[1] Univ S Manchester Hosp, Dept Clin Biochem, Manchester M23 9LT, Lancs, England
[2] Univ Leeds, Sch Med, Leeds LS2 9NL, W Yorkshire, England
[3] Christie Pathol Partnership, Manchester M20 4BX, Lancs, England
[4] Christie NHS Fdn Trust, Dept Endocrinol, Manchester M20 4BX, Lancs, England
[5] Univ Manchester, Manchester Acad Hlth Sci Ctr, Inst Human Dev, Ctr Endocrinol & Diabet, Manchester M13 9PL, Lancs, England