1. Department of Endocrinology and Nutrition, CIBER of Diabetes and Associated Metabolic Diseases, Health Sciences Research Institute and University Hospital Germans Trias i Pujol, 08916 Badalona, Spain
2. Diabetes Centre, Tameside Hospital NHS Foundation Trust, Ashton-under-Lyne OL6 9RW, UK
3. Manchester University and Manchester Metropolitan University, Manchester M13 9PL, UK
4. Sezione Dipartimentale Piede Diabetico, Dipartimento di Area Medica, Azienda Ospedaliero-Universitaria Pisana, 56124 Pisa, Italy
5. Department of Medicine, University of Pisa, Pisa, Italy
6. Phoenix VA Health Care System, Phoenix, AZ 85012, USA
7. Midwestern University, Glendale, AZ, USA