1. Department of Clinical Biochemistry, Central Pathology Laboratory, North Staffs Hospital NHS Trust, Hartshill Road, Stoke-on-Trent, ST4 7PA
2. Department of Clinical Biochemistry, University Hospital Birmingham NHS Trust, Selly Oak Hospital, Birmingham, UK
3. Regional Endocrine Laboratory, University Hospital Birmingham NHS Trust, Selly Oak Hospital, Birmingham, UK
4. Diabetes Centre, University Hospital Birmingham NHS Trust, Selly Oak Hospital, Birmingham, UK