Rehabilitation in Pulmonary Sarcoidosis: a Prospective Study

Sarcoidosis is a heterogeneous multisystem disorder of unknown etiology which often presents with bilateral hilar lymphadenopathy, pulmonary infiltration and ocular and skin lesions. In addition to possible changes in forced vital capacity (FVC) and carbon monoxide transfer factor (TLCO), a higher prevalence of clinical depression, reduced health status and exercise intolerance have been observed in patients with sarcoidosis.

Reduced health status has been related to decreased pulmonary function, depressive symptoms, and to respiratory muscle weakness. Exercise capacity is believed to be limited by dyspnea, an insufficient heart rate response, decreased arterial oxygen tension during exercise, excessive and inefficient ventilation and by respiratory muscle weakness.

In the past, exercise capacity was shown to be limited by skeletal muscle weakness in patients with chronic pulmonary or cardiac disease. 67% of the sarcoidosis patients studied by Miller et al terminated their peak exercise test due to "leg complaints". Skeletal muscle weakness is therefore still assumed to be present in patients with sarcoidosis.

Treatment with oral corticosteroids, clinical symptoms of depression, myositis, self-reported complaints of fatigue and high circulating levels of tumour necrosis factor-α (TNF-α) are all present in patients with sarcoidosis and can all affect skeletal muscle force and exercise capacity. Additionally, low levels of circulating insulin-like growth factor I (IGF-I), which can be induced by high levels of TNF-α, and high circulating levels of interleukin (IL)-6 and IL-8 (CXCL8) have been associated with skeletal muscle weakness. These interleukins are part of the current concept of the immunopathogenesis of sarcoidosis16 and may be raised in patients with stable sarcoidosis.

Recent studies have shown that pulmonary rehabilitation program can lead to improve in the health status and anxiety among patients with chronic obstructive lung disease .However, no study has evaluated the role of pulmonary rehabilitation among patients with sarcoidosis.