Proliferative Diabetic Retinopathy in Type 2 Diabetes Is Related to Coronary Artery Calcium in the Veterans Affairs Diabetes Trial (VADT)

Abstract

Increasing evidence suggests that macrovascular disease and retinopathy may be more closely linked than previously believed. We determined the relationship between retinopathy and coronary atherosclerosis as measured by computed tomography-detectable coronary artery calcium (CAC). The cross-sectional association between CAC and retinopathy was assessed on a Veteran Affairs Diabetes Trial subsample of 204 subjects with a mean duration of type 2 diabetes of 12.3 +/- 8.3 years. Retinopathy was correlated with CAC (r = 0.19, P = 0.006). Median CAC increased across retinopathy categories: 197 in those with no retinopathy, 229 in those with microaneurysms only, 364 in those with mild nonproliferative diabetic retinopathy (NPDR), 300 in those with moderate to severe NPDR, and 981 in those with proliferative diabetic retinopathy (PDR). Stepwise multivariable linear regression analysis was performed to find a parsimonious subset of relevant risk factors to include along with PDR in predicting CAC. After adjustment for either this subset of standard factors (P = 0.047) or a more extensive panel of risk factors (P = 0.035), PDR was significantly associated with CAC. Moreover, using logistic regression, individuals with PDR were approximately sixfold more likely to have CAC >400 than those with no PDR, even after adjustment for other CVD risk factors. These data indicate an important relationship between retinopathy and extent of CAC and suggest the potential to identify and treat shared risk factors for these common micro- and macrovascular complications.