, and Embase were searched on March 8, 2023. Non-randomized controlled trials and crossover trials investigating the impact of acute exercise or exercise training on B cell counts and proportions, immunoglobulin levels, salivary flow rate, or secretory immunoglobulin A secretion rate were included. Quality and reporting of exercise training studies were assessed using the Tool for the Assessment of Study Quality and reporting in Exercise. Study characteristics, outcome measures, and statistically significant changes were summarized tabularly.

RESULTS

Of the 67 eligible studies, 22 applied acute exercise and 45 applied exercise training. All included outcomes revealed significant alterations over time in acute exercise and exercise training context, but only a few investigations showed significant differences compared to control conditions. Secretory and plasma immunoglobulin A levels were most consistently increased in response to exercise training.

CONCLUSION

B cell-related outcomes are altered by acute exercise and exercise training, but evidence-based conclusions cannot be drawn with high confidence due to the large heterogeneity in populations and exercise modalities. Well-designed trials with large sample sizes are needed to clarify how exercise shapes B cell-related immunity.

The impact of exercise on the gut microbiota in middle-aged amateur serious runners: a comparative study

Introduction

Exercise, health, and the gut microbiota (GM) are strongly correlated. Research indicates that professional athletes, especially ultra-marathon runners, have unique GM characteristics. However, more research has focused on elite athletes, with little attention given to amateur sports enthusiasts, especially those in the middle-aged population. Therefore, this study focuses on the impact of long-term running on the composition and potential functions of the GM in middle-aged individuals.

Methods

We compared the GM of 25 middle-aged serious runnerswith 22 sedentary healthy controls who had minimal exercise habitsusing 16S rRNA gene sequencing. Additionally, we assessed dietary habits using a food frequency questionnaire.

Results and Discussion

Statistical analysis indicates that there is no significant difference in dietary patterns between the control group and serious runners. Diversity analysis results indicate that there is no significant difference in α diversity between the two groups of GM, but there is a significant difference in β diversity. Analysis of the composition of GM reveals that Ruminococcus and Coprococcus are significantly enriched in serious runners, whereas Bacteroides, Lachnoclostridium, and Lachnospira are enriched in the control group. Differential analysis of functional pathway prediction results reveals significant differences in the functional metabolism levels of GM between serious runners and the control group. Further correlation analysis results indicate that this difference may be closely related to variations in GM. In conclusion, our results suggest that long-term exercise can lead to changes in the composition of the GM. These changes have the potential to impact the overall health of the individual by influencing metabolic regulation.

Do sports protect us from COVID-19? An evaluation of COVID-19 infection, vaccination status, and cardiac examination findings in children who exercise

AIM

The COVID-19 pandemic which has devastated the whole world for the past 3 years affects different patient groups differently. This study aims to evaluate the prevalence, symptoms, and severity of COVID-19 infection, vaccination status, and cardiac pathologies of children who exercise.

MATERIAL AND METHODS

The records of the children and adolescents who applied to our paediatric cardiology outpatient clinic for preparticipation examinations between 01.01.22 and 31.12.2022 were scanned retrospectively, and information about their COVID-19 history, the severity of infection, symptoms during the infection, at the time of the examination, and vaccination status was obtained. The results were analysed using MS Excel 2016 software.

RESULTS

The study consisted of 240 children [82 (34.17%) girls and 158 (65.83%) boys] whose mean age was 12.64 ± 2.64 years, mean weight was 50.03 ± 15.53 kg, mean height was 157 ± 15.09 cm, and mean body mass index was 19.65 ± 3.59. 129 cases had a COVID-19 history, 74 cases had no COVID-19 history, and 37 only had contact but no polymerase chain reaction positivity. 84 cases were mild, 19 were moderate, and 12 were asymptomatic. The most common symptoms were fatigue, malaise, headache, sore throat, and fever. 51 cases (35.15%) were vaccinated against COVID-19. No significant cardiac pathologies were detected in electrocardiography or echocardiography.

CONCLUSIONS

This study shows that COVID-19 infections in children who exercise are generally mild and self-limiting. Our findings suggest that exercise may have positive effects on immunity.

