Reproducibility and Validity of the 6-Minute Stationary Walk Test Associated With Virtual Reality in Subjects With COPD.

BACKGROUND: The importance of evaluating the functional capacity of patients with COPD is well known, and there is a wide range of tests described in the literature. The 6-min stationary walk test associated with virtual reality (STVR-6) was created in light of the current limitations of evaluation tests. It does not require a large physical space or sophisticated equipment, and it is not costly; furthermore, it can be performed by a single rater. The objective of this study was to evaluate intra- and inter-rater reproducibility and to verify the criterion validity of the STVR-6. METHODS: 50 subjects with COPD were evaluated over the course of 3 d. The execution order of the tests was randomized; the STVR-6 was performed over 2 d, and the 6-min walk test was performed in 1 d. The 6-min walk distance variables and number of steps in the STVR-6 were obtained with a gas analysis performed for both tests. RESULTS: Relative reproducibility was found for intraclass correlation coefficient values (0.57-0.94, P < .001) between the number of steps and the highest value of oxygen consumption during the test (V̇O2 peak), intra- and inter-rater. In terms of absolute reproducibility, the standard error of measurement and minimum detectable difference values were verified. In the Bland-Altman analysis, the intra- and inter-rater mean difference values were 21 and 17 steps and 0.002 and 0.242 mL/min/kg, respectively. Pearson correlation values were 0.57-0.75 (P < .001) between the number of steps and V̇O2 peak. CONCLUSIONS: STVR-6 had excellent intra-rater reproducibility and excellent to good inter-rater reproducibility, but the high values of error measures demonstrated that there is a learning effect and a need to perform at least 2 tests. In addition, there was high to moderate correlation between the STVR-6 and the 6-min walk test. Therefore, the STVR-6 proved to be reproducible and valid for evaluating the functional capacity of subjects with COPD.

Functional and systemic effects of whole body electrical stimulation post bariatric surgery: study protocol for a randomized controlled trial.

BACKGROUND: Obesity represents a major public health problem and is the fifth leading risk factor for mortality. Morbid obesity is associated with chronic systemic inflammation which increases the risk of comorbidities. Bariatric surgery (BS) is considered an effective intervention for obese patients. However, BS is associated with dietary restriction, potentially limiting physical activity. Whole-body neuromuscular electrical stimulation (WBS) could represent an innovative option for the rehabilitation of BS patients, especially during the early postoperative phase when other conventional techniques are contraindicated. WBS is a safe and effective tool to combat sarcopenia and metabolic risk as well as increasing muscle mass, producing greater glucose uptake, and reducing the proinflammatory state. Therefore, the objective of this study is to evaluate the effects of WBS on body composition, functional capacity, muscle strength and endurance, insulin resistance, and pro- and anti-inflammatory circulating markers in obese patients undergoing BS. METHODS/DESIGN: The present study is a randomized, double-blind, placebo-controlled, parallel groups clinical trial approved by the Ethics Committee of our Institution. Thirty-six volunteers (body mass index (BMI) > 35 kg/m2) between 18 and 45 years of age will be randomized to the WBS group (WBSG) or control (Sham) group (ShamG) after being submitted to BS. Preoperative assessments will include maximal and submaximal exercise testing, body composition, blood inflammatory markers, and quadriceps strength and endurance. The second day after discharge, body composition will be evaluated and a 6-min walk test (6MWT) will be performed. The WBS or Sham protocol will consist of 30 daily sessions for 6 consecutive weeks. Afterwards, the same assessments that were performed in the preoperative period will be repeated. DISCUSSION: Considering the important role of WBS in skeletal muscle conditioning and its value as an aid in exercise performance, the proposed study will investigate this technique as a tool to promote early rehabilitation in these patients, and as a strategy to enhance exercise capacity, weight loss, and peripheral muscle strength with positive systemic effects. The present study is still ongoing, and data will be published after its conclusion. TRIAL REGISTRATION: REBEC, RBR-99qw5h . Registered on 20 February 2015.

