GSTM1 and type 2 diabetes mellitus: We found that the mean RBC lifespan of men (90.4 ± 30.4 days) was significantly lower than that of women (99.7 ± 29.5 days) in patients with T2DM, which may be the cause of the difference in Hb concentration between genders and also gender difference in T2DM complications [11,22].