The role of exercise on the innate immunity of the elderly

Potential mechanisms of multimodal prehabilitation effects on surgical complications: a narrative review

Continuous advances in prehabilitation research over the past several decades have clarified its role in improving preoperative risk factors, yet the evidence demonstrating reduced surgical complications remains uncertain. Describing the potential mechanisms underlying prehabilitation and surgical complications represents an important opportunity to establish biological plausibility, develop targeted therapies, generate hypotheses for future research, and contribute to the rationale for implementation into the standard of care. In this narrative review, we discuss and synthesize the current evidence base for the biological plausibility of multimodal prehabilitation to reduce surgical complications. The goal of this review is to improve prehabilitation interventions and measurement by outlining biologically plausible mechanisms of benefit and generating hypotheses for future research. This is accomplished by synthesizing the available evidence for the mechanistic benefit of exercise, nutrition, and psychological interventions for reducing the incidence and severity of surgical complications reported by the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). This review was conducted and reported in accordance with a quality assessment scale for narrative reviews. Findings indicate that prehabilitation has biological plausibility to reduce all complications outlined by NSQIP. Mechanisms for prehabilitation to reduce surgical complications include anti-inflammation, enhanced innate immunity, and attenuation of sympathovagal imbalance. Mechanisms vary depending on the intervention protocol and baseline characteristics of the sample. This review highlights the need for more research in this space while proposing potential mechanisms to be included in future investigations.

Exercise modulates the immune system in cardiorespiratory disease patients: Implications for clinical practice during the COVID-19 pandemic

BACKGROUND

Patients with cardiorespiratory problems often suffer from systemic inflammation. Stress due to the disease and continuous inflammation can undermine the success of the rehabilitation program.

OBJECTIVE

This review has been undertaken primarily to understand the effectiveness of exercise training on the immune system in individuals undergoing cardiorespiratory rehabilitation and its implications for further management during the COVID-19 pandemic.

METHODS

Assessors analyzed related studies identified in the MEDLINE, PROQUEST, PUBMED, Cochrane Library, CINAHL, EMBASE, Google Scholar, Physiotherapy Evidence, and Science Direct databases. The studies were divided into groups focused on the effect of exercise on blood leukocytes, the anti-inflammatory effect, and the role of nutrition and exercise in resolving inflammation.

RESULTS

Twenty-eight studies were included in this review. The number of studies included in each section was as follows: the effects of exercise training on leukocytes in cardiorespiratory conditions (n = 8), anti-inflammatory effect (n = 6), and the role of nutrition and exercise in resolving inflammation (n = 14). The bias risk assessment showed poor internal validity; most included studies were assigned no and unclear descriptors.

CONCLUSIONS

Substantive evidence is presented that emphasizes the role of moderate-intensity exercise in boosting the immune system in patients with cardiorespiratory diseases. Exercise has anti-inflammatory effects that are vital for overall well-being and resolving longstanding inflammation. Individuals with an active lifestyle had a better pathogen immune response than more sedentary individuals. Our findings highlight the current need to investigate the long-term effects of cardiorespiratory rehabilitation programs.

The Effects of Exercise on Aging-Induced Exaggerated Cytokine Responses: An Interdisciplinary Discussion

Aging is generally known to be associated with dynamic biological changes, physiological dysfunction, and environmental and psychological decline. Several studies have suggested that aging is associated with increased inflammatory cytokines, causing several diseases. However, the effect of exercise on aging has been less delineated, and the relationships between cytokine activation, aging, and exercise also need further study. Here, we discuss some ideas about the effect of exercise on aging-induced exaggerated cytokine responses and discuss the possible roles of the aging-induced exaggerated cytokine response following exercise. Evidence from these findings suggests that exercise is a beneficially applicable model to use in studies on the mechanisms underlying the age-associated gradated cytokine response, and these results may provide guidelines for health professionals with diverse backgrounds.

