Asymmetric dimethylarginine and homocysteine in exudative age-related macular degeneration

Abstract

Introduction: The oxidative stress has been proposed as an important case of exudative age-related macular degeneration (E-ARMD). The aim of the present study was to investigate homocysteine (Hcy), asymmetric dimethylarginine (ADMA) and oxidized low-density lipoprotein cholesterol (Ox-LDL-C) levels, the factors involved in oxidative stress, in the patients with E-ARMD. Methods: In a cross-sectional study, 45 patients with E-ARMD were compared with 45 sex- and age-matched healthy controls. The levels of biochemical factors, Hcy, ADMA, and of Ox-LDL were estimated by standard methods in both study groups. Results: The levels of Hcy (15.4 ± 7.2 vs. 10.7 ± 3.7 μM, P = 0.001), Ox-LDL (52.2 ± 13.8 vs. 37.8 ± 10.8 U/l, P = 0.001), and ADMA (0.84 ± 0.23 vs. 0.71 ± 0.26 μM, P = 0.012) were significantly higher in the patients with E-ARMD than those in the controls. In the patient group, there was a positive and significant correlation between serum Ox-LDL and Hcy concentrations (r = 0.719, P = 0.001), but no correlation was found between serum ADMA and Ox-LDL (r = 0.010, P = 0.900) and also between serum Hcy and ADMA levels (r = -0.070, P = 0.600). Conclusion: The high levels of Hcy as an oxidant agent and ADMA as an endogenous nitric oxide synthase inhibitor can lead to increase Ox-LDL levels, and they may have important roles in oxidative stress, which can be a trigger in E-ARMD.

Keywords: Age related macular degeneration, Oxidative stress, Asymmetric dimethylarginine, Homocysteine, Oxidized LDL cholesterol