[1] Democritus Univ Thrace, Dept Internal Med 2, Ctr Diabet, Alexandroupolis, Greece
[2] Heinrich Heine Univ, Leibniz Ctr Diabet Res, German Diabet Ctr, Inst Clin Diabetol, Dusseldorf, Germany
[3] Heinrich Heine Univ, Fac Med, Dept Endocrinol & Diabetol, Dusseldorf, Germany