[1] Charite Univ Med Berlin, Dept Psychosomat Med & Psychotherapy, D-12200 Berlin, Germany
[2] Univ Bergen, Fac Psychol, Dept Psychosocial Sci, N-5020 Bergen, Norway
[3] Charite Univ Med Berlin, Inst Clin Biochem & Pathobiochem, Berlin, Germany
[4] Univ Hosp Freiburg, Div Nephrol & Gen Med, Dept Internal Med 4, Freiburg, Germany