1. Department of Diabetes and Endocrinology, Glan Clwyd Hospital, Rhuddlan Road, Bodelwyddan, Rhyl LL18 5UJ, UK
2. Department of Diabetes and Endocrinology, Wrexham Maelor Hospital, Croesnewyyd Road, Wrexham LL13 7TD, UK
3. Department of Respiratory Medicine, Wrexham Maelor Hospital, Croesnewyyd Road, Wrexham LL13 7TD, UK