In addition, this study reported that T2DM patients with well controlled glucose levels (HbA1c ≤ 7%) did not display any differences in DPP-4 activity following oral glucose tolerance test as compared to the T2DM with poor glycaemic control (HbA1C > 7%), inferring that the degree of hyperglycaemia has direct correlation to circulating DPP-4 activity [40]. This evidence concerns the gene DPP4 and type 2 diabetes mellitus.