1. Department of Medicine, Division of Geriatrics, UCLA, 10945 Le Conte Ave, Suite 2339, Los Angeles, CA 90095, United States
2. Department of Medicine, Endocrine Unit, Massachusetts General Hospital, 50 Blossom St, Boston, MA 02114, United States
3. Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, 4420 Bayard Street, Suite 600, Pittsburgh, PA 15260, United States