Muscle weakness and atrophy are important consequences of chronic obstructive pulmonary disease (COPD) and can affect both respiratory and peripheral muscles. Impaired muscle regeneration is thought to be implicated in the process of muscle atrophy. In this study the investigators will evaluate muscle regenerative potential of the Vastus Lateralis (VL) and diaphragm of patients with COPD, compared to patients with normal lung function.

Preliminary results suggest that the activation and differentiation processes of satellite cells isolated from the VL of patients with COPD could be altered. The investigators propose to compare the regenerative potential of the VL and the diaphragm in 15 patients with COPD and 15 individuals with normal lung function undergoing a thoracic surgery. From muscle biopsies, satellite cells will be isolated and cultured to assess their proliferation and differentiation rates, and the expression level of myogenic effectors (MyoD, Myf5, myogenin, and MRF4). Alterations in these measurements will confirm the hypotheses that the regenerative potential is lower in both muscle groups in patients with COPD compared to controls and that in COPD, the regenerative potential is lower in VL compared to the diaphragm.

Inclusion Criteria:

• Patient with a scheduled thoracic surgery
• ≥ 40 years
• Smoking cessation ≥ 1 month
• Smoking history ≥ 10 pack-year

Exclusion Criteria:

• Subjects who received either chemiotherapy or radiotherapy
• Hypoxemia
• Body weight loss ≥ 10%
• Use of systemic corticosteroid in the last month

Patient with a scheduled thoracic surgery