Retinal Vessel Diameter and the Incidence of Coronary Artery Disease in Type 1 Diabetes

PurposeTo examine the relationship between retinal vessel diameter and coronary artery disease (CAD) incidence in type 1 diabetes (T1D) using data from the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study.DesignProspective cohort study of childhood-onset T1D.MethodsData are from 448 participants who had retinal photographs taken at baseline examination (May 1986 to November 1988) and no history of laser photocoagulation. Computer-assisted grading was used to measure retinal arteriolar and venular caliber. CAD incidence (CAD death, myocardial infarction, revascularization/stenosis ≥50%, ischemic electrocardiogram, or physician-diagnosed angina) was ascertained over a median follow-up time of 18 years (range, 2 months to 20.5 years).ResultsMean baseline arteriolar and venular caliber were 180.0 μm (standard deviation [SD], 15.2 μm) and 273.3 μm (SD, 28.0 μm), respectively; 80 (17.9%) CAD events occurred during follow-up. After covariate adjustment for T1D duration, gender, hypertension, serum lipids, and smoking status, smaller arteriolar caliber was significantly associated with CAD (hazard ratio [HR], 1.42; P = .03), but larger venular caliber was not. A vessel diameter-gender interaction term was significant for arteriolar caliber (P = .006). Stratified by gender, smaller arteriolar caliber was significantly associated with the incidence of CAD in women (HR, 1.92; P = .004), but not men. Venular caliber was not associated with CAD in either gender.ConclusionSmaller arteriolar caliber may indicate an increased risk of CAD in women, but not men, with T1D. Additional studies are needed to further examine the role of microvascular disease in the pathogenesis of CAD in women with T1D.