1. Endocrine Unit Massachusetts General Hospital/Harvard Medical School Boston MA USA
2. Department of Medicine III Universitätsklinikum Dresden Dresden Germany
3. Center for Healthy Aging Universitätsklinikum Dresden Dresden Germany
4. Division of Endocrinology, Diabetes, Metabolism, and Nutrition Mayo Clinic Rochester MN USA
5. Department of Medicine University of California, San Francisco San Francisco CA USA
6. Department of Epidemiology and Biostatistics University of California, San Francisco San Francisco CA USA
7. Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA