Haemodynamic compensations for exercise tissue oxygenation in early stages of COPD: an integrated cardiorespiratory assessment study.

BACKGROUND: Cardiovascular comorbidities are increasingly being recognised in early stages of chronic obstructive pulmonary disease (COPD) yet complete cardiorespiratory functional assessments of individuals with mild COPD or presenting with COPD risk factors are lacking. This paper reports on the effectiveness of the cardiocirculatory-limb muscles oxygen delivery and utilisation axis in smokers exhibiting no, or mild to moderate degrees of airflow obstruction using standardised cardiopulmonary exercise testing (CPET). METHODS: Post-bronchodilator spirometry was used to classify participants as 'ever smokers without' (n=88), with 'mild' (n=63) or 'mild-moderate' COPD (n=56). All underwent CPET with continuous concurrent monitoring of oxygen uptake (V'O2) and of bioimpedance cardiac output (Qc) enabling computation of arteriovenous differences (a-vO2). Mean values of Qc and a-vO2 were mapped across set ranges of V'O2 and Qc isolines to allow for meaningful group comparisons, at same metabolic and circulatory requirements. RESULTS: Peak exercise capacity was significantly reduced in the 'mild-moderate COPD' as compared with the two other groups who showed similar pulmonary function and exercise capacity. Self-reported cardiovascular and skeletal muscle comorbidities were not different between groups, yet disease impact and exercise intolerance scores were three times higher in the 'mild-moderate COPD' compared with the other groups. Mapping of exercise Qc and a-vO2 also showed a leftward shift of values in this group, indicative of a deficit in peripheral O2 extraction even for submaximal exercise demands. Concurrent with lung hyperinflation, a distinctive blunting of exercise stroke volume expansion was also observed in this group. CONCLUSION: Contrary to the traditional view that cardiovascular complications were the hallmark of advanced disease, this study of early COPD spectrum showed a reduced exercise O2 delivery and utilisation in individuals meeting spirometry criteria for stage II COPD. These findings reinforce the preventive clinical management approach to preserve peripheral muscle circulatory and oxidative capacities.

Mitochondrial Function in Healthy Human White Adipose Tissue: A Narrative Review.

As ¾ of the global population either have excess or insufficient fat, it has become increasingly critical to understand the functions and dysfunctions of adipose tissue (AT). AT serves as a key organ in energy metabolism, and recently, attention has been focused on white AT, particularly its mitochondria, as the literature evidence links their functions to adiposity. This narrative review provides an overview of mitochondrial functionality in human white AT. Firstly, it is noteworthy that the two primary AT depots, subcutaneous AT (scAT) and visceral AT (vAT), exhibit differences in mitochondrial density and activity. Notably, vAT tends to have a higher mitochondrial activity compared to scAT. Subsequently, studies have unveiled a negative correlation between mitochondrial activity and body mass index (BMI), indicating that obesity is associated with a lower mitochondrial function. While the impact of exercise on AT mitochondria remains uncertain, dietary interventions have demonstrated varying effects on AT mitochondria. This variability holds promise for the modulation of AT mitochondrial activity. In summary, AT mitochondria exert a significant influence on health outcomes and can be influenced by factors such as obesity and dietary interventions. Understanding the mechanisms underlying these responses can offer potential insights into managing conditions related to AT and overall health.

Eccentric and concentric exercises induce different adaptions in adipose tissue biology

Alterations in adipose tissue (AT) metabolism related to inflammation and adipokine’s production lead to perturbations in its capacity to store lipids and release fatty acids (FA) during feeding/fasting transition or during exercise. Exercise has a beneficial effect on AT metabolism, but conventional trainings are not always suitable for patients with functional limitations. Dynamic eccentric (ECC) exercise prevents the accumulation of AT and may then overcome those limitations. Consequently, this study aimed at investigating AT’s adaptations after ECC training. Nine-week-old male rats were randomly assigned to a control sedentary or three-trained groups for which treadmill slopes modulated exercise oxygen consumption (VO2) and mechanical work (n = 15 per group): (1) + 15% uphill-concentric group (CONC), (2) − 15% downhill group (ECC15, same mechanical work as CONC) and (3) − 30% downhill group (ECC30, same VO2, or oxygen cost as CONC). Body composition and energy expenditure (EE) were measured before and after 8 weeks of training. Subcutaneous AT was collected to study total FA profile and gene expression. Higher total EE was driven by lean mass gain in trained animals. In AT, there was a decrease in arachidonic acid with CONC or ECC15 training. Increased adiponectin, leptin, lipases, Glut4 and Igf1 mRNA levels in ECC15 group suggested major metabolic adaption in AT. In conclusion, ECC could induce beneficial modifications in AT fatty acid profile and the expression of key genes related to metabolism and insulin sensitivity. (AU)

Eccentric and concentric exercises induce different adaptions in adipose tissue biology.

Alterations in adipose tissue (AT) metabolism related to inflammation and adipokine's production lead to perturbations in its capacity to store lipids and release fatty acids (FA) during feeding/fasting transition or during exercise. Exercise has a beneficial effect on AT metabolism, but conventional trainings are not always suitable for patients with functional limitations. Dynamic eccentric (ECC) exercise prevents the accumulation of AT and may then overcome those limitations. Consequently, this study aimed at investigating AT's adaptations after ECC training. Nine-week-old male rats were randomly assigned to a control sedentary or three-trained groups for which treadmill slopes modulated exercise oxygen consumption (VO2) and mechanical work (n = 15 per group): (1) + 15% uphill-concentric group (CONC), (2) - 15% downhill group (ECC15, same mechanical work as CONC) and (3) - 30% downhill group (ECC30, same VO2, or oxygen cost as CONC). Body composition and energy expenditure (EE) were measured before and after 8 weeks of training. Subcutaneous AT was collected to study total FA profile and gene expression. Higher total EE was driven by lean mass gain in trained animals. In AT, there was a decrease in arachidonic acid with CONC or ECC15 training. Increased adiponectin, leptin, lipases, Glut4 and Igf1 mRNA levels in ECC15 group suggested major metabolic adaption in AT. In conclusion, ECC could induce beneficial modifications in AT fatty acid profile and the expression of key genes related to metabolism and insulin sensitivity.

Casein structures differently affect postprandial amino acid delivery through their intra-gastric clotting properties.

We aimed to assess if casein structure affects its digestion and its subsequent amino acid delivery kinetic. Higher nitrogen levels were recovered in dialysates after in vitro digestions of sodium caseinate (SC, formed of small aggregates) compared to micellar casein (MC, native form of casein) and calcium caseinate (CC, intermediate structure). Likewise, plasma indispensable amino-acid concentration peak was higher after SC compared to MC or CC ingestion in healthy volunteers in a randomized, double blind, cross-over study. In pigs, gamma-scintigraphy using labelled meals revealed that SC was mainly localized in the proximal part of the stomach whereas MC was distributed in the whole gastric cavity. Caseins were found in both solid and liquid phases and partly hydrolyzed casein in the solid phase shortly after SC drink ingestion. These data support the concept of slow (MC) and rapid (SC) casein depending of casein structure, likely due to their intra-gastric clotting properties.

Effects of exercise-induced metabolic and mechanical loading on skeletal muscle mitochondrial function in male rats.

Over the past decades, a growing interest in eccentric (ECC) exercise has emerged, but mitochondrial adaptations to ECC training remain poorly documented. Using an approach for manipulating mechanical and metabolic exercise power, we positioned that for the same metabolic power, training using concentric (CON) or ECC contractions would induce similar skeletal muscle mitochondrial adaptations. Sixty adult rats were randomly assigned to a control (CTRL) or three treadmill training groups running at 15 m·min-1 for 45 min, 5 days weekly for 8 wk at targeted upward or downward slopes. Animals from the CON (+15%) and ECC30 (-30%) groups were trained at iso-metabolic power, whereas CON and ECC15 (-15%) exercised at iso-mechanical power. Assessments were made of vastus intermedius mitochondrial respiration (oxygraphy), enzymatic activities (spectrophotometry), and real-time qPCR for mRNA transcripts. Maximal rates of mitochondrial respiration were 14%-15% higher in CON and ECC30 compared with CTRL and ECC15. Apparent Km for ADP for trained groups was 40%-66% higher than CTRL, with statistical significance reached for CON and ECC30. Complex I and citrate synthase activities were 1.6 (ECC15) to 1.8 (ECC30 and CON) times values of CTRL. Complex IV activity was higher than CTRL (P < 0.05) only for CON and ECC30. mRNA transcripts analyses showed higher TFAM, SLC25A4, CKMT2, and PPID in the ECC30 compared with CTRL. Findings confirm that training-induced skeletal muscle mitochondrial function adaptations are governed by the extent of metabolic overload irrespective of exercise modality. The distinctive ECC30 mRNA transcript pattern may reflect a cytoskeleton damage-repair or ECC adaptive cycle that differs from that of biogenesis.NEW & NOTEWORTHY Anticipating outcomes of eccentric versus concentric training is confounded by differences in mechanical efficiency. Our observations in groups of rats submitted to uphill and downhill running regimens inducing similar levels of metabolic demands or same external power outputs reaffirm that independent of modality, oxygen requirements and not external work governs skeletal muscle mitochondrial function adaptations.

