Effects of isolated cycle ergometer training on patients with moderate-to-severe chronic obstructive pulmonary disease

Background: Pulmonary rehabilitation (PR) programs are beneficial to patients with chronic obstructive pulmonary disease (COPD), and lower-extremity training is considered a fundamental component of PR. Nevertheless, the isolated effects of each PR component are not well established. Objective: We aimed to evaluate the effects of a cycle ergometry exercise protocol as the only intervention in a group of COPD patients, and to compare these results with a control group. Methods: 25 moderate-to-severe COPD patients were evaluated regarding pulmonary function, respiratory muscle strength, exercise capacity, quality of life and body composition. Patients were allocated to one of two groups: (a) the trained group (TG; n=13; 6 men) was submitted to a protocol of 24 exercise sessions on a cycle ergometer, with training intensity initially set at a heart rate (HR) close to 80% of maximal HR achieved in a maximal test, and load increase based on dyspnea scores, and (b) the control group (CG; n=12; 6 men) with no intervention during the protocol period. Results: TG showed within-group significant improvements in endurance cycling time, 6-min walking distance test, maximal inspiratory pressure and in the domain 'dyspnea' related to quality of life. Despite the within-group changes, no between-group significant differences were observed. Conclusion: In COPD patients, the results of isolated low-to-moderate intensity cycle ergometer training are not comparable to effects of multimodality and high-intensity training programs. Copyright (C) 2004 S. Karger AG, Basel.

The six-minute walk test and body weight-walk distance product in healthy Brazilian subjects

We assessed the 6-min walk distance (6MWD) and body weight x distance product (6MWw) in healthy Brazilian subjects and compared measured 6MWD with values predicted in five reference equations developed for other populations. Anthropometry, spirometry, reported physical activity, and two walk tests in a 30-m corridor were evaluated in 134 subjects (73 females, 13-84 years). Mean 6MWD and 6MWw were significantly greater in males than in females (622 ± 80 m, 46,322 ± 10,539 kg.m vs 551 ± 71 m, 36,356 ± 8,289 kg.m, P < 0.05). Four equations significantly overestimated measured 6MWD (range, 32 ± 71 to 137 ± 74 m; P < 0.001), and one significantly underestimated it (-36 ± 86 m; P < 0.001). 6MWD significantly correlated with age (r = -0.39), height (r = 0.44), body mass index (r = -0.24), and reported physical activity (r = 0.25). 6MWw significantly correlated with age (r = -0.21), height (r = 0.66) and reported physical activity (r = 0.25). The reference equation devised for walk distance was 6MWDm = 622.461 - (1.846 x Ageyears) + (61.503 x Gendermales = 1; females = 0); r2 = 0.300. In an additional group of 85 subjects prospectively studied, the difference between measured and the 6MWD predicted with the equation proposed here was not significant (-3 ± 68 m; P = 0.938). The measured 6MWD represented 99.6 ± 11.9% of the predicted value. We conclude that 6MWD and 6MWw variances were adequately explained by demographic and anthropometric attributes. This reference equation is probably most appropriate for evaluating the exercise capacity of Brazilian patients with chronic diseases.

The Incremental Shuttle Walk Test in Older Brazilian Adults

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A Simple Approach to Assess VT During a Field Walk Test

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Three-year follow-up study of respiratory and systemic manifestations of chronic obstructive pulmonary disease

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Treinamento de força para pacientes com doença pulmonar obstrutiva crônica

