 In this proposal, we will implement a randomized controlled trial to determine whether nocturnal NIMV applied for 3 months: 1 improves disease-specific health related quality of life HRQL of COPD patients compared to a control group of patients treated with sham NIMV therapy primary outcome; 2 improves exercise tolerance and walking capacity of COPD patients; 3 reduces the number of clinical relapses in COPD patients; 4 improves heart rate variability and decreases sympathetic tone in COPD; and 5 is a cost-effective therapy. 