Depression predicts first but not recurrent diabetic foot ulcers

Aims/hypothesis This study examined the relationshipbetween symptoms of depression and the development ofdiabetic foot ulcers.Methods Participants were 333 patients (71%male; mean age62 years; 73% with type 2 diabetes) with diabetic peripheralneuropathy (DPN), but without peripheral vascular disease(PVD). Severity of DPN and the presence of PVD wereassessed by clinical examination. Depression, other diabetescomplications and foot self-care were assessed by self-report.Cox regression tested whether depression was an independentpredictor of foot ulceration over 18 months, whether thisrelationship was moderated by foot ulcer history, and whetherfoot self-care mediated this relationship.Results During follow-up, 63 patients developed a foot ulcer.Those with prior foot ulcers had more than four-fold greaterrisk of subsequent foot ulceration compared with thosewithout a history of foot ulcer. A significant interaction effectshowed that depression was significantly related to thedevelopment of first but not recurrent foot ulcers. Thisrelationship was independent of biological risk factors. Inthe final model, each standard deviation increase in depressionsymptoms was significantly associated with increased risk ofdeveloping first foot ulcers (HR 1.68, 95% CI 1.20–2.35),while foot self-care was associated with lower risk (HR 0.61,95% CI 0.40–0.94). Foot self-care did not mediate therelationship between depression and foot ulceration.Conclusions/interpretation These data suggest that depressionis associated with increased risk of first foot ulcers inDPN patients and that this relationship is independent ofbiological risk factors and foot self-care. Interventions thattarget depression and foot self-care before the developmentof foot ulcers may maximise the likelihood of successfulprevention of foot ulceration