Retinal vascular changes and 20-year incidence of lower extremity amputations in a cohort with diabetes

Abstract

Objective: To examine the association of retinal vascular changes with the incidence of lower extremity amputations (LEAs) in a cohort with diabetes mellitus. Methods: Baseline examinations were performed in a cohortof996personswithdiabetesdiagnosedbeforethe age of 30 years and using insulin. History of LEAwas obtained at baseline and at 4, 10, 14, and 20 years. The cumulative 20-year incidence of first LEA was calculated by the product-limit method in 906 persons with follow-up information. Retinal arterioles and venules were measured on digitized fundus photographs obtained at baseline by a standard protocol. Generalized arteriolar narrowingwasdefinedasthelowest25%ofthearteriolevenuleratio.Measurementswereobtainedinatleastone eye for 820 persons. Focal arteriolar narrowing and arteriovenous nicking were also determined from fundus photographs by a standard protocol. Results:The 20-year cumulative incidence of LEAs was 9.9%.TheunadjustedriskofundergoingaLEAwashigher in persons with generalized arteriolar narrowing than in those without it (15.7% vs 5.7%; odds ratio [OR], 3.08; 95% confidence interval [CI], 1.60-4.68), and in personswithfocalnarrowing(33.1%vs6.8%;OR,5.59;95% CI,3.27-9.54).Theresultsforarteriovenousnickingwere not significant. With control for age, sex, levels of glycosylated hemoglobin, diastolic blood pressure, and history of ulcers of the feet, the relationships were attenuated but still statistically significant for both generalized narrowing (OR, 1.89; 95% CI, 1.06-3.35) and focal narrowing (OR, 3.56; 95% CI, 1.87-6.78).