Enhanced Oxidative Stress and Other Potential Biomarkers for Retinopathy in Type 2 Diabetics: Beneficial Effects of the Nutraceutic Supplements

Abstract

We have studied the global risk of retinopathy in a Mediterranean population of type 2 diabetes mellitus (T2DM) patients, according to clinical, biochemical, and lifestyle biomarkers. The effects of the oral supplementation containing antioxidants/omega 3 fatty acids (A/ω3) were also evaluated. Suitable participants were distributed into two main groups: (1) T2DMG (with retinopathy (+DR) or without retinopathy (−DR)) and (2) controls (CG). Participants were randomly assigned (+A/ω3) or not (−A/ω3) to the oral supplementation with a daily pill of Nutrof Omega (R) for 18 months. Data collected including demographics, anthropometrics, characteristics/lifestyle, ophthalmic examination (best corrected visual acuity, ocular fundus photographs, and retinal thickness as assessed by optical coherence tomography), and blood parameters (glucose, glycosylated hemoglobin, triglycerides, malondialdehyde, and total antioxidant capacity) were registered, integrated, and statistically processed by the SPSS 15.0 program. Finally, 208 participants (130 diabetics (68 +DR/62 −DR) and 78 controls) completed the follow-up. Blood analyses confirmed that the T2DMG+DR patients had significantly higher oxidative stress (p < 0.05), inflammatory (p < 0.05), and vascular (p < 0.001) risk markers than the T2DMG−DR and the CG. Furthermore, the A/ω3 oral supplementation positively changed the baseline parameters, presumptively by inducing metabolic activation and ameliorating the ocular health after 18 months of supplementation.

Clinical and Molecular-Genetic Insights into the Role of Oxidative Stress in Diabetic Retinopathy: Antioxidant Strategies and Future Avenues

“…In addition, the mean T2DM lastingness at 38-months follow-up was 15 (3) years in −DR patients vs. 22 (5) years for the +DR patients. Nevertheless, additional factors also play critical roles in managing DR at any stage [1][2][3][4][5][6]19,[26][27][28], with a special interest in diabetics without clinically detectable retinopathy and those suffering from the early DR stage [37,38]. When corrected, these data for multiple testing, significantly lowered SLC23A2 gene expression (fold change) in the T2DM vs.…”

“…Baseline data were recorded as: Socio-demographics, personal/familial background (DM duration and treatment) and personal characteristics [nutrition-mediterranean diet (MedDiet) adherence by the validated 14-items questionnaire; Prevención con Dieta Mediterránea (PREDIMED), as previously reported [19], body mass index (BMI) and regular physical activity classified as to practice (1) or no (2) exercise. At the first visit, patients underwent an ophthalmological examination in both eyes: best-corrected visual acuity (BCVA), intraocular pressure (IOP), ocular fundus examination/retinography, and spectral domain optical coherence tomography (SD-OCT).…”

“…Fluorescence was measured in duplicate at 544 nm excitation, 590 nm emission in relation to standard samples fluorescence. The concentration was calculated by extrapolating all data in the standard curve, as reported [19,29]. -Determination of total GSH.…”

“…The OS markers were assayed in plasma samples from the groups and subgroups of participants. At baseline, comparison of the CG and the T2DM patients reflected significantly higher plasma levels of MDA/TBARS [2.9 (0.1) µM vs. 2.1 (0.2) µM (p = 0.001)] and significantly lower plasma levels of TAC [2.3 (0.1) mM vs. 3.1 (0.3) mM (p = 0.001)], GSH [2 (0.2) µM vs. 2.8 (0.2) µM (p = 0.002)] and vit C [40 (19) µM/mL vs. 56 (20) µM/mL (p = 0.001)]. Therefore, diabetics displayed significantly higher circulating pro-oxidant markers and lower antioxidant levels than the non-diabetic study population.…”

Elevated Levels of Serum β2-Glycoprotein I/Oxidized Low-Density Lipoprotein Complexes Are Associated with Cerebral Infarction in Patients with Type 2 Diabetes Mellitus

“…It is generally recognized that T2DM-associated vascular disease is mainly associated with vascular endothelial injury and endothelial dysfunction, which are the initial steps leading to atherosclerosis. Recently, some studies analyzed the key factors of the occurrence and development of oxidative stress and inflammatory injuries in T2DM with cerebral infarction, and these factors include oxidative stress molecules and inflammatory factors [ 10 – 12 ] such as oxidized low-density lipoproteins (oxLDL), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin (IL)-6 [ 13 , 14 ].…”