Department of Diabetes and Endocrinology, St. Vincent's Hospital, Sydney, Australia. Department of Clinical Pharmacology and Toxicology, St. Vincent's Hospital, Sydney, Australia. Diabetes and Metabolism, Garvan Institute of Medical Research, Sydney, Australia. St. Vincent's Clinical School, University of NSW, Sydney, Australia. Department of Diabetes and Endocrinology, St. Vincent's Hospital, Sydney, Australia. j.greenfield@garvan.org.au. Diabetes and Metabolism, Garvan Institute of Medical Research, Sydney, Australia. j.greenfield@garvan.org.au. St. Vincent's Clinical School, University of NSW, Sydney, Australia. j.greenfield@garvan.org.au.