A Retrospective Cohort Study on Diabetic Foot Disease: Ascertainment of Ulcer Locations by Age Group

Background and aims Diabetic foot ulcer location is a known independent predictor for cure with a better healing gradient proximal to distal. Although advanced age is one of the main factors associated with greater diabetic foot ulcer severity, there are no studies evaluating diabetic foot ulcer location specifically in the elderly population in an outpatient setting. This study evaluated diabetic foot ulcer location and age-group interactions in diabetic foot presentation. Methods A retrospective cohort study including adult patients with diabetic foot ulcers observed on their first visit to our center's Diabetic Foot Unit in 2018, divided into younger adults (YA) (18 to 64 years) and older adults (OA) (≥65 years). Results A total of 435 patients were included in the study with 159 (36.6%) in the YA, and 276 (63.4%) in the OA group. Neuro-ischemic diabetic foot ulcers were more frequent in the OA group (71.4% vs 43.4%, p<0.001). The number of patients with a history of diabetic foot ulcers was lower in the OA group (18.1% vs 25.2%, p=0.03). A smaller proportion of forefoot diabetic foot ulcers (74.9% vs 86.2%, p=0.007) and plantar location diabetic foot ulcers (9.4% vs 24.5%, p<0.001) occurred in the OA group. By univariate logistic regression analysis, we found two associations with older age: proximal (odds ratio (OR) 2.09 (1.23-3.53), p=0.006), and non-plantar (OR 3.13 (1.82-5.37), p<0.001) diabetic foot ulcer location. After adjusting for potential confounders in a multivariate analysis, older age lost the association to more proximal (OR 1.72 (0.94-3.15), p=0.081) and non-plantar (OR 1.78 (0.83-3.77), p=0.133) diabetic foot ulcer location. Conclusions There are essential age differences in diabetic foot ulcer presentation. The OA group more frequently presents neuro-ischemic diabetic foot ulcers with more proximal and non-plantar locations.