Non-invasive lower limb small arterial measures co-segregate strongly with foot complications in people with diabetes

Aims
It is unclear how well non-invasive lower-limb vascular assessments can identify those at risk of foot complications in people with diabetes. We aimed to investigate the relationship between a history of foot complication (ulceration or amputation) and non-invasive vascular assessments in people with diabetes.

Methods
Bilateral ankle–brachial index (ABI), toe brachial index (TBI) and continuous wave Doppler (CWD) were performed in 127 adults with diabetes (97% type 2; age 66.08 ± 11.4 years; 55% men; diabetes duration 8.8 ± 7.6 years; 28% on insulin therapy; 31% with foot complication history. Correlations were performed between known risk factors for, and documented history of, foot complication. Regression analysis was used to determine the effect of TBI on the likelihood of a prior foot complication.

Results
By logistic regression, the likelihood of foot complication history was highest in those with TBI < 0.6 (OR = 7.74, p = 0.001); then longer diabetes duration (OR = 1.06, p = 0.05). HbA1c did not independently predict history of foot complications (OR = 1.10, p = 0.356).

Conclusions
Likelihood of previous foot complication in this population was ~ 8 times higher when TBI was < 0.6. Such clinical risk profiling was not shown by other non-invasive measures. Prioritizing TBI as a measure of lower-limb vascular disease may be useful to prospectively identify those at risk of diabetic foot complications.