[1] Univ Hull, Inst Rehabil, Kingston Upon Hull HU3 2PG, N Humberside, England
[2] Univ Aberdeen, Surg Metab & Nutr Unit, Aberdeen AB9 1FX, Scotland
[3] Univ Aberdeen, Dept Surg, Aberdeen AB9 1FX, Scotland
[4] Univ Aberdeen, Dept Pathol, Aberdeen AB9 1FX, Scotland
[5] Univ Aberdeen, Dept Med, Aberdeen AB9 1FX, Scotland
[6] Univ Nottingham, Dept Surg, Nottingham NG7 2RD, England