1. Department of Medicine, Division of Metabolism, Endocrinology, and Diabetes (N.H.E.), Ann Arbor, Michigan 48106
2. Department of Surgery, Division of Endocrine Surgery (D.T.H.), Ann Arbor, Michigan 48106
3. Department of Surgery (H.Y.), Ann Arbor, Michigan 48106
4. Department of Biostatistics (M.B.), Ann Arbor, Michigan 48106
5. Department of Medicine, Division of Metabolism, Endocrinology, and Diabetes and Division of Hematology/Oncology (M.R.H.), University of Michigan, Ann Arbor, Michigan 48106