[1] Ajman Univ, Coll Med, POB 346, Ajman, U Arab Emirates
[2] Milton Keynes Univ Hosp NHS Fdn Trust, Dept Med, Milton Keynes MK6 5LD, England
[3] Milton Keynes Univ Hosp NHS Fdn Trust, HIV Metab Clin, Milton Keynes MK6 5LD, England
[4] Milton Keynes Univ Hosp NHS Fdn Trust, Dept Geriatr Med, Milton Keynes MK6 5LD, England
[5] Univ Buckingham, Fac Med & Hlth Sci, Buckingham MK18 1EG, England