Randomized controlled trial of dietary creatine as an adjunct therapy to physical training in chronic obstructive pulmonary disease

Comparative Efficacy of Nutritional Supplements in Modulating Lung Function and Exercise Capacity in COPD Patients: A Network Meta-Analysis

Objective

To compare the effects of nutritional supplements on lung function and exercise tolerance in chronic obstructive pulmonary disease (COPD).

Methods

We searched PubMed, Embase, Cochrane Library, and Web of Science for randomized controlled trials (RCTs) on nutritional supplements in COPD patients, with the search ending December 31, 2023. Two authors independently screened studies, extracted data, and assessed quality using the Cochrane risk of bias tool. Data were analyzed using RevMan 5.4 and R 4.2.3.

Results

Forty-eight studies with 2481 COPD patients were included. Network meta-analysis showed six supplements significantly improved the 6-minute walk distance (6MWD) (all p<0.05), with the top three being: Coenzyme Q10+ Creatine [MD=63, 95% CI (36, 90)], L-carnitine [MD=53, 95% CI (24, 82)], and anabolic steroids [MD=44, 95% CI (7.1, 82)]. Four supplements improved FEV1%(all p<0.05): nanocurcumin [MD=13, 95% CI (7.7, 18)], Vitamin D [MD=7.5, 95% CI (5.1, 9.9)], probiotics [MD=7.1, 95% CI (5.2, 9.1)] and BSO [MD=4.9, 95% CI (1.6, 8.3)]. In pairwise comparisons, nanocurcumin outperformed BSO and Probiotics. Nanocurcumin [MD=12, 95% CI (4.6, 19), p<0.05] improved FEV1/FVC, and nitrate [MD=26, 95% CI (9.7, 42), p<0.05] was effective for the Incremental Shuttle Walk Test (ISWT). Traditional Chinese Medicine (TCM) products [MD=-1.3, 95% CI (-1.9, -0.67)], melatonin (MLT) [MD=-0.9, 95% CI (-1.6, -0.21)] and Calcitriol [MD=-0.66, 95% CI (-0.93, -0.39)] improved the modified Medical Research Council(mMRC) dyspnea score (all p<0.05), with comparable efficacy among them.

Conclusion

Nutritional supplements improve lung function and exercise endurance in COPD. Coenzyme Q10+Creatine is most effective for endurance, while Nanocurcumin has the greatest impact on lung function.

Nutritional Support of Chronic Obstructive Pulmonary Disease

Background: COPD is a heterogenous disease of the respiratory tract caused by diverse genetic factors along with environmental and lifestyle-related effects such as industrial dust inhalation and, most frequently, cigarette smoking. These factors lead to airflow obstruction and chronic respiratory symptoms. Additionally, the increased risk of infections exacerbates airway inflammation in COPD patients. As a consequence of the complex pathomechanisms and difficulty in treatment, COPD is among the leading causes of mortality both in the western countries and in the developing world. Results: The management of COPD is still a challenge for the clinicians; however, alternative interventions such as smoking cessation and lifestyle changes from a sedentary life to moderate physical activity with special attention to the diet may ameliorate patients' health. Here, we reviewed the effects of different dietary components and supplements on the conditions of COPD. Conclusions: COPD patients are continuously exposed to heavy metals, which are commonly present in cigarette smoke and polluted air. Meanwhile, they often experience significant nutrient deficiencies, which affect the detoxification of these toxic metals. This in turn can further disrupt nutritional balance by interfering with the absorption, metabolism, and utilization of essential micronutrients. Therefore, awareness and deliberate efforts should be made to check levels of micronutrients, with special attention to ensuring adequate levels of antioxidants, vitamin D, vitamin K2, magnesium, and iron, as these may be particularly important in reducing the risk of COPD development and limiting disease severity.

Creatine supplementation protocols with or without training interventions on body composition: a GRADE-assessed systematic review and dose-response meta-analysis

BACKGROUND

Despite the robust evidence demonstrating positive effects from creatine supplementation (primarily when associated with resistance training) on measures of body composition, there is a lack of a comprehensive evaluation regarding the influence of creatine protocol parameters (including dose and form) on body mass and estimates of fat-free and fat mass.

METHODS

Randomized controlled trials (RCTs) evaluating the effect of creatine supplementation on body composition were included. Electronic databases, including PubMed, Web of Science, and Scopus were searched up to July 2023. Heterogeneity tests were performed. Random effect models were assessed based on the heterogeneity tests, and pooled data were examined to determine the weighted mean difference (WMD) with a 95% confidence interval (CI).

RESULTS

From 4831 initial records, a total of 143 studies met the inclusion criteria. Creatine supplementation increased body mass (WMD: 0.86 kg; 95% CI: 0.76 to 0.96, I2 = 0%) and fat-free mass (WMD: 0.82 kg; 95% CI: 0.57 to 1.06, I2 = 0%) while reducing body fat percentage (WMD: -0.28 %; 95% CI: -0.47 to -0.09; I2 = 0%). Studies that incorporated a maintenance dose of creatine or performed resistance training in conjunction with supplementation had greater effects on body composition.

CONCLUSION

Creatine supplementation has a small effect on body mass and estimates of fat-free mass and body fat percentage. These findings were more robust when combined with resistance training.

Creatine supplementation for optimization of physical function in the patient at risk of functional disability: A systematic review and meta-analysis

BACKGROUND

The efficacy of creatine replacement through supplementation for the optimization of physical function in the population at risk of functional disability is unclear.

METHODS

We conducted a systematic literature search of MEDLINE, EMBASE, the Cochrane Library, and CINAHL from inception to November 2022. Studies included were randomized controlled trials (RCTs) comparing creatine supplementation with placebos in older adults and adults with chronic disease. The primary outcome was physical function measured by the sit-to-stand test after pooling data using random-effects modeling. We also performed a Bayesian meta-analysis to describe the treatment effect in probability terms. Secondary outcomes included other measures of physical function, muscle function, and body composition. The risk of bias was assessed using the Cochrane risk-of-bias tool.

RESULTS

We identified 33 RCTs, comprising 1076 participants. From six trials reporting the primary outcome, the pooled standardized mean difference (SMD) was 0.51 (95% confidence interval [CI]: 0.01-1.00; I2 = 62%; P = 0.04); using weakly informative priors, the posterior probability that creatine supplementation improves physical function was 66.7%. Upper-body muscle strength (SMD: 0.25; 95% CI: 0.06-0.44; I2 = 0%; P = 0.01), handgrip strength (SMD 0.23; 95% CI: 0.01-0.45; I2 = 0%; P = 0.04), and lean tissue mass (MD 1.08 kg; 95% CI: 0.77-1.38; I2 = 26%; P < 0.01) improved with creatine supplementation. The quality of evidence for all outcomes was low or very low because of a high risk of bias.

CONCLUSION

Creatine supplementation improves sit-to-stand performance, muscle function, and lean tissue mass. It is crucial to conduct high-quality prospective RCTs to confirm these hypotheses (PROSPERO number, CRD42023354929).

