Background: Decreased physical activity is associated with higher mortality in subjects with COPD. The aim of this\r\nstudy was to assess clinical characteristics and physical activity levels (PALs) in subjects with COPD.\r\nMethods: Seventy-three subjects with COPD (67 �± 7 yrs, 44 female) with one-second forced expiratory volume\r\npercentage (FEV1%) predicted values of 43 �± 16 were included. The ratio of total energy expenditure (TEE) and\r\nresting metabolic rate (RMR) was used to define the physical activity level (PAL) (PAL = TEE/RMR). TEE was assessed\r\nwith an activity monitor (ActiReg), and RMR was measured by indirect calorimetry. Walking speed (measured over\r\n30-meters), maximal quadriceps muscle strength, fat-free mass and systemic inflammation were measured as clinical\r\ncharacteristics. Hierarchical linear regression was applied to investigate the explanatory values of the clinical\r\ncorrelates to PAL.\r\nResults: The mean PAL was 1.47 �± 0.19, and 92% of subjects were classified as physically very inactive or sedentary.\r\nThe walking speed was 1.02 �± 0.23 m/s, the quadriceps strength was 31.3 �± 11.2 kg, and the fat-free mass index\r\n(FFMI) was 15.7 �± 2.3 kg/m2, identifying 42% of subjects as slow walkers, 21% as muscle-weak and 49% as FFM-depleted.\r\nThe regression model explained 45.5% (p < 0.001) of the variance in PAL. The FEV1% predicted explained the largest\r\nproportion (22.5%), with further improvements in the model from walking speed (10.1%), muscle strength (7.0%) and\r\nFFMI (3.0%). Neither age, gender nor systemic inflammation contributed to the model.\r\nConclusions: Apart from lung function, walking speed and muscle strength are important correlates of physical activity.\r\nFurther explorations of the longitudinal effects of the factors characterizing the most inactive subjects are warranted.
Loading....