Parallel, randomized and controlled clinical trial to evaluate the effect of 12 months of noninvasive mechanical ventilation versus conventional treatment in hypercapnic patients with stable COPD.

Main objective: To evaluate the effect of 12 months of noninvasive ventilation on c-reactive protein concentration and daily physical activity in hypercapnic patients with stable COPD.

Secondary objectives: To compare the plasmatic concentration of other inflammatory biomarkers between COPD patients with conventional treatment and wich noninvasive ventilation. To determine the response of breathlessness, health-related quality of life and lung function to noninvasive ventilation. To identify the COPD patients with a higher gasometric and clinic response to noninvasive ventilation.

Inclusion Criteria:

• Age: 45-75 yrs.
• COPD diagnosis (postbronchodilator FEV1/FVC < 0.7) for at least 6 months.
• FEV1 < 45% predicted
• Baseline pH 7.35-7.45
• Baseline PaCO2>45 mmHg breathing current air
• Smoking history (>15 pack-year)
• Clinically stable for at least the last three months
• Pharmacological treatment optimized in the last two years.

Exclusion Criteria:

• Previous diagnosis of asthma, other airway obstructive disease, sleep apnea syndrome, interstitial lung disease, chest wall disease or neuromuscular disease.
• Apnea-hypopnea index > 10/h
• Morbid obesity (BMI > 45 Kg/m2)
• Previous diagnosis of ischaemic heart disease, cardiac failure, cirrhosis, chronic renal failure, rheumatoid arthritis or other inflammatory disease.