Anti-inflammatory effects of sericin and swimming exercise in treating experimental Achilles tendinopathy in rat

The aim of this study was to assess the effectiveness of combining sericin with swimming exercise as a treatment for type-I collagenase-induced Achilles tendinopathy (AT) in rats, with a focus on inflammatory cytokines. An experimental AT model was established using type-I collagenase in male Sprague-Dawley rats, categorized into five groups: Group 1 (Control + Saline), Group 2 (AT), Group 3 (AT + exercise), Group 4 (AT + sericin), and Group 5 (AT + sericin + exercise). Intratendinous sericin administration (0.8 g/kg/mL) took place from days 3 to 6, coupled with 30 min daily swimming exercise sessions (5 days/week, 4 weeks). Serum samples were analyzed using ELISA for tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-10 (IL-10), and total antioxidant-oxidant status (TAS-TOS), alongside histopathological and immunohistochemical assessments of Achilles tendon samples. Elevated TNF-α and IL-1β and decreased IL-10 levels were evident in Group 2; Of these, TNF-α and IL-1β were effectively reduced and IL-10 increased across all treatment groups, particularly groups 4 and 5. Serum TAS was notably lower in Group 2 and significantly increased in Group 5 compared to Group 2. Histopathologically, Group 2 displayed severe degeneration, irregular fibers, and round cell nuclei, while Group 5 exhibited decreased degeneration and spindle-shaped fibers. The Bonar score increased in Group 2 and decreased in groups 4 and 5. Collagen type-I alpha-1 (Col1A1) expression was notably lower in Group 2 (P = 0.001) and significantly increased in groups 4 and 5 compared to Group 2 (P = 0.011 and 0.028, respectively). This study underscores the potential of sericin and swimming exercises in mitigating inflammation and oxidative stress linked to AT pathogenesis, presenting a promising combined therapeutic strategy.

The Influence of COVID-19 on University Students' Well-Being, Physical Activity, Body Composition, and Strength Endurance

BACKGROUND

Very few scientific studies have simultaneously evaluated changes in well-being (WB), physical activity (PA), and strength endurance (SE) based on results from before and during the COVID-19 pandemic.

AIM

The aim of the study was to assess WB, PA, and SE levels, as well as body composition parameters in university students before and during the pandemic.

METHODS

The study included 30 males and 30 females (mean age: 21.7 ± 2.51 and 21.6 ± 2.34 years, respectively). Well-being using the Self-Perception Questionnaire (POMS), PA from the Polish regular version of the International Physical Activity Questionnaire (IPAQ), body composition parameters using the InBody 270 analyzer, and SE based on the results of a 12 min test involving a Concept 2PM-5 rowing ergometer were assessed before and during the pandemic.

RESULTS

An assessment of university students' WB revealed a significant increase in variables such as tension, depression, anger, confusion, and a significant decline in vigor (p < 0.05). In both sexes, PA and SE decreased significantly-from 2115.4 to 1822.8 METs-min/week and from 2184.5 to 2035 m, respectively, in males, and from 1793.5 to 1699.8 METs-min/week and from 2021.5 to 1943.8 m, respectively, in females. At the same time, body mass and BMI values increased significantly (p < 0.001) in both females and males.

CONCLUSIONS

The COVID-19 pandemic caused a significant decrease in WB, PA and SE levels in young females and males, and led to a significant increase in their body mass and BMI.

