The pooled SMD in RBC parameters in T2DM were as follows: RBC: -0.57 (10<sup>6</sup>/μL), Hb: -0.73 g/dL and HCT: -1.22%, Where as in T1DM RBC, Hb and HCT were -1.23 (10<sup>6</sup>/μL), -0.80 g/dL and -0.29%, respectively.<h4>Conclusion</h4>Patients with T2DM had significantly increased TLC counts, absolute neutrophil, basophil, lymphocyte, monocyte counts and relative counts of neutrophils and basophils in comparison to controls. Here, GSTM1 is linked to type 2 diabetes mellitus.