Effect of Waters Enriched in O2 by Injection or Electrolysis on Performance and the Cardiopulmonary and Acid-Base Response to High Intensity Exercise.

Several brands of water enriched with O2 (O2-waters) are commercially available and are advertised as wellness and fitness waters with claims of physiological and psychological benefits, including improvement in exercise performance. However, these claims are based, at best, on anecdotal evidence or on a limited number of unreliable studies. The purpose of this double-blind randomized study was to compare the effect of two O2-waters (~110 mg O2·L-1) and a placebo (10 mg O2·L-1, i.e., close to the value at sea level, 9-12 mg O2·L-1) on the cardiopulmonary responses and on performance during high-intensity exercise. One of the two O2-waters and the placebo were prepared by injection of O2. The other O2-water was enriched by an electrolytic process. Twenty male subjects were randomly allocated to drink one of the three waters in a crossover study (2 L·day-1 × 2 days and 15 mL·kg-1 90 min before exercise). During each exercise trial, the subjects exercised at 95.9 ± 4.7% of maximal workload to volitional fatigue. Exercise time to exhaustion and the cardiopulmonary responses, arterial lactate concentration and pH were measured. Oxidative damage to proteins, lipids and DNA in blood was assessed at rest before exercise. Time to exhaustion (one-way ANOVA) and the responses to exercise (two-way ANOVA [Time; Waters] with repeated measurements) were not significantly different among the three waters. There was only a trend (p = 0.060) for a reduction in the time constant of the rapid component of VO2 kinetics with the water enriched in O2 by electrolysis. No difference in oxidative damage in blood was observed between the three waters. These results suggest that O2-water does not speed up cardiopulmonary response to exercise, does not increase performance and does not trigger oxidative stress measured at rest.

Unveiling the Correlation between Inadequate Energy/Macronutrient Intake and Clinical Alterations in Volunteers at Risk of Metabolic Syndrome by a Predictive Model.

Although lifestyle-based interventions are the most effective to prevent metabolic syndrome (MetS), there is no definitive agreement on which nutritional approach is the best. The aim of the present retrospective analysis was to identify a multivariate model linking energy and macronutrient intake to the clinical features of MetS. Volunteers at risk of MetS (F = 77, M = 80) were recruited in four European centres and finally eligible for analysis. For each subject, the daily energy and nutrient intake was estimated using the EPIC questionnaire and a 24-h dietary recall, and it was compared with the dietary reference values. Then we built a predictive model for a set of clinical outcomes computing shifts from recommended intake thresholds. The use of the ridge regression, which optimises prediction performances while retaining information about the role of all the nutritional variables, allowed us to assess if a clinical outcome was manly dependent on a single nutritional variable, or if its prediction was characterised by more complex interactions between the variables. The model appeared suitable for shedding light on the complexity of nutritional variables, which effects could be not evident with univariate analysis and must be considered in the framework of the reciprocal influence of the other variables.

Sarcopenia in patients after an episode of acute decompensated heart failure: An underdiagnosed problem with serious impact.

