1. University of Cambridge Metabolic Research Laboratories (R.K.S., D.B.S., S.O.), Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom;
2. Clinical Endocrinology Branch (E.K.C., P.G.), National Institute of Diabetes, Digestive and Kidney Diseases, Bethesda, Maryland 20892