[1] Univ Turin, Dept Internal Med, Turin, Italy
[2] Imperial Coll Sch Med, Natl Heart & Lung Inst, London, England
[3] Maastrict Univ, Med Ctr, Dept Internal Med, Maastricht, Netherlands
[4] Steno Diabet Ctr, Epidemiol Res Grp, DK-2820 Gentofte, Denmark
[5] Royal Free & Univ Coll London, Dept Epidemiol & Publ Hlth, Sch Med, London, England