[1] Res Consortium, Andover, England
[2] Oxford Ctr Diabet Endocrinol & Metab, Oxford, England
[3] Univ Hosp North Midlands NHS Trust, North Midlands & Cheshire Pathol Serv, Dept Clin Biochem, Stoke On Trent, Staffs, England
[4] Keele Univ, Sch Med, Keele, Staffs, England
[5] Walsall Manor Hosp, Black Country Pathol Serv, Walsall, W Midlands, England
[6] Salford Royal Hosp, Salford, Lancs, England
[7] Univ Warwick, Warwick Med Sch, Warwick, W Midlands, England
[8] Univ Manchester, Sch Med, Manchester, Lancs, England
[9] Univ Manchester, Manchester Acad Hlth Sci Ctr, Manchester, Lancs, England