Clinical characteristics and survival of patients with diabetes mellitus following non-traumatic lower extremity amputation

Background: Diabetes mellitus-related lower extremity amputation is a major complication severely affecting patient survival and quality of life. Objectives: To analyze epidemiological and clinical trends in the incidence and survival of lower extremity amputations among diabetes patients. Methods: We conducted a retrospective observational cohort study of 565 consecutive diabetes patients who underwent their first non-traumatic lower extremity amputation between January 2002 and December 2009. Results: Major amputations were performed in 316 (55.9%) patients: 142 above the knee (25.1%) and 174 below (30.8%); 249 (44.1%) had a minor amputation. The incidence rates of amputations decreased from 2.9 to 2.1 per 1000 diabetes patients. Kaplan-Meier survival analysis showed that first year mortality rates were lower among patients with minor amputations (31.7% vs. 39.6%, P = 0.569). First year mortality rates following below-knee amputation were somewhat lower than above-knee amputation (33.1 vs.45.1%, respectively). Cox regression model of survival at 1 year after the procedure found that age (HR 1.06 per year, 95% CI 1.04–1.07, P < 0.001), above-knee amputation (HR 1.36, 95% CI 1.01–1.83, P = 0.045) and ischemic heart disease (HR 1.68, 95% CI 1.26–2.24, P < 0.001) significantly increased one year mortality risk. Conclusions: In this population-based study the incidence rate of non-traumatic amputations in diabetes patients between January 2002 and December 2009 decreased slightly. However, one year mortality rates after the surgery did not decline and remained high, stressing the need for a multidisciplinary effort to prevent amputations in diabetes patients.