ACUTE EFFECT OF AEROBIC EXERCISE OF DIFFERENT INTENSITIES IN CYTOKINES OF UNIVERSITY STUDENTS

ABSTRACT Introduction: A single exercise training session promotes stimuli for changes in the immune system that are cumulatively considered adaptations to the exercise. Objective: This paper explores the acute effect of different intensities of aerobic exercise on anti-inflammatory and proinflammatory markers in apparently healthy university students. Methods: Eighteen volunteers underwent two sessions of aerobic exercise, the first at 65-70% estimated heart rate (HR), and after seven days, a second session at 80-85% HR. Before and after each session, venous blood was drawn, in order to analyze interleukin (IL) 6 and 10 in a Milliplex Kit. The participants’ level of physical activity was determined using a questionnaire. For statistical comparisons, two-way ANOVA was used for the variables hemodynamics and perceived exertion. The cytokine results were compared through the Student's t-test for repeated measurements. The exclusion criteria were the practice of physical exercise and having drunk alcohol on the day before the intervention sessions, the presence of osteomioarticular conditions, and missing one of the sessions. Results: This study showed that IL-6 was not significantly decreased when comparing the two sessions. IL-10 was significantly decreased (p=0.033) in the 65-70% HR session but not in the 80-85% HR session. The delta variation for IL-10 showed a tendency (p=0.053) towards a greater decrease in the 65-70% HR session when compared to the 80-85% HR session. There were no differences in the acute effect of exercise when comparing the levels of physical activity. Conclusion: This study highlights that two different zones of high intensity exercise can induce different inflammatory responses, as demonstrated by the significant decrease in IL-10 in the 65-70%HR zone. The study also shows that there was no difference in physical exercise response in individuals with moderate and high physical activity levels. Level of evidence III; Comparative study.

Attitudes of elite athletes and their support staff to the influenza vaccine

BACKGROUND

Influenza is an important public health issue, even amongst healthy adults. Uptake rates of the influenza vaccine amongst elite athletes vary and can depend on the attitudes of their coaches, fellow athletes and support staff. International studies have documented a fear amongst elite athletes to the potential side effects of the vaccine.

AIMS

Determine the influenza vaccine uptake rates in elite Irish athletes and their support staff along with attitudes, fears and barriers to receiving it.

METHODS

A cross-sectional survey was performed in the Sport Ireland Institute. Elite athletes and support staff from the 2019 database were invited to participate via an anonymous online survey. The database included a variety of sports, e.g. athletics, boxing, cycling, rowing, swimming and para-athletics.

RESULTS

From 218 athletes and staff invited, 39% (n = 87 [43 male, 44 female]) responded to the online survey. Fifty-nine percent (n = 51) of participants received the influenza vaccine during the 2018/2019 season. Forty-six percent (n = 40) completely agree that the influenza vaccine is safe. Fourteen percent (n = 12) of participants believe the vaccine causes influenza. "Getting sick" from the vaccine was the biggest fear for participants. Athletes were least likely to recommend the influenza vaccine to others and most likely to fear missing time from training or work as a result of it.

CONCLUSIONS

Elite Irish athletes are vulnerable to contracting influenza annually, despite free access to immunisation. Barriers to receiving the vaccine include location access, education and fear of side effects.

Muscle changes after stroke and their impact on recovery: time for a paradigm shift? Review and commentary

In stroke rehabilitation there is a growing body of evidence that not all patients have the same potential to recover. Understanding the processes that give rise to the heterogeneous treatment responses in stroke survivors will lay foundations for any conceivable advance in future rehabilitation interventions. This review was set out to shine new light on the debate of biomarkers in stroke rehabilitation by linking fundamental insights from biogerontological sciences to neurorehabilitation sciences. In particular, skeletal muscle changes and inflammation are addressed as two potential constructs from which biomarkers for stroke rehabilitation can be derived. Understanding the interplay between these constructs as well as their relation to recovery could enhance stroke rehabilitation in the future. The rationale for the selection of these constructs is three-fold: first, recent stroke literature emphasizes the importance of identifying muscle wasting (also called stroke-induced muscle wasting) in stroke patients, a concept that is widely investigated in geriatrics but less in the stroke population. Second, insights from transdisciplinary research domains such as gerontology have shown that inflammation has severe catabolic effects on muscles, which may impede rehabilitation outcomes such as gait recovery. Last, it has been proven that (high-intensity) muscle strengthening exercises have strong anti-inflammatory effects in a non-stroke population. Therefore, an evidence-based rationale is presented for developing research on individual changes of muscle and inflammation after a stroke.

