1. From the Department of Public Health, University of Applied Sciences, Braunschweig/Wolfenbu¨ttel, Wolfsburg, Germany; the
2. Department of Biometrics and Epidemiology, German Diabetes Research Institute, and the
3. Department of Metabolic Diseases and Nutrition, World Health Organization Collaborating Center for Diabetes, Heinrich Heine University, Du¨sseldorf, Germany.