Risk Factors for Diabetic Foot Ulcers and the Role of Thermal Imaging in Early Detection

Background and aim Diabetes is the main cause of foot ulcers and limb amputation. The primary aim of our study was to identify clinical risk factors for the development of foot ulcers in patients with diabetes. The secondary aim was to evaluate the benefits of using a thermal camera and AI to detect feet at high risk of developing foot ulcers. Methods A two-year prospective study was conducted including all diabetic patients admitted to the endocrinology department at Mohammed VI University Hospital of Agadir. Data were collected from patient records, and thermal imaging was performed in all diabetic patients, with or without foot ulcers, after obtaining informed consent. Results The study included 158 diabetic patients admitted to the endocrinology department at Mohammed VI University Hospital of Agadir. Foot ulcer prevalence was 14.6% (n = 23). In patients with ulcers, the average age was 51 years, with a predominance of males (56%) (n = 13); the average time since diagnosis of diabetes was 6.5 years. High blood pressure was found in 26% (n = 6) of the patients, hyperlipidemia in 30% (n = 7), smoking in 47% (n = 11), and overweight in 34% (n = 8), with an average body mass index of 27 kg/m², poor diabetes control with an average hemoglobin A1c of 11%, and a high average fasting blood glucose level of 3.6 g/L. Foot examination of patients with ulcers revealed neuropathy in 86% (n = 20) and peripheral artery disease with a low ankle-brachial index in 82% (n = 19). We found that 56% (n = 13/23) of the patients with ulcers had a positive thermal imaging delta on admission, with an average delta of 3.3 ± 0.6 °C. In the group of patients with ulcers, a statistically significant correlation was found with smoking (p = 0.001), overweight (p = 0.017), poor glycemic control (p = 0.002), diabetic retinopathy (p < 0.001), diabetic neuropathy (p < 0.001), peripheral artery disease (p < 0.001), and foot deformity (p < 0.001). Finally, high thermal delta was found to be significantly more common in the ulcer group (p < 0.001). Conclusions Evaluating a foot at risk of ulceration requires time and trained medical staff, making thermal imaging cameras useful for detecting hyperthermia 15 days before an ulcer appears. The assessment of a diabetic foot at risk of developing an ulcer requires a physical examination to identify the main risk factors in our study: neuropathy, arteriopathy, and foot deformity. Hyperthermia detected by a thermal imaging camera is a new marker that may enable the early detection of foot ulcers, allowing earlier intervention to prevent amputations.