Differential Reduction of IP-10 and C-Reactive Protein via Aerobic Exercise or Mindfulness-Based Stress-Reduction Training in a Large Randomized Controlled Trial

Exercise and meditation improve health and well-being, potentially through decreasing systemic inflammation. In this study, healthy adults (N = 413) were randomized to 8 weeks of training in aerobic exercise, matched mindfulness-based stress reduction, or wait-list control. Three inflammation-related biomarkers (C-reactive protein, interleukin-6, and interferon-gamma-inducible protein-10) were assessed preintervention, directly postintervention, and 17 weeks later. Within-group analyses found that exercise participants had decreased serum interferon-gamma-inducible protein-10 postintervention and 17 weeks later, whereas C-reactive protein was lower in mindfulness-based stress-reduction participants 17 weeks postintervention only. Self-reported physical activity or amount of meditation practice did not predict biomarker changes. This study suggests that (a) training in aerobic exercise can lower interferon-gamma-inducible protein-10, a chemokine associated with interferon activity and illness, and (b) training in mindfulness meditation may have a delayed effect on C-reactive protein, an important inflammatory biomarker. The findings highlight the likelihood of multiple, distinct pathways underlying the health-promoting effects of these lifestyle interventions.

Exercise, Immunity, and Illness

It is generally accepted that moderate amounts of exercise improve immune system functions and hence reduce the risk of infection whereas athletes engaged in regular prolonged and/or intensive training have a higher than “normal” incidence of minor infections, especially of the upper respiratory tract (URT, e.g., common cold and influenza). This is likely related to regular acute (and possibly chronic) periods of exercise-induced changes in immune function. URT infections can compromise performance directly if suffered shortly before or during competition or indirectly if suffered at other times via effects on training and/or physiological adaptations. This chapter covers the effects of exercise (acute and chronic), both positive and negative, on immune function and consequent infection risk, and considers the current state-of-the-art for monitoring and assessing this in athletes.

Exercise activates vagal induction of dopamine and attenuates systemic inflammation

Physical exercise is one of the most important factors improving quality of life, but it is not feasible for patients with morbidity or limited mobility. Most previous studies focused on high-intensity or long-term exercise that causes metabolic stress or physiological adaption, respectively. Here, we studied how moderate-intensity swimming affects systemic inflammation in 6-8 week old C57BL/6J male mice during endotoxemia. One-hour swimming prevented hypokalemia, hypocalcemia, attenuated serum levels of inflammatory cytokines, increased anti-inflammatory cytokines but affected neither IL6 nor glycemia before or after the endotoxic challenge. Exercise attenuated serum TNF levels by inhibiting its production in the spleen through a mechanism mediated by the subdiaphragmatic vagus nerve but independent of the splenic nerve. Exercise increased serum levels of dopamine, and adrenalectomy prevented the potential of exercise to induce dopamine and to attenuate serum TNF levels. Dopaminergic agonist type-1, fenoldopam, inhibited TNF production in splenocytes. Conversely, dopaminergic antagonist type-1, butaclamol, attenuated exercise control of serum TNF levels. These results suggest that vagal induction of dopamine may contribute to the anti-inflammatory potential of physical exercise.

Short-term resource allocation during extensive athletic competition

OBJECTIVES

Following predictions from life history theory, we sought to identify acute trade-offs between reproductive effort (as measured by psychological arousal) and somatic maintenance (via functional measures of innate immunity) during conditions of severe energetic imbalance.

METHODS

Sixty-six male ultramarathon runners (ages 20 to 37 years) were sampled before and after a lengthy race. Saliva and sera were collected for testosterone and immunological analyses (hemolytic complement activity and bacterial killing ability). Lean body mass was assessed by bioelectrical impedance, and libido was measured using a slideshow of arousing and neutral images.

RESULTS

Following predictions, there was a significant decrease in salivary testosterone levels (109.59 pg/mL versus 97.61 pg/mL, P < .001) and arousal scores in response to provocative images (5.40 versus 4.89, P = .001) between prerace and postrace time points. Additionally, participant bacterial killing ability (P = .035) and hemolytic complement activity (P = .021) increased between prerace and postrace.

CONCLUSIONS

Decreased libido and testosterone with concomitant heightened innate immune responses suggest a shift in energetic priorities away from reproduction and toward maintenance/defense during a period of energetic stress.