Pacientes com doença pulmonar obstrutiva crônica apresentam comumente fraqueza muscular periférica associada à intolerância ao exercício. Embora efetivo, o exercício aeróbio apresenta pouco ou nenhum efeito na fraqueza e atrofia muscular, além de não ser tolerado pela maioria dos pacientes com DPOC. Nesse sentido, o treinamento de força é opção racional para aumentar a força muscular, além de já ter se mostrado mais tolerável que o exercício aeróbio. O aumento de força muscular periférica é o benefício mais consistente do treinamento de força e, quando este é associado ao exercício aeróbio, não resulta em melhora adicional da capacidade de exercício, da dispnéia e da qualidade de vida. Contudo, observa-se que o treinamento combinado é fisiologicamente mais completo e pode ser uma opção de condicionamento físico mais diversificado. O treinamento de moderada a alta intensidade resulta em maiores adaptações fisiológicas, entretanto o exercício de baixa intensidade é tolerável, simples, de fácil execução domiciliar, não requer equipamentos sofisticados e resulta em benefícios significativos. Este exercício é indicado, sobretudo, para os pacientes com DPOC mais avançada. Finalmente, há evidências recentes de que o treinamento de força para os músculos do tronco é alternativa válida para melhorar a capacidade funcional de exercício e a função pulmonar em pacientes com DPOC. A presente revisão de literatura sugere a incorporação do treinamento de força como estratégia de rotina nos programas de reabilitação pulmonar. Pesquisas futuras são necessárias para avaliar os efeitos do treinamento de força na saúde mental, no desempenho em atividades de vida diária, na saúde osteoarticular, no risco de quedas e na função pulmonar, entre outros.

Comparison between actual and predicted postoperative stair-climbing test, walk test and spirometric values in patients undergoing lung resection

OBJETIVO: Verificar se os testes: Volume Expiratório Forçado no 1º segundo (VEF1), Teste de Caminhada de 6 minutos (TC6) e Teste de Escada (TE) se alteram proporcionalmente ao pulmão funcionante ressecado. MÉTODOS: Foram incluídos pacientes candidatos a toracotomia para ressecção pulmonar. No pré-operatório (pré) e no mínimo três meses após a cirurgia (pós), realizaram espirometria, TC6 e TE. O TE foi realizado em escada com 12,16m de altura. O tempo para subir todos os degraus o mais rápido possível foi chamado tempo de escada (tTE). Os cálculos dos valores dos testes preditos para o pós-operatório (ppo) foram realizados conforme o número de segmentos funcionantes perdidos. Os valores pré, ppo e pós foram comparados entre si para cada teste. Estatística: foi utilizada a análise de variância para medidas repetidas (ANOVA), com significância de 5%. RESULTADOS: Foram estudados 40 pacientes. A ressecção pulmonar variou desde o ganho de dois segmentos funcionantes até a perda de 9. Os valores pré, ppo e pós foram respectivamente: VEF1 -pré = 2,6±0,8L, ppo = 2,3±0,8L, pós = 2,3±0,8L (VEF1pré > VEF1ppo = VEF1pós), TC6-pré = 604±63m, ppo = 529±103m, pós = 599±74m (TC6pré = TC6pós > TC6ppo), tTE-pré = 32,9±7,6s, ppo = 37,8±12,1s, pós = 33,7±8,5s (tTEpré = tTEpós < tTEppo). CONCLUSÃO: Nas ressecções pulmonares, este grupo de pacientes perdeu função pulmonar medida através da espirometria, mas não perdeu a capacidade de exercício, medida através dos testes de escada e caminhada.

Relationship between disease severity and quality of life in patients with chronic obstructive pulmonary disease

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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; FEV(1) = 46 +/- 16 % of predicted; body mass index = 27 +/- 6 kg/m(2)) 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 George's 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/s(2); 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.

Myostatin and follistatin expression in skeletal muscles of rats with chronic heart failure

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determination of anaerobic threshold in rats using the lactate minimum test

The break point of the curve of blood lactate vs exercise load has been called anaerobic threshold (AT) and is considered to be an important indicator of endurance exercise capacity in human subjects. There are few studies of AT determination in animals. We describe a protocol for AT determination by the lactate minimum test in rats during swimming exercise. The test is based on the premise that during an incremental exercise test, and after a bout of maximal exercise, blood lactate decreases to a minimum and then increases again. This minimum value indicates the intensity of the AT. Adult male (90 days) Wistar rats adapted to swimming for 2 weeks were used. The initial state of lactic acidosis was obtained by making the animals jump into the water and swim while carrying a load equivalent to 50% of body weight for 6 min (30-s exercise interrupted by a 30-s rest). After a 9-min rest, blood was collected and the incremental swimming test was started. The test consisted of swimming while supporting loads of 4.5, 5.0, 5.5, 6.0 and 7.0% of body weight. Each exercise load lasted 5 min and was followed by a 30-s rest during which blood samples were taken. The blood lactate minimum was determined from a zero-gradient tangent to a spline function fitting the blood lactate vs workload curve. AT was estimated to be 4.95 ± 0.10% of body weight while interpolated blood lactate was 7.17 ± 0.16 mmol/l. These results suggest the application of AT determination in animal studies concerning metabolism during exercise.

