[1] Hippokrateion Hosp, Dept Endocrinol, Thessaloniki 54642, Greece
[2] UCL, Univ Coll Med Sch, Dept Clin Biochem, Vasc Prevent Clin, London, England
[3] UCL, Univ Coll Med Sch, Dept Surg, London, England
[4] Aristotle Univ Thessaloniki, Hippokration Hosp, Sch Med, Propedeut Dept Internal Med 2, GR-54006 Thessaloniki, Greece