[1] Hannover Med Sch, Dept Resp Med, D-30623 Hannover, Germany
[2] German Ctr Lung Res, Hannover, Germany
[3] Univ Michigan Hlth Syst, Dept Internal Med, Ann Arbor, MI USA
[4] King Faisal Specialist Hosp & Res Ctr, Sect Pulm Med, Riyadh 11211, Saudi Arabia
[5] Kyorin Univ, Sch Med, Div Cardiol, Dept Med, Tokyo, Japan
[6] Univ Bologna, Dept Expt Diagnost & Specialty Med DIMES, Bologna, Italy