Renal function but not asymmetric dimethylarginine is independently associated with retinopathy in type 2 diabetes

Background. Asymmetric dimethylarginine (ADMA) is associated with macrovascular disease and possibly with microangiopathy in type 2 diabetes (T2DM). We tested the hypothesis that ADMA is related to diabetic retinopathy (DR) independently of macrovascular disease. Methods. This cross-sectional study included 127 T2DM patients selected to achieve equal distributions of patients with and without macrovascular disease in the groups with and without DR. Results. Patients with DR had increased ADMA, longer diabetes duration, and reduced glomerular filtration rate (GFR). ADMA correlated with GFR (ρ = -0.35; P < .001), diabetes duration (ρ = 0.19; P = .048), and age (ρ = 0.19; P = .033). Logistic regression analysis revealed an association of ADMA with DR. After adjustment for macrovascular disease, this association remained significant (OR 1.48; 95% CI: 1.02-2.15; P = .039). Inclusion of GFR and T2DM duration into the model abolished this significant relationship. GFR remained the only independent predictor for DR. A 10 mL/min/1.73 m(2) GFR decrease was associated with DR in a multivariate model (OR 1.30; 95% CI: 1.08-1.56; P = .006). Conclusions. These findings indicate an association between ADMA and DR in T2DM independent of macrovascular disease. This relationship is modified by GFR, the only parameter significantly related to DR in multivariate analysis.