Diabetic Retinopathy May Be a Predictor of Stroke in Patients With Diabetes Mellitus.

Background: It is unclear whether diabetic retinopathy (DR) can be a predictor of stroke. In this research context, the objective of our study was to investigate whether there is a significant association between DR and stroke in diabetic patients by meta-analysis. Methods: After a systematic search of studies in electronic databases, we screened all studies reporting the risk of DR status and stroke incidence and calculated their odds ratios (ORs) and hazard ratios (HRs). The effects of type of diabetes and severity of DR were also considered for subgroup analysis. Results: We included 19 studies involving 45 495 patients. A pooled HR = 1.62 (1.28-2.06) were found for the risk of DR and stroke in diabetic patients. In a subgroup analysis performed on the type of diabetes, the results showed a significant association between stroke incidence and DR status in patients with type 2 diabetes (T2D) (OR: 1.78; 95% CI, 1.53-2.08), but this association was not conclusive in type 1 diabetes (T1D) (OR: 1.77; 95% CI, 0.48-6.61). The results of the subgroup analysis with diabetes severity showed that both mild and moderate nonproliferative diabetic retinopathy (NPDR) status and severe NPDR and worse status significantly increased the risk of stroke with HRs of 2.01 (1.45-2.78) and 2.27 (1.52-3.39), respectively. Conclusion: DR status in diabetic patients is associated with an increased risk of stroke. This correlation was robust in patients with T2D, but uncertain in T1D. Based on this result, we have perhaps found the new factor for stroke management, so we analyzed the necessity and advantages of considering DR as a factor for stroke screening and risk management in our studies.