To the Editors:
We read with great interest the paper by Swallow et al. 1, comparing skeletal muscle function in chronic obstructive pulmonary disease (COPD) patients and patients with idiopathic scoliosis. In our opinion, the reported muscular weakness in patients with a chronic noninflammatory respiratory disease may have important implications in rehabilitation and prevention of chronic respiratory diseases.
Pulmonary rehabilitation is defined as an “evidence-based, multidisciplinary, comprehensive intervention for patients with chronic respiratory diseases…” 2, but most of the scientific literature is about COPD patients, with less attention devoted to other chronic respiratory diseases. In COPD patients, the cause of skeletal muscle limitation is a subject of debate; whether the reduction of physical activity is because of the respiratory symptoms or the so-called systemic effects of the disease 2. If, as suggested by Swallow et al. 1, the common determinant of muscular impairment in COPD and scoliosis is the deconditioning caused by the disease, there is a basis for pulmonary rehabilitation in the majority of patients with chronic pulmonary disease, regardless of the cause. Recently, good results have been reported in the rehabilitation of patients with non-COPD respiratory diseases, such as interstitial lung diseases including idiopathic pulmonary fibrosis 3. Furthermore, rehabilitation is possible in patients previously excluded by this kind of treatment, such as those with pulmonary hypertension 4.
Another interesting topic is the prevention of loss of exercise capacity in pulmonary patients. Recently, we described the case of a 70-yr-old COPD patient who, having exercised regularly since a young age, maintained a good physical performance (peak oxygen uptake 130% of predicted) despite a significant pulmonary function limitation (forced expiratory volume in 1 s 60% pred) 5. Garcia-Aymerich et al. 6 reported a reduced pulmonary function decline and reduced risk of COPD in smokers practising regular physical activity. The study by Watz et al. 7 showed a reduction of physical activity across the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages in COPD patients. There is a significant body of evidence about the beneficial anti-inflammatory effect of exercise 8. It is generally accepted that the amount of exercise required to prevent the loss of exercise capacity is less than that required to improve physical performance. If this is the case, in the future, much attention must be devoted to early diagnosis of chronic respiratory diseases to prevent the decline of exercise capacity, which is a major determinant of the quality of life of such patients, by a regular physical activity.
Statement of interest
None declared.
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