Date Published: January 17, 2019
Publisher: Public Library of Science
Author(s): Ola Hjelmgren, Ulf Strömberg, Karl Gellerman, Anders Thurin, Madeleine Zetterberg, Göran Bergström, Rayaz A. Malik.
To study if retinopathy increases the risk of stroke recurrence in stroke patients with type 2 diabetes. Also, to study if stroke patients with type 2 diabetes have an increased risk of stroke recurrence compared to non-diabetics and if stroke patients with type 2 diabetes, regardless of retinopathy, have a higher incidence of carotid stenosis. Also, to study if stroke patients with type 2 diabetes retinopathy have increased incidence of carotid stenosis.
We included 445 patients with type 2 diabetes mellitus and a matched control group of 445 patients without diabetes, who had all suffered their first stroke or TIA. Information on retinopathy, risk factors and stroke recurrence were obtained from registers and medical records.
Retinopathy did not increase the risk of stroke recurrence in diabetes patients, HR 0.89 (0.51–1.53), p = 0.67. The risk of stroke recurrence was not increased in diabetics compared to non-diabetes. Diabetes patients had an increased prevalence of carotid stenosis compared to non-diabetics, 1.69 (1.15–2.48), p = 0.008. The prevalence of carotid stenosis in diabetics with retinopathy was not increased compared to diabetics without retinopathy.
Retinopathy is not a predictor of stroke recurrence or carotid stenosis in type 2 diabetes patients.
Patients with type 2 diabetes mellitus (T2DM) have an increased risk of ischemic stroke and other cardiovascular diseases . Furthermore, patients with diabetic retinopathy (DR), a common microvascular diabetes complication affecting the retinal vessels of the eye , have an even higher risk of ischemic stroke (IS) [3–9], as well as higher overall cardiovascular and all-cause mortality [3, 10, 11]. Embolic stroke from carotid artery stenosis (CAS) constitutes an important etiological subtype of ischemic stroke , and carotid surgery of symptomatic CAS reduces the risk of recurrent stroke . The risk of recurrent stroke in patients with diabetes and CAS appears to be even further increased . Interestingly, it has been suggested that the microvascular pathologies found in the retina of patients with DR may also be present in atherosclerotic plaque . In fact, a recent study found signs of increased carotid vasa vasorum vascularization in patients with retinopathy . This is of pathophysiological interest since the vascularization of atherosclerotic plaques has been suggested to both increase the growth rate of plaques and result in a more vulnerable plaque phenotype, suggesting a higher risk of stroke .
This is the first study to examine the relationship between DR, CAS and recurrent stroke in an exclusively symptomatic population. In this study, T2DM was associated with an increased prevalence of CAS, but the association with recurrent stroke was not significant. Furthermore, DR was not associated with CAS and not associated with recurrent stroke.
In summary, our study of T2DM patients with their first ischemic stroke or TIA found no association between DR and recurrent stroke and no significant association between diabetes and recurrent stroke. We found an association between the presence of CAS and diabetes but no association between DR and the presence of CAS. We conclude that DR, in this study, is not an indicator of the presence of carotid artery stenosis or the risk of recurrent stroke.