BACKGROUND & AIMS: Sarcopenia is a multifactorial syndrome resulting in a decrease in both muscle mass and function. Little is known about the prevalence and prognostic impact of sarcopenia in patients with acutely decompensated chronic heart failure (ADHF). We aimed to evaluate the prevalence (main endpoint) and impact of sarcopenia on ADHF patients. METHODS: 140 ADHF patients were enrolled between November 2014 and September 2018 in a multicenter prospective longitudinal study. A similar, independent multi-departmental cross-sectional study in 165 ADHF patients was used for external validation of prevalence data. All subjects were assessed on the European Working Group on Sarcopenia criteria. RESULTS: Ninety-one patients (65%) had sarcopenia (vs. 53.6% in the external replication regional cohort). Patients with sarcopenia were older and more likely to have eGFR <60 ml/min/1.73 m2 (p < 0.001 and p = 0.002). Sarcopenia was associated with impaired functional status [lower 6 min walking test (220 ± 108 vs. 279 ± 170, p = 0.03) and 4 m gait speed (0.56 ± 0.24 vs. 0.80 ± 0.37, p < 0.001)] and autonomy [Instrumental activities of daily living: 6.7 ± 1.4 vs. 7.3 ± 1.2, p = 0.005]. Over up to 4 years' follow-up, 30 cardiovascular (CV) deaths and 42 non-CV deaths occurred. In a multivariable analysis, sarcopenia was associated with time to first non-CV hospitalization (hazard ratio 1.93; 95% confidence interval 1.14-3.24; p = 0.014) but not with any other hospitalization, any mortality endpoint, or a composite endpoint of CV death and HF hospitalization. CONCLUSIONS: The prevalence of sarcopenia in ADHF patients is high and associated with greater risk of non-CV hospitalizations, highlighting the importance of identifying and managing the condition in a multidisciplinary approach. CLINICAL TRIAL REGISTRATION: NCT03153774.

Food matrix structure (from Biscuit to Custard) has an impact on folate bioavailability in healthy volunteers.

PURPOSE: We examined the impact of matrix food structure on post-prandial folate bioavailability (and other macronutrients) in human volunteers using a randomized, controlled, crossover experimental design. METHODS: Twelve healthy male volunteers (22.6 ± 0.4 years old) were offered four food models (differing in matrix structure: Custard, Pudding, Sponge cake and Biscuit) to which 1 mg of folic acid was added, according to a randomized, controlled, crossover experimental design. Plasma folates, glucose, insulin, alpha amino nitrogen and triglycerides were measured over the post-prandial period (from T0 to T480 min). RESULTS: Food matrix structure was capable of altering folate plasma availability. The highest folate availability was observed for pudding and to a lesser extent Sponge cake whereas the lowest was for the two matrices presenting extreme rheological properties: Custard (liquid) (P < 0.05 total AUC) and to a lesser extent Biscuit (hard solid) (P < 0.05, AUC 180 min). The analysis of plasma kinetics of appearance of other nutrients/metabolites helps to understand/explain the lower bioavailability of folates in Custard and Biscuit. CONCLUSION: A least overall efficient bio-accessibility of all macronutrients and folic acid is observed in the gut lumen for Biscuit (delayed/incomplete destructuration of biscuit along the digestive tract). On the contrary, the lower folic acid absorption observed with custard does not fit with the rapid plasma appearance of other nutrients and should require further investigation.

Eccentric Cycling Training Improves Health-Related Quality of Life in Adolescents with Obesity.

INTRODUCTION: While eccentric (ECC) training appears to be more efficient than concentric (CON) training at improving body composition in adolescent with obesity, its impact on health-related quality of life (HRQOL) has never been studied. OBJECTIVE: The aim of this study is to compare the effects of 2 cycling training modalities, i.e., ECC vs. CON, in adolescents with obesity on HRQOL and health perception (HP). METHODS: A total of 24 adolescents with obesity, aged 12-16 years, were randomized to either a 12-week ECC or a CON cycling training program performed at the same oxygen consumption (VO2). Anthropometric measurements, body composition, maximal incremental tests, HRQOL (Vécu et Santé Percue de l'Adolescent [VSP-A], Medical Outcome Study Short Form [SF-36]), and HP were assessed at before and after training. RESULTS AND CONCLUSION: Both CON and ECC cycling trainings promoted significant improvements in BMI, VO2peak, total fat mass, and fat-free mass, with better improvements in body composition parameters in the ECC group (p < 0.05). The VSP-A total score increased after CON (p < 0.01) and ECC (p < 0.001) training, with better enhancement for the ECC group (p < 0.05). The SF-36 physical score increased after both CON (p < 0.01) and ECC (p < 0.001) trainings. The global HP score increased only after ECC training (p < 0.001). Except for the energy-vitality item, no significant correlation was found between changes in HRQOL and its subdomains and anthropometric, body composition, and functional parameters. Both ECC and CON cycling trainings are associated with positive changes in HRQOL and HP. However, ECC seems to induce greater improvements in HRQL and HP than CON cycling training, which is probably not due to the anthropometric, body composition, and functional changes.