Affected pathways and transcriptional regulators in gene expression response to an ultra-marathon trail: Global and independent activity approaches

Gene expression (GE) analyses on blood samples from marathon and half-marathon runners have reported significant impacts on the immune and inflammatory systems. An ultra-marathon trail (UMT) represents a greater effort due to its more testing conditions. For the first time, we report the genome-wide GE profiling in a group of 16 runners participating in an 82 km UMT competition. We quantified their differential GE profile before and after the race using HuGene2.0st microarrays (Affymetrix Inc., California, US). The results obtained were decomposed by means of an independent component analysis (ICA) targeting independent expression modes. We observed significant differences in the expression levels of 5,084 protein coding genes resulting in an overrepresentation of 14% of the human biological pathways from the Kyoto Encyclopedia of Genes and Genomes database. These were mainly clustered on terms related with protein synthesis repression, altered immune system and infectious diseases related mechanisms. In a second analysis, 27 out of the 196 transcriptional regulators (TRs) included in the Open Regulatory Annotation database were overrepresented. Among these TRs, we identified transcription factors from the hypoxia-inducible factors (HIF) family EPAS1 (p< 0.01) and HIF1A (p<0.001), and others jointly described in the gluconeogenesis program such as HNF4 (p< 0.001), EGR1 (p<0.001), CEBPA (p< 0.001) and a highly specific TR, YY1 (p<0.01). The five independent components, obtained from ICA, further revealed a down-regulation of 10 genes distributed in the complex I, III and V from the electron transport chain. This mitochondrial activity reduction is compatible with HIF-1 system activation. The vascular endothelial growth factor (VEGF) pathway, known to be regulated by HIF, also emerged (p<0.05). Additionally, and related to the brain rewarding circuit, the endocannabinoid signalling pathway was overrepresented (p<0.05).

Effects of resistance training at different loads on inflammatory markers in young adults

PURPOSE

Suppressing inflammaging at an early stage in life via exercise might prevent chronic diseases later in life. The aim was to investigate the influence of resistance training at different external loads on inflammatory markers in healthy young adults.

METHODS

Serum was collected for basal levels of cytokines (IL-1beta, IL-6, IL-8, sTNFR1, IL-1RA, IL-10 and GM-CSF) before and after 9 weeks exercise from 36 young (22 ± 2 years) healthy subjects who were randomized to three times weekly supervised resistance training at either HI_max (n = 12, 1 × 10-12 repetitions at 80% 1RM), LO (n = 12, 1 × 10-12 repetitions at 40% 1RM), or LO_max (n = 12, 1 × 10-12 repetitions at 40% 1RM preceded by 60 repetitions at 20-25% 1RM) respectively.

RESULTS

Overall, IL-8 increased (p < 0.001) and IL-6 decreased (p = 0.001) after training, but no significant time*group interaction was found (respectively, p = 0.283 and p = 0.058 for IL-8 and IL-6). When analyzed separately, IL-8 increased significantly in HI_max (p = 0.022) and LO_max (p = 0.024); and IL-6 decreased significantly in LO_max (p = 0.009) and LO (p = 0.013). No significant overall time effect was observed for sTNFR1 and IL-1RA; however, in HI_max sTNFR1 (p = 0.031) and IL-1RA (p = 0.014) increased significantly, but remained unchanged in LO_max and LO. IL-1beta, IL-10 and GM-CSF levels remained undetectable in most participants.

CONCLUSIONS

Nine weeks of resistance training-irrespective of the external load-have beneficial effects on circulating IL-8 and IL-6. In addition, training at high external load increases the anti-inflammatory cytokines sTNFR1 and IL-1RA. The results of this study show that resistance training has anti-inflammatory effects in healthy young persons and that the response of the different inflammatory mediators depends on the magnitude of the external load.

