New research using data from a large UK database has confirmed the association between diabetic foot ulcers and an increased risk of death. Mortality rates of patients with a newly onset diabetic foot ulcer was 8% after 12 months, and 42% after five years. These rates were much higher than for people with diabetes without a foot ulcer, and could not be explained by other major diabetes complications. At any point in time, a person with a diabetic foot ulcer is three times more likely to die compared to their nonulcerated counterparts.
Whilst people with a diabetic foot ulcer do not die from the ulcer itself, it is still unclear how to explain this higher mortality risk. The authors postulate that additional, unmeasured factors likely exist, or that a foot ulcer is a marker of increased medical frailty necessitating increased healthcare provider vigilance in the care of the patient.
An important limitation of the study is the lack of information on ulcer characteristics and treatment. This is well-known limitation of using a major database, as information such as presence of infection, peripheral artery disease and ulcer size and depth is almost never captured as well.
More surprising is the lack of information with regard to amputation, especially because the authors have used the same database to investigate the association between amputation and death in another publication last year. This is a missed opportunity. Comparing the two papers shows similar 1-year mortality for ulcers and amputations (8% vs 9%), but surprisingly much lower 5-year mortality rates for amputation (42% for ulcers vs 27% for amputation). This contradicts wide held beliefs on amputation increasing the mortality of people with diabetic foot ulcers.
What is clear from these important findings, however, is that people who present themselves in your clinic with a diabetic foot ulcer need to be carefully managed. Their ulcer should be seen as a major warning sign of an increased risk of death, necessitating discussion of this with your patient and close follow-up.