INS and type 2 diabetes mellitus: Sun et al and Jehn et al in two different study populations reported that subjects with higher levels of ferritin were at higher risk of MetS and type 2 diabetes.23,24 Low ferritin is an indicator of iron deficiency anemia.1 Furthermore, a recent study on male blood donors revealed that serum levels of ferritin and iron are adversely associated with insulin sensitivity,25 which is a key element of MetS.26 Considering iron deficiency as the main cause of anemia in our subjects based on MCV and MCHC, we showed the negative association between anemia and MetS.