Leukocyte Populations are Associated with Heart Rate Variability After a Triathlon

The purpose of this study was to analyze cellular immune components and their association with heart rate variability in triathlon athletes. Twelve athletes were included (age 36.41 ± 5.57 years, body mass 81.84 ± 10.97 kg) and blood samples were taken one week before, immediately, at 2 and 48 hours, and one week after competition. Total lymphocytes and their subpopulations, neutrophils, basophils, eosinophils and monocytes were analyzed. At the same time, heart rate variability was recorded for 30 minutes using Polar Team2®. A significant difference between lymphocyte subpopulations and heart rate variability was found in the different study periods. A positive correlation was found between total lymphocytes and rMSSD (r = .736, p <0.05), CD3+ and rMSSD (r = .785, p <0.05), and CD4+ and rMSSD (r = .795, p < 0.05) at the end of the competition. After one week of competition, a negative correlation was found between eosinophils and MRR, SDNN, pNN50, and rMSSD (p <0.01); and basophils and MRR, SDNN, pNN50, and rMSSD (p <0.01); while a positive correlation was found between CD19+ (B cells) and pNN50 (r = .678, p <0.05). Our results suggest that it is possible to predict the effect of training with regard to the athlete's performance.

The Impaired Function of Macrophages Induced by Strenuous Exercise Could Not Be Ameliorated by BCAA Supplementation

The aim of this study was to evaluate the effect of strenuous exercise on the functions of peritoneal macrophages in rats and to test the hypothesis that branched-chain amino acid (BCAA) supplementation will be beneficial to the macrophages of rats from strenuous exercise. Forty male Wistar rats were randomly divided into five groups: (C) Control, E) Exercise, (E1) Exercise with one week to recover, (ES) Exercise + Supplementation and (ES1) Exercise + Supplementation with 1 week to recover. All rats except those of the sedentary control were subjected to four weeks of strenuous exercise. Blood hemoglobin, serum testosterone and BCAA levels were tested. Peritoneal macrophages functions were also determined at the same time. The data showed that hemoglobin, testosterone, BCAA levels, and body weight in group E decreased significantly as compared with that of group C. Meanwhile, phagocytosis capacity (decreased by 17.07%, p = 0.031), reactive oxygen species (ROS) production (decreased by 26%, p = 0.003) and MHC II mRNA (decreased by 22%, p = 0.041) of macrophages decreased in the strenuous exercise group as compared with group C. However, the chemotaxis of macrophages did not change significantly. In addition, BCAA supplementation could slightly increase the serum BCAA levels of rats from strenuous exercise (increased by 6.70%, p > 0.05). Moreover, the body weight, the blood hemoglobin, the serum testosterone and the function of peritoneal macrophages in group ES did not change significantly as compared with group E. These results suggest that long-term intensive exercise impairs the function of macrophages, which is essential for microbicidal capability. This may represent a novel mechanism of immunosuppression induced by strenuous exercise. Moreover, the impaired function of macrophage induced by strenuous exercise could not be ameliorated by BCAA supplementation in the dosing and timing used for this study.

Nutritional and Physical Activity Interventions to Improve Immunity

Physical activity and nutrition are important in a healthy lifestyle with potential benefits to immunity often overlooked. Infection of the upper respiratory tract, and the associated symptoms, are the most frequent presentations to general practitioners and may have significant economic and social impact. In this review, we consider the role of physical activity and nutrition in improving immunity. Evidence suggests that regular moderate activity is particularly beneficial for immune enhancement and reducing the risk of infection. We also discuss some nutritional strategies. Unfortunately, the evidence for many is weak. Avoiding nutritional deficiencies seems the most pragmatic recommendation. This can be achieved with a balanced diet. Including a variety of fruits and vegetables may help ensure adequate intake of essential nutrients with little risk of excess intake of any single nutrient. Supplementation with individual nutrients is generally not recommended. Multinutrients may be beneficial for those with a preexisting deficiency but not if normal dietary intake is sufficient. Further benefit may be gained from some supplements including probiotics, bovine colostrum, and some plant-derived products (Echinacea, black elderberry, and some polyphenols) but only in specific situations/contexts. Individuals should consider their personal needs, use caution, and avoid the indiscriminate use of supplements.

Immunological and hormonal effects of exercise: implications for cancer cachexia

PURPOSE OF REVIEW

There is increasing interest in the use of therapeutic exercise for cancer cachexia. Apart from the directly beneficial effects on muscle, exercise has the potential to attenuate some of the immunological and hormonal abnormalities found in cachexia. This review summarizes the findings of recent studies, which have explored such effects in patients with cancer, and discusses their relevance to patients with cancer cachexia.