Bone response to eccentric versus concentric cycling in adolescents with obesity.

OBJECTIVES: Because adolescents with obesity are susceptible to bone fragility during weight loss (WL), we evaluated the impact of eccentric (ECC) versus classical concentric (CON) training at the same oxygen consumption (V˙O2) on bone density, geometry and strength. METHODS: Thirty five adolescents were included into 2 training (CON and ECC cycling) and a control (CTR, without training) groups. Anthropometry, dual-energy X-ray absorptiometry, hip structural analysis and quantitative bone ultrasound were assessed before and after the 12-week intervention. RESULTS: The trainings promoted significant improvements in body mass index, total fat (FM) and lean mass (LM), with better improvements for FM and LM in the ECC group (p < 0.05). Leg LM percentage increased only in the ECC group (p < 0.05). Total body bone mineral content and density increased in both training groups (p < 0.001) with significant time x group interactions only between ECC and CTR (p < 0.05). Buckling ratio at the intertrochanteric region and femoral shaft increased only in CTR and CON groups (p < 0.05). Speeds of sounds at the calcaneum increased only in ECC group (p < 0.01). CONCLUSIONS: Bone fragility, from a compromised relationship between density, geometry and strength, might be prevented with the ECC modality.

Food Structure Modulates the Bioavailability of Triglycerides and Vitamin D, and Partly That of Lutein: A Randomized Trial with a Crossover Design in Adults.

SCOPE: The specific effect of the food matrix structure on fat-soluble micronutrient bioavailability is only partly understood. Evaluating fat-soluble micronutrient bioavailability after consumption of foods displaying similar composition but different structure is aimed at. METHODS AND RESULTS: Twelve healthy subjects are enrolled in a randomized, open label, crossover postprandial trial. Four different model foods are tested: custard, pudding, sponge cake, and biscuit. Vitamin D3 , lutein, and triglyceride chylomicron responses, evaluated as postprandial areas under the curve, are then assayed. Custard triglyceride response is higher than pudding and biscuit responses (up to +122.7%, p < 0.0001). Sponge cake vitamin D3 response is higher than biscuit response (+26.6%, p = 0.047). No difference between the model foods are observed regarding lutein responses. Triglyceride responses peak at 3 h for all conditions, while vitamin D3 and lutein peaks are delayed by 1 h with the biscuit matrix compared to other model foods. CONCLUSION: Food structure can significantly impact on triglyceride and vitamin D3 bioavailability in terms of absorbed amounts and/or maximum absorption time. The data highlight positive correlations between triglyceride, vitamin D, and lutein nutrient responses. These results are of particular interest to develop functional foods for population subgroups such as the elderly.

Eccentric versus conventional cycle training to improve muscle strength in advanced COPD: A randomized clinical trial.

OBJECTIVES: To compare eccentric (ECC) and conventional concentric (CON) cycle training on quadriceps muscle strength in advanced COPD. Secondary objective was to assess functional capacity. METHODS: A parallel-group, assessor-blind, randomized trial was conducted. Severe COPD patients were randomized to either an ECC (n = 13) or CON (n = 11) cycling program for 30-min, 3 times/week for 10 weeks. ECC group trained at ∼4-fold higher power than the CON group at similar relative heart rate intensity. RESULTS: Isometric and isokinetic quadriceps peak torque improved after ECC but not CON; between group difference was significant for isometric peak muscle force (p < 0.05). Peak cycling power and endurance time increased in both groups (p < 0.05). Dyspnea at peak cycling power improved only after ECC training (p < 0.05). Sensory intensity ratings of dyspnea and leg fatigue were significantly lower (p < 0.05) during ECC compared with CON at equivalent relative heart rate intensities. CONCLUSIONS: ECC could be an effective alternative and/or adjunct modality to pulmonary rehabilitation in severely ventilatory limited COPD patients.

