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 + or - 8 years of age; FEV(1) = 46 + or - 16 % of predicted; body mass index = 27 + or - 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 + or - 33 vs. 80 + or - 28 min/day; p = 0.001), as movement intensity was lower (1.9 + or - 0.4 vs. 2.3 + or - 0.6 m/s(2); p = 0.004). The COPD patients also tended to spend more time seated (294 + or - 114 vs. 246 + or - 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 < or = r < or = -0.43; p < or = 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.