[1] Univ Birmingham, Coll Med & Dent Sci, Birmingham, W Midlands, England
[2] Haberdashers Adams Grammar Sch, Birmingham, W Midlands, England
[3] Walsall NHS Trust, Dept Diabet & Endocrinol, Birmingham, W Midlands, England
[4] Sandwell & West Birmingham Hosp NHS Trust, Dept Diabet & Endocrinol, Birmingham, W Midlands, England
[5] Univ Hosp Birmingham NHS FT, Dept Diabet & Endocrinol, Birmingham, W Midlands, England
[6] Univ Birmingham, Inst Metab & Syst Res, Birmingham, W Midlands, England