Metabolic syndrome impact on cardiac autonomic modulation and exercise capacity in obese adults.

Obesity is often associated with increased risk of cardiometabolic morbidities and mortality. However, evidence shows that some obese individuals are more likely to develop such risk factors early in life, including those with Metabolic Syndrome (MetS). Whether the presence of MetS in obese people impairs cardiac autonomic modulation (CAM) remains to be investigated. METHODS: Cross-sectional study. Sixty-six subjects were classified as normal-weight (NW, n = 24) or obese (BMI ≥ 30 kg·m-2): metabolically healthy (MHO, n = 19) vs unhealthy (MUHO, n = 23: NCEP/ATPIII-MetS criteria). Body composition (bioimpedance), metabolic (glucose-insulin/lipid) and inflammatory profiles were determined. Linear and nonlinear heart rate variability (HRV) indices were computed at rest and during the submaximal six-minute step test (6MST). Blood pressure (BP) and metabolic and ventilatory variables were assessed (oxygen uptake, VO2; carbon dioxide production, VCO2; minute ventilation, VE) during the 6MST and the maximal cardiopulmonary exercise testing (CPX). RESULTS: All groups reached the same 6MST intensity (VO2 ~ 80% and HR ~ 87% of CPX peak values). Both obese groups, independently of MetS, presented higher BP and lower maximal VO2 than NW. However, HRV differed between groups according to MetS at rest and during exercise: MUHO had lower meanRRi and SD1 than NW and lower RMSSD and pNN50 than MHO at rest; during exercise, the lowest SDNN, TINN, SD1 and Shannon entropy were observed for MUHO. Significant correlations were found between MetS, insulin resistance and HRV indices; and between insulin resistance and aerobic capacity (VO2peak). CONCLUSION: Obesity per se impairs aerobic-hemodynamic responses to exercise. However, MetS in obese young adults negatively impacts overall HRV, parasympathetic activity and HRV complexity.

Reproducibility of inspiratory muscle endurance testing using PowerBreathe for COPD patients.

BACKGROUND: Assessing the strength and endurance of respiratory muscles is fundamental for characterizing respiratory muscle dysfunction. Although a variety of tests are used to evaluate respiratory muscle endurance, not all of them are applicable in clinical practice. Assessments can be made using a practical device called PowerBreathe®, but its reproducibility has not been tested in chronic obstructive pulmonary disease (COPD) patients. AIM: To verify the reproducibility of the inspiratory muscle endurance test using a manometer and PowerBreathe® in COPD patients. METHODS: A cross-sectional study was used. In total, 19 moderate-severe COPD patients, male and female, aged 50 to 80 years took part in the research. This evaluation consisted of 2 tests: an incremental test and a constant one held on the same day and repeated after 48 hr. The incremental test started with 10-cm H2 O, adding 10-cm H2 O every 2 min and taking 1 min of rest before increasing the load. The highest load that could be sustained for at least 1 min was considered the sustained maximum inspiratory pressure (SMIP) value. The constant test was performed at an intensity of 80% of the SMIP and the maximum time limit was 30 min. RESULTS: In the incremental test, there was a significant increase in the SMIP compared to the test-retest (61 ± 24/64.7 ± 23.8; p = .015); the value of the relative reproducibility was 0.96, the standard error of the absolute measurement was 4.7 (95% confidence interval 9.2), and the minimum detectable difference was 10.9. In the Bland-Altman analysis, the mean error was 4.2 (confidence interval -7.6 to 16.1). The constant test was not reproducible. CONCLUSION: It was observed that the incremental test was reproducible to evaluate inspiratory muscle endurance in COPD patients. Furthermore, 2 tests needed to be carried out due to the learning effect.

Effects of Inspiratory Muscle Training and Calisthenics-and-Breathing Exercises in COPD With and Without Respiratory Muscle Weakness.

