1. Division of Endocrinology and Metabolism (K.A.), A-8036 Graz, Austria;
2. Department of Anesthesia, Critical Care, and Pain Medicine (S.A.Q.), Boston, Massachusetts 02114;
3. Channing Division of Network Medicine and Pulmonary and Critical Care Division (A.A.L.), Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115;
4. Division of Pulmonary and Critical Care Medicine (F.K.G.), Boston, Massachusetts 02114;
5. Department of Internal Medicine, and Division of Endocrinology and Metabolism (T.R.P.), Department of Internal Medicine, Medical University of Graz, A-8036 Graz, Austria;
6. Department of Medicine, and Department of Emergency Medicine (C.A.C.), Massachusetts General Hospital, Boston, Massachusetts 02114;
7. Departments of Nutrition and Epidemiology (E.G.), Boston, Massachusetts 02115
8. Harvard School of Public Health, and The Nathan E. Hellman Memorial Laboratory (K.B.C.), Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115