Profile of patients with chronic obstructive pulmonary disease classified as physically active and inactive according to different thresholds of physical activity in daily life

ABSTRACT Objective To compare the profiles of patients with chronic obstructive pulmonary disease (COPD) considered physically active or inactive according to different classifications of the level of physical activity in daily life (PADL). Method Pulmonary function, dyspnea, functional status, body composition, exercise capacity, respiratory and peripheral muscle strength, and presence of comorbidities were assessed in 104 patients with COPD. The level of PADL was quantified with a SenseWear Armband activity monitor. Three classifications were used to classify the patients as physically active or inactive: 30 minutes of activity/day with intensity >3.2 METs, if age ≥65 years, and >4 METs, if age <65 years; 30 minutes of activity/day with intensity >3.0 METs, regardless of patient age; and 80 minutes of activity/day with intensity >3.0 METs, regardless of patient age. Results In all classifications, when compared with the inactive group, the physically active group had better values of anthropometric variables (higher fat-free mass, lower body weight, body mass index and fat percentage), exercise capacity (6-minute walking distance), lung function (forced vital capacity) and functional status (personal care domain of the London Chest Activity of Daily Living). Furthermore, patients classified as physically active in two classifications also had better peripheral and expiratory muscle strength, airflow obstruction, functional status, and quality of life, as well as lower prevalence of heart disease and mortality risk. Conclusion In all classification methods, physically active patients with COPD have better exercise capacity, lung function, body composition, and functional status compared to physically inactive patients.

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. .

Physical activity in daily life in physically independent elderly participating in community-based exercise program / Atividade física na vida diária de idosos fisicamente independentes participantes de programas de exercício físico oferecidos à comunidade

BACKGROUND: It is unclear whether participation in exercise programs specifically developed for elderly translates into a more active lifestyle. OBJECTIVES: To compare the objectively measured level of physical activity in daily life (PADL) between physically independent elderly who participate or do not participate in community-based exercise programs; and to evaluate which factors are associated with the higher level of PADL in these subjects. METHOD: 134 elderly participants in community-based exercise programs (PG) and 104 non-participants (NPG) had their level of PADL measured using pedometers during 7 days. Other measurements: 6-minute walking test (6MWT), incremental shuttle walking test (ISWT), muscle strength, flexibility and balance. RESULTS: The PG had higher 1-week mean daily step count than NPG (8314 [IQR 5971-10060] vs. 6250 [IQR 4346-8207] steps/day, p<0.0001), as well as higher step count in any day of the week. There was a higher proportion of physically active subjects (>8000 steps/day) in PG than in NPG (37% vs. 16%, respectively; p<0.001), as well as the proportion of sedentary subjects (<5000 steps/day) (14% vs. 33%, respectively; p<0.001). Participation in exercise programs, 6MWT and ISWT explained a higher daily steps count (model r²=0.56, p<0.0001). CONCLUSIONS: In physically independent elderly, a higher level of physical activity in daily life occurs in those who participate in community-based exercise programs, regardless of the weekday and including non-program days. Participation of elderly in community-based exercise programs should be more systematically available and encouraged due to its close link to higher activity levels and better exercise capacity.

CONTEXTUALIZAÇÃO: Não está claro se a participação em programas de exercício físico específicos para idosos se traduz em um estilo de vida mais ativo. OBJETIVOS: Comparar o nível de atividade física na vida diária (AFVD) entre idosos fisicamente independentes (IFI) participantes e não participantes de programas de exercício oferecidos à comunidade e estudar os fatores associados ao maior nível de AFVD nesses indivíduos. MÉTODO: Cento e trinta e quatro IFI participantes de programas de exercício (GP) e 104 não participantes (GNP) tiveram seu nível de AFVD avaliado utilizando-se pedômetros durante sete dias. Outras avaliações foram teste de caminhada de 6 minutos (TC6min), incremental shuttle walking test (ISWT), força muscular, flexibilidade e equilíbrio. RESULTADOS: O GP apresentou maior média de passos/dia em sete dias do que o GNP (mediana [IRQ25%-75%] 8314[5971-10060] vs 6250[4346-8207] passos/dia, p<0,0001), bem como maior número de passos em qualquer dia da semana. Houve maior proporção de idosos fisicamente ativos (>8000 passos/dia) no GP em comparação com o GNP (37% vs 16%, respectivamente; p<0,001), assim como menor proporção de sedentários (<5000 passos/dia) (14% vs 33% respectivamente; p<0,001). Um modelo de regressão linear múltipla mostrou que participação em programas, TC6min e ISWT explicaram uma maior média de passos/dia (r²=0,56, p<0,0001). CONCLUSÕES: Em IFI, maior nível de AFVD ocorreu naqueles participantes de programas de exercício oferecidos à comunidade, mesmo analisando-se finais de semana e dias sem programa. A participação nesse tipo de programa deveria ser encorajada devido à sua relação com um estilo de vida mais ativo e melhor capacidade de exercício.

