Impacto de diferentes testes de avaliação funcional sobre o sistema cardiorrespiratório e subjetivo de mulheres obesas: implementando recursos em protótipo para avaliação funcional

Obesity is considered a worldwide epidemic, with high prevalence in females. It is associated to increased mortality rates due to adverse consequences, such as cardiovascular and metabolic diseases. In addition, obese individuals show impaired cardiorespiratory fitness and functional capacity. In this context, we have proposed two observational and cross-sectional studies that could contribute to the understanding the cardiovascular, metabolic, ventilatory, and perceptual responses in this population to different exercise tests, such as the maximum cardiopulmonary test (CPX), considered the gold standard assessment for cardiorespiratory fitness, as well as functional field tests, which were less expensive and more similar to daily activities, such as the six-minute walk test (6MWT), incremental shuttle walk test (ISWT), and the six-minute step test (6MST). Moreover, we have proposed an innovative step ergometer, which provides a performance recorder and a software for following the user´s progression. The first study é entitled "Are cardiovascular and metabolic responses to field walking tests interchangeable and obesity-dependent?". Aimed to investigate if the physiological responses to the ISWT and 6MWT were in agreement with those obtained in CPX and determine if the submaximal tests could be interchangeable in obese women and controls. Fifty one obese women were evaluated (ObG) and 21 controls (CG) through clinical evaluation, CPX, ISWT and 6MWT. There was agreement between CPX and both the 6MWT [oxygen uptake (VO2, mL•kg-1•min-1) = 6.9 (CI: 5.7-8.1), and heart rate (bpm) = 37.0 (CI: 33.3-40.7)] and ISWT [VO2 (mL•kg-1•min-1) = 6.1 (CI: 4.9-7.3), and heart rate (bpm) = 36.2 (CI: 32.1-40.3)]. We found similar cardiovascular and metabolic responses to both tests in the ObG but not in the CG. Strong correlations were demonstrated between 6MWT and ISWT variables: VO2 (r=0.70); dyspnea (r=0.80); and, leg fatigue (r=0.70). The 6MWT and the ISWT may both hold interchangeable clinical value when contrasted with CPX in obese women and may be a viable alternative in the clinical setting when resources and staffing are limited. The second study was entitled "Six-minute step test as a predictor of cardiorespiratory fitness in obese women" and aimed to assess the 6MST accuracy to determinate cardiorespiratory fitness (CRF) and its ability to predict xiii peak oxygen uptake (VO2) and heart rate (HR) achieved during CPX in sedentary obese women. Fifty-six sedentary obese women underwent clinical evaluation, CPX and 6MST. There was a satisfactory concurrent validity between the CPX and 6MST, with a mean difference of 5.1±3.6 mL•kg-1•min-1 and 23±13 bpm in relation to peak VO2 and HR, respectively. The 6MST demonstrated moderate accuracy in predicting CPX responses (area under the curve: 0.72, 95% CI: 0.59 - 0.83). The number of step cycles and peak HR during the 6MST explained 31% and 39% of the total variance in peak VO2 and HR obtained during CPX, respectively. We conclude that the 6MST is accurate to discriminate obese women with an adequate CRF from women with a poor status and it can predict metabolic and cardiovascular maximal exercise values, as well as it may be a valid means of assessing CRF in sedentary obese women, particularly in clinical settings where space and resources are limited. The third study is related to a proposal of a innovative utility model registered in the Instituto Nacional de Propriedade Intelectual, in Brazil, as a patent and is entitled "constructive provision introduced in portable exercise step with performance recorder and software." The exercise step aims to fill a gap in the current trade showing improvements over currently available steps, regarding performance, usability, cost, portability, maintenance, safety and ergonomics. Financial support: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq 141331/2011-9), Brasília, DF, Brasil; and, Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP 2009/01842-0).Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)A obesidade é considerada uma epidemia mundial, com maior prevalência em mulheres. Está associada a elevadas taxas de mortalidade devido as suas consequências adversas, como doenças cardiovasculares e metabólicas. Além disso, indivíduos obesos apresentam declínio da aptidão cardiorrespiratória e da capacidade funcional. Nesse contexto, propusemos a realização de dois estudos observacionais e transversais que poderiam contribuir no entendimento das respostas cardiovasculares, metabólicas, ventilatórias e perceptuais dessa população frente a diferentes testes de exercício, incluindo o teste máximo exercício cardiopulmonar (TECP), padrão-ouro para avaliação da aptidão cardiorrespiratória, assim como testes funcionais de campo, menos onerosos e mais similares às atividades do cotidiano dos indivíduos, como o teste de caminhada de seis minutos (TC6), teste de caminhada incremental (TCI) e o teste de degrau de seis minutos (TD6). Além disso, propusemos a criação de um novo ergômetro de degrau, que provê um registrador de desempenho e um software acoplado para acompanhamento da evolução do usuário. O primeiro estudo é intitulado “Testes funcionais de caminhada de seis minutos e de caminhada incremental são intercambiáveis e obesidade-dependentes?” e teve como objetivos investigar se as respostas fisiológicas frente ao TCI e ao TC6 eram concordantes com as do TECP e determinar se a aplicação dos testes funcionais poderia ser intercambiável tanto em mulheres obesas como em eutróficas. Foram avaliadas 51 obesas (GOb) e 21 eutróficas (GC) por meio de avaliação clínica, TECP, TCI e TC6. Constatou-se que houve concordância entre o TECP e o TC6 [consumo de oxigênio (VO2, mL•kg-1•min-1) = 6,9 (IC: 5,7-8,1), e frequência cardíaca (FC, bpm) = 37 (IC: 33-40)] e entre TECP e o TCI [VO2 (mL•kg-1•min-1) = 6,1 (IC: 4,9-7,3) e a FC (bpm) = 36 (IC: 32-40)]. Foram encontradas respostas cardiovasculares e metabólicas similares entre os testes de campo para o GOb e fortes correlações entre variáveis-desfecho dos dois testes funcionais de caminhada. Concluímos que o TCI e o TC6 são concordantes com o TECP e podem ter aplicação intercambiável em mulheres obesas, revelando ser uma alternativa viável em condições clínicas em que haja limitada disponibilidade de recursos e/ou de equipe técnica qualificada. O segundo estudo foi intitulado “Teste de degrau de seis minutos como um preditor xi de aptidão cardiorrespiratória em mulheres obesas” e teve como objetivo avaliar se o TD6 seria acurado para determinar a aptidão cardiorrespiratória (ACR) em mulheres obesas e ainda se seria possível predizer as respostas de VO2 e FC alcançadas durante o TECP. Cinquenta e seis mulheres obesas sedentárias foram submetidas à avaliação clínica, ao TECP e ao TD6. Houve validade concorrente satisfatória entre o TECP e o TD6, com uma diferença média de 5,1±3,6 mL•kg-1•min-1 e 23±13 bpm em relação ao VO2 pico e a FC, respectivamente. O TD6 apresentou acurácia moderada em predizer as respostas do TECP (área abaixo da curva: 0,72, 95% IC: 0,59 – 0,83). O número dos ciclos de subida e descida no degrau e a FC no pico do TD6 explicaram 31% e 39% da variância total do VO2 pico e da FC obtidos durante o TECP, respectivamente. Concluímos que o TD6 é acurado para discriminar as mulheres obesas com ACR adequada e fraca, e pode predizer valores metabólicos e cardiovasculares do exercício máximo, sendo uma ferramenta válida para avaliar a ACR em mulheres obesas sedentárias, especialmente quando o espaço e os recursos são limitados na prática clínica. O terceiro estudo trata-se da implementação de um modelo de utilidade registrado no Instituto Nacional da Propriedade Industrial como patente e é intitulado: “Disposição construtiva introduzida em degrau ergométrico portátil com registrador de desempenho e software”. O degrau ergométrico visa preencher uma lacuna no mercado apresentando melhorias em relação aos degraus (steps) atualmente disponíveis, no que tange ao desempenho, usabilidade, custo, portabilidade, manutenção, segurança e ergonomia. Apoio financeiro: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq 141331/2011-9), Brasília, DF, Brasil; e Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP 2009/01842-0).FAPESP: 2009/01842-0CNPq: 141331/2011-

