[1] Harvard Med Sch, Endocrine Unit, Massachusetts Gen Hosp, Boston, MA 02115 USA
[2] Univ Klinikum Dresden, Dept Med 3, Dresden, Germany
[3] Univ Klinikum Dresden, Ctr Hlth Aging, Dresden, Germany
[4] Mayo Clin, Div Endocrinol Diabet Metab & Nutr, Rochester, MN 55905 USA
[5] Univ Calif San Francisco, Dept Med, San Francisco, CA 94143 USA
[6] Univ Calif San Francisco, Dept Epidemiol & Biostat, San Francisco, CA USA
[7] Mayo Clin, Robert & Arlene Kogod Ctr Aging, Rochester, MN 55905 USA