The Association between Diabetic Retinopathy and Levels of Ischemia-Modified Albumin, Total Thiol, Total Antioxidant Capacity, and Total Oxidative Stress in Serum and Aqueous Humor

Abstract

Purpose. To investigate the oxidant and antioxidant status of patients with type 2 diabetes mellitus and nonproliferative diabetic retinopathy (DRP). Methods. Forty-four patients who had cataract surgery were enrolled in the study. We included 22 patients with DRP in one group and 22 patients in the control group. Samples of aqueous humor and serum were taken from all patients. Serum and aqueous ischemia-modified albumin (IMA), total thiol, total antioxidant capacity (TAC), and total oxidative stress (TOS) levels were compared in two groups. Results. Median serum IMA levels were 44.80 absorbance units in the DRP group and 40.15 absorbance units in the control group (P = 0.031). Median serum total thiol levels in the DRP group were significantly less than those in the control group (3051.13 and 3910.12, resp., P = 0.004). Mean TOS levels in the serum were 2.93 ± 0.19 in the DRP group and 2.61 ± 0.26 in the control group (P = 0.039). The differences in mean total thiol, TAC, and TOS levels in the aqueous humor and mean TAC levels in the serum were not statistically significant. Conclusion. IMA, total thiol, and TOS levels in the serum might be useful markers in monitoring the risk of DRP development.

Altered superoxide dismutase-1 activity and intercellular adhesion molecule 1 (ICAM-1) levels in patients with type 2 diabetes mellitus

“…The decreased thiol levels of T2DM patients compared to controls found in our study probably reflects the higher thiol consumption in an environment of increased oxidative stress. Our results are corroborated by previous data showing decreased thiol levels in T2DM patients [26–28], which have also been linked to the presence of diabetes complications [26, 27].…”

Correlation of the aqueous humor total antioxidant capacity, total oxidant status, and levels of IL-6 and VEGF with diabetic retinopathy status

“…They found a significant decrease in plasma TAC levels and an increase in plasma TOS levels, but there were no significant differences in the AH TAC and TOS levels (11) . Kırboğa et al did not find a significant difference in the plasma levels of TAC and TOS between patients with DR and control subjects; the TOS level in the AH was significantly higher in the DR group, but the TAC level in the AH was not significantly different between both groups (16) . In these studies, DR was not classified into subgroups.…”

Oxidative Stress Status in Sera and Saliva of Type 2 Diabetic Iraqi Patients with and without Proliferative Diabetic Retinopathy

“…Chronic oxidative stress in case of diabetic not only creates a vicious cycle of damage to membrane lipids, cell's proteins, nucleic acids as well as disrupting cellular homeostasis, it also amplifies ROS production by activating other metabolic pathways including inflammation, polyol pathway, protein kinase C pathway (PKC), accumulation of advanced glycation end products (AGEs), and the flux of hexosamine pathway which are involved in the development of diabetic retinopathy. All of these mechanisms appear to be associated with mitochondrial over production of reactive oxygen species (ROS) which are known to promote the breakdown of bloodretinal barrier and to alter retinal blood flow [23][24][25].…”