Diabetic foot ulcer prevention depends heavily on daily behaviour: inspecting the feet, wearing protective footwear, checking glucose, and seeking care early when a problem appears. Each of these tasks draws on memory, attention, planning, and judgment. Cognitive impairment is therefore a plausible and under-recognized contributor to ulcer risk, delayed presentation, and poor healing. This article reviews what the published evidence says about cognition in people with diabetic foot disease, and where that evidence remains limited.
Cognitive Function in People With Diabetic Foot Ulcers
One of the most cited studies is a case-control investigation by Natovich and colleagues in Diabetes Care (2016). The authors compared 99 adults aged 45 to 75 with diabetic foot ulcers against 95 adults with type 2 diabetes and no ulcer, matched for diabetes duration and sex. Using a computerized neuropsychological battery, they found significantly lower scores in the ulcer group (P < 0.001) across memory, executive function, reaction time, attention, and psychomotor domains. Estimated premorbid cognition did not differ, which suggests the ulcer group had experienced a decline relative to their own earlier ability. The differences persisted after adjustment for depression and smoking. The authors concluded that people with foot ulcers may have fewer cognitive resources available for self-management.
A later cross-sectional study from Perth, Australia, by Siru and colleagues in the Journal of Clinical Medicine (2021), produced a more nuanced picture. Among 55 people attending multidisciplinary foot clinics and 56 people with type 2 diabetes but no ulcer, mean screening scores on the Mini-Mental State Examination and Montreal Cognitive Assessment did not differ significantly between groups. However, roughly half of all participants showed at least mild impairment on the Montreal Cognitive Assessment, indicating that reduced cognition is common in outpatient diabetes populations regardless of ulcer status. Interestingly, the clinic-based ulcer group reported better foot self-care and glycemic control, which may reflect the effect of ongoing specialist education. Differences in study design, sampling, and testing instruments likely explain the discordant findings between the two studies.
Cognition and Ulcer Outcomes
Evidence linking cognition to healing and amputation is more limited. A retrospective cohort analysis presented by Girgis at the Symposium on Advanced Wound Care followed patients with diabetic foot ulcers at a single academic centre for two years. Patients with a recorded diagnosis of cognitive impairment had more frequent non-healing at 3 and 6 months, more foot-related admissions, and a higher risk of major amputation. The investigator suggested that more advanced ulcers at presentation may account for part of the amputation signal, and the study did not measure adherence directly. As a conference presentation based on diagnostic codes in medical records, it should be viewed as hypothesis-generating rather than definitive.
Why Cognition May Matter for Foot Care
Several mechanisms are plausible. Daily foot inspection requires remembering to perform it, recognizing an abnormal finding, and acting on it. Offloading devices and therapeutic footwear require sustained adherence, even when neuropathy removes the pain that would otherwise discourage weight-bearing. Complex dressing regimens, medication schedules, and follow-up appointments add further demands. Shared vascular and metabolic risk factors, including chronic hyperglycemia and microvascular disease, may also contribute to both cognitive decline and foot complications, so the relationship is unlikely to be one-directional. None of the studies above establish causation, and residual confounding from age, depression, education, and disease severity remains possible.
Implications for Education and Prevention
The IWGDF 2023 guideline on prevention of foot ulcers in people with diabetes (published in Diabetes/Metabolism Research and Reviews) recommends that people at risk be educated about foot self-care and about not walking without suitable foot protection, and that those at moderate to high risk be educated about wearing therapeutic footwear. The guideline does not make cognition-specific recommendations. Even so, the findings above support several practical, evidence-informed considerations: education delivered in short, repeated, and demonstrated steps rather than a single session; involvement of caregivers or family members when screening suggests impairment; simplified regimens; and routine consideration of cognitive status when planning offloading and follow-up. Whether formal cognitive screening improves foot outcomes has not been tested in trials.
Key Takeaways
Cognitive impairment is common among adults with diabetes, and at least one well-designed case-control study found broader cognitive deficits in those with active foot ulcers. Other studies have not found a consistent difference, and data on healing and amputation outcomes are preliminary. Self-care demands in diabetic foot disease are substantial, so recognizing cognitive limitations is a reasonable component of individualized education and risk assessment. Prospective studies that measure cognition, adherence, and clinical outcomes together are needed.
References
- Natovich R, Kushnir T, Harman-Boehm I, et al. Cognitive dysfunction: part and parcel of the diabetic foot. Diabetes Care. 2016;39(7):1202-1207.
- Siru R, Burkhardt M, Davis W, et al. Cognitive impairment in people with diabetes-related foot ulceration. Journal of Clinical Medicine. 2021;10(13):2808.
- Girgis C. Cognitive impairment and diabetic foot ulcer outcomes: retrospective cohort analysis. Presented at the Symposium on Advanced Wound Care (SAWC) Fall meeting, 2024.
- Bus SA, et al. Guidelines on the prevention of foot ulcers in persons with diabetes (IWGDF 2023 update). Diabetes/Metabolism Research and Reviews. 2024;40(3):e3651.
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