In hemodialysis patients, hypo hemoglobinemia and hypoalbuminemia are risk factors for death.[18] Although we did not find that positive death patients had lower Hb than surviving patients, the probability of conversion to severe and critical illness was significantly higher in positive surviving patients with anemia than those without anemia, implying that anemia is a risk factor for disease exacerbation. This evidence concerns the gene GSTM1 and anemia (phenotype).