Why do so many diabetes people who have lost a limb or foot die within 15 yrs.?

Vascular disease: Limb loss in diabetes is often from a combination of nerve damage, which causes numbness, ulcerations, or deformities; and vascular disease with impaired blood flow to the lower legs. The vascular disease is usually not limited to the legs, it is a total body problem. We see higher rates of heart attack and stroke in this group. There is more kidney disease as well. All of these reduce longevity.

Disease everywhere: Foot infections is a reflection of how diabetes has severely damaged the circulation leading to the feet. But remember circulation is everywhere so diabetic disease is everywhere. And if you have disease everywhere, anything can fail. Commonly, the circulation to heart is affecte. In other words, heart disease, heart attacks.