Abstract
Abstract: :
Purpose: To examine the association of generalized retinal arteriolar narrowing with incidence of lower extremity amputation (LEA) in a cohort with diabetes. Methods: Baseline examinations were performed in a cohort of 996 persons with younger onset diabetes (diagnosed before age 30 years and using insulin). History of LEA was obtained at baseline and at 4, 10, 14, and 20-year follow-up examinations. The cumulative 20-year incidence of the first LEA was calculated by the product-limit method in 906 persons with follow-up information. For measurement of generalized retinal arteriolar narrowing, fundus photographs obtained at baseline were digitized, and the diameters of individual retinal vessels were measured by a standard protocol and summarized by a computer program. Generalized arteriolar narrowing was expressed as an arteriole-to-venule ratio (AVR) which is an estimate of the relative diameter of the arterioles with respect to the venules. Generalized narrowing was defined as the lowest 25% of the AVR. Measurements were obtained in at least one eye of 820 persons. Results: The 20-year cumulative incidence of LEA was 9.9%. The unadjusted risk of LEA was higher in persons with generalized narrowing compared to those without (15.7 vs 5.7%, relative risk (RR) 2.99, 95% confidence interval (CI) 1.79-4.99). After controlling for age and sex, a similar result was found (RR 2.73, 95% CI 1.60-4.68). With further control for glycosylated hemoglobin, diastolic blood pressure, and history of sores and ulcers of the feet and ankles, the relationship was attenuated but still statistically significant (RR 1.89, 95% CI 1.06-3.35). Conclusions: In persons with diabetes, generalized retinal arteriolar narrowing may reflect damage to the microvasculature which manifests itself elsewhere in the body as lower extremity amputations.
Keywords: 387 diabetes • 353 clinical (human) or epidemiologic studies: outcomes/complications • 355 clinical (human) or epidemiologic studies: risk factor assessment