Systematic review and meta-analysis of nutrient supplements for treating sarcopenia in people with chronic obstructive pulmonary disease

Individuals with chronic obstructive pulmonary disease (COPD) are prone to malnutrition and sarcopenia as a result of nutritional deficiencies and increased energy metabolism. However, the effects of nutrient supplements (NS) on treating sarcopenia in patients with COPD are not well established from systematic evidence. This meta-analysis examined the effect of NS on sarcopenia in patients with COPD. A systematic search of multiple databases was conducted, and 29 randomized controlled trials involving 1625 participants (age, mean [SD] = 67.9 [7.8] years) were analyzed. NS demonstrated significant improvements in body weight (MD,1.33 kg; 95% CI, 0.60, 2.05 kg; P = 0.0003; I2 = 87%), fat-free mass index (MD, 0.74 kg/m2; 95% CI, 0.21, 1.27 kg/m2; P = 0.007; I2 = 75%), and 6-min walk test (MD, 19.43 m; 95% CI, 4.91, 33.94 m; P = 0.009; I2 = 81%) compared with control. However, NS had nonsignificant effects on handgrip strength (SMD, 0.36; 95% CI, - 0.15, 0.88; P = 0.16; I2 = 87%) and quadriceps muscle strength (SMD, 0.11; 95% CI, -  0.06, 0.27; P = 0.20; I2 = 25%) compared with the control. In conclusion, NS may be an effective treatment for improving body composition and physical performance in COPD. Future studies should explore the effects of intervention durations, specific NS types, or combined training in patients with COPD and sarcopenia.

Efficacy of interventions to alter measures of fat-free mass in people with COPD: a systematic review and meta-analysis

Introduction

Low fat-free mass (FFM) is linked to poor health outcomes in COPD, including impaired exercise tolerance and premature death. The aim of this systematic review was to synthesise evidence on the effectiveness of interventions for increasing FFM in COPD.

Methods

Searches of electronic databases (MEDLINE, Cochrane Library, Embase, Web of Science, Scopus) and trial registers (ClinicalTrials.gov) were undertaken from inception to August 2022 for randomised studies of interventions assessing measures of FFM in COPD. The primary outcome was change in FFM (including derivatives). Secondary outcomes were adverse events, compliance and attrition.

Results

99 studies (n=5138 people with COPD) of 11 intervention components, used alone or in combination, were included. Exercise training increased mid-thigh cross-sectional area (k=3, standardised mean difference (SMD) 1.04, 95% CI 0.02-2.06; p=0.04), but not FFM (k=4, SMD 0.03, 95% CI -0.18-0.24; p=0.75). Nutritional supplementation significantly increased FFM index (k=11, SMD 0.31, 95% CI 0.13-0.50; p<0.001), but not FFM (k=19, SMD 0.16, 95% CI -0.06-0.39; p=0.16). Combined exercise training and nutritional supplementation increased measures related to FFM in 67% of studies. Anabolic steroids increased FFM (k=4, SMD 0.98, 95% CI 0.24-1.72; p=0.009). Neuromuscular electrical stimulation increased measures related to FFM in 50% of studies. No interventions were more at risk of serious adverse events, low compliance or attrition.

Discussion

Exercise training and nutritional supplementation were not effective in isolation to increase FFM, but were for localised muscle and index measures, respectively. Combined, exercise and nutritional supplementation shows promise as a strategy to increase FFM in COPD. Anabolic steroids are efficacious for increasing FFM in COPD.

Creatine supplementation for older adults: Focus on sarcopenia, osteoporosis, frailty and Cachexia

Sarcopenia refers to the age-related reduction in strength, muscle mass and functionality which increases the risk for falls, injuries and fractures. Sarcopenia is associated with other age-related conditions such as osteoporosis, frailty and cachexia. Identifying treatments to overcome sarcopenia and associated conditions is important from a global health perspective. There is evidence that creatine monohydrate supplementation, primarily when combined with resistance training, has favorable effects on indices of aging muscle and bone. These musculoskeletal benefits provide some rationale for creatine being a potential intervention for treating frailty and cachexia. The purposes of this narrative review are to update the collective body of research pertaining to the effects of creatine supplementation on indices of aging muscle and bone (including bone turnover markers) and present possible justification and rationale for its utilization in the treatment of frailty and cachexia in older adults.

Increased energy and/or protein intake improves anthropometry and muscle strength in chronic obstructive pulmonary disease patients: a systematic review with meta-analysis on randomised controlled clinical trials

Compromised nutritional status is associated with a poor prognosis in chronic obstructive pulmonary disease (COPD) patients. However, the impact of nutritional support in this group of patients is controversial. The present study systematically reviewed the effect of energy and or protein supplements or food fortification on anthropometry and muscle strength of COPD patients. We searched MEDLINE (PubMed), EMBASE, Cochrane Library and Scopus for all published randomised clinical trials without language restriction up to May 2021. Three reviewers performed study selection and data extraction independently. We judged the risk of bias by RoB 2 and the certainty of evidence by the GRADE approach. We included thirty-two randomised controlled trials and compiled thirty-one of them (1414 participants) in the random-effects model meta-analyses. Interventions were energy and/or protein oral nutritional supplements or food fortification added to the diet for at least one week. Pooled analysis revealed that nutritional interventions increased body weight (muscle circumference (MD) = 1·44 kg, 95 % CI 0·81, 2·08, I2 = 73 %), lean body mass (standardised mean difference (SMD) = 0·37; 95 % CI 0·15, 0·59, I2 = 46 %), midarm muscle circumference (MD = 0·29 mm2, 95 % CI 0·02, 0·57, I2 = 0 %), triceps skinfold (MD = 1·09 mm, 95 % CI 0·01, 2·16, I2 = 0 %) and handgrip strength (SMD = 0·39, 95 % CI 0·07, 0·71, I2 = 62 %) compared with control diets. Certainty of evidence ranged from very low to low, and most studies were judged with some concerns or at high risk of bias. This meta-analysis revealed, with limited evidence, that increased protein and/or energy intake positively impacts anthropometric measures and handgrip strength of COPD patients.

Nutritional Status and Body Composition in Patients Suffering From Chronic Respiratory Diseases and Its Correlation With Pulmonary Rehabilitation

As part of an individualized intervention to improve the physical, emotional, and social functioning of patients with chronic respiratory diseases in general and chronic obstructive pulmonary disease in particular, awareness of the presence and consequences of changes in body composition increased enormously during the last decades, and nutritional intervention is considered as an essential component in the comprehensive approach of these patients. This review describes the prevalence and the clinical impact of body composition changes and also provides an update of current intervention strategies. It is argued that body composition, preferentially a three-component evaluation of fat, lean, and bone mass, must become part of a thorough assessment of every patient, admitted for pulmonary rehabilitation.