BACKGROUND: Patients with COPD may experience respiratory muscle weakness. Two therapeutic approaches to the respiratory muscles are inspiratory muscle training and calisthenics-and-breathing exercises. The aims of the study are to compare the effects of inspiratory muscle training and calisthenics-and-breathing exercises associated with physical training in subjects with COPD as an additional benefit of strength and endurance of the inspiratory muscles, thoracoabdominal mobility, physical exercise capacity, and reduction in dyspnea on exertion. In addition, these gains were compared between subjects with and without respiratory muscle weakness. METHODS: 25 subjects completed the study: 13 composed the inspiratory muscle training group, and 12 composed the calisthenics-and-breathing exercises group. Subjects were assessed before and after training by spirometry, measurements of respiratory muscle strength and test of inspiratory muscle endurance, thoracoabdominal excursion measurements, and the 6-min walk test. Moreover, scores for the Modified Medical Research Council dyspnea scale were reported. RESULTS: After intervention, there was a significant improvement in both groups of respiratory muscle strength and endurance, thoracoabdominal mobility, and walking distance in the 6-min walk test. Additionally, there was a decrease of dyspnea in the 6-min walk test peak. A difference was found between groups, with higher values of respiratory muscle strength and thoracoabdominal mobility and lower values of dyspnea in the 6-min walk test peak and the Modified Medical Research Council dyspnea scale in the inspiratory muscle training group. In the inspiratory muscle training group, subjects with respiratory muscle weakness had greater gains in inspiratory muscle strength and endurance. CONCLUSIONS: Both interventions increased exercise capacity and decreased dyspnea during physical effort. However, inspiratory muscle training was more effective in increasing inspiratory muscle strength and endurance, which could result in a decreased sensation of dyspnea. In addition, subjects with respiratory muscle weakness that performed inspiratory muscle training had higher gains in inspiratory muscle strength and endurance but not of dyspnea and submaximal exercise capacity. (ClinicalTrials.gov registration NCT01510041.).

Limitation of Activities of Daily Living and Quality of Life Based on COPD Combined Classification.

BACKGROUND: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 update recommends that the management and treatment of COPD be made to combine the impact of disease and future risk of exacerbation. These patients have worsening quality of life and limitation of activities of daily living (ADLs), which can be manifested as a decrease in S(pO2) and progressive dyspnea. The aim of this study was to determine whether the COPD combined classification proposed by GOLD 2011 is able to differentiate patients with ADL limitation, such as oxygen desaturation or dyspnea, and impaired quality of life. METHODS: This was an observational, cross-sectional study. Forty-four subjects were categorized in 4 GOLD groups (A-D). The mean age was 69 ± 8.8 y, with FEV1 of 1.33 ± 0.53 L (49 ± 15.7% of predicted). The Modified Medical Research Council dyspnea and London Chest Activity of Daily Living (LCADL) scales and the St George Respiratory Questionnaire (SGRQ) were applied. The 6-min walk test and ADL simulation in an appropriate laboratory were also conducted. RESULTS: There was no association between the COPD combined evaluation groups and the presence of oxygen desaturation and dyspnea (chi-square test), although a higher prevalence of oxygen desaturation was noticed in group D subjects. With regard to dyspnea, there were subjects with dyspnea in all groups when ADLs were performed. No correlation between dyspnea and oxygen desaturation variation was found. Group B and D subjects showed higher ADL dyspnea (total LCADL scores of 28% and 30%) compared with group A subjects. Group D subjects showed poorer quality of life (total SGRQ score of 49.3%) compared with less symptomatic groups. CONCLUSIONS: The COPD combined classification was not efficient in determining oxygen desaturation and dyspnea while subjects were performing ADLs. The subjects in the symptomatic groups with increased risk of exacerbation showed poorer quality of life and higher dyspnea levels. (ClinicalTrials.gov registration NCT01977469).