Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts. Electronic address: dsimonso@hsph.harvard.edu. Center for Metabolic and Bariatric Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts. Research Division, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts. Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts. Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Research Division, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts.