Risk factors of diabetic foot ulcer in patients with type 2 diabetes: a retrospective cohort study.

Abstract

The aim of this study is to investigate the risk factors of diabetic foot ulcer (DFU) in patients with Type 2 diabetes. Baseline characteristics of DFU-free patients with Type 2 diabetes were retrospectively collected and DFU was identified during the follow-up. Incidence of DFU was calculated and cumulative incidence was estimated by Kaplan-Meier method. Cox regression model was used to explore factors associated with DFU. A total of 980 patients were included with a median follow-up time of 28.7 months. 259 (26.4%) patients developed DFU with an incidence rate of 11.3 per 100 person-years. The cumulative incidences of DFU at 1 year and 2 years during the follow-up were 5.4% (95% CI 3.9-6.9%) and 14.1% (95% CI 11.7-16.5%), respectively. Cox regression analysis indicated that factors associated with developing DFU included age (hazard ratio (HR)=1.06, 95% CI 1.05-1.07, per 1-year increase), body mass index (HR=1.05, 95% CI 1.02-1.07), higher level of education (HR=0.77, 95% CI 0.60-0.98), hypertension (HR=1.90, 95% CI 1.47-2.45), hyperlipidemia (HR=2.63, 95% CI 2.02-3.43), coronary heart disease (HR=2.88, 95% CI 2.22-3.75), heart failure (HR=2.47, 95% CI 1.91-3.20), stroke (HR=2.44, 95% CI 1.86-3.19), diabetic retinopathy (HR=1.86, 95% CI 1.40-2.48), diabetic kidney disease (HR=1.89, 95% CI 1.41-2.53), diabetic neuropathy (HR=1.73, 95% CI 1.31-2.30), poor glycemic control (HR=1.13, 95% CI 1.07-1.19, per 1% glycosylated hemoglobin increase), and course of diabetes (HR=1.01, 95% CI 1.00-1.01, per 1-month increase). The results showed a relatively high incidence of DFU, and revealed several baseline characteristics identified as risk factors of developing DFU.