Forest-bathing and physical activity as weapons against COVID-19: a review

Strengthening the immune system in order to better withstand the threat of COVID-19 is an important way to ensure the protection of our health against the current pandemic associated with SARS-CoV-2. There are many ways to achieve this, but with current circumstances, certain modalities stand out as being the most valid and are certainly worth greater consideration. Here we review the effects that particular immuno-strengthening activities can have on limiting the severity of COVID-19 disease as well as preventing virus infection. Physical activity, in particular, should not be discounted as an important method of prevention of viral diseases as it triggers many biological processes within the human body which in turn lead to heightened natural defences against viral infections. When exercise is performed in forested areas, these protective health benefits may be increased since many plant species emit biogenic volatile compounds (VOCs) which, when inhaled, have many protective properties. These VOCs have been shown in particular to have immunostimulatory effects on the human body and, thus, they could be of use in the prevention and/or treatment of COVID-19. Being amongst trees may also help to alleviate stress and anxiety, lowering cortisol levels and consequently helping the proper functioning of the immune system. In the following work, we have performed an analysis of the available scientific literature which looks at the effects of physical exercise as well as 'forest-bathing' on the immune system's ability to fight disease, especially of course as it relates to COVID-19. Our review aims at shedding light on the benefits of exercising outdoors in green areas and suggests reforestation as a protective measure against future outbreaks.

Vaccination as a preventative measure contributing to immune fitness

The primary goal of vaccination is the prevention of pathogen-specific infection. The indirect consequences may include maintenance of homeostasis through prevention of infection-induced complications; trained immunity that re-programs innate cells to respond more efficiently to later, unrelated threats; slowing or reversing immune senescence by altering the epigenetic clock, and leveraging the pool of memory B and T cells to improve responses to new infections. Vaccines may exploit the plasticity of the immune system to drive longer-term immune responses that promote health at a broader level than just the prevention of single, specific infections. In this perspective, we discuss the concept of “immune fitness” and how to potentially build a resilient immune system that could contribute to better health. We argue that vaccines may contribute positively to immune fitness in ways that are only beginning to be understood, and that life-course vaccination is a fundamental tool for achieving healthy aging.

Exercise-induced immune system response: Anti-inflammatory status on peripheral and central organs

A wide array of molecular pathways has been investigated during the past decade in order to understand the mechanisms by which the practice of physical exercise promotes neuroprotection and reduces the risk of developing communicable and non-communicable chronic diseases. While a single session of physical exercise may represent a challenge for cell homeostasis, repeated physical exercise sessions will improve immunosurveillance and immunocompetence. Additionally, immune cells from the central nervous system will acquire an anti-inflammatory phenotype, protecting central functions from age-induced cognitive decline. This review highlights the exercise-induced anti-inflammatory effect on the prevention or treatment of common chronic clinical and experimental settings. It also suggests the use of pterins in biological fluids as sensitive biomarkers to follow the anti-inflammatory effect of physical exercise.

Effects of Acute and Chronic Exercise on Immunological Parameters in the Elderly Aged: Can Physical Activity Counteract the Effects of Aging?

Immunosenescence is characterized by deterioration of the immune system caused by aging which induces changes to innate and adaptive immunity. Immunosenescence affects function and phenotype of immune cells, such as expression and function of receptors for immune cells which contributes to loss of immune function (chemotaxis, intracellular killing). Moreover, these alterations decrease the response to pathogens, which leads to several age-related diseases including cardiovascular disease, Alzheimer's disease, and diabetes in older individuals. Furthermore, increased risk of autoimmune disease and chronic infection is increased with an aging immune system, which is characterized by a pro-inflammatory environment, ultimately leading to accelerated biological aging. During the last century, sedentarism rose dramatically, with a concomitant increase in certain type of cancers (such as breast cancer, colon, or prostate cancer), and autoimmune disease. Numerous studies on physical activity and immunity, with focus on special populations (i.e., people with diabetes, HIV patients) demonstrate that chronic exercise enhances immunity. However, the majority of previous work has focused on either a pathological population or healthy young adults whilst research in elderly populations is scarce. Research conducted to date has primarily focused on aerobic and resistance exercise training and its effect on immunity. This review focuses on the potential for exercise training to affect the aging immune system. The concept is that some lifestyle strategies such as high-intensity exercise training may prevent disease through the attenuation of immunosenescence. In this context, we take a top-down approach and review the effect of exercise and training on immunological parameters in elderly at rest and during exercise in humans, and how they respond to different modes of training. We highlight the impact of these different exercise modes on immunological parameters, such as cytokine and lymphocyte concentration in elderly individuals.