Does the BODE index reflect the level of physical activity in daily life in patients with COPD? / O índice BODE reflete o nível de atividade física na vida diária de pacientes com DPOC?

OBJECTIVES: To study the relationship between the level of physical activity in daily life and disease severity assessed by the BODE index in patients with chronic obstructive pulmonary disease (COPD). METHODS: Sixty-seven patients with COPD (36 men) with forced expiratory volume in the first second (FEV1) of 39 (27-47) percent predicted and age of 66 (61-72) years old were evaluated by spirometry, dyspnea levels (measured by the Medical Research Council scale, MRC) and by the 6-minute walking test (6MWT). The BODE index was calculated based on the body mass index (weight/height²), FEV1, MRC and 6MWT, and then the patients were divided in four quartiles according to their scores (Quartile I: 0 to 2 points, n=15; Quartile II: 3 to 4 points, n=20; Quartile III: 5 to 6 points, n=23; Quartile IV: 7 to 10 points, n=9). Two activity monitors (DynaPort® and SenseWear®) were used to evaluate the level of physical activity in daily life. The Kruskal-Wallis test (Dunns's post-hoc test), the Mann-Whitney test and the Spearman Correlation Coefficient were used for statistical analysis. RESULTS: There were modest correlation between the BODE index and the time spent walking per day, the total daily energy expenditure and the time spent in moderate and vigorous activities per day (-0.32 < r <- 0.47; p<0.01 for all variables). When comparing the pooled quartiles I+II with III+IV, there were significant difference between the time spent walking per day, the total daily energy expenditure and the time spent in moderate activities per day (p<0.05). CONCLUSION: The level of physical activity in daily life has a modest correlation with the classification of COPD severity assessed by the BODE index, reflecting only differences between patients with classified as mild-moderate and severe-very severe COPD.

OBJETIVOS: Estudar a relação entre nível de atividade física na vida diária (AFVD) e gravidade da Doença Pulmonar Obstrutiva Crônica (DPOC) avaliada pelo índice BODE. MÉTODOS: Sessenta e sete pacientes com DPOC (36 homens), com volume expiratório forçado no primeiro segundo (VEF1) 39(27-47) por centoprevisto, e 66(61-72)anos foram submetidos a avaliações de espirometria, grau de dispneia (Medical Research Council scale, MRC) e teste de caminhada de 6 minutos (TC6). O índice BODE foi calculado com base no índice de massa corpórea (peso/estatura²), VEF1, MRC e TC6, e os pacientes foram subdivididos em quatro quartis de acordo com sua pontuação no BODE (quartil I: 0 a 2 pontos, n=15; quartil II: 3 a 4 pontos, n=20; quartil III: 5 a 6 pontos, n=23; quartil IV: 7 a 10 pontos, n=9). O nível de AFVD foi avaliado por dois monitores de atividade física (DynaPort® e SenseWear®). Os testes de Kruskal-Wallis (pós-teste Dunns), Mann-Whitney e Coeficiente de Correlação de Spearman foram utilizados na análise estatística. RESULTADOS: Houve correlação modesta entre os escores do índice BODE e o tempo gasto andando/dia, gasto energético total e tempo gasto/dia em atividades moderadas e vigorosas (-0,32< r <-0,47; p<0.01 para todos). Quando comparados os quartis agrupados I+II com III+IV, houve diferença significante entre o tempo gasto andando/dia, gasto energético total e tempo gasto em atividades moderadas (p<0,05). CONCLUSÃO: O nível de AFVD apresenta correlação modesta com a classificação da gravidade da DPOC dada pelo índice BODE, refletindo apenas diferenças entre pacientes com doença leve-moderada e grave-muito grave.