The Independent Contributions of Diabetic Neuropathy and Yasculopatny in Foot Ulceration: How great are the risks?
- Marguerite J McNeely, MD,
- Edward J Boyko, MD,
- Jessie H Ahroni, MN,
- Victoria L Stensel,
- Gayle E Reiber, PHD,
- Douglas G Smith, MD and
- Roger E Pecoraro, MD†
- Medical Service, Seattle Veterans Affairs Medical Center
- Health Services Research and Development Program, Seattle Veterans Affairs Medical Center
- Division of General Internal Medicine, University of Washington Seattle, Washington
- Department of Medicine, School of Medicine, the Department of Epidemiology, University of Washington Seattle, Washington
- School of Public Health and Community Medicine, and the Department of Orthopedic Surgery, University of Washington Seattle, Washington
- Address correspondence and reprint requests to Edward J. Boyko, MD, MPH, Section of General Internal Medicine (111M), Veterans Affairs Medical Center, 1660 S. Columbian Way, Seattle, WA 98108.
Abstract
OBJECTIVE To describe the relative contributions of neurological and vascular abnormalities to the overall risk of diabetic foot ulceration.
RESEARCH DESIGN AND METHODS A case-control study of diabetic veterans from the Seattle Veterans Affairs Medical Center was conducted using data collected from 46 patients with diabetic foot ulcers and 322 control subjects. Neuropathy was determined by vibratory, monofilament, and tendon reflex testing. Macro-vascular disease was measured by ankle-arm blood pressure index, and cutaneous perfusion was measured by transcutaneous oxygen tension (TcPO2) on the dorsal foot. A multi variate logistic regression model was used to adjust for confounding variables and to calculate the odds ratios (ORs) for each independent risk factor.
RESULTS Three variables were significant independent predictors of foot ulceration: absence of Achilles tendon reflexes (adjusted OR 6.48, 95% confidence interval [CI] 2.37–18.06), insensate to the 5.07 monofilament (adjusted OR 18.42, 95% CI 3.83–88.47), and TcPO2 <30 mmHg (adjusted OR 57.87, 95% CI 5.08–658.96). Absent vibratory sensation and low ankle-arm blood pressure index were not significant independent risk factors.
CONCLUSIONS Both neuropathy and vasculopathy are strong independent risk factors for the development of diabetic foot ulcers. In our model, the strongest risk factor is impaired cutaneous oxygenation. However, in the clinical setting, sensory examination with a 5.07 monofilament probably remains the single most practical measure of risk assessment.
- Received April 29, 1994.
- Revision received September 22, 1994.
- Accepted September 22, 1994.
- Copyright © 1995 by the American Diabetes Association
