Foot ulcer location is an independent risk determinant of mortality in people with diabetes

In a recently published study in the journal Diabetic Medicine, we reported a very high long-term mortality rate in individuals presenting with a diabetes foot ulcer, with mortality rates greater for those with a hind foot ulcer than foot ulcers in other locations (Schofield et al, 2021). We also reported a close relation between risk of sepsis/renal failure and mortality in people with a foot ulcer.

The increased mortality rate associated with hind foot versus fore foot ulcers highlights the more serious nature of ulcers at that location – likely associated with poorer tissue perfusion in patients with such an ulcer location. Also, hind foot ulceration is a marker of poorer overall health, with reduced mobility being a consequence of that poor health.

It has previously been demonstrated that the 5-year mortality rate for diabetes with foot ulceration is around 40% (Apelqvist et al, 1993; Walsh et al, 2016). The results in our study are of a similar order of magnitude. It is likely that the higher mortality rates observed occur as a result of cardiovascular and non-cardiovascular complications of diabetes, such as sepsis, as reported here.

There are some substantive things that we can do to reduce the risk. Notably, a study by Young et al (2008) showed that an aggressive programme of cardiovascular risk management can reduce mortality rates to as low as 26% in individuals with diabetes foot ulceration. The programme included treatment with aspirin or clopidogrel, unless otherwise contraindicated, and targeted antihypertensive treatment with an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker, plus beta-blockers for all patients with existing cardiovascular disease or in whom blood pressure was still uncontrolled despite ACE inhibition. Our findings again provide evidence in support of addressing all risk factors as soon as people present with a foot ulcer. All measures must be taken to achieve and sustain good glycaemic control. It is incumbent on all healthcare professionals involved in looking after people with diabetes to bear this in mind if they meet someone with a foot ulcer.