Protocols for hyperlactatemia induction in the lactate minimum test adapted to swimming rats

The lactate minimum test (LACmin) has been considered an important indicator of endurance exercise capacity and a single session protocol can predict the maximal steady state lactate (MLSS). The objective of this study was to determine the best swimming protocol to induce hyperlactatemia in order to assure the LACmin in rats (Rattus norvegicus), standardized to four different protocols (P) of lactate elevation. The protocols were PI: 6 min of intermittent jumping exercise in water (load of 50% of the body weight - bw); P2: two 13% bw load swimming bouts until exhaustion (thin); P3: one thin 13% bw load swimming bout; and P4: two 13% bw load swimming bouts (1st 30 s, 2nd to thin), separated by a 30 s interval. The incremental phase of LACmin beginning with initial loads of 4% bw, increased in 0.5% at each 5 min. Peak lactate concentration was collected after 5, 7 and 9 min (mmol L-1) and differed among the protocols P 1 (15.2 +/- 0.4, 14.9 +/- 0.7, 14.8 +/- 0.6) and P2 (14.0 +/- 0.4, 14.9 +/- 0.4, 15.5 +/- 0.5) compared to P3 (5.1 +/- 0.1, 5.6 +/- 0.3, 5.6 +/- 0.3) and P4 (4.7 +/- 0.2, 6.8 +/- 0.2, 7.1 +/- 0.2). The LACmin determination success rates were 58%, 55%, 80% and 91% in P1, P2, P3 and P4 protocols, respectively. The MLSS did not differ from LACmin in any protocol. The LACmin obtained from P4 protocol showed better assurance for the MLSS identification in most of the tested rats. (c) 2007 Elsevier B.V. All rights reserved.

BODE Index and GOLD Staging as Predictors of 1-Year Exacerbation Risk in Chronic Obstructive Pulmonary Disease

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Alterations in pulmonary structure by elastase administration in a model of emphysema in mice is associated with functional disturbances

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Gender differences in predictors of health status in patients with COPD

Objective: To evaluate the health status (HS) of COPD patients and to identify the main predictors of HS in these patients according to gender. Methods: The study included 90 COPD patients (60 males and 30 females; mean age = 64 +/- 9 years) with a wide range of airway obstruction disorders (mean FEV(1) = 56 +/- 19% of predicted). The men were individually matched to the women by % of predicted FEV(1) (ratio: 2:1). The patients were assessed regarding body composition; six-minute walk distance; perception of dyspnea using the Modified Medical Research Council Dyspnea Scale; Saint George's Respiratory Questionnaire (SGRQ); Charlson comorbidity index; and the multidimensional Body mass index, airway Obstruction, Dyspnea, and Exercise capacity (BODE) index. Multiple linear regression analysis was performed to identify the predictors of HS by gender. Results: Impairment of HS was greater among the women than among the men for SGRQ total score and for all SGRQ domains (total: 51 +/- 18% vs. 38 19%; p = 0.002; symptoms: 61 +/- 22% vs. 42 +/- 21%; p < 0.001; activity: 62 +/- 18% vs. 49 +/- 21%; p = 0.004; and impact: 41 +/- 19% vs. 27 +/- 18%; p = 0.001). The multiple linear regression showed that age and perception of dyspnea correlated with SGRQ total score for both genders (males, r(2) = 0.42; females, r(2) = 0.70; p < 0.05). Conclusions: Our results showed an association between gender and HS in COPD patients. Age and dyspnea are determinants of HS in both genders.