In multivariate analysis including other predictors of anemia (i.e. age in years, sex, lead-in, Hb at baseline and albumin at baseline [10,12]), rs1127654 and rs7270101 major alleles were strongly and independently associated with early significant Hb decline (rs1127354, OR = 7.83[2.64–29.2], P = 6.0x10-4; rs7270101, OR = 3.28[1.65–6.95], P = 1.2x10-3). This evidence concerns the gene GSTM1 and anemia.