Vanessa S. Probst

Resistance Training Prevents Deterioration in Quadriceps Muscle Function During Acute Exacerbations of Chronic Obstructive Pulmonary Disease

RATIONALE Exacerbations of chronic obstructive pulmonary disease (COPD) acutely reduce skeletal muscle strength and result in long-term loss of functional capacity. OBJECTIVES To investigate whether resistance training is feasible and safe and can prevent deteriorating muscle function during exacerbations of COPD. METHODS Forty patients (FEV(1) 49 +/- 17% predicted) hospitalized with a severe COPD exacerbation were randomized to receive usual care or an additional resistance training program during the hospital admission. Patients were followed up for 1 month after discharge. Primary outcomes were quadriceps force and systemic inflammation. A muscle biopsy was taken in a subgroup of patients to assess anabolic and catabolic pathways. MEASUREMENTS AND MAIN RESULTS Resistance training did not yield higher systemic inflammation as indicated by C-reactive protein levels and could be completed uneventfully. Enhanced quadriceps force was seen at discharge (+9.7 +/- 16% in the training group; -1 +/- 13% in control subjects; P = 0.05) and at 1 month follow-up in the patients who trained. The 6-minute walking distance improved after discharge only in the group who received resistance training (median 34; interquartile range, 14-61 m; P = 0.002). In a subgroup of patients a muscle biopsy showed a more anabolic status of skeletal muscle in patients who followed training. Myostatin was lower (P = 0.03) and the myogenin/MyoD ratio tended to be higher (P = 0.08) in the training group compared with control subjects. CONCLUSIONS Resistance training is safe, successfully counteracts skeletal muscle dysfunction during acute exacerbations of COPD, and may up-regulate the anabolic milieu in the skeletal muscle. Clinical trial registered with www.clinicaltrials.gov (NCT00877084).

Perfil do nível de atividade física na vida diária de pacientes portadores de DPOC no Brasil

OBJECTIVE: To evaluate characteristics of physical activities in daily life in COPD patients in Brazil, correlating those characteristics with physiological variables. METHODS: Physical activities in daily life were evaluated in 40 COPD patients (18 males; 66 ± 8 years of age; FEV1 = 46 ± 16 % of predicted; body mass index = 27 ± 6 kg/m2) and 30 healthy age- and gender-matched subjects, using a multiaxial accelerometer-based sensor for 12 h/day on two consecutive days. We also assessed maximal and functional exercise capacity, using the incremental exercise test and the six-minute walk test (6MWT), respectively; MIP and MEP; peripheral muscle force, using the one-repetition maximum test and the handgrip test; quality of life, using the Saint Georges Respiratory Questionnaire (SGRQ); functional status, using the London Chest Activity of Daily Living questionnaire; and dyspnea sensation, using the Medical Research Council (MRC) scale. RESULTS: Mean walking time/day was shorter for COPD patients than for the controls (55 ± 33 vs. 80 ± 28 min/day; p = 0.001), as movement intensity was lower (1.9 ± 0.4 vs. 2.3 ± 0.6 m/s2; p = 0.004). The COPD patients also tended to spend more time seated (294 ± 114 vs. 246 ± 122 min/day, p = 0.08). Walking time/day correlated with the 6MWT (r = 0.42; p = 0.007) and maximal workload (r = 0.41; p = 0.009), as well as with age, MRC scale score and SGRQ activity domain score (-0.31 < r < -0.43; p < 0.05 for all). CONCLUSIONS: This sample of Brazilian patients with COPD, although more active than those evaluated in studies conducted in Europe, were less active than were the controls. Walking time/day correlated only moderately with maximal and functional exercise capacity.

