Risk factors associated with diabetic retinopathy in patients with diabetes mellitus type 2

BACKGROUND: Diabetes mellitus (DM) is associated with microvascular complications, such as diabetic retinopathy (DR). DR is one of the main causes of visual loss in individuals aged 20-64 years old. This study aims to investigate the independent associations between the stage of DR and a variety of possible risk factors, including years since DM diagnosis, HbA(1c )levels, the coexistence of hypertension, age and gender. FINDINGS: 120 patients were recruited in the Department of Internal Medicine, Veroia General Hospital, Veroia, Greece, and the DR stage was defined by an ophthalmologist. Afterwards, the DR association with the aforementioned factors was examined. Univariate and multivariate analysis (multivariate ordinal logistic regression) was performed. At the univariate analysis, there was a positive association between DR severity and age (Spearman's rho = 0.4869, p < 0.0001), years since DM diagnosis (Spearman's rho = 0.6877, p < 0.0001), HbA(1c )levels (Spearman's rho = 0.6315, p < 0.0001), history of hypertension (2.47 ± 1.37 vs. 0.50 ± 0.80 for patients without hypertension; p < 0.0001) and male sex (2.56 ± 1.41 vs. 2.05 ± 1.45 for female patients; p = 0.045, MWW). All these factors, except for age, retained their statistical significance at the multivariate ordinal logistic model. CONCLUSIONS: Years since DM diagnosis, hypertension, HbA(1c )levels and male sex are independently associated with severe DR. The effect of age seems to reflect a confounding association.