Trace Elements, and Antioxidant Enzymes in Type 2 Diabetes Mellitus: Relationship with Diabetic Retinopathy Severity

İngilizce (OpenAlex)

Background/Objectives: Diabetic retinopathy (DR) is one of the most common microvascular complications in type 2 diabetes mellitus (T2DM), in which oxidative stress, inflammation and angiogenic pathways are associated with the development and progression beyond glycemic control. Serum trace element levels (Cu, Zn, Fe, Mg, Cr, Mn, Cd, and Se), antioxidant enzyme activities (superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px)) were measured in patients with T2DM, with and without DR, as well as in healthy controls, and their associations with the presence and severity of DR were evaluated. Methods: 61 T2DM patients, 27 healthy controls. Patients with T2DM were classified into T2DM without DR (n = 30) and T2DM with DR (n = 31). Non-proliferative DR (NPDR, n = 19) and proliferative DR (PDR, n = 12) were classified as the T2DM with DR group. Inductively coupled plasma–mass spectrometry (ICP-MS) was used to quantify serum trace elements. SOD and GSH-Px activities were measured using colorimetric assays. Results: Significant differences were observed in trace element levels and antioxidant enzyme activities among the study groups (p < 0.001 to 0.05). The DR subgroup had lower levels of Cr, Cu and Se compared to the T2DM without DR group; Cd, Zn and Mn were also higher in the T2DM with DR than in the T2DM without DR group. Fe levels were significantly higher in the PDR subgroup than in the T2DM without DR group (p < 0.001). The PDR group showed greater declines of Cr, Cu and GSH-Px compared to NPDR while higher values for Mn, Fe, and Zn were obtained (p < 0.001). Several biomarkers remained significantly associated with DR after adjustment for metabolic variables. Correlation analysis between trace elements, and antioxidant enzymes showed significant associations. Conclusions: Trace element imbalance, and reduced antioxidant enzyme activities may contribute to the development and progression of DR in T2DM. These findings suggest that oxidative stress and micronutrient imbalance may be linked to DR-related biochemical alterations.