1. West-German Centre of Diabetes and Health, Düsseldorf Catholic Hospital Group, Düsseldorf, Germany.
2. Sana Hospital Gerresheim, Sana Clinics Düsseldorf GmbH, Düsseldorf, Germany.
3. Department of Psychosomatic Medicine and Psychotherapy, Justus-Liebig-University Gießen, Gießen, Germany.