Diabetes-related lower-extremity amputation incidence and risk factors: a prospective seven-year study in Costa Rica

Abstract

To analyze the incidence and determinants of lower-extremity amputation (LEA) in people with diabetes in a low-income community in Costa Rica. Data on LEA incidence were collected during a seven-year follow-up (2001-2007) in a diabetes patient cohort (n = 572). Risk factors were analyzed using the Cox proportional hazards regression model and baseline variables from the year 2000 (socio- demographic characteristics, comorbidity, metabolic control, treatment, and chronic microvascular complications). LEA incidence was 6.02 per 1 000 person-years (8.65 in men and 4.50 in women). Known risk factors (sex, years of diabetes, elevated glycated hemoglobin [HbA1c], retinopathy, insulin therapy, and prior amputation) were highly significant. Those most likely to undergo LEA among Costa Rican diabetic patients were men with 10 or more years of diabetes and average HbA1c > 8% who used insulin and had diabetic retinopathy. Patients on insulin therapy were at greatest risk, especially those with a previous amputation. Diabetic patients with the above-mentioned profile should be considered to be at very high risk of LEA and followed closely by the health care system.