To assess the efficacy and safety of a 24-week treatment with sitagliptin , a highly selective once-daily oral dipeptidyl peptidase-4 ( DPP-4 ) inhibitor , in patients with type 2 diabetes who had inadequate glycaemic control [ glycosylated haemoglobin ( HbA ( 1c ) ) > or = 7.5 % and < or = 10.5 % ] while on glimepiride alone or in combination with metformin .
