Inflammatory and growth factor response to continuous and intermittent exercise in youth with cystic fibrosis

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.

Interval versus constant-load exercise training in adults with Cystic Fibrosis

BACKGROUND

The efficacy of interval exercise (IE) compared to constant-load exercise (CLE) training remains unsettled in adults with Cystic Fibrosis (CF).

METHODS

Twenty-four adults with CF were randomised to 30-min IE (100 % peak work capacity (WRpeak) for 30-s alternated with 40 % WRpeak for 30-s; n = 12) or 30-min CLE (70 % WRpeak; n = 12) training, 3 times weekly, for 12 weeks. Isometric quadriceps muscle strength was assessed using a strain gauge Myometer.

RESULTS

The magnitude of improvement in quadriceps muscle strength was greater (p = 0.037) in the IE (by 32 ± 13 Nm) compared to the CLE (by 23 ± 12 Nm) groups. Maximum inspiratory and expiratory mouth pressures were significantly improved only in the IE group (by 30 ± 10 cmH₂O; p = 0.009 and 13 ± 4 cmH₂O; p = 0.007, respectively). Arterial oxygen saturation during training was higher (p = 0.002) for IE (94 ± 1%) compared to CLE (91 ± 1%), whereas dyspnoea scores were lower (p = 0.001) for IE (3.8 ± 0.7) compared to CLE (5.9 ± 0.8) CONCLUSIONS: IE is superior to CLE in improving peripheral and respiratory muscle strength and preferable to CLE because it is associated with lower exercise-induced arterial oxygen desaturation and breathlessness.

Effects of aerobic interval training on glucose tolerance in children and adolescents with cystic fibrosis: a randomized trial protocol

BACKGROUND

Individuals with cystic fibrosis (CF) may develop CF-related diabetes (CFDR). This comorbidity is related to a poorer quality of life, microvascular complications, a decline in lung function, and an increase in exacerbations, as well as delayed growth and puberty. Evidence exists that physical exercise contributes to glycemic control in individuals with non-CF-related diabetes. This exercise is usually continuous with moderate intensity and long duration, which can cause muscle dyspnea and fatigue in CF individuals. Aerobic interval training (AIT) emerges as a safe and effective alternative for treating these individuals. The objective of this study is to evaluate the effects of AIT on glucose tolerance in children and adolescents with CF.

METHODS

This study will be a two-arm, prospectively registered, randomized controlled trial with blind assessors and twenty 6- to 18-year-old individuals with cystic fibrosis (CF) from two different Brazilian states. People with CF will be randomly allocated to either the experimental or control group using block randomization, stratified by puberty stage,. Participants from both groups will receive an educational intervention and will be asked to continue their usual daily treatment for the full duration of the study. Those in the experimental group will perform AIT on a cycle ergometer at home three times a week, for 8 consecutive weeks. The sample characterization will include an assessment of puberty stage, socioeconomic status, dyspnea, and anthropometry. The primary outcome will be the change in glucose tolerance, while the secondary outcomes will include lung function, exercise tolerance, respiratory muscle strength, quality of life, and CF exacerbations. All outcomes will be assessed at baseline, week 9, and week 17.

DISCUSSION

This is the first study to evaluate the effects of AIT on glucose tolerance in children and adolescents with CF. This study will serve as a basis for guiding clinical practice and decision-making in treating glucose intolerance and CF-related diabetes (CFRD) in children and adolescents with CF.

TRIAL REGISTRATION

ClinicalTrials.gov Protocol Registration System: NCT03653949. Registered on August 31, 2018.

Effects of high intensity interval training on exercise capacity in people with cystic fibrosis: study protocol for a randomised controlled trial

BACKGROUND

In people with cystic fibrosis (CF), higher exercise capacity is associated with better health-related quality of life (HRQoL), reduced risk of hospitalisation for a respiratory infection and survival. Therefore, optimisation of exercise capacity is an important treatment goal. The Australian and New Zealand clinical practice guidelines recommend that people with CF complete 30 to 60 min of moderate intensity aerobic exercise on most days of the week. This recommendation can be difficult to achieve by people with CF because of time constraints, and intolerable breathlessness and muscle fatigue during continuous exercise. In contrast, a low-volume, high intensity interval training (HIIT) program may be a more achievable and efficient training method to improve exercise capacity in people with CF.

