Cognitive Performance and Diabetic Retinopathy: What Your Eyes Can Reveal About Your Brain

Abstract

Background: Diabetic retinopathy (DR) is a chronic diabetes complication. People with Type 2 Diabetes Mellitus (T2DM) have two times the risk for dementia, suggesting it is a new chronic diabetes complication Objective: Evaluate the association of DR with cognitive performance in a T2DM population. Methods: Cross-sectional study with 251 T2DM adults from whom socio-demographic, clinical, laboratory data, a screening test for depression symptoms [Patient Health Questionaire-9 (PHQ-9)], Mini-Mental State Examination (MMSE), Semantic Verbal Fluency Test, Trail Making Test A and B, Word Memory test were collected and performed. All cognitive test scores were converted into Global Cognition z-Score [GCS(z)]. The association between GCS(z) < 0 with DR was performed using a multivariate binary logistic regression model adjusted for age ≥ 65 years, school years ≤ 6 years, DM duration ≥ 10 years, depression symptoms score > 9 at PHQ-9, arterial hypertension, physical activity, diabetic retinopathy, macular edema, and cardiovascular disease. Results: After exclusions, the 251 eligible patients were 56.6% female, with a mean age of 61.1(±9.8) years, DM duration of 12.6(±8.9) years, and 7.6(±4.2) years of school education. DR prevalence was 46.5%. Multivariate Logistic Regression Model showed an association between DR and GCS(z) < 0, with odds ratio (CI95%) of 2.50 (1.18-5.34), adjusted for age, low education level, arterial hypertension and depression symptoms [OD and CI95% respectively: 5.46(2.42-12.34); 12.19(5.62-26.46); 2.55(0.88-7.39); 3.53(1.55-8.07)]. Conclusion: In this T2DM population, having DR increased the chance for worse cognitive performance even when adjusted for age, low education level, presence of arterial hypertension, and depression symptoms.