1. Diabetes and Obesity Unit, Athens Medical Center, 15125 Athens, Greece
2. Endocrine Unit, Athens Medical Center, 15125 Athens, Greece
3. Private Practice, 26 G. Venizelou St., 65302 Kavala, Greece
4. Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43614, USA