Metabolic and clinical comparative analysis of treadmill six-minute walking test and cardiopulmonary exercise testing in obese and eutrophic women Análise clínica e metabólica comparativa entre o teste de caminhada de seis minutos e o teste de exercício cardiopulmonar em mulheres obesas e eutróficas

BACKGROUND: Impaired exercise tolerance is directly linked to decreased functional capacity as a consequence of obesity. OBJECTIVES: To analyze and compare the cardiopulmonary, metabolic, and perceptual responses during a cardiopulmonary exercise test (CPX) and a treadmill six-minute walking test (tread6MWT) in obese and eutrophic women. METHOD: Twenty-nine female participants, aged 20-45 years were included. Fourteen were allocated to the obese group and 15 to the eutrophic group. Anthropometric measurements and body composition assessment were performed. RESULTS: In both tests, obese women presented with significantly higher absolute oxygen uptake, minute ventilation, and systolic and diastolic blood pressure; they also presented with lower speed, distance walked, and oxygen uptake corrected by the weight compared to eutrophics. During the maximal exercise test, perceived dyspnea was greater and the respiratory exchange ratio was lower in obese subjects compared to eutrophics. During the submaximal test, carbon dioxide production, tidal volume, and heart rate were higher in obese subjects compared to eutrophic women. When analyzing possible correlations between the CPX and the tread6MWT at peak, there was a strong correlation for the variable heart rate and a moderate correlation for the variable oxygen uptake. The heart rate obtained in the submaximal test was able to predict the one obtained in the maximal test. Bland-Altman plots demonstrated the agreement between both tests to identify metabolic and physiological parameters at peak exercise. CONCLUSIONS: The six-minute walking test induced ventilatory, metabolic, and cardiovascular responses in agreement with the maximal testing. Thus, the six-minute walking test proves to be important for functional evaluation in the physical therapy routine.<br>CONTEXTUALIZAÇÃO: A reduzida tolerância ao exercício está relacionada à diminuída capacidade funcional consequente da obesidade. Objetivos: Analisar e comparar respostas cardiopulmonares, metabólicas e subjetivas durante um teste de esforço cardiopulmonar e um teste de caminhada de seis minutos na esteira em mulheres obesas e eutróficas. MÉTODO: Foram incluídas 29 mulheres com idades entre 20 e 45 anos. Catorze voluntárias foram alocadas no grupo de obesas e 15, no grupo de eutróficas. Foram realizadas medidas antropométricas e de composição corporal. RESULTADOS: Em ambos os testes, as obesas apresentaram maiores valores de consumo absoluto de oxigênio, ventilação-minuto e pressão arterial sistólica e diastólica; ainda apresentaram menor velocidade de caminhada, distância percorrida e consumo de oxigênio relativo, quando comparadas com as eutróficas. Durante o teste máximo de exercício, a dispneia percebida foi maior e o quociente respiratório menor nas obesas em relação às eutróficas. Durante o teste submáximo, produção de dióxido de carbono, volume corrente e frequência cardíaca foram maiores nas obesas, comparadas às eutróficas. Houve forte correlação entre a frequência cardíaca e moderada correlação entre o consumo de oxigênio no pico dos testes. A frequência cardíaca obtida no teste submáximo aplicado foi capaz de predizer a frequência cardíaca obtida no teste máximo. Os gráficos de Bland-Altman demonstraram concordância entre os testes para identificar parâmetros metabólicos e fisiológicos no pico do exercício. CONCLUSÃO: O teste de caminhada de seis minutos induziu respostas ventilatórias, metabólicas e cardiovasculares concordantes com as do teste máximo, provando ser importante na rotina de avaliação funcional fisioterápica de mulheres obesas

Prediction of Cardiorespiratory Fitness by the Six-Minute Step Test and Its Association with Muscle Strength and Power in Sedentary Obese and Lean Young Women: A Cross-Sectional Study.

