A, C57BL/6 mice were fed control or HF diets for 1, 2 or 4 months. Age-matched LDLr-/- mice were fed the HF diet for 4 months. AAA incidence increased progressively with longer durations of HF-feeding in C57BL/6 mice (18%, 36% and 60% AAA incidence, respectively). AAA incidence was similar in both C57BL/6 and LDLr-/- mice fed a HF diet for 4 months (57% and 60%, respectively). B, AAA incidence was increased in ob/ob (76%) compared to ob/+ mice (32%). Data are mean ± SEM from n = 10/group. *, P < 0.05 vs ob/+. **, P < 0.05 compared to control, 1 month HF.