The aim of this study was to investigate the role of systolic blood pressure (SBP) and diastolic blood pressure (DBP) in the development of diabetic retinopathy (DR) in type 1 and type 2 diabetes and to determine the differences between these two types of diabetes. This cross-sectional study included 84 patients with type 1 diabetes (T1DM) and 107 patients with type 2 diabetes (T2DM). Ophthalmologic retinal examination included indirect slit-lamp fundoscopy, color fundus photography according to EURODIAB (EUROpe and DIABetes) protocol and optical coherence tomography. Blood pressure was measured with a mercury sphygmomanometer after a 10-minute rest period. In T1DM, DR was positively associated with SBP (p = 0.035), HbA1cmedian (p < 0.001) and hypertensive retinopathy (p < 0.001), while in T2DM DR was positively related only to HbA1cmedian (p = 0.021). Binary logistic regression analysis (no DR/DR) showed that diabetes duration and HbA1cmedian were the main predictors of DR in both types of diabetes. In contrast, SBP (OR = 1.05, p = 0.045) and hypertensive retinopathy (OR = 3.75, p < 0.001) were the main predictors/indicators of DR only in T1DM. In conclusion, blood pressure is associated with DR in type 1 but not in type 2 diabetes.
Keywords: blood pressure; retinopathy; risk factors; type 1 and type 2 diabetes.