Meta-Analysis Examining the Importance of Creatine Ingestion Strategies on Lean Tissue Mass and Strength in Older Adults

Creatine supplementation in conjunction with resistance training (RT) augments gains in lean tissue mass and strength in aging adults; however, there is a large amount of heterogeneity between individual studies that may be related to creatine ingestion strategies. Therefore, the purpose of this review was to (1) perform updated meta-analyses comparing creatine vs. placebo (independent of dosage and frequency of ingestion) during a resistance training program on measures of lean tissue mass and strength, (2) perform meta-analyses examining the effects of different creatine dosing strategies (lower: ≤5 g/day and higher: >5 g/day), with and without a creatine-loading phase (≥20 g/day for 5-7 days), and (3) perform meta-analyses determining whether creatine supplementation only on resistance training days influences measures of lean tissue mass and strength. Overall, creatine (independent of dosing strategy) augments lean tissue mass and strength increase from RT vs. placebo. Subanalyses showed that creatine-loading followed by lower-dose creatine (≤5 g/day) increased chest press strength vs. placebo. Higher-dose creatine (>5 g/day), with and without a creatine-loading phase, produced significant gains in leg press strength vs. placebo. However, when studies involving a creatine-loading phase were excluded from the analyses, creatine had no greater effect on chest press or leg press strength vs. placebo. Finally, creatine supplementation only on resistance training days significantly increased measures of lean tissue mass and strength vs. placebo.

The Application of Creatine Supplementation in Medical Rehabilitation

Numerous health conditions affecting the musculoskeletal, cardiopulmonary, and nervous systems can result in physical dysfunction, impaired performance, muscle weakness, and disuse-induced atrophy. Due to its well-documented anabolic potential, creatine monohydrate has been investigated as a supplemental agent to mitigate the loss of muscle mass and function in a variety of acute and chronic conditions. A review of the literature was conducted to assess the current state of knowledge regarding the effects of creatine supplementation on rehabilitation from immobilization and injury, neurodegenerative diseases, cardiopulmonary disease, and other muscular disorders. Several of the findings are encouraging, showcasing creatine's potential efficacy as a supplemental agent via preservation of muscle mass, strength, and physical function; however, the results are not consistent. For multiple diseases, only a few creatine studies with small sample sizes have been published, making it difficult to draw definitive conclusions. Rationale for discordant findings is further complicated by differences in disease pathologies, intervention protocols, creatine dosing and duration, and patient population. While creatine supplementation demonstrates promise as a therapeutic aid, more research is needed to fill gaps in knowledge within medical rehabilitation.

Current Evidence and Possible Future Applications of Creatine Supplementation for Older Adults

Sarcopenia, defined as age-related reduction in muscle mass, strength, and physical performance, is associated with other age-related health conditions such as osteoporosis, osteosarcopenia, sarcopenic obesity, physical frailty, and cachexia. From a healthy aging perspective, lifestyle interventions that may help overcome characteristics and associated comorbidities of sarcopenia are clinically important. One possible intervention is creatine supplementation (CR). Accumulating research over the past few decades shows that CR, primarily when combined with resistance training (RT), has favourable effects on aging muscle, bone and fat mass, muscle and bone strength, and tasks of physical performance in healthy older adults. However, research is very limited regarding the efficacy of CR in older adults with sarcopenia or osteoporosis and no research exists in older adults with osteosarcopenia, sarcopenic obesity, physical frailty, or cachexia. Therefore, the purpose of this narrative review is (1) to evaluate and summarize current research involving CR, with and without RT, on properties of muscle and bone in older adults and (2) to provide a rationale and justification for future research involving CR in older adults with osteosarcopenia, sarcopenic obesity, physical frailty, or cachexia.

Effects of Creatine Supplementation on Properties of Muscle, Bone, and Brain Function in Older Adults: A Narrative Review

Aging is associated with reductions in muscle and bone mass and brain function, which may be counteracted by several lifestyle factors, of which exercise appears to be most beneficial. However, less than 20% of older adults (> 55 years of age) adhere to performing the recommended amount of resistance training (≥ 2 days/week) and less than 12% regularly meet the aerobic exercise guidelines (≥ 150 min/week of moderate to vigorous intensity aerobic exercise) required to achieve significant health benefits. Therefore, from a healthy aging and clinical perspective, it is important to determine whether other lifestyle interventions (independent of exercise) can have beneficial effects on aging muscle quality and quantity, bone strength, and brain function. Creatine, a nitrogen containing organic compound found in all cells of the body, has the potential to have favorable effects on muscle, bone, and brain health (independent of exercise) in older adults. The purpose of this narrative review is to examine and summarize the small body of research investigating the effects of creatine supplementation alone on measures of muscle mass and performance, bone mineral and strength, and indices of brain health in older adults.

A double-blind randomised controlled trial of protein supplementation to enhance exercise capacity in COPD during pulmonary rehabilitation: a pilot study

BACKGROUND

Pulmonary rehabilitation is a cost-effective management strategy in chronic obstructive pulmonary disease (COPD) which improves exercise performance and health-related quality of life. Nutritional supplementation may counter malnutrition and enhance pulmonary rehabilitation outcomes but rigorous evidence is absent. We aimed to investigate the effect of high-protein supplementation (Fortisip Compact Protein (FCP)) during pulmonary rehabilitation on exercise capacity.

METHODS

This was a double-blind randomised controlled trial comparing FCP (intervention) with PreOp (a carbohydrate control supplement) in COPD patients participating in a pulmonary rehabilitation programme. Participants consumed the supplement twice a day during pulmonary rehabilitation and attended twice-weekly pulmonary rehabilitation sessions, with pre- and post-pulmonary rehabilitation measurements, including the incremental shuttle walk test (ISWT) distance at 6 weeks as the primary outcome. Participants' experience using supplements was assessed.

RESULTS

68 patients were recruited (intervention n=36 and control n=32). The trial was stopped early due to the COVID-19 pandemic. Although statistical significance was not reached, there was the suggestion of a clinically meaningful difference in the ISWT distance at 6 weeks favouring the intervention group (intervention 342±149 m (n=22) versus control 305±148 m (n=22); p=0.1). Individuals who achieved an improvement in the ISWT had a larger mid-thigh circumference at baseline (responders 62±4 cm versus nonresponders 55±6 cm; p=0.006). 79% of the patients were satisfied with the taste and 43% would continue taking the FCP.

CONCLUSIONS

Although the data did not demonstrate a statistically significant difference in the ISWT, high-protein supplementation in COPD during pulmonary rehabilitation may result in a clinically meaningful improvement in exercise capacity and was acceptable to patients. Large, adequately powered studies are justified.

Risk of Adverse Outcomes in Females Taking Oral Creatine Monohydrate: A Systematic Review and Meta-Analysis

Creatine Monohydrate (CrM) is a dietary supplement routinely used as an ergogenic aid for sport and training, and as a potential therapeutic aid to augment different disease processes. Despite its increased use in recent years, studies reporting potential adverse outcomes of CrM have been mostly derived from male or mixed sex populations. A systematic search was conducted, which included female participants on CrM, where adverse outcomes were reported, with meta-analysis performed where appropriate. Six hundred and fifty-six studies were identified where creatine supplementation was the primary intervention; fifty-eight were female only studies (9%). Twenty-nine studies monitored for adverse outcomes, with 951 participants. There were no deaths or serious adverse outcomes reported. There were no significant differences in total adverse events, (risk ratio (RR) 1.24 (95% CI 0.51, 2.98)), gastrointestinal events, (RR 1.09 (95% CI 0.53, 2.24)), or weight gain, (mean difference (MD) 1.24 kg pre-intervention, (95% CI -0.34, 2.82)) to 1.37 kg post-intervention (95% CI -0.50, 3.23)), in CrM supplemented females, when stratified by dosing regimen and subject to meta-analysis. No statistically significant difference was reported in measures of renal or hepatic function. In conclusion, mortality and serious adverse events are not associated with CrM supplementation in females. Nor does the use of creatine supplementation increase the risk of total adverse outcomes, weight gain or renal and hepatic complications in females. However, all future studies of creatine supplementation in females should consider surveillance and comprehensive reporting of adverse outcomes to better inform participants and health professionals involved in future trials.

