About half of all nontraumatic lower extremity amputations are performed on diabetic patients (1,2), and foot ulcers precede 71–84% of all lower extremity amputations (3,4). In the Caucasian population, 15% of diabetic patients will develop a foot ulcer during their lifetime (5), and 6–43% of diabetic patients with a foot ulcer will eventually progress to lower extremity amputation (3,4,6). To this author’s knowledge, there has not been any previous nationwide epidemiologic survey on diabetic foot problems in Taiwan, and the clinical outcomes of diabetic foot ulcers are still unknown.
To survey diabetic foot problems in the Taiwanese population, a total of 16,994 non–type 1 diabetic patients were randomly selected for telephone interview from a group covered by the National Health Insurance (>96% of the total population is covered by this health care system). They were questioned on whether they had diabetic foot problems, as indicated by ulcer, gangrene, or amputation on the lower extremities. Lifetime prevalence was calculated, and various risk factors were analyzed. A total of 12,531 case subjects (response rate 73.7%) were successfully interviewed. Diabetic foot problems were present in 369 patients (prevalence 2.9%) with 540 initiating events. Ulcers represented 86.7% of all initiating events. Approximately 26.9% of the ulcers progressed to gangrene or amputation, and ulcers preceded 71.9% of all amputations. In univariate analyses, diabetic foot problems were characterized by older age, male preponderance, longer duration of diabetes, smoking, poorer glycemic control, more insulin users, hypertension, hyperlipidemia, higher diastolic and systolic blood pressure, lower education level, and living in rural areas. In logistic regression, the multivariate-adjusted odds ratios (95% CI) were significant for men 1.461 (1.063–2.008); duration of diabetes 1.048 (1.033–1.063); insulin therapy 2.921 (2.199–3.881); education level (vs. a high school education or higher) 1.450 (1.089–1.931) and 2.194 (1.543–3.121) for elementary school and illiteracy, respectively; ex-smokers <5 years versus nonsmokers 1.645 (1.030–2.627); systolic blood pressure 1.019 (1.008–1.030); and hyperlipidemia 1.478 (1.117–1.956). In conclusion, diabetic foot problems are present in 2.9% of Taiwanese non-type 1 diabetic subjects. Although foot ulcers are less common among Taiwanese than Caucasian subjects, the outcomes are not better. Conventional risk factors for atherosclerosis are important, but particular attention should be focused on patients with a lower education level and those who use insulin.
