The lower end risk elevation may represent an end-stage anemia phenomenon, whereas the low Hb-T2D association due to the chronic impairment of insulin action and low-grade inflammation, among others, that eventually lead to many long-term micro- and macrovascular complications [70], suggests more of a causal relationship specifically for the etiology of diabetes mellitus, since other MetS components did not show this clear negative association. This evidence concerns the gene INS and type 2 diabetes mellitus.