GSTM1 and anemia (phenotype): As per the results demonstrated in Table 5, among the subjects without anemia (as Hb ≥ 11 g/dL), a 1 SD increase in serum iron demonstrated a 17.9% reduction in the risk of RRT (HR 0.821; 95% CI 0.687 to 0.980) as well as a 14.6% decrease in RRT combined with a 50% decline in eGFR (HR 0.854; 95% CI 0.749 to 0.975).