INS and type 2 diabetes mellitus: Moreover, despite the strong evidence showing the causal association of Hcy level with the development of T2DM [30], the Prospective Investigation of the Vasculature study in Uppsala Seniors (PIVUS) cohort (n  =  1016) showed no evidence of a causal relationship of levels of plasma homocysteine with fasting glucose, fasting insulin, or T2DM [33].