Increased Mortality Associated with Diabetic Foot Ulcer

The objective of this study was to evaluate the relationship between foot ulceration and short-term mortality in veterans of the American military services with diabetes mellitus. A total of 725 diabetic subjects participated in a prospective study of risk factors for lower extremity complications between 1990 and 1994. Mean follow-up was 691.8 days (± SD 339.9, range 28–1436 days). Subjects who died during follow-up (n = 72) had a similar mean duration of diabetes to those who survived (12.6 years vs 11.2), but their mean age was greater (65.9 years vs 63.2, p = 0.026). The relative risk (RR) of death was 2.39 (95% confidence interval (CI) 1.13 to 4.58) in the subjects who developed foot ulcer (n = 88) compared to those who did not. The risk of death for those with foot ulcer was 12.1 per 100 person-years of follow-up compared to 5.1 in those without foot ulcer. Cox regression analysis demonstrated a greater than two-fold increased risk of death in ulcerated subjects after adjustment for age; diabetes type, duration, and treatment; glycosylated hemoglobin level; history of lower extremity amputation; and cumulative pack years smoked. Higher ankle–arm index was significantly related to lower mortality risk, independent of foot ulcer occurrence. We conclude that foot ulcer and lower extremity vascular disease are related to a higher risk of death in diabetic subjects. The reasons for this excess mortality require further investigation.