The 25-Year Cumulative Incidence of Lower Extremity Amputations in People With Type 1 Diabetes

Abstract

OBJECTIVE To examine the 25-year cumulative incidence of lower-extremity amputation (LEA) in people with type 1 diabetes. RESEARCH DESIGN AND METHODS Cumulative incidence of LEA was ascertained in Wisconsin Epidemiologic Study of Diabetic Retinopathy participants (n = 943) using the Kaplan-Meier approach accounting for competing risk of death. Relationships of baseline characteristics with incidence of LEA were explored using a proportional hazards approach with discrete linear regression modeling. RESULTS The overall 25-year incidence of LEA was 10.1%. In multivariate analyses (results reported as odds ratio; 95% CI), being male (3.90; 2.29–6.65), heavy smoking (2.07; 1.11–3.85), having hypertension (3.36; 1.91–5.93), diabetic retinopathy (2.62; 1.13–6.09), neuropathy (1.68; 1.02–2.76), and higher HbA1c (per 1% 1.40; 1.24–1.58) were independently associated with the incidence of LEA. CONCLUSIONS Our results show a high 25-year incidence of LEA and suggest that glycemic control and blood pressure control and preventing heavy smoking may result in reduction in its incidence.