A possible explanation behind the association between high baseline hemoglobin levels and low baseline hemopexin with aneurysm growth rate (but not AAA prevalence), could be a steady conversion of RBC bound Hb to toxic cell-free Hb/heme through gradually increasing hemolysis and decline in Hb scavenging capacity, along the AAA disease progression. This evidence concerns the gene GSTM1 and triple-A syndrome.