1. Endocrinology, Division of Medicine; University College London; Royal Free Hospital; London UK
2. Department of Surgery and Cancer; Imperial College London; St Mary's Hospital; London UK
3. Section of Investigative Medicine; Division of Diabetes, Endocrinology and Metabolism; Imperial College London; London UK
4. Department of Clinical Biochemistry; North West London Pathology; Charing Cross Hospital; London UK
5. Department of Surgery; Imperial College Healthcare NHS Trust; Hammersmith Hospital; London UK
6. Department of Endocrine Surgery; Imperial College Healthcare NHS Trust; Hammersmith Hospital; London UK