title: Risk factors for amputation in patients with diabetes mellitus. A case-control study.
abstract: OBJECTIVE
  To identify and quantify risk factors for lower extremity amputation in persons with diabetes mellitus.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  A Veterans Affairs medical center.
  
  
  METHODS
  Eighty patients having amputation associated with diabetes and 236 diabetic controls without limb lesions were enrolled before surgery from the 21,167 inpatient care and outpatient surgical patients seen at the Seattle Veterans Affairs Medical Center during a 30-month period.
  
  
  METHODS
  Selected vascular, neuropathic, environmental, health care, self care, nutritional, metabolic, lifestyle, and psychosocial risk factors were measured in all patients before surgery.
  
  
  RESULTS
  Statistically significant risk factors identified from analysis included insufficient mean below-knee and foot cutaneous circulation (odds ratio, 161; 95% CI, 55.1 to 469); ankle-arm blood pressure index less than 0.45 (odds ratio, 55.8; CI, 14.9 to 209); absence of lower leg vibratory perception (odds ratio, 15.5; CI, 8.3 to 28.7); low levels of high-density lipoprotein (HDL) subfraction 3 less than or equal to 0.7 mumol/L (odds ratio, 4.9; CI, 2.9 to 8.3); and no previous outpatient diabetes education (odds ratio, 3.2; CI, 1.6 to 6.6). A logistic regression analysis done to control for the potentially confounding effects of age; race; socioeconomic status; diabetes duration, type, and severity confirmed these findings and added a statistically significant interaction between foot transcutaneous oxygen tension and peripheral vascular disease history. Clinical interventions to alter these risk factors were identified, including aggressive treatment of infection, diabetes education, protective footwear, and preventive footcare.
  
  
  CONCLUSIONS
  Multiple risk factors exist along the continuum of conditions and events leading to lower extremity amputation in diabetes. Modification of certain risk factors by patients and health professionals may reduce the risk for amputation and thus decrease the human and dollar costs that accompany limb loss in this prevalent chronic disease.
authors.affiliation: Health Services Research & Development, Seattle VA Medical Center, WA 98108.
authors.forename: G E
authors.initials: GE
authors.lastname: Reiber
authors.forename: R E
authors.initials: RE
authors.lastname: Pecoraro
authors.forename: T D
authors.initials: TD
authors.lastname: Koepsell
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical; D016022:Case-Control Studies; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000503:physiopathology; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007866:Leg / Q000503:physiopathology / Q000601:surgery*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012944:Social Support; D013223:Statistics as Topic