RECENT FINDINGS

Our search identified 11 studies in patients with breast, colorectal, lung, and prostate cancer, predominantly with early stage disease or following primary curative treatment. Overall, exercise was associated with reduced levels of C-reactive protein (CRP), but not other markers of systemic inflammation. There was no consistent impact on levels of glucose, insulin or measures of insulin sensitivity or, in patients with prostate cancer, on levels of testosterone.

SUMMARY

There is limited scope to extrapolate these findings to patients with cancer cachexia, who are more likely to have advanced disease, higher levels of systemic inflammation, and greater degrees of metabolic dysfunction. Studies specific to this group are required to explore what, if any, changes exercise can make to levels of CRP and other immune and hormonal biomarkers, along with their potential clinical relevance.

The effects of moderate exercise on chronic stress-induced intestinal barrier dysfunction and antimicrobial defense

The purpose of this study was to examine the effect of moderate exercise on repeated restraint stress (RRS)-induced intestinal barrier dysfunction and explore possible mechanisms in a mouse model. Male Balb/c mice (6weeks) were randomized into 7 groups: CON functioned as controls with no intervention; RRS was subjected to 6h per day RRS for 7 consecutive days; RRS+SWIM received 30min per day of swimming prior to RRS; CON+SWIM only received 30min per day of swimming; and the other groups received one session of 30min swimming prior to sacrifice at 1-, 3- and 6h recovery. Intestinal permeability was quantified with FITC-dextran. Bacterial translocation was determined by quantification of bacterial colony forming units (CFUs) in cultured mesenteric lymph nodes (MLN), and with fluorescence in situ hybridization (FISH). Antimicrobial related gene expression at baseline and 1h after one session of 30min swimming was tested by quantitative real-time polymerase chain reaction (Q-PCR) in small intestinal segments. Protein expression of 5 genes with statistically significant increase was measured at baseline, and 1-, 3- and 6h post-swimming using enzyme-linked immunosorbent assay (ELISA). Thirty minutes per day of swimming before RRS attenuated bacterial translocations and maintained intestinal permeability. Gene expression and protein levels for four antimicrobial peptides (α-defensin 5, β-defensin 1, RegIIIβ and RegIIIγ) were significantly increased after one 30min swimming session. In conclusion, moderate exercise attenuated chronic stress-induced intestinal barrier dysfunction in mice, possibly due to augmentation of antimicrobial responses in the small intestine.

Sitting time, physical activity and cervical intraepithelial neoplasia in Australian women: a preliminary investigation

ISSUE ADDRESSED

Physical activity affects the immune system, which in turn may modify the risk of cervical intraepithelial neoplasia (CIN). The effect of sitting on CIN is unknown. This study investigated the relationship between sitting time, physical activity and the risk of CIN.

METHODS

Community-dwelling adult women within metropolitan Perth, Western Australia, who had had a Papanicolaou (Pap) smear test at any of five clinics and medical centres, were approached by their general practitioners. In total, 348 women were recruited and interviewed for information on sitting time, physical activity level and lifetime physical activity exposure using the International Physical Activity Questionnaire (IPAQ)--short form. Associations of exposure variables with CIN risk were assessed by unconditional logistic regression analyses.

RESULTS

The prevalence of abnormal Pap smear status indicating CIN was found to be 15.8%. Women with prolonged sitting duration (≥42 h per week) had significantly increased risk of CIN (adjusted OR 3.49, 95% CI 1.12-10.88) than women who sat less than 24.5h per week. Although the effect of total physical activity level was non-significant (P=0.408), being always involved in physical activity during the entire life appeared to be inversely associated with the CIN risk (P=0.036).

CONCLUSIONS

Prolonged sitting time was significantly associated with increased risk of abnormal Pap smear status indicating CIN. SO WHAT?: This preliminary investigation highlights a new prospect for health-promotion intervention to reduce the risk of CIN. Health practitioners should encourage women to reduce their sitting time and maintain physically active throughout their life course.