In previous studies carried out in Tibet, an important relationship was observed among ferritin levels, high levels of Hb and Hct, and environmental factors that make the prevalence of diabetes higher in this population (Okumiya K et al., 2008; Okumiya K et al., 2010; Okumiya K et al., 2016; Okumiya K et al., 2022). This evidence concerns the gene GSTM1 and diabetes mellitus.