Nutritional supplementation during pulmonary rehabilitation in COPD: A systematic review

Uptake of nutritional supplementation during pulmonary rehabilitation (PR) for people with chronic obstructive pulmonary disease (COPD) has been limited by an absence of rigorous evidence-based studies supporting use. The objective was to report and summarise the current evidence supporting the use of nutritional supplementation to improve outcomes during PR in stable COPD patients. A systematic search was conducted up to 7 August 2019 (registration number CRD42018089142). The preferred reporting items for systematic reviews and meta-analyses guidelines were used. Six databases were included: Medical Literature Analysis and Retrieval System Online or MEDLARS Online, Allied and Complementary Medicine Database, the Cochrane Database of Systematic Reviews, Excerpta Medica dataBASE, Cumulative Index of Nursing and Allied Health Literature and Web of Science. This systematic search generated 580 initial matches, of which 22 studies (917 COPD participants) met the pre-specified criteria and were included. Sixteen of 19 studies that used nutritional supplements in addition to PR did not show additional benefit compared to PR alone when measuring exercise capacity. Nutritional supplements significantly increased body weight in 7 of 11 studies. Body mass index increased significantly in two of six studies. Handgrip strength did not improve, while quadriceps muscle strength significantly improved in 3 of 11 studies. Four of eight studies showed a significant improvement in inspiratory muscle function. Only 2 of 14 studies demonstrated a significant improvement in quality of life with supplementation in addition to PR. There remains insufficient evidence on the effect of nutritional supplementation on improving outcomes during PR in patients with COPD due to heterogeneity in supplements, outcome measures and PR programmes. Therefore, controversy remains and further research is needed.

Lifestyle Interventions with a Focus on Nutritional Strategies to Increase Cardiorespiratory Fitness in Chronic Obstructive Pulmonary Disease, Heart Failure, Obesity, Sarcopenia, and Frailty

Cardiorespiratory fitness (CRF) is an independent predictor for all-cause and disease-specific morbidity and mortality. CRF is a modifiable risk factor, and exercise training and increased physical activity, as well as targeted medical therapies, can improve CRF. Although nutrition is a modifiable risk factor for chronic noncommunicable diseases, little is known about the effect of dietary patterns and specific nutrients on modifying CRF. This review focuses specifically on trials that implemented dietary supplementation, modified dietary pattern, or enacted caloric restriction, with and without exercise training interventions, and subsequently measured the effect on peak oxygen consumption (VO2) or surrogate measures of CRF and functional capacity. Populations selected for this review are those recognized to have a reduced CRF, such as chronic obstructive pulmonary disease, heart failure, obesity, sarcopenia, and frailty. We then summarize the state of existing knowledge and explore future directions of study in disease states recently recognized to have an abnormal CRF.

Skeletal Muscle Dysfunction in Chronic Obstructive Pulmonary Disease. What We Know and Can Do for Our Patients

Skeletal muscle dysfunction occurs in patients with chronic obstructive pulmonary disease (COPD) and affects both ventilatory and nonventilatory muscle groups. It represents a very important comorbidity that is associated with poor quality of life and reduced survival. It results from a complex combination of functional, metabolic, and anatomical alterations leading to suboptimal muscle work. Muscle atrophy, altered fiber type and metabolism, and chest wall remodeling, in the case of the respiratory muscles, are relevant etiological contributors to this process. Muscle dysfunction worsens during COPD exacerbations, rendering patients progressively less able to perform activities of daily living, and it is also associated with poor outcomes. Muscle recovery measures consisting of a combination of pulmonary rehabilitation, optimized nutrition, and other strategies are associated with better prognosis when administered in stable patients as well as after exacerbations. A deeper understanding of this process' pathophysiology and clinical relevance will facilitate the use of measures to alleviate its effects and potentially improve patients' outcomes. In this review, a general overview of skeletal muscle dysfunction in COPD is offered to highlight its relevance and magnitude to expert practitioners and scientists as well as to the average clinician dealing with patients with chronic respiratory diseases.

Changes in Fat Mass Following Creatine Supplementation and Resistance Training in Adults ≥50 Years of Age: A Meta-Analysis

Aging is associated with an increase in fat mass which increases the risk for disease, morbidity and premature mortality. Creatine supplementation in combination with resistance training has been shown to increase lean tissue mass in adults ≥50 years of age; however, the synergetic effects of creatine and resistance training on fat mass in this population are unclear. Creatine metabolism plays an important role in adipose tissue bioenergetics and energy expenditure. Thus, the combination of creatine supplementation and resistance training may decrease fat mass more than resistance training alone. The purpose of this review is two-fold: (1) to perform meta-analyses on studies involving creatine supplementation during resistance training on fat mass in adults ≥50 years of age, and (2) to discuss possible mechanistic actions of creatine on reducing fat mass. Nineteen studies were included in our meta-analysis with 609 participants. Results from the meta-analyses showed that adults ≥50 years of age who supplemented with creatine during resistance training experienced a greater reduction in body fat percentage (0.55%, p = 0.04) compared to those on placebo during resistance training. Despite no statistical difference (p = 0.13), adults supplementing with creatine lost ~0.5 kg more fat mass compared to those on placebo. Interestingly, there are studies which have linked mechanism(s) explaining how creatine may influence fat mass, and these data are also discussed.

Variables Influencing the Effectiveness of Creatine Supplementation as a Therapeutic Intervention for Sarcopenia

Sarcopenia is an age-related muscle condition characterized by a reduction in muscle quantity, force generating capacity and physical performance. Sarcopenia occurs in 8-13% of adults ≥ 60 years of age and can lead to disability, frailty, and various other diseases. Over the past few decades, several leading research groups have focused their efforts on developing strategies and recommendations for attenuating sarcopenia. One potential nutritional intervention for sarcopenia is creatine supplementation. However, research is inconsistent regarding the effectiveness of creatine on aging muscle. The purpose of this perspective paper is to: (1) propose possible reasons for the inconsistent responsiveness to creatine in aging adults, (2) discuss the potential mechanistic actions of creatine on muscle biology, (3) determine whether the timing of creatine supplementation influences aging muscle, (4) evaluate the evidence investigating the effects of creatine with other compounds (protein, conjugated linoleic acid) in aging adults, and (5) provide insight regarding the safety of creatine for aging adults.