Relationship between pulmonary function and physical activity in daily life in patients with COPD

BACKGROUND It remains unclear how closely the physical inactivity observed in patients with Chronic Obstructive Pulmonary Disease (COPD) relates to the severity of their airflow limitation. Furthermore, it is unknown whether spirometric variables such as maximal voluntary ventilation (MVV) and inspiratory capacity (IC) reflect the level of physical activity in daily life better than the forced expiratory volume in the first second (FEV(1)), the main spirometric variable used to determine the severity of COPD. The objective of the present study was to investigate the relationship between physical activity in daily life and the severity of COPD assessed by different spirometric variables: MVV, IC and FEV(1). METHODS Forty patients with COPD (21 men; 68+/-7 years; FEV(1) 41+/-14% predicted) were performed spirometry and assessment of the physical activity level in daily life using an accelerometer (SenseWear Armband). RESULTS MVV was significantly correlated to total energy expenditure per day, energy expenditure per day in activities demanding more than 3 metabolic equivalents (METs), number of steps per day and time spent per day in moderate and vigorous activities (0.42<or=r<or=0.52; p<0.01 for all). Correlation of these variables with IC and especially FEV(1) was more modest, borderline or not statistically significant. There was no difference in time spent in vigorous activities among patients classified according to the FEV(1)-based GOLD stages II, III and IV, differently than that observed when patients were classified in groups according to their MVV. CONCLUSION In COPD patients, MVV better reflects the physical activity level in daily life than FEV(1) and IC.

Step Counting and Energy Expenditure Estimation in Patients With Chronic Obstructive Pulmonary Disease and Healthy Elderly: Accuracy of 2 Motion Sensors

OBJECTIVE To compare the accuracy of 2 motion sensors (a pedometer and a multisensor) in terms of step counting and estimation of energy expenditure (EE) in patients with chronic obstructive pulmonary disease (COPD) and in healthy elderly. DESIGN In this descriptive study, all participants wore both motion sensors while performing a treadmill walking protocol at 3 different speeds corresponding to 30%, 60%, and 100% of the average speed achieved during a six-minute walk test. As criterion methods, EE was estimated by indirect calorimetry, and steps were registered by videotape. SETTING Research laboratory at a university hospital. PARTICIPANTS Patients with COPD (n=30; 17 men; mean age +/- SD, 67+/-8 y; mean forced expiratory volume in the first second [FEV(1)] predicted +/- SD, 46%+/-17%; mean body mass index [BMI] +/- SD, 24+/-4 kg.m(2)) and matched healthy elderly (n=30; 15 men; mean age +/- SD, 68+/-7 y; mean FEV(1) predicted +/- SD, 104%+/-21%; mean BMI +/- SD, 25+/-3 kg.m(2)). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURE Step counting and EE estimation during a treadmill walking protocol. RESULTS The pedometer was accurate for step counting and EE estimation in both patients with COPD and healthy elderly at the higher speed. However, it showed significant underestimation at the 2 slower speeds in both groups. The multisensor did not detect steps accurately at any speed, although it accurately estimated EE at all speeds in healthy elderly and at the intermediate and higher speeds in patients with COPD. CONCLUSIONS In both patients with COPD and healthy elderly, the multisensor showed better EE estimates during most walking speeds than the pedometer. Conversely, for step counting, accuracy is observed only with the pedometer during the higher walking speed in both groups.

Reference equations for the six-minute walk distance based on a Brazilian multicenter study

Background It is important to include large sample sizes and different factors that influence the six-minute walking distance (6MWD) in order to propose reference equations for the six-minute walking test (6MWT). Objective To evaluate the influence of anthropometric, demographic, and physiologic variables on the 6MWD of healthy subjects from different regions of Brazil to establish a reference equation for the Brazilian population. Method In a multicenter study, 617 healthy subjects performed two 6MWTs and had their weight, height, and body mass index (BMI) measured, as well as their physiologic responses to the test. Delta heart rate (∆HR), perceived effort, and peripheral oxygen saturation were calculated by the difference between the respective values at the end of the test minus the baseline value. Results Walking distance averaged 586±106m, 54m greater in male compared to female subjects (p<0.001). No differences were observed among the 6MWD from different regions. The quadratic regression analysis considering only anthropometric and demographic data explained 46% of the variability in the 6MWT (p<0.001) and derived the equation: 6MWDpred=890.46-(6.11×age)+(0.0345×age2)+(48.87×gender)-(4.87×BMI). A second model of stepwise multiple regression including ∆HR explained 62% of the variability (p<0.0001) and derived the equation: 6MWDpred=356.658-(2.303×age)+(36.648×gender)+(1.704×height)+(1.365×∆HR). Conclusion The equations proposed in this study, especially the second one, seem adequate to accurately predict the 6MWD for Brazilians.

