Risk factors for amputation in diabetic patients: a case-control study.

BACKGROUND: The objective was to quantify risk factors for lower extremity amputation in patients with diabetes mellitus in an attempt to prevent amputation.
METHODS: This investigation was conducted as a case control study among diabetic males from 30-90 years of age with an average clinical duration of diabetes of 10 years: included were 80 cases which required a supracondyle amputation associated with diabetes mellitus, and 240 controls without injuries in the lower extremities. Measurements included the following: socioeconomic level, psychosocial risk factors, neuropathics, peripheral vascular factors, high blood pressure, smoking; environmental factors, health care, self care, and nutritional and metabolic factors in patients with diabetes mellitus before surgery. Statistically significant risk factors identified from analyses were: absence of lower leg vibratory perception (odds ratio = 14.9, 95% CI: 8.2-27.9); peripheral vascular disease (OR = 8.9, 95% CI: 5.3-15.9); high blood cholesterol > 450 mg (OR = 3.8, 95% CI: 2.9-8.6); low blood albumin < 3.5 g (OR = 7.9, 95% CI: 4.8-14.9); hyperurea blood nitrogen > 3.5 mg (OR = 3.1, 95% CI: 1.7-4.9); obesity (OR = 4.2, 95% CI: 1.51-9.8); time of evolution of diabetes mellitus > 10 years (OR = 3.47, 95% CI: 1.40-8.56); cracks in feet (OR = 3.45, 95% CI: 1.33-8.82); feet soaked in water (OR = 1.8, 95% CI: 1.07-2.93); ingrown toenails (OR = 2.0, 95% CI: 0.6-5.3), and lack of outpatient diabetes education (OR = 3.2, 95% CI: 1.5-6.7).
CONCLUSIONS: Different risk factors for lower extremity amputation in diabetes mellitus patients were quantified, identifying certain aspects of preventive impact (patient education, glycemic control, careful daily foot hygiene, and appropriate footwear) which may be applicable in environmental factors and which have the possibility of success in lowering the rate of risk for lower extremity amputation.