The research on people with diabetes who develop foot ulcers are at more risk of dying prematurely than those without the complication:
In Su-jok medicine terms, the process of destruction of beta-cells is powered by energy of Burn (the autoimmune attack), which in sequence leaves the opposite energy of Cold=Yin in body, becoming a main diabetes energy.
Feet are controlled by energy of Cold=Yin in body energy mapping (ulcers formation has energy of Dryness behind, which is also involved in diabetes development).
Besides, feet are in Gomo=Yin part of body (below diaphragm).
So this shows that body destruction has reached the stage or is at pace to become life-threatening, and confirms the idea that this can be an indicator to that.
Additional proof of the above is the quoted statistics of death being from heart attack and stroke,
both caused exactly by pathogenic energy of Cold.