In a former study, the investigator observed significant differences in the response to pulmonary rehabilitation between COPD patients with the "normal" genetic variant of alpha-1 antitrypsin (PiMM) and those with a homozygous deficient variant (PiZZ) (Jarosch et al., 2016, DOI: 10.1159/000449509). PiZZ COPD patients showed less improvement in exercise capacity compared to PiMM patients. This latter finding was mirrored by an increase of oxidative myofiber type I proportion - that is important for aerobic exercises in daily life - in PiMM but not PiZZ patients.

Based on this finding of impaired skeletal muscle adaptation, the aim of this study is to compare the effects of pulmonary rehabilitation including exercise training on a) specific enzymes of energy metabolism reflecting the oxidative capacity of the skeletal muscle and b) the analogue gene expression of these oxidative enzymes in a cohort of PiMM and PiZZ COPD patients.

Inclusion Criteria:

• Chronic obstructive pulmonary disease
• phenotype PiMM or PiZZ
• written informed consent

Exclusion Criteria:

• any comorbidities that prevent patients from participating in an exercise Training program
• necessity of anticoagulant therapy
• other genetic variants of alpha-1 antitrypsin than PiMM or PiZZ