[1] Univ Klinikum Schleswig Holstein, Klin Kinder & Jugendmed, D-23538 Lubeck, Germany
[2] Univ Clin Schleswig Holstein, Dept Pediat, Lubeck, Germany
[3] Univ Dusseldorf, German Diabetes Res Inst, Dept Biometr & Epidemiol, Dusseldorf, Germany
[4] Univ Ulm, Dept Appl Informat Technol, D-89069 Ulm, Germany
[5] Univ Ulm, Dept Epidemiol, D-89069 Ulm, Germany