Deterioration of Limb Muscle Function during Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Important features of both stable and acute exacerbation of chronic obstructive pulmonary disease (COPD) are skeletal muscle weakness and wasting. Limb muscle dysfunction during an exacerbation has been linked to various adverse outcomes, including prolonged hospitalization, readmission, and mortality. The contributing factors leading to muscle dysfunction are similar to those seen in stable COPD: disuse, nutrition/energy balance, hypercapnia, hypoxemia, electrolyte derangements, inflammation, and drugs (i.e., glucocorticoids). These factors may be the trigger for a downstream cascade of local inflammatory changes, pathway process alterations, and structural degradation. Ultimately, the clinical effects can be wide ranging and include reduced limb muscle strength. Current therapies, such as pulmonary/physical rehabilitation, have limited impact because of low participation rates. Recently, novel drugs have been developed in similar disorders, and learnings from these studies can be used as a foundation to facilitate discovery in patients hospitalized with a COPD exacerbation. Nevertheless, investigators should approach this patient population with knowledge of the limitations of each intervention. In this Concise Clinical Review, we provide an overview of acute muscle dysfunction in patients hospitalized with acute exacerbation of COPD and a strategic approach to drug development in this setting.

Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis

The loss of muscle mass and strength with aging results in significant functional impairment. Creatine supplementation has been used in combination with resistance training as a strategy for increasing lean tissue mass and muscle strength in older adults, but results across studies are equivocal. We conducted a systematic review and meta-analysis of randomized controlled trials of creatine supplementation during resistance training in older adults with lean tissue mass, chest press strength, and leg press strength as outcomes by searching PubMed and SPORTDiscus databases. Twenty-two studies were included in our meta-analysis with 721 participants (both men and women; with a mean age of 57–70 years across studies) randomized to creatine supplementation or placebo during resistance training 2–3 days/week for 7–52 weeks. Creatine supplementation resulted in greater increases in lean tissue mass (mean difference =1.37 kg [95% CI =0.97–1.76]; p<0.00001), chest press strength (standardized mean difference [SMD] =0.35 [0.16–0.53]; p=0.0002), and leg press strength (SMD =0.24 [0.05–0.43]; p=0.01). A number of mechanisms exist by which creatine may increase lean tissue mass and muscular strength. These are included in a narrative review in the discussion section of this article. In summary, creatine supplementation increases lean tissue mass and upper and lower body muscular strength during resistance training of older adults, but potential mechanisms by which creatine exerts these positive effects have yet to be evaluated extensively.

Effect of "add-on" interventions on exercise training in individuals with COPD: a systematic review

The aim of this review was to identify the effectiveness of therapies added on to conventional exercise training to maximise exercise capacity in patients with chronic obstructive pulmonary disease (COPD). Electronic databases were searched, identifying trials comparing exercise training with exercise training plus "add-on" therapy. Outcomes included peak oxygen uptake (V'_O2peak), work rate and incremental/endurance cycle and field walking tests. Individual trial effects on exercise capacity were extracted and collated into eight subgroups and pooled for meta-analysis. Sensitivity analyses were conducted to explore the stability of effect estimates across studies employing patient-centred designs and those deemed to be of "high" quality (PEDro score >5 out of 10). 74 studies (2506 subjects) met review inclusion criteria. Interventions spanned a broad scope of clinical practice and were most commonly evaluated via the 6-min walking distance and V'_O2peak. Meta-analysis revealed few clinically relevant and statistically significant benefits of "add-on" therapies on exercise performance compared with exercise training. Benefits favouring "add-on" therapies were observed across six different interventions (additional exercise training, noninvasive ventilation, bronchodilator therapy, growth hormone, vitamin D and nutritional supplementation). The sensitivity analyses included considerably fewer studies, but revealed minimal differences to the primary analysis. The lack of systematic benefits of "add-on" interventions is a probable reflection of methodological limitations, such as "one size fits all" eligibility criteria, that are inherent in many of the included studies of "add-on" therapies. Future clarification regarding the exact value of such therapies may only arise from adequately powered, multicentre clinical trials of tailored interventions for carefully selected COPD patient subgroups defined according to distinct clinical phenotypes.

Creatine supplementation attenuates pulmonary and systemic effects of lung ischemia and reperfusion injury

BACKGROUND

Creatine (Cr) is a dietary supplement that presents beneficial effects in experimental models of heart and brain ischemia and reperfusion (I/R) injury. It can improve adenosine 5'-triphosphate generation and reduce cell damage. This study evaluated the effects of Cr supplementation in a model of lung I/R.

METHODS

Forty male Wistar rats were divided into 4 groups: sham operated, Cr+sham, I/R, and Cr+I/R. We investigated the effects of 5 days of Cr supplementation (0.5 g/kg/day by gavage) before left pulmonary artery ischemia (90 minutes) and reperfusion (120 minutes) on pulmonary and systemic response.

RESULTS

Cr inhibited the I/R-induced increase in exhaled nitric oxide (p < 0.05), total cells (p < 0.01), and neutrophils (p < 0.001) in bronchoalveolar lavage fluid and in the systemic circulation (p < 0.001). The levels of interleukin-1β (p < 0.05), tissue damping, and tissue elastance (p < 0.05) were also minimized. Cr also inhibited pulmonary edema formation (total proteins in bronchoalveolar lavage fluid, p < 0.001; histologic edema index, p < 0.001) and neutrophils accumulation in lung tissue (p < 0.001). As possible mechanisms underlying Cr effects, we observed a reduced expression of caspase 3 (p < 0.05), reduced expression of Toll-like receptor (TLR) 4, and increased expression of TLR7 in lung tissue (p < 0.001).

CONCLUSIONS

Cr supplementation presents pulmonary and systemic protective effects in acute lung injury induced by I/R in rats. These beneficial effects seem to be related to the anti-inflammatory and anti-oxidant properties of Cr and modulation of TLRs.

Use of exercise testing in the evaluation of interventional efficacy: an official ERS statement

This document reviews 1) the measurement properties of commonly used exercise tests in patients with chronic respiratory diseases and 2) published studies on their utilty and/or evaluation obtained from MEDLINE and Cochrane Library searches between 1990 and March 2015.

Exercise tests are reliable and consistently responsive to rehabilitative and pharmacological interventions. Thresholds for clinically important changes in performance are available for several tests. In pulmonary arterial hypertension, the 6-min walk test (6MWT), peak oxygen uptake and ventilation/carbon dioxide output indices appear to be the variables most responsive to vasodilators. While bronchodilators do not always show clinically relevant effects in chronic obstructive pulmonary disease, high-intensity constant work-rate (endurance) tests (CWRET) are considerably more responsive than incremental exercise tests and 6MWTs. High-intensity CWRETs need to be standardised to reduce interindividual variability. Additional physiological information and responsiveness can be obtained from isotime measurements, particularly of inspiratory capacity and dyspnoea. Less evidence is available for the endurance shuttle walk test. Although the incremental shuttle walk test and 6MWT are reliable and less expensive than cardiopulmonary exercise testing, two repetitions are needed at baseline. All exercise tests are safe when recommended precautions are followed, with evidence suggesting that no test is safer than others.

Guidelines for the evaluation and treatment of muscle dysfunction in patients with chronic obstructive pulmonary disease

In patients with chronic obstructive pulmonary disease (COPD), skeletal muscle dysfunction is a major comorbidity that negatively impacts their exercise capacity and quality of life. In the current guidelines, the most recent literature on the various aspects of COPD muscle dysfunction has been included. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) scale has been used to make evidence-based recommendations on the different features. Compared to a control population, one third of COPD patients exhibited a 25% decline in quadriceps muscle strength, even at early stages of their disease. Although both respiratory and limb muscles are altered, the latter are usually more severely affected. Numerous factors and biological mechanisms are involved in the etiology of COPD muscle dysfunction. Several tests are proposed in order to diagnose and evaluate the degree of muscle dysfunction of both respiratory and limb muscles (peripheral), as well as to identify the patients' exercise capacity (six-minute walking test and cycloergometry). Currently available therapeutic strategies including the different training modalities and pharmacological and nutritional support are also described.

