[1] Christie Hosp, Diabet & Endocrinol, 550 Wilmslow Rd, Manchester M20 4BX, Lancs, England
[2] Salford Royal NHS Fdn Trust, Diabet & Endocrinol, Salford, Greater Manches, England
[3] Univ Teaching Hosp, Salford, Greater Manches, England
[4] Univ Manchester, Fac Med & Human Sci, Manchester, Lancs, England