Incidence of diabetic foot ulcer in Japanese patients with type 2 diabetes mellitus: The Fukuoka diabetes registry

Abstract

AimsAlthough diabetic foot ulcer (DFU) is a serious diabetic complication, there have been no large-scale epidemiological studies of DFU in Japan. We prospectively investigated the incidences of DFU and limb amputation, the risk for developing DFU, and mortality in Japanese patients with type 2 diabetes. MethodsWe followed 4870 participants (mean age, 65 years) with type 2 diabetes attending an outpatient diabetes clinic for a median of 5.3 years (follow-up rate, 97.7%). The primary outcome was the development of DFU. ResultsDuring the follow-up period, DFU occurred in 74 participants (incidence rate, 2.9/1000 person-years) and limb amputation in 12 (incidence rate, 0.47/1000 person-years). DFU recurrence was observed in 21.4% of participants with history of DFU. History of DFU, chronic kidney disease (estimated glomerular filtration rate <60 mL/min/1.73 m2), depressive symptoms, and poor glycemic control were significant risk factors for developing DFU. Survival was significantly lower in participants with DFU and/or history of DFU compared with those without (5-year survival rates: with DFU, 87.7%, without DFU, 95.3%; P < .0001). The hazard ratio for death was 1.80 (95% confidence interval, 1.13–2.73, P = .014) in those with DFU and/or history of DFU in a multi-adjusted model. The most common cause of death was cardiovascular disease among participants with DFU, whereas it was malignant neoplasm among those without. ConclusionsIncidences of DFU and limb amputation were 0.3% and 0.05% per year in this Japanese cohort, respectively. Mortality significantly increased approximately 2-fold in those with DFU and/or history of DFU compared with those without.