[1] Univ Hosp Duesseldorf, Div Specif Endocrinol, Dusseldorf, Germany
[2] Tech Univ Dresden, Univ Hosp Carl Gustav Carus, Dept Med 3, Dresden, Germany
[3] Tech Univ Dresden, Fac Med, DZD German Ctr Diabet Res,Helmholtz Ctr Munich, Univ Clin Carl Gustav Carus,Paul Langerhans Inst, Dresden, Germany
[4] Tech Univ Dresden, Ctr Regenerat Therapies, Dresden, Germany
[5] Kings Coll London, Diabet & Nutr Sci Div, London, England
[6] Eunice Kennedy Shriver Natl Inst Child Hlth & Hum, Sect Endocrinol & Genet, Bethesda, MD USA