Centenarians and supercentenarians: a black swan. Emerging social, medical and surgical problems

The Black Swan Theory was described by Nassim Nicholas Taleb in his book “The Black Swan”. This theory refers to “high-impact, hard-to-predict, and rare events beyond the realm of normal expectations”. According to Taleb’s criteria, a Black Swan Event is a surprise, it has a major impact and after the fact, the event is rationalized by hindsight, as if it had been expected. For most of human history centenarians were a rare and unpredictable phenomenon. The improvements of the social-environmental conditions, of medical care, and the quality of life caused a general improvement of the health status of the population and a consequent reduction of the overall morbidity and mortality, resulting in an overall increase of life expectancy. The study of centenarians and supercentenarians had the objective to consider this black swan and to evaluate the health, welfare, social and economic consequences of this phenomenon.

Exercício resistido em idosos frágeis: uma revisão da literatura

INTRODUÇÃO: A síndrome da fragilidade, bastante comum em pessoas de idade avançada, consiste em um conjunto de sinais e sintomas no qual estão presentes critérios como perda de peso corporal não intencional em um ano (aproximadamente 5%), diminuição na velocidade da marcha, níveis baixos de atividade física, exaustão subjetiva e diminuição de força muscular. Os consequentes efeitos dessas mudanças relacionadas à idade, que incluem sarcopenia, disfunção imunológica e desregulação neuroendócrina, aumentam a vulnerabilidade do organismo ao estresse, reduzindo a habilidade de adaptar, compensar ou modular esses estímulos. Diferentes intervenções têm sido propostas para atenuar esse processo, sendo o exercício resistido (ER) uma das opções estudadas. OBJETIVO: Realizar uma revisão bibliográfica averiguando os efeitos dos ER na fisiopatologia da síndrome da fragilidade. MATERIAIS E MÉTODOS: Foi realizada uma revisão bibliográfica do período de 2004 a 2010, por meio das bases de dados LILACS, MEDLINE e PubMed. RESULTADOS: Por meio das análises dos estudos, foram observadas alterações nos sistemas hormonal e imune, atuando de forma sistêmica na reversão ou minimização dos efeitos da sarcopenia exercendo influência positiva na síndrome da fragilidade. CONCLUSÃO: O ER deve ser indicado como opção terapêutica para idosos frágeis ou pré-frágeis que não apresentem contraindicações para realização desta modalidade de exercício.

[Changes in mental health index, serum biochemical parameters and neutrophil function after start of the wheelchair use at a nursing home in Korea]

OBJECTIVES

In Korea, long-term care insurance has been provided to the elderly since 2008. We conducted a health survey of the elderly in a nursing home in Korea from 2007 to 2010. Since the introduction of the insurance system, many of the elderly have started using wheelchairs. We aimed to determine the effect of using wheelchairs on mental health index, serum biochemical parameters, and neutrophil function.

METHODS

The subjects were 32 elderly persons (mean age: 74.44 ± 5.79 years) who could walk unaided in 2007 and were not bedridden until 2010. We classified the subjects into the walking group (subjects could walk unaided or with a cane until 2010; 10 men, 9 women) and the wheelchair group (subjects required the use of a wheelchair from 2007 to 2010; 2 men, 11 women). We determined stress score, stress tolerance, subjective well-being score in accordance with the Philadelphia Geriatric Center Morale Scale, and serum biochemical parameters. We also analyzed oxidant production and phagocytosis by neutrophils and estimated the balance between oxidant production and phagocytosis by correlation analysis.