Comparison of daily physical activity between COPD patients from Central Europe and South America

BACKGROUND In healthy elderly and adults, lower physical activity level in daily life has been associated with lower socio-economic level and non-Caucasian race. The objective of this study was to determine if this is also applicable in chronic obstructive pulmonary disease (COPD) by comparing physical activity levels in daily life in stable patients from two countries (Austria and Brazil) with different socio-economic and ethnic characteristics. METHODS Physical activity in daily life was objectively assessed in 40 Austrian and 40 Brazilian COPD patients. Groups were matched for age, gender, body mass index, disease severity, smoking history, presence of concomitant heart disease, lung function, dyspnea and functional exercise capacity. In addition, climatic conditions were similar during the period of data collection in the two groups. RESULTS In comparison to Brazilian patients, Austrian patients had a significantly lower walking time (p=0.04), higher sitting time (p=0.02) and lower movement intensity (p=0.0001). The proportion of patients who did not reach an average of 30min of walking per day was 48% in the Austrian group and 23% in the Brazilian group. CONCLUSIONS Austrian patients with COPD showed a significantly lower daily physical activity level in comparison to matched Brazilian patients. Socio-economic and ethnic factors appear to influence stable COPD patients differently than described in previous studies including healthy subjects.

Effects of 2 Exercise Training Programs on Physical Activity in Daily Life in Patients With COPD

BACKGROUND: The effects of different exercise training programs on the level of physical activity in daily life in patients with COPD remain to be investigated. OBJECTIVE: In patients with COPD we compared the effects of 2 exercise/training regimens (a high-intensity whole-body endurance-and-strength program, and a low-intensity calisthenics-and-breathing-exercises program) on physical activity in daily life, exercise capacity, muscle force, health-related quality of life, and functional status. METHODS: We randomized 40 patients with COPD to perform either endurance-and-strength training (no. = 20, mean ± SD FEV1 40 ± 13% of predicted) at 60–75% of maximum capacity, or calisthenics-and-breathing-exercises training (no. = 20, mean ± SD FEV1 39 ± 14% of predicted). Both groups underwent 3 sessions per week for 12 weeks. Before and after the training programs the patients underwent activity monitoring with motion sensors, incremental cycle-ergometry, 6-min walk test, and peripheral-muscle-force test, and responded to questionnaires on health-related quality of life and functional status (activities of daily living, pulmonary functional status, and dyspnea). RESULTS: Time spent active and energy expenditure in daily life were not significantly altered in either group. Exercise capacity and muscle force significantly improved only in the endurance-and-strength group. Health-related quality of life and functional status improved significantly in both groups. CONCLUSIONS: Neither training program significantly improved time spent active or energy expenditure in daily life. The training regimens similarly improved quality of life and functional status. Exercise capacity and muscle force significantly improved only in the high-intensity endurance-and-strength group.

