Factors predicting lower extremity amputations in patients with type 1 or type 2 diabetes mellitus: a population-based 7-year follow-up study

Objectives, The aim of the study was to find factors predicting lower extre mity amputation in patients with type 1 or type 2 diabetes mellitus through a year follow-up period. Design. Follow-up study, Subjects. Altogether 733 diabetic patients, aged 10-79 years, were drawn fr om the national drug reimbursement register. Methods. At baseline, the patients underwent a pediatric, circulatory and n europhysiological examination. Seven years later a follow-up study was perf ormed based on clinical and register data. Patient data for those who died during the followup were collected from hospital records and death certific ates. All amputations were recorded. The patients with amputation were comp ared with the other patients and also, in a case-control manner, by taking three nonamputated patients matched by sex, type of diabetes, and age for e ach patient with amputation. Results. The number of amputations was 25 in the sample. Compared with all patients without amputation, patients with amputation differed in altogethe r 24 variables concerning diabetes and its complications, Compared with the matched nonamputated patients, the amputated patients had longer duration of diabetes, lower ankle/brachial pressure index (ABI), more often history of retinopathy, nephropathy, and hypertension, more often visual handicap, elevated serum creatinine level, abnormal neurophpsiological indices and el ectrophysiological findings. In the logistic regression analysis, vibration perception threshold, low ABI, history of retinopathy, visual handicap, an d male sex were independently associated with lower extremity amputation. Conclusions. Lower extremity amputations were strongly associated with reti nopathy, nephropathy, and neuropathy. The presence of any of these complica tions should lead to intensified actions in order to prevent amputations. A s far as arterial circulation is concerned, claudication or absent peripher al pulses were not good predictors of amputation, whereas low,ABI, despite its known weaknesses, was a reliable indicator of future amputation.