The relationships among pulmonary function, aerobic fitness, and cognitivefunctioning in older COPD patients

Study objectives: To study the predictive relationships among age,pulmonary function, aerobic fitness, and cognition in people with COPD, Design: Observational study conducted. during baseline:testing with COPD pa tients who volunteered to participate in an exercise intervention. Particip ants: Older adults (age, 56 to 80 years) with COPD. Measurements and results: Age, depression, education level, aerobic fitness , blood oxygen saturation levels, and pulmonary function were assessed, Par ticipants were randomly assigned to take cognitive tests of (1) fluid intel ligence, (2) processing speed and working memory span, or (3) processing sp eed and inhibition. After controlling for-education and depression (F-2,F-5 7 = 7.43; r(2) = 0.21), performance on the 6-min walk (F-1,F-56 = 15.27; r( 2) = 0.17) and age (F-1,F-55 = 7.52; r(2) = 0.08) were significant predicto rs of fluid intelligence. On the speed-of-processing task, performance on t he 6-min walk (F-1,F-30 = 8.17; r(2) = 0.20), maximum voluntary ventilation (F-1,F-29 = 5.81; r(2) = 0,16), and age (F-1,F-28 = 5.26; r(2) = 0.20) wer e significant predictors, FVC was a significant predictor (F-1,F-25 = 6.37; r(2) = 0.18) of working memory span. The ability to inhibit a response was not significantly predicted by any of the variables assessed, Conclusions: In an older COPD sample, age, aerobic fitness, and pulmonary f unction are predictive of cognitive performance on various tasks. In partic ular, age and aerobic fitness are predictive of speed of processing, which is a cognitive:variable that may itself underlie performance on a majority of cognitive tasks.