Diabetic foot syndrome: Evaluating the prevalence and incidence of foot pathology in Mexican Americans and non-Hispanic whites from a diabetes disease management cohort

OBJECTIVE - To report the incidence of diabetes-related lower-extremity complications in a cohort of patients enrolled in a diabetes disease management program. RESEARCH DESIGN AND METHODS - We evaluated screening results and clinical outcomes for the first 1,666 patients enrolled in a disease management program for a period of 24 months (50.3% men, aged 69.1 ± 11.1 years). RESULTS - The incidence of ulceration, infection, amputation, and lower-extremity bypass was 68.4, 36.5, 5.9, and 7.7 per 1,000 persons with diabetes per year. Amputation incidence was higher in Mexican Americans than in non-Hispanic whites (7.4/1,000 vs. 4.1/1,000; P = 0.003, odds ratio [OR] 1.8, 95% CI 1.2-2.7). The amputation-to-ulcer ratio was 8.7%. The incidence of Charcot arthropathy was 8.5/1,000 per year. Charcot was more common in non-Hispanic whites than in Mexican Americans (11.7/1,000 vs. 6.4/1,000; P = 0.0001, 1.8, 1.3-2.5). The prevalence of peripheral vascular disease was 13.5%, with no significant difference based on ethnicity (P = 0.3). There was not a significant difference in incidence of foot infection (P = 0.9), lower-extremity bypass (P = 0.3), or ulceration (P = 0.1) based on ethnicity. However, there were more failed bypasses in Mexican Americans (33%) than in non-Hispanic whites (7.1%). Mexican Americans were 3.8 times more likely to have a failed bypass (leading to an amputation) or be diagnosed as "nonbypassable" than non-Hispanic whites (75.0 vs. 44.0%; P = 0.01, 3.8, 1.2-11.8). CONCLUSIONS - The incidence of amputation is higher in Mexican Americans, despite rates of ulceration, infection, vascular disease, and lower-extremity bypass similar to those of non-Hispanic whites. There may be factors associated with failed or failure to bypass that mandate further investigation.