Background:
Diabetic retinopathy is a common microvascular complication of diabetes. Previous research has shown that the macrovascular complications of diabetes, including stroke, are often comorbid with shared and, possibly, synergistic pathology.
Methods:
This is a secondary analysis of the subgroup of patients who enrolled in the ACCORD Eye study of ACCORD. The primary outcome is stroke during follow-up. The primary predictor was presence of diabetic retinopathy on the Early Treatment Diabetic Retinopathy Study Severity Scale as assessed from seven-field stereoscopic fundus photographs at study baseline. We fit adjusted Cox models to the primary outcome to provide hazard ratios for stroke and included interaction terms with the ACCORD randomization arms.
Results:
We included 2,828 patients with a mean (SD) age of 62.1 years and 61.8% were male. The primary outcome of stroke was met by 117 patients during a mean (SD) of 5.4 (1.8) years of follow-up. Diabetic retinopathy was present in 874/2,828 (30.9%) of patients at baseline, and was more common in patients with stroke versus without stroke (41.0 vs 30.5%, p=0.016). In the Cox model, adjusted for baseline patient age, gender, race, total cholesterol, Hgb A1c, smoking, and randomization arm, we found that diabetic retinopathy remained associated with incident stroke (HR 1.60, 95% CI 1.10-2.32, p=0.015) (Figure 1). This association was not affected by randomization to the ACCORD glucose intervention (p=0.305), lipid intervention (p=0.546), or blood pressure intervention (p=0.422).
Conclusion:
Diabetic retinopathy is associated with an increased risk of stroke, which suggests that the microvascular pathology inherent to diabetic retinopathy has larger cardiovascular implications.
Variability in grading diabetic retinopathy from stereo fundus photographs: comparison of physician and lay readers.
