Limb muscle dysfunction, characterized by atrophy and weakness, is amongst the most troublesome systemic consequences of chronic obstructive pulmonary disease (COPD) leading to poor functional status and premature mortality.

One prevailing hypothesis stipulates that the deterioration in muscle structure and function during COPD results from a spillover of inflammatory mediators from the lungs to the systemic circulation and then to the muscles.

The investigators objective is to investigate the impact of COPD on key signaling pathways involved in the muscle atrophy. Moderate to severe COPD patients (FEV1 under 60% of predicted) and healthy controls will be recruited. All of the investigators patients will undergo a thorough baseline assessment in pulmonary capacity, muscle force and body composition. Blood sampling and biopsy of the quadriceps will be done. Key proteins of signaling intramuscular pathways involved in protein synthesis and degradation will be measured in the quadriceps.

Inclusion Criteria:

• male
• COPD with an FEV1 of under 60% of predicted
• non-smoker
• between 55 and 75 years old

Exclusion Criteria:

• all inflammatory disease (HIV, cancer, renal and cardiac deficiency)
• hormonal dysregulation
• inferior limb pathology
• neuromuscular pathology
• history of tobacco or alcool abuse
• oxygen dependent
• recent exacerbation (2 months) of the symptoms of COPD

Patients with COPD