[1] Erasmus MC, Dept Internal Med, NL-3015 GD Rotterdam, Netherlands
[2] Erasmus MC, Dept Epidemiol & Biostat, NL-3015 GD Rotterdam, Netherlands
[3] Univ Ioannina, Sch Med, Clin & Mol Epidemiol Unit, Dept Hyg & Epidemiol, GR-45110 Ioannina, Greece
[4] Fdn Res & Technol Hellas, Biomed Res Inst, Ioannina, Greece
[5] Tufts Univ, Sch Med, Dept Med, New England Med Ctr, Boston, MA 02111 USA