RESULTS

Increases in the stress tolerance of the wheelchair group in 2008 and 2009 and the subjective well-being score in 2009 in the survey were observed. However, in 2010, the stress tolerance and the subjective well-being score decreased to the levels in 2007. In 2010, the levels of serum albumin and high-density lipoprotein cholesterol of the wheelchair group were significantly lower than those of the walking group, and the balance between phagocytosis and oxidant production in the wheelchair group improved.

Non-melanoma skin cancers in elderly patients

Non-melanoma skin cancers are a common reality worldwide. The principal cause that determines the occurrence of these diseases is the exposition of the sun, which principally causes an alteration in the immune system. Therefore, it is possible that other forms of innate or acquired alterations of the immune system could favor the occurrence of non-melanoma skin cancers. For example, several studies have demonstrated that immunosenescence creates an immunosuppressive state that encourages the development of malignances, and new discoveries have noted the importance of T cells and in particular of T regulatory cells (Treg) and T receptor CD28 in this mechanism. Similar results are obtained analyzing the effect of immunosuppressive drugs. The importance of the immune system and its alteration in the genesis of non-melanoma skin cancers is fundamental for the creation of a new therapeutic and less invasive approach.

Physical activity, immunity and infection

During the last few decades, scientific evidence has confirmed a wide range of health benefits related to regular physical activity. How physical activity affects the immune function and infection risk is, however, still under debate. Commonly, intensive exercise suppresses the activity and levels of several immune cells, while other immune functions may be stimulated by moderate physical activity. With this knowledge, the understanding of the relationship between different levels of physical activity on the immune function has been raised as a potential tool to protect health not only in athletes but also in the general population; the mechanisms that translate a physically active lifestyle into good health continue to be investigated. Reviewing the literature, although several outcomes (i.e. the mechanisms by which different levels and duration of physical activity programmes affect numerous cell types and responses) remain unclear, given that the additional benefits encompass healthy habits including exercise, the use of physical activity programmes may result in improved health of elderly populations. Moderate physical activity or moderate-regulated training may enhance the immune function mainly in less fit subjects or sedentary population and the pre-event fitness status also seems to be an important individual factor regarding this relationship. Although adequate nutrition and regular physical activity habits may synergistically improve health, clinical trials in athletes using nutritional supplements to counteract the immune suppression have been inconclusive so far.Further research is necessary to find out to what extent physical activity training can exert an effect on the immune function.

The role of immunity in elderly cancer

The increased incidence of malignancies in elderly patients living in industrialized countries has led to both identify the causes that alter the normal homeostatic balance in elderly and designate the specific treatments. The progressive decline of the immune system (immunosenescence) involving cellular and molecular alterations impact both innate and adaptive immunity. The immunosenescence leads to increased incidence of infectious diseases morbidity and mortality as well as heightened rates of other immune disorders such as autoimmunity, cancer, and inflammatory conditions. Here, we summarize the knowledge on the major changes in the immune system associated with aging in primary lymphoid organs as well as a description of molecular mechanisms, and the impact on cancer development.

Acquired immunity: immunosenescence and physical activity

Several lines of evidence indicate that infectious diseases, cancer, and autoimmune disorders occur more frequently in elderly people, thus suggesting that altered function of immune organs and cells, such as thymus and T and B lymphocytes are of primary importance in the pathogenesis of these diseases. Furthermore, old subjects are less responsive to vaccine than younger because of immune changes. The most common changes accompanying the adaptive immune system include decrement of T and B cells proliferation, repertoire degeneracy, increase of the memory cell type, decreased numbers of naive cells, and shift from T helper1 (Th1) to T helper2 (Th2) response. Regular exercise in the elderly may improve the alterations in acquired immunity which follow the physiological process of aging, allowing a major resistance against external pathogens and a better quality of life.