[1] Schoen Klin Berchtesgadener Land, Dept Resp Med & Pulm Rehabil, Schoenau, Germany
[2] Tech Univ Munich, Klinikum Rechts Isar, Dept Prevent Rehabil & Sports Med, Munich, Germany
[3] Philipps Univ Marburg, Dept Internal Med, Div Pulm Dis, Marburg, Germany
[4] Stanford Univ, Div Cardiovasc Med, Stanford, CA 94305 USA
[5] Paracelsus Med Univ, Res Dept Biostat, Salzburg, Austria
[6] Philipps Univ Marburg, Marburg, Germany