This study was supported in part by grants from the German Federal Ministry of Education and Research to the Competence Network for Diabetes mellitus (FKZ 01GI0805-07), the Deutsche Forschungsgemeinschaft (ZI 310/12-6), and the Juvenile Diabetes Research Foundation (P.A. 11-2005-1117). The Micromedic Technologies kits were kindly provided by M. Becker, Genzyme Virotech, Rüsselsheim, Germany.
Duality of interest
The authors declare that there is no duality of interest associated with this manuscript.