Impaired cardiorespiratory fitness (CRF) is a hallmark characteristic in obese and lean sedentary young women. Peak oxygen consumption (VO2peak) prediction from the six-minute step test (6MST) has not been established for sedentary females. It is recognized that lower-limb muscle strength and power play a key role during functional activities. The aim of this study was to investigate cardiorespiratory responses during the 6MST and CPX and to develop a predictive equation to estimate VO2peak in both lean and obese subjects. Additionally we aim to investigate how muscle function impacts functional performance. Lean (LN = 13) and obese (OB = 18) women, aged 20-45, underwent a CPX, two 6MSTs, and isokinetic and isometric knee extensor strength and power evaluations. Regression analysis assessed the ability to predict VO2peak from the 6MST, age and body mass index (BMI). CPX and 6MST main outcomes were compared between LN and OB and correlated with strength and power variables. CRF, functional capacity, and muscle strength and power were lower in the OB compared to LN (<0.05). During the 6MST, LN and OB reached ~90% of predicted maximal heart rate and ~80% of the VO2peak obtained during CPX. BMI, age and number of step cycles (NSC) explained 83% of the total variance in VO2peak. Moderate to strong correlations between VO2peak at CPX and VO2peak at 6MST (r = 0.86), VO2peak at CPX and NSC (r = 0.80), as well as between VO2peak, NSC and muscle strength and power variables were found (p<0.05). These findings indicate the 6MST, BMI and age accurately predict VO2peak in both lean and obese young sedentary women. Muscle strength and power were related to measures of aerobic and functional performance

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

Abstract 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

Underlying mechanisms of oxygen uptake kinetics in chronic post-stroke individuals: A correlational, cross-sectional pilot study.

Post-stroke individuals presented deleterious changes in skeletal muscle and in the cardiovascular system, which are related to reduced oxygen uptake ([Formula: see text]) and take longer to produce energy from oxygen-dependent sources at the onset of exercise (mean response time, MTRON) and during post-exercise recovery (MRTOFF). However, to the best of our knowledge, no previous study has investigated the potential mechanisms related to [Formula: see text] kinetics response (MRTON and MRTOFF) in post-stroke populations. The main objective of this study was to determine whether the MTRON and MRTOFF are related to: 1) body composition; 2) arterial compliance; 3) endothelial function; and 4) hematological and inflammatory profiles in chronic post-stroke individuals. Data on oxygen uptake ([Formula: see text]) were collected using a portable metabolic system (Oxycon Mobile®) during the six-minute walk test (6MWT). The time to achieve 63% of [Formula: see text] during a steady state (MTRON) and recovery (MRTOFF) were analyzed by the monoexponential model and corrected by a work rate (wMRTON and wMRTOFF) during 6MWT. Correlation analyses were made using Spearman's rank correlation coefficient (rs) and the bias-corrected and accelerated bootstrap method was used to estimate the 95% confidence intervals. Twenty-four post-stroke participants who were physically inactive took part in the study. The wMRTOFF was correlated with the following: skeletal muscle mass (rs = -0.46), skeletal muscle mass index (rs = -0.45), augmentation index (rs = 0.44), augmentation index normalized to a heart rate of 75 bpm (rs = 0.64), reflection magnitude (rs = 0.43), erythrocyte (rs = -0.61), hemoglobin (rs = -0.54), hematocrit (rs = -0.52) and high-sensitivity C-reactive protein (rs = 0.58), all p < 0.05. A greater amount of oxygen uptake during post-walking recovery is partially related to lower skeletal muscle mass, greater arterial stiffness, reduced number of erythrocytes and higher systemic inflammation in post-stroke individuals