Preoperative respiratory muscle endurance training improves ventilatory capacity and prevents pulmonary postoperative complications after lung surgery.

BACKGROUND: Resection surgery is the main treatment for non-small cell lung cancer (NSCLC). Postoperative complications and mortality are mostly linked to respiratory failure consecutive to respiratory muscle overload. AIM: We aimed to evaluate the effect of preoperative respiratory muscle endurance training (RMET) on respiratory muscle capacity and postoperative complications in patients undergoing NSCLC resection. DESIGN: Randomized controlled trial. SETTING: French university hospital. POPULATION: Patients eligible for NSCLC resection. METHODS: The training group (T group) performed a 3-week preoperative RMET added to usual chest physical therapy while the control group (C group) had only the latter. The primary outcome was the change in respiratory muscle endurance. Secondary outcomes were postoperative complications and mortality. Assessments were performed similarly at baseline and after the intervention. We conducted multivariable analyses with analysis of covariance (ANCOVA) taking into account baseline values for isocapnic hyperpnoea endurance test, exercise capacity and pulmonary function tests. The number of pulmonary postoperative complication was analyzed by Fisher-exact test. RESULTS: We included 26 patients with NSCLC (14 in the T group and 12 in the C group). Respiratory muscle endurance significantly increased in the T group after the RMET compared with C group (+229±199 vs. -5±371 sec, P=0.001). This increase was associated with a significantly lower number of pulmonary postoperative complications (2 vs. 10, P=0.037). CONCLUSIONS: Preoperative RMET improved respiratory muscle endurance and decreased pulmonary postoperative complications after surgery for NSCLC. These positive results obtained after RMET may help improve the perioperative course for such patients. These results should be confirmed in larger randomized controlled trials, including higher number of patients especially with altered respiratory muscle function. CLINICAL REHABILITATION IMPACT: Low-cost and easy to perform, RMET training could serve as complementary tool to usual chest physical therapy, before lung resection surgery.

Aerobic Metabolic Adaptations in Endurance Eccentric Exercise and Training: From Whole Body to Mitochondria.

A characteristic feature of eccentric as compared with concentric exercise is the ability to generate greater mechanical loads for lower cardiopulmonary demands. Current evidence concurs to show that eccentric training translates into considerable gains in muscle mass and strength. Less is known, however, regarding its impact on oxygen transport and on factors to be considered for optimizing its prescription and monitoring. This article reviews the existing evidence for endurance eccentric exercise effects on the components of the oxygen transport system from systemic to mitochondria in both humans and animals. In the studies reviewed, specially designed cycle-ergometers or downhill treadmill running were used to generate eccentric contractions. Observations to date indicate that overall, the aerobic demand associated with the eccentric training load was too low to significantly increase peak maximal oxygen consumption. By extension, it can be inferred that the very high eccentric power output that would have been required to solicit a metabolic demand sufficient to enhance peak aerobic power could not be tolerated or sustained by participants. The impact of endurance eccentric training on peripheral flow distribution remains largely undocumented. Given the high damage susceptibility of eccentric exercise, the extent to which skeletal muscle oxygen utilization adaptations would be seen depends on the balance of adverse and positive signals on mitochondrial integrity. The article examines the protection provided by repeated bouts of acute eccentric exercise and reports on the impact of eccentric cycling and downhill running training programs on markers of mitochondrial function and of mitochondrial biogenesis using mostly from animal studies. The summary of findings does not reveal an impact of training on skeletal muscle mitochondrial respiration nor on selected mitochondrial messenger RNA transcripts. The implications of observations to date are discussed within future perspectives for advancing research on endurance eccentric exercise physiological impacts and using a combined eccentric and concentric exercise approach to optimize functional capacity.

