Amputation and mortality in new-onset diabetic foot ulcers stratified by etiology

Abstract

Objective: Foot ulcers and their complications are an important cause of morbidity and mortality in diabetes. The present study aims to examine the long-term outcome in terms of amputations and mortality in patients with new-onset diabetic foot ulcers in subgroups stratified by etiology.

Research design and methods: Patients presenting with new ulcers (duration <1 month) to a dedicated diabetic foot clinic between 1994 and 1998 were studied. Outcomes were determined until March 2000 (or death) from podiatry, hospital, and district registers. Baseline clinical examination was done to classify ulcers as neuropathic, ischemic, or neuroischemic. Five-year amputation and mortality rates were derived from Kaplan-Meier survival analysis curves.

Results: Of the 185 patients studied, 41% had peripheral vascular disease (PVD) and 61% had neuropathy; 45%, 16%, and 24% of patients had neuropathic, ischemic, and neuroischemic ulcers, respectively. The mean follow-up period was 34 months (range 1-65) including survivors and patients who died during the study period. Five-year amputation rates were higher for ischemic (29%) and neuroischemic (25%) than neuropathic (11%) ulcers. Five-year mortality was 45%, 18%, and 55% for neuropathic, neuroischemic, and ischemic ulcers, respectively. Mortality was higher in ischemic ulcers than neuropathic ulcers. On multivariate regression analysis, only increasing age predicted shorter survival time.

Conclusions: All types of diabetic foot ulcers are associated with high morbidity and mortality. The increased mortality appears to be independent of factors increasing ulcer risk-that is, neuropathy and PVD-in patients with established foot ulcers.