Diabetic Retinopathy and Risk of Stroke: A Secondary Analysis of the ACCORD Eye Study

Abstract

Background and purpose: Diabetic retinopathy (DR) is a common microvascular complication of diabetes, which causes damage to the retina and may lead to rapid vision loss. Previous research has shown that the macrovascular complications of diabetes, including stroke, are often comorbid with DR. We sought to explore the association between DR and subsequent stroke events.

Methods: This is a secondary analysis of patients enrolled in the ACCORD Eye study (Action to Control Cardiovascular Risk in Diabetes). The primary outcome was stroke during follow-up. The exposure was presence of DR at study baseline. We fit adjusted Cox proportional hazards models to provide hazard ratios for stroke and included interaction terms with the ACCORD randomization arms.

Results: We included 2828 patients, in whom the primary outcome of stroke was met by 117 (4.1%) patients during a mean (SD) of 5.4 (1.8) years of follow-up. DR was present in 874 of 2828 (30.9%) patients at baseline and was more common in patients with than without incident stroke (41.0% versus 30.5%; P=0.016). In an adjusted Cox regression model, DR was independently associated with incident stroke (hazard ratio, 1.52 [95% CI, 1.05-2.20]; P=0.026). This association was not affected by randomization arm in the ACCORD glucose (P=0.300), lipid (P=0.660), or blood pressure interventions (P=0.469).

Conclusions: DR is associated with an increased risk of stroke, which suggests that the microvascular pathology inherent to DR has larger cerebrovascular implications. This association appears not to be mediated by serum glucose, lipid, and blood pressure interventions.

Keywords: cerebral hemorrhage; diabetes; follow-up studies; glucose; humans.

Figure 1.

Kaplan-Meier curves showing stroke events in patients without diabetic retinopathy at baseline (ETDRS 1–3) versus those with diabetic retinopathy (ETDRS ≥4).