Creatine supplementation during resistance training in older adults-a meta-analysis

INTRODUCTION

Age-related sarcopenia and dynapenia have negative effects on strength and the ability to perform activities of daily living. Resistance training (RT) increases muscle mass and strength in older adults and is an established countermeasure for sarcopenia and dynapenia, and creatine may enhance this effect. We aimed to determine whether the addition of Cr to RT increased gains in muscle mass, strength, and function in older adults over RT alone by conducting a systematic review and meta-analysis.

METHODS

PubMed and Healthstar databases were searched. Randomized, placebo-controlled trials that involved older adults supplemented with Cr and included RT regimens (>6 wk) were included. Data were analyzed using fixed or random (if data were heterogeneous) effects meta-analysis using RevMan 5.

RESULTS

The meta-analysis comprised 357 older adults (average ± SD Cr: 63.6 ± 5.9 yr, Pl: 64.2 ± 5.4 yr) with 12.6 ± 4.9 wk of RT. Cr + RT increased total body mass (P = 0.004) and fat-free mass (P < 0.0001) with no effect on fat mass as compared with RT alone. Cr + RT increased chest press (P = 0.004) and leg press (P = 0.02) one-repetition maximum to a greater extent than RT alone, with no difference in the effect on knee extension or biceps curl one-repetition maximum, isokinetic or isometric knee extension peak torque. Cr + RT had a greater effect than RT alone on the 30-s chair stand test (P = 0.03).

CONCLUSION

Retention of muscle mass and strength is integral to healthy aging. The results from this meta-analysis are encouraging in supporting a role for Cr supplementation during RT in healthful aging by enhancing muscle mass gain, strength, and functional performance over RT alone; however, the limited number of studies indicates further work is needed.

Nutritional assessment and therapy in COPD: a European Respiratory Society statement

Nutrition and metabolism have been the topic of extensive scientific research in chronic obstructive pulmonary disease (COPD) but clinical awareness of the impact dietary habits, nutritional status and nutritional interventions may have on COPD incidence, progression and outcome is limited. A multidisciplinary Task Force was created by the European Respiratory Society to deliver a summary of the evidence and description of current practice in nutritional assessment and therapy in COPD, and to provide directions for future research. Task Force members conducted focused reviews of the literature on relevant topics, advised by a methodologist. It is well established that nutritional status, and in particular abnormal body composition, is an important independent determinant of COPD outcome. The Task Force identified different metabolic phenotypes of COPD as a basis for nutritional risk profile assessment that is useful in clinical trial design and patient counselling. Nutritional intervention is probably effective in undernourished patients and probably most when combined with an exercise programme. Providing evidence of cost-effectiveness of nutritional intervention is required to support reimbursement and thus increase access to nutritional intervention. Overall, the evidence indicates that a well-balanced diet is beneficial to all COPD patients, not only for its potential pulmonary benefits, but also for its proven benefits in metabolic and cardiovascular risk.

Creatine, L-carnitine, and ω3 polyunsaturated fatty acid supplementation from healthy to diseased skeletal muscle

Myopathies are chronic degenerative pathologies that induce the deterioration of the structure and function of skeletal muscle. So far a definitive therapy has not yet been developed and the main aim of myopathy treatment is to slow the progression of the disease. Current nonpharmacological therapies include rehabilitation, ventilator assistance, and nutritional supplements, all of which aim to delay the onset of the disease and relieve its symptoms. Besides an adequate diet, nutritional supplements could play an important role in the treatment of myopathic patients. Here we review the most recent in vitro and in vivo studies investigating the role supplementation with creatine, L-carnitine, and ω3 PUFAs plays in myopathy treatment. Our results suggest that these dietary supplements could have beneficial effects; nevertheless continued studies are required before they could be recommended as a routine treatment in muscle diseases.

Approaches to outcome assessment in pulmonary rehabilitation

A comprehensive assessment is the foundation of a successful pulmonary rehabilitation programme. There is a broad selection of outcome measures that tend to be categorized into measures of exercise performance (including measures of strength) quality of life (health status), psychological well-being, nutritional status and more recently knowledge and self-efficacy. There is a growing interest in the measurement of physical activity too, although this is a current line of research activity. A sophisticated suite of outcomes allows the rehabilitation program to be personalised to the individual and deliver effective rehabilitation.

An official American Thoracic Society/European Respiratory Society statement: update on limb muscle dysfunction in chronic obstructive pulmonary disease

BACKGROUND

Limb muscle dysfunction is prevalent in chronic obstructive pulmonary disease (COPD) and it has important clinical implications, such as reduced exercise tolerance, quality of life, and even survival. Since the previous American Thoracic Society/European Respiratory Society (ATS/ERS) statement on limb muscle dysfunction, important progress has been made on the characterization of this problem and on our understanding of its pathophysiology and clinical implications.

PURPOSE

The purpose of this document is to update the 1999 ATS/ERS statement on limb muscle dysfunction in COPD.

METHODS

An interdisciplinary committee of experts from the ATS and ERS Pulmonary Rehabilitation and Clinical Problems assemblies determined that the scope of this document should be limited to limb muscles. Committee members conducted focused reviews of the literature on several topics. A librarian also performed a literature search. An ATS methodologist provided advice to the committee, ensuring that the methodological approach was consistent with ATS standards.

RESULTS

We identified important advances in our understanding of the extent and nature of the structural alterations in limb muscles in patients with COPD. Since the last update, landmark studies were published on the mechanisms of development of limb muscle dysfunction in COPD and on the treatment of this condition. We now have a better understanding of the clinical implications of limb muscle dysfunction. Although exercise training is the most potent intervention to address this condition, other therapies, such as neuromuscular electrical stimulation, are emerging. Assessment of limb muscle function can identify patients who are at increased risk of poor clinical outcomes, such as exercise intolerance and premature mortality.

CONCLUSIONS

Limb muscle dysfunction is a key systemic consequence of COPD. However, there are still important gaps in our knowledge about the mechanisms of development of this problem. Strategies for early detection and specific treatments for this condition are also needed.

Resistance training as a preconditioning strategy for enhancing aerobic exercise training outcomes in COPD

PURPOSE

Aerobic exercise training is a recognized approach for improving functional capacity in COPD. People with greater disease severity often have difficulty achieving higher aerobic exercise training intensity. The effects of resistance training prior to aerobic training were examined to determine if this sequential approach was associated with greater gains in functional status than aerobic training alone or concurrent aerobic and resistance training.

METHODS

Patients were randomized to: 1) sequential resistance then aerobic training (RT-then-AT) (8 weeks resistance training followed by 8 weeks aerobic exercise training), 2) control group (CE-then-AT + RT) (8 weeks of 'sham' training followed by 8 weeks concurrent aerobic and resistance training), 3) control group (CE-then-AT) (8 weeks 'sham' training followed by 8 weeks aerobic training). Outcomes were assessed at study entry, after week 8, and after week 16: aerobic exercise performance; muscle strength and endurance.

