DPP4 and type 2 diabetes mellitus: Type 2 diabetes, pre-existing coronary, cardiovascular or peripheral atherosclerotic disease, >50 years, baseline HBA1c 6.5-8% (48-64mmol/L)Mean age 65 years.Exclusion: those on DPP4 inhibitor, GLP-1 agonist, Rosiglitzone during the preceding three months, >2SH episodes in the previous 12 months, eGFR <30 ml/minFollow-up median of 3 years