Função pulmonar e força muscular respiratória em pacientes com doença renal crônica submetidos à hemodiálise

OBJECTIVE: To evaluate pulmonary function and respiratory muscle strength in chronic renal failure patients, correlating these variables with hemodialysis-related weight fluctuation; to study the correlation between the duration hemodialysis and potential respiratory alterations. METHODS: Seventeen patients (median age, 47 years; interquartile range, 41-52 years), submitted to three weekly hemodialysis sessions for a median of 27 months (interquartile range, 14-55) were evaluated. Twelve of the patients were male. The patients underwent spirometry. Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were measured prior to and after the first hemodialysis session of the week. Body weight was quantified prior to and after each of the three weekly sessions. RESULTS: Before the first hemodialysis session of the week, 8 patients presented mild restrictive defect, which normalized after the session in 2 of those patients. After dialysis, there was a significant increase in forced vital capacity (p = 0.02) and a significant decrease in body weight (p = 0.0001). Weight fluctuation over 3 days without hemodialysis tended to correlate with the variation in forced vital capacity in the first weekly session (r = 0.47; p = 0.055). Duration of hemodialysis correlated with predialysis MIP (r = -0.3; p = 0.03) and MEP (r = -0.63; p = 0.006). CONCLUSIONS: More pronounced weight gain in the interdialytic period is associated with worsening of lung function, which is almost fully reversible by hemodialysis. In addition, longer duration of hemodialysis is associated with decreased respiratory muscle strength.

Validation of the Portuguese version of the London Chest Activity of Daily Living Scale (LCADL) in chronic obstructive pulmonary disease patients

INTRODUCTION While there are several subjective English tools, such as the London Chest Activity of Daily Living scale (LCADL), aimed at assessing dyspnoea during activities of daily living (ADL) in patients with Chronic Obstructive Pulmonary Di- sease (COPD), none of these questionnaires has ever been translated into Portuguese. The aim of this study was to investigate the validity and reproducibility of the LCADLs Portuguese version in patients with COPD. METHODS 31 patients with COPD (17 male; 69+/-7 years; FEV1 44+/-15 %predicted) completed the Portuguese version of the LCADL twice with a 1-week interval. The traditional Saint George Respiratory Questionnaire (SGRQ), already validated in Portuguese, was used as the criterion method. RESULTS There were no significant differences between test and retest of the LCADL. Intraclass Correlation Coefficient between test and retest concerning the different scale components was Self-care r=0.96; Domestic r=0.99; Physical r=0.92; Leisure r=0.95; Total Score r=0.98. There were significant correlations of the LCADL Total Score with the SGRQs different components and total score (0.36<r<0.74; p<0.05 for all). The LCADL Total Score was also significantly correlated with the 6-minute walking distance test (r= -0.48; p=0.006). CONCLUSION The Portuguese version of the LCADL is valid and reproducible in patients with COPD, making this study a new and important tool for assessing the limitations of performing ADL in this population.

Validação da versão em português da escala London Chest Activity of Daily Living (LCADL) em doentes com doença pulmonar obstrutiva crónica

Introduction: While there are several subjective English tools, such as the London Chest Activity of Daily Living scale (LCADL), aimed at assessing dyspnoea during activities of daily living (ADL) in patients with Chronic Obstructive Pulmonary Disease (COPD), none of these questionnaires has ever been translated into Portuguese. The aim of this study was to investigate the validity and reproducibility of the LCADL’s Portuguese version in patients with COPD. Methods: 31 patients with COPD (17 male; 69 ± 7 years; FEV1 44 ± 15 %predicted) completed the Portuguese version of the LCADL twice with a 1-week interval. The traditional Saint George Respiratory Questionnaire (SGRQ), already validated in Portuguese, was used as the criterion method. Results: There were no significant differences between test and retest of the LCADL. Intraclass Correlation Coefficient between test and retest concerning the different scale components was Self-care r = 0.96; Domestic r = 0.99; Physical r = 0.92; Leisure r = 0.95; Total Score r = 0.98. There were significant correlations of the LCADL Total Score with the SGRQ’s different components and total score (0.36<r<0.74; p<0.05 for all). The LCADL Total Score was also significantly correlated with the 6-minute walking distance test (r = -0.48; p = 0.006). Conclusion: The Portuguese version of the LCADL is valid and reproducible in patients with COPD, making this study a new and important tool for assessing the limitations of performing ADL in this population. Rev Port Pneumol 2008; XIV (1): 27-47