RESULTS

75 patients completed training: FEV1 %pred 40 ± 10, V˙O(2peak) %predicted, 71 ± 22, fat-free mass index 19.5 ± 3.1. RT-then-AT had greater acquisition of peripheral muscle endurance than CE-then-AT + RT and CE-then-AT, but improvements in aerobic exercise performance were similar. Improvements in muscle strength were similar between RT-then-AT and CE-then-AT + RT. Sarcopenia was associated with poorer attendance, and lower aerobic and resistance training volumes.

CONCLUSION

Although the sequential approach to resistance and aerobic training yielded a greater increase in muscle endurance and higher resistance training volume compared to concurrent resistance and aerobic training, other training outcomes were similar between the two groups, thus the sequential approach is not clearly superior to the concurrent approach in severe COPD. ClinicalTrials.gov Identifier: NCT01058213.

The systemic nature of chronic lung disease

The systemic effects and comorbidities of chronic respiratory disease such as COPD contribute substantially to its burden. Symptoms in COPD do not solely arise from the degree of airflow obstruction as exercise limitation is compounded by the specific secondary manifestations of the disease including skeletal muscle impairment, osteoporosis, mood disturbance, anemia, and hormonal imbalance. Pulmonary rehabilitation targets the systemic manifestations of COPD, the causes of which include inactivity, systemic inflammation, hypoxia and corticosteroid treatment. Comorbidities are common, including cardiac disease, obesity, and metabolic syndrome and should not preclude pulmonary rehabilitation as they may also benefit from similar approaches.

Creatine supplementation and aging musculoskeletal health

Sarcopenia refers to the progressive loss of muscle mass and muscle function and is a contributing factor for cachexia, bone loss, and frailty. Resistance training produces several physiological adaptations which improve aging musculoskeletal health, such as increased muscle and bone mass and strength. The combination of creatine supplementation and resistance training may further lead to greater physiological benefits. We performed meta-analyses which indicate creatine supplementation combined with resistance training has a positive effect on aging muscle mass and upper body strength compared to resistance training alone. Creatine also shows promise for improving bone mineral density and indices of bone biology. The combination of creatine supplementation and resistance training could be an effective intervention to improve aging musculoskeletal health.

Phenotyping airways disease: an A to E approach

The airway diseases asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous conditions with overlapping pathophysiological and clinical features. It has previously been proposed that this heterogeneity may be characterized in terms of five relatively independent domains labelled from A to E, namely airway hyperresponsiveness (AHR), bronchitis, cough reflex hypersensitivity, damage to the airways and surrounding lung parenchyma, and extrapulmonary factors. Airway hyperresponsiveness occurs in both asthma and COPD, accounting for variable day to day symptoms, although the mechanisms most likely differ between the two conditions. Bronchitis, or airway inflammation, may be predominantly eosinophilic or neutrophilic, with different treatments required for each. Cough reflex hypersensitivity is thought to underlie the chronic dry cough out of proportion to other symptoms that can occur in association with airways disease. Structural changes associated with airway disease (damage) include bronchial wall thickening, airway smooth muscle hypertrophy, bronchiectasis and emphysema. Finally, a variety of extrapulmonary factors may impact upon airway disease, including rhinosinusitis, gastroesophageal reflux disease, obesity and dysfunctional breathing. This article discusses the A to E concept in detail and describes how this framework may be used to assess and treat patients with airway diseases in the clinic.

Undernutrition in patients with COPD and its treatment

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disorder of the lung and whole body caused mainly by tobacco smoking. Patients with advanced COPD are in a state of undernutrition, referred to as pulmonary cachexia; the exercise performance and quality of life (QOL) of these patients are deteriorated, the vital prognosis is unfavorable, and the medico-economic burden posed by poorly nourished COPD patients is high. The mainstays of COPD treatment are pharmacotherapy, mainly with bronchodilators, and non-pharmacotherapeutic approaches such as respiratory rehabilitation and nutrition counseling. Nutritional supplement therapy, consisting primarily of high calorie intake, has been demonstrated to be effective for maintaining and improving the muscle strength and exercise tolerance in poorly nourished COPD patients. The efficacy of intake of various nutrients, besides a high calorie intake, for amelioration of the disease state of COPD has also been reported. The roles of adipokines in the pathophysiology of COPD have begun to receive attention recently, and not only their regulatory effects on appetite and nutritional status, but also their influence on systemic inflammation have been increasingly clarified. We review the papers on COPD and nutrition and discuss the role of nutritional supplement therapy in the treatment of COPD.

Should all patients with COPD be exercise trained?

Exercise training is one of the most powerful interventions to provide symptomatic relief in patients with chronic obstructive pulmonary disease (COPD). The purpose of this minireview is to discuss how exercise training can improve limb muscle dysfunction in this disease. Various exercise training strategies will be outlined, along with their beneficial effects and potential limitations. Strategies to optimize the gains achievable with exercise training will be presented. Whether exercise training may exert deleterious effects in some patients will also be discussed.

Responsiveness of Various Exercise-Testing Protocols to Therapeutic Interventions in COPD

Exercise intolerance is a key element in the pathophysiology and course of Chronic Obstructive Pulmonary Disease (COPD). As such, evaluating exercise tolerance has become an important part of the management of COPD. A wide variety of exercise-testing protocols is currently available, each protocol having its own strengths and weaknesses relative to their discriminative, methodological, and evaluative characteristics. This paper aims to review the responsiveness of several exercise-testing protocols used to evaluate the efficacy of pharmacological and nonpharmacological interventions to improve exercise tolerance in COPD. This will be done taking into account the minimally important difference, an important concept in the interpretation of the findings about responsiveness of exercise testing protocols. Among the currently available exercise-testing protocols (incremental, constant work rate, or self-paced), constant work rate exercise tests (cycle endurance test and endurance shuttle walking test) emerge as the most responsive ones for detecting and quantifying changes in exercise capacity after an intervention in COPD.

Nutritional targets to enhance exercise performance in chronic obstructive pulmonary disease

PURPOSE OF REVIEW

This review presents current knowledge regarding the rationale and efficacy of nutrition as an ergogenic aid to enhance the effects of exercise and training in chronic obstructive pulmonary disease (COPD).

RECENT FINDINGS

Altered body composition and skeletal muscle dysfunction in COPD suggest that exercise capacity can be targeted via several metabolic routes. Muscle metabolic alterations in COPD include a reduced oxidative metabolism and enhanced susceptibility for oxidative stress. Muscle wasting may be associated with deficiencies of vitamin D and low branched-chain amino acid levels. Exercise training is of established benefit in COPD but clear-cut clinical trial evidence to support the performance enhancing effect of nutritional intervention is lacking. One randomized controlled trial suggested that augmentation of training with polyunsaturated fatty acids may improve exercise capacity. Conflicting results are reported on dietary creatine supplementation in patients with COPD receiving pulmonary rehabilitation and results from acute intervention studies do not directly imply long-term effects of glutamate or glutamine supplementation as an ergogenic aid in COPD. Recent data indicate that not only muscle but also visceral fat may be an important additional target for combined nutrition and exercise intervention in COPD to improve physical performance and decrease cardiometabolic risk.

