Abstract
BACKGROUND: Reductions in quadriceps strength and peak aerobic capacity (VO2) in patients with chronic obstructive pulmonary disease (COPD) have been studied in relatively small samples over a short period. Moreover, results were not corrected for confounding variables, such as lean muscle mass, gender, and gas transfer capacity of the lungs. OBJECTIVES: To compare quadriceps muscle strength and peak V.O2 in women and men while stratifying for age and gas transfer capacity. We then corrected for lower-limb lean muscle mass to see whether and to what extent the age-graded reduction remained evident. METHODS: Retrospectively, data of 374 women and 593 men with COPD were analyzed: lung function, current drug therapy, quadriceps strength, peak V.O2, lower-limb lean muscle mass, and gas transfer capacity. RESULTS: Quadriceps strength and peak V.O2 were lower in older women and men with a gas transfer capacity of <50% predicted, also after adjustment for lower-limb lean muscle mass. Moreover, quadriceps strength and peak V.O2 were lower in older women and men with a gas transfer capacity of <50% predicted, also after adjustment for lower-limb lean muscle mass. Moreover, quadriceps strength and peak V.O2 were related to age in COPD, particularly in women and men with a gas transfer capacity of >50% predicted. Yet, counter to our hypothesis, lower-limb lean muscle mass did not show an age-graded reduction and, in turn, could not account for the relationship of age with quadriceps strength and peak V.O2. CONCLUSIONS: It is apparent that there is an age-graded reduction in skeletal muscle function in patients with COPD. Therefore, prevention of an age-graded decline in quadriceps muscle strength and peak V.O2 may need to become an outcome of pulmonary rehabilitation of patients with COPD.
Original language | English |
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Pages (from-to) | 148-156 |
Number of pages | 9 |
Journal | Revista Brasileira de Fisioterapia |
Volume | 16 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Jan 2012 |
Keywords
- Chronic obstructive pulmonary disease
- lower-limb lean muscle mass
- peak aerobic capacity
- quadriceps muscle strength
- isokinetic quadriceps peak torque
- aging
- OBSTRUCTIVE PULMONARY-DISEASE
- VASTUS LATERALIS MUSCLE
- FAT-FREE MASS
- SKELETAL-MUSCLE
- EXERCISE CAPACITY
- BODY-COMPOSITION
- LUNG-DISEASE
- DAILY-LIFE
- WEAKNESS
- REHABILITATION