Limb muscle dysfunction, characterized by loss of capillaries, 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 modification in the expression of miR-204 leads to change the regulation of angiogenesis in vastus lateralis of patients with COPD when compared to controls.

The investigators objective is to investigate the impact of COPD on key signaling pathways involved in the muscle angiogenesis. Mild to severe COPD patients and healthy controls will be recruited. All of the investigators patients will undergo a thorough baseline assessment in pulmonary capacity and body composition. Blood sampling and biopsy of the quadriceps will be done. Key proteins and microRNAs of signaling intramuscular pathways involved in angiogenesis will be measured in the quadriceps.

Inclusion Criteria:

• COPD (FEV1/FVC < 0.70)
• Healthy subjects: no evidence of airways obstruction (FEV1/FVC > 0.70 and FEV1 > 0.80 predicted)
• Smoking history > 10 pack-years
• Ex-smoker >6 months

Exclusion Criteria:

• Chronic hypoxemia and/or hypercapnia (PaO2 < 60 mmHg or SpO2 < 88% at rest and/or PaCO2 > 45 mmHg)
• Recent exacerbation or oral corticosteroids (< 2 months)
• Recent cancer (< 3 years)
• Diabetes
• Myopathy, neuromuscular, neurological or articular diseases
• Kidney disease
• Other respiratory diseases
• Unstable cardiac disease
• Physical activity score > 9 in the Voorips questionnaire
• BMI > 30

Patients with COPD