Prevalência da retinopatia diabética e seus fatores de risco em pacientes com diabetes tipo 1 no Brasil

Abstract

This study aims to evaluate the prevalence of diabetic retinopathy, its main risk factors and its relationship with cardiovascular disease and inflammatory factors in patients with type 1 diabetes in Brazil. This thesis is based on a multicenter study involving 1760 patients submitted to a questionnaire, laboratory and clinical examinations, including screening for diabetic retinopathy with indirect ophthalmoscopy and further classification into mild, moderate, severe nonproliferative diabetic retinopathy and proliferative diabetic retinopathy. Retinopathy was considered as vision threatening in severe nonproliferative, proliferative, and macular edema, and as referable in moderate, severe, proliferative, and macular edema. The results of the thesis were presented in scientific articles. The first article and a letter to the editor, both published, showed a 35% prevalence of diabetic retinopathy, the vision-threatening retinopathy in 12% and referable retinopathy in 18%. The main risk factors related to diabetic retinopathy, regardless of severity grouping were: duration of diabetes, glycated hemoglobin levels and elevated serum uric acid levels. Arterial hypertension was also related to the presence of diabetic retinopathy and the referable form. Chronic kidney disease has been associated with the vision-threatening diabetic retinopathy and the referable form. The third published article demonstrated that the presence of diabetic retinopathy can be considered an indicator of cardiovascular risk. The fourth article submitted demonstrated an association between serum C-reactive protein levels and proliferative diabetic retinopathy, but there was no relationship with the other inflammatory factors investigated (interleukin-6, vascular endothelial growth factor and tumor necrosis factor-⍺). We conclude that the prevalence of diabetic retinopathy in Brazil resembles the worldwide prevalence, as well as the main risk factors that were similar to those already established, except for uric acid, which probably due to its pro-oxidant characteristics, was also related to the presence of diabetic retinopathy. The association of diabetic retinopathy with cardiovascular disease suggests that patients with type 1 diabetes and diabetic retinopathy should be investigated for cardiovascular disease, and fundoscopy can help in identifying patients at risk for this important cause of mortality, especially in patients with diabetes. Regarding inflammatory factors, further studies are needed to evaluate the role of these cytokines in the pathophysiology of proliferative diabetic retinopathy.