1. Section in Men's Health and Aging, Clinical Research Unit, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
2. Division of Endocrinology, Diabetes and Metabolism, University of Florida, Gainesville, Florida, USA.
3. Department of Internal Medicine, Mount Sinai Medical Center, Miami Beach, Florida, USA.
4. Division of Endocrinology, University of Miami, Miller School of Medicine, Miami, Florida, USA.