1. Division of Endocrinology, Washington Hospital Center, Washington, District of Columbia.
2. Department of Endocrinology and Diabetology, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Torun, Bydgoszcz, Poland.
3. Division of Nuclear Medicine, Department of Medicine, Washington Hospital Center, Washington, District of Columbia.
4. Biostatistics and Epidemiology Department, MedStar Health Research Institute, Hyattsville, Maryland.
5. Division of Endocrinology and Medicine, Department of Medicine, Georgetown University Hospital, Washington, District of Columbia.