This might explain the fact that both average Hb-A1c and Hb-A1c variability were associated with lower limb vascular event(s) (including also lower limb revascularization) and particularly the correlation of Hb-A1c variability, but not average Hb-A1c, with ulceration/gangrene alone. Here, GSTM1 is linked to gangrene.