METHODS

A randomised controlled trial will be undertaken. Forty people with CF (aged ≥15 years) will be randomly allocated, on a 1:1 ratio, to either the experimental or control group. Regardless of their group allocation, all participants will be asked to continue with their usual daily treatment for the study duration. Those in the experimental group will complete 8 weeks of thrice weekly HIIT on a cycle ergometer. Those in the control group will receive weekly contact with the investigators. The primary outcome of this study is exercise capacity. Secondary outcomes are HRQoL, exercise self-efficacy, feelings of anxiety, depression and enjoyment. These outcomes will be recorded at baseline (i.e. prior to randomisation) and following the 8-week intervention period. The study will also report other outcomes of the HIIT program (cardiovascular responses, symptom response, post-exercise muscle soreness and tolerance) and behaviour change techniques such as reinforcement, feedback and goal setting, used during the HIIT program.

DISCUSSION

This study will determine the effects of 8-weeks of supervised, low-volume HIIT, completed on a cycle ergometer on measures of exercise capacity, HRQoL, exercise self-efficacy, feelings of anxiety, depression and enjoyment. If effective, this type of training could be an attractive alternative to traditional continuous training because it may be more achievable and time efficient.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry (ANZCTR):12617001271392 (04/09/2017).

Exercise-Induced Oxidative Stress Responses in the Pediatric Population

Adults demonstrate an upregulation of their pro- and anti-oxidant mechanisms in response to acute exercise while systematic exercise training enhances their antioxidant capacity, thereby leading to a reduced generation of free radicals both at rest and in response to exercise stress. However, less information exists regarding oxidative stress responses and the underlying mechanisms in the pediatric population. Evidence suggests that exercise-induced redox perturbations may be valuable in order to monitor exercise-induced inflammatory responses and as such training overload in children and adolescents as well as monitor optimal growth and development. The purpose of this review was to provide an update on oxidative stress responses to acute and chronic exercise in youth. It has been documented that acute exercise induces age-specific transient alterations in both oxidant and antioxidant markers in children and adolescents. However, these responses seem to be affected by factors such as training phase, training load, fitness level, mode of exercise etc. In relation to chronic adaptation, the role of training on oxidative stress adaptation has not been adequately investigated. The two studies performed so far indicate that children and adolescents exhibit positive adaptations of their antioxidant system, as adults do. More studies are needed in order to shed light on oxidative stress and antioxidant responses, following acute exercise and training adaptations in youth. Available evidence suggests that small amounts of oxidative stress may be necessary for growth whereas the transition to adolescence from childhood may promote maturation of pro- and anti-oxidant mechanisms. Available evidence also suggests that obesity may negatively affect basal and exercise-related antioxidant responses in the peripubertal period during pre- and early-puberty.

[Insights into cystic fibrosis-related bone disease]

With the increasing life expectancy of patients with cystic fibrosis (CF), prevalence of late complications such as CF-related bone disease (CFBD) has increased. It was initially described in 24% of the adult population with CF and has also been reported in the pediatric population. CFBD is multifactorial and progresses in different steps. Both decreased bone formation and increased bone resorption (in different amounts) are observed. CFBD is likely primitive (directly related to the CFTR defect itself), but is also worsened by acquired secondary factors such as lung infections, chronic inflammation, denutrition, vitamin deficiency, and decreased physical activity. CFBD may be clinically apparent (i.e., mainly vertebral and costal fractures), or clinically asymptomatic (therefore corresponding to abnormalities in bone density and architecture). CFBD management mainly aims to prevent the occurrence of fractures. Prevention and regular monitoring of bone disease as early as 8 years of age is of the utmost importance, as is the control of possible secondary deleterious CFBD factors. New radiological tools, such as high-resolution peripheral quantitative computed tomography, allow an accurate evaluation of cortical and trabecular bone micro-architecture in addition to compartmental density; as such, they will likely improve the assessment of the bone fracture threat in CF patients in the near future.

