1. 1Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
2. 2Department of Surgery, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
3. 3Department of Surgery, North Shore Hospital, Waitemata District Health Board, Auckland, New Zealand
4. 4Department of Endocrinology, North Shore Hospital, Waitemata District Health Board, Auckland, New Zealand