A TUG Value Longer Than 11 s Predicts Fall Risk at 6-Month in Individuals with COPD.

Risk of a fall is increased in individuals with chronic obstructive pulmonary disease (COPD), and is usually evaluated using the Berg Balance Scale (BBS), but this is difficult to perform in everyday clinical practice. We aimed to prospectively predict short-term fall recurrence in COPD patients using a predetermined cut-off value of the Timed Up and Go test (TUG). In stable COPD patients, we collected self-reported records of the number of falls in the previous year, and measured TUG and BBS scores for each individual. Records of fall recurrence were obtained prospectively at 6-months after the initial evaluation. Among the 50 patients recruited, 23 (46%) had at least one fall during the past year. The optimal diagnosis value for the TUG to detect a fall was 10.9 s with a sensitivity of 100% and a specificity of 97%. A cut-off of 11 s predicted fall recurrence with high sensitivity and specificity (93% and 74%, respectively). The TUG as well as the BBS score detected fallers, and a cut-off value of 11 s predicted fall recurrence. TUG could be easily incorporated into the scheduled functional evaluations of COPD patients, could predict the risk of a fall and when appropriate, could guide specific balance training exercises to prevent fall.

Effectiveness of combined eccentric and concentric exercise over traditional cardiac exercise rehabilitation programme in patients with chronic heart failure: protocol for a randomised controlled study.

INTRODUCTION: Exercise-based rehabilitation is a standard feature of chronic heart failure management. The effectiveness of eccentric exercise could offer new opportunities for better tailoring rehabilitation programme to patients' limitations. The goal of the study is to contrast the impact of a mixed eccentric and concentric cycling training programme, to that of conventional concentric cycling rehabilitation in patients with chronic heart failure (peak oxygen consumption (VO2Peak) < 15 mL⋅kg-1⋅min-1, ejection fraction <40%). METHODS AND ANALYSIS: It is a prospective, open, controlled and randomised study (2×25 subjects) carried out in a single centre. Subjects will perform five exercise sessions per week per the randomisation outcome, with the intervention group performing eccentric in three of the five weekly sessions while the control group will perform the five sessions of concentric exercise. Cycling intensity will be the same in both groups and fixed to the power associated with the first ventilatory threshold. Self-management education programme, callisthenics sessions and muscle strength trainings will also be carried out as for any heart failure patient normally included in the rehabilitation programme. The primary outcome will be the change in distance covered during the 6 min walk test. Secondary outcomes will include other physical mobility parameters, functional exercise capacities, quality of life and body composition as well as skeletal muscle properties including mitochondrial function parameters. ETHICS AND DISSEMINATION: The study has been approved by the institutional ethics review board (17.079) and the French regulatory authority for research (2017-A00969-44). Adverse events that could occur during the protocol will be reported to the principal investigator. The results will be published in an international peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT03716778.

Validation of intracardiac shunt using thoracic bioimpedance and inert gas rebreathing in adults before and after percutaneous closure of atrial septal defect in a cardiology research unit: study protocol.

INTRODUCTION: Intrathoracic shunt quantification is a major factor for appropriate clinical management of heart and pulmonary diseases. Intracardiac shunts quantified by pulmonary to systemic output ratio (Qp/Qs) are generally assessed by Doppler echocardiography, MRI or catheterisation. Recently, some authors have suggested the concomitant use of thoracic bioimpedance (TB) and inert gas rebreathing (IGR) techniques for shunt quantification. The purpose of this study is to validate the use of this approach under conditions where shunt fraction is directly quantified such as in patients with isolated atrial septal defect (ASD). METHODS AND ANALYSIS: This trial is a prospective, observational single-centre, non-blinded study of adults seen for percutaneous closure of ASD. Qp/Qs ratio will be directly measured by Doppler echocardiography and direct Fick. IGR and TB will be used simultaneously to measure the cardiac output before and after closure: the ratio of outputs measured by IGR and TB reflecting the shunt fraction. The primary outcome will be the comparison of shunt values measured by TB-IGR and Doppler echocardiography. ETHICS AND DISSEMINATION: The study has been approved by an independent Research Ethics Committee (2017-A03149-44 Fr) and registered as an official clinical trial. The results will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT03437148; Pre-results.