Physical activity and pediatric multiple sclerosis: Developing a research agenda

Three-quarters of children with multiple sclerosis (MS) experience fatigue or depression, and progressive neurocognitive decline may be seen as early as two years after MS diagnosis. Furthermore, a higher magnetic resonance imaging disease burden is seen in pediatric-onset MS compared with adult-onset MS. To date, limited knowledge exists regarding behavioral methods for managing symptoms and disease progression in pediatric MS. To that end, this paper builds an evidence-based argument for the possible symptomatic and disease-modifying effects of exercise and physical activity in pediatric MS. This will be accomplished through: (a) a review of pediatric MS and its consequences; (b) a brief overview of physical activity and its consequences in children and adults with MS; and (c) a selective review of research on the neurological benefits of physical activity in pediatric populations. This topical review concludes with a list of 10 questions to guide future research on physical activity and pediatric MS. The objective of this paper is the provision of a research interest, focus and agenda involving pediatric MS and its lifelong management though exercise and physical activity behavior. Such an agenda is critical as the effects and maintenance of physical activity and exercise track across the lifespan, particularly when developed in the early stages of life.

The effects of resting and exercise serum from children with cystic fibrosis on C2C12 myoblast proliferation in vitro

Chronic systemic inflammation is a clinical symptom in children with cystic fibrosis (CF), but the effects on skeletal muscle development are unknown. The aims of this study were to determine (1) the effects of systemic factors from children with CF and healthy controls on myoblast proliferation, and (2) whether exercise serum can have an effect on proliferation in vitro. Eleven children with CF and 11 biological age-matched controls completed two 30-min bouts of cycling at an intensity set at 50% peak mechanical power. Serum samples were collected before exercise (REST), immediately following exercise (EX), and after 60 min of recovery (REC). Serum samples prepared in group-specific pools were used for cell culture experiments. C2C12 myoblasts were incubated in 5% serum and media for 1 h and then immediately harvested for protein and mRNA analysis, or incubated in growth media for 2 days to examine proliferation. C2C12 myoblasts treated with CF serum displayed greater proliferation phenotype than myoblasts treated with control serum. Proliferation did not change with EX or REC serum from children with CF compared to CF REST serum, while proliferation was increased with EX and REC serum from control compared to control REST serum. These findings suggest that systemic factors from children with CF at rest and after exercise can alter myoblast proliferation responses when compared to systemic factors from healthy children, which may have implications on skeletal muscle development.

Reduced fat oxidation rates during submaximal exercise in boys with cystic fibrosis

BACKGROUND

Exercise is a viable form of therapy for children with cystic fibrosis (CF). Understanding the energy sources used during exercise would aid CF patients in obtaining proper nutrition in order to sustain an active lifestyle.

METHODS

Six boys with CF (mean age ± SD: 14.8 ± 2.3 yrs, FEV1: 99 ± 18% predicted) and six matched controls (14.0 ± 2.2 yrs) completed a session of two 30 min bouts of cycling at an intensity set at 50% peak mechanical power. Rates of total fat and carbohydrate (CHO) oxidation were calculated from expired gases. Plasma insulin, glucose and free fatty acid (FFA) were determined before, during and at the end of the exercise.

RESULTS

Rates of fat oxidation (expressed in mean mg × kg body weight(-1) × min(-1) ± SD) were significantly lower in children with CF (5.7 ± 1.6) compared to controls (8.6 ± 1.8, p < 0.05). Children with CF also had lower values than controls in amount of fat oxidized (CF: 17.3 ± 5.0 g, controls: 26.1 ± 5.9 g, p < 0.05) and percent of total energy expenditure from fat (CF: 32 ± 6%, controls: 43 ± 7%, p < .0.05), but a higher contribution from CHO (CF: 68 ± 6%, controls: 57 ± 7% p < .0.05). Plasma FFA was significantly lower in children with CF compared to controls during (CF: 252.5 ± 117.9 μM, controls: 602.2 ± 295.6) and at the end of exercise (CF: 430.9 ± 180.6, controls: 1147.5 ± 473.5). There were no differences in the rates of CHO oxidation, insulin or glucose between groups.

CONCLUSION

Fat metabolism during exercise is impaired in boys with CF and may be attributed to an inability to mobilize FFA.