SUMMARY

There is a clear need for adequately powered and controlled intervention and maintenance trials to establish the role of nutritional supplementation in the enhancement of exercise performance and training and the wider management of the systemic features of the disease.

Pulmonary rehabilitation programs for patients with COPD

Pulmonary rehabilitation programs are aimed at providing benefits to COPD patients, in various aspects. Our objective was to review the literature on COPD patient rehabilitation. This systematic review involved articles written in English, Spanish, or Portuguese; published between 2005 and 2009; and indexed in national and international databases. Articles were classified in accordance with the Global Initiative for Chronic Obstructive Lung Disease criteria for the determination of the level of scientific evidence (grade of recommendation A, B, or C). The outcome measures were exercise, quality of life, symptoms, exacerbations, mortality, and pulmonary function. Treatments were classified as standard rehabilitation, partial rehabilitation, strength exercises, and resistance exercises. Of the 40 articles selected, 4, 18, and 18 were classified as grades A, B, and C, respectively. Of the 181 analyses made in these articles, 61, 50, 23, 23, 20, and 4, respectively, were related to the outcome measures quality of life, exercise, symptoms, exacerbations, pulmonary function, and mortality. The standard rehabilitation programs showed positive effects on all of the outcomes evaluated, except for mortality (because of the small number of analyses). However, we found no differences among the various rehabilitation programs regarding their effects on the outcomes studied. Rehabilitation programs can be considered important tools for the treatment of COPD. Therefore, health administrators should implement public policies including such programs in the routine of health care facilities.

Nutritional support in chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND

The efficacy of nutritional support in the management of malnutrition in chronic obstructive pulmonary disease (COPD) is controversial. Previous meta-analyses, based on only cross-sectional analysis at the end of intervention trials, found no evidence of improved outcomes.

OBJECTIVE

The objective was to conduct a meta-analysis of randomized controlled trials (RCTs) to clarify the efficacy of nutritional support in improving intake, anthropometric measures, and grip strength in stable COPD.

DESIGN

Literature databases were searched to identify RCTs comparing nutritional support with controls in stable COPD.

RESULTS

Thirteen RCTs (n = 439) of nutritional support [dietary advice (1 RCT), oral nutritional supplements (ONS; 11 RCTs), and enteral tube feeding (1 RCT)] with a control comparison were identified. An analysis of the changes induced by nutritional support and those obtained only at the end of the intervention showed significantly greater increases in mean total protein and energy intakes with nutritional support of 14.8 g and 236 kcal daily. Meta-analyses also showed greater mean (±SE) improvements in favor of nutritional support for body weight (1.94 ± 0.26 kg, P < 0.001; 11 studies, n = 308) and grip strength (5.3%, P < 0.050; 4 studies, n = 156), which was not shown by ANOVA at the end of the intervention, largely because of bias associated with baseline imbalance between groups.

CONCLUSION

This systematic review and meta-analysis showed that nutritional support, mainly in the form of ONS, improves total intake, anthropometric measures, and grip strength in COPD. These results contrast with the results of previous analyses that were based on only cross-sectional measures at the end of intervention trials.

Developing the model of pulmonary rehabilitation for chronic heart failure

Patients with chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF) commonly suffer from exertional symptoms of breathlessness and fatigue. The similar systemic manifestations of the conditions, including skeletal muscle dysfunction, are a major contributing factor to the limitation in exercise capacity. A period of exercise training has been shown to improve exercise performance and health-related quality of life for both conditions. Exercise training is a key component of pulmonary rehabilitation (PR) which is now a standard of care for patients with COPD and is symptom based. Although it may be assumed that patients with CHF could be incorporated into cardiac rehabilitation, this is predominantly a secondary prevention programme for patients who are largely asymptomatic. It has been shown that patients with CHF can be successfully trained together with patients with COPD by the same therapists within PR. There are comparable outcome measures that can be used for both COPD and CHF. Many patients with CHF still do not have access to an exercise rehabilitation programme and incorporating them into the PR model of care could be one solution. This article reviews the (1) similar symptoms, mechanisms and consequences between COPD and CHF, (2) rationale and evidence for exercise training in CHF, (3) model of PR, (4) safety of exercise training in CHF, (5) evidence for combined exercise rehabilitation for CHF and COPD, (6) adaptations necessary to include patients with CHF into PR, (7) the chronic care model and (8) summary.

Respiratory Dysfunction in Ventilated Patients: Can Inspiratory Muscle Training Help?

Respiratory muscle dysfunction is associated with prolonged and difficult weaning from mechanical ventilation. This dysfunction in ventilator-dependent patients is multifactorial: there is evidence that inspiratory muscle weakness is partially explained by disuse atrophy secondary to ventilation, and positive end-expiratory pressure can further reduce muscle strength by negatively shifting the length-tension curve of the diaphragm. Polyneuropathy is also likely to contribute to apparent muscle weakness in critically ill patients, and nutritional and pharmaceutical effects may further compound muscle weakness. Moreover, psychological influences, including anxiety, may contribute to difficulty in weaning. There is recent evidence that inspiratory muscle training is safe and feasible in selected ventilator-dependent patients, and that this training can reduce the weaning period and improve overall weaning success rates. Extrapolating from evidence in sports medicine, as well as the known effects of inspiratory muscle training in chronic lung disease, a theoretical model is proposed to describe how inspiratory muscle training enhances weaning and recovery from mechanical ventilation. Possible mechanisms include increased protein synthesis (both Type 1 and Type 2 muscle fibres), enhanced limb perfusion via dampening of a sympathetically-mediated metaboreflex, reduced lactate levels and modulation of the perception of exertion, resulting in less dyspnoea and enhanced exercise capacity.

Role of creatine supplementation on exercise-induced cardiovascular function and oxidative stress

Many degenerative diseases are associated with increased oxidative stress. Creatine has the potential to act as an indirect and direct antioxidant; however, limited data exist to evaluate the antioxidant capabilities of creatine supplementation within in vivo human systems. This study aimed to investigate the effects of oral creatine supplementation on markers of oxidative stress and antioxidant defenses following exhaustive cycling exercise. Following preliminary testing and two additional familiarization sessions, 18 active males repeated two exhaustive incremental cycling trials (T1 and T2) separated by exactly 7 days. The subjects were assigned, in a double-blind manner, to receive either 20 g of creatine (Cr) or a placebo (P) for the 5 days preceding T2. Breath-by-breath respiratory data and heart rate were continually recorded throughout the exercise protocol and blood samples were obtained at rest (preexercise), at the end of exercise (postexercise), and the day following exercise (post24 h). Serum hypdroperoxide concentrations were elevated at postexercise by 17 ± 5% above preexercise values (p = 0.030). However, supplementation did not influence lipid peroxidation (serum hypdroperoxide concentrations), resistance of low density lipoprotein to oxidative stress (t_1/2max LDL oxidation) and plasma concentrations of non-enzymatic antioxidants (retinol, α-carotene, β-carotene, α-tocopherol, γ-tocopherol, lycopene and vitamin C). Heart rate and oxygen uptake responses to exercise were not affected by supplementation. These findings suggest that short-term creatine supplementation does not enhance non-enzymatic antioxidant defence or protect against lipid peroxidation induced by exhaustive cycling in healthy males.