Oxidized low density lipoprotein and total antioxidant capacity in type-2 diabetic and impaired glucose tolerance Saudi men

Abstract

BackgroundOxidative modification of low density lipoproteins (LDL) convert these native particles into pathogenic, immunogenic and atherogenic particles. Factors enhance LDL oxidation are poorly understood, especially in conditions of hyperglycemia. The present study was conducted to investigate which metabolic conditions are associated with the promotion of LDL oxidation in different glycemic situations.MethodsAdult male participants (274) were selected from patients admitted to the outpatient department of Diabetes Center in Al-Noor Specialized Hospital in Makkah and other citizens and residents in the city. The studied group was classified into three sub-groups: Group-I: control group of non-diabetic normal subjects, Group-II: subjects with impaired glucose tolerance (IGT) and Group-III: cases of type-2 diabetes mellitus (DM). Measurement of fasting blood glucose, 2 hour post-prandial blood glucose, glycosylated hemoglobin (HbA1c), triglycerides, serum cholesterol, HDL-cholesterol, LDL-cholesterol, ox-LDL, Total Antoxidant capacity (TAC) and Malondialdehyde (MDA) were performed. The obtained results were statistically analyzed.ResultsOxidation of native LDL increase nearly two folds in Type-2 DM group compared to controls. There is also significant increase in Ox-LDL of IGT group compared to controls. The correlation between Ox-LDL concentration and HbA1c in the whole population of the study confirms the increased Ox-LDL in subjects with hyperglycemia. A negative correlation exists between the concentration of Ox-LDL and total antioxidant capacity (TAC) in each studied group and in the whole population of the study as well. A positive correlation also exists between Ox-LDL concentrations and LDL values, more clear in controls and Type-2 DM, while this correlation was not significant in IGT group. The ratio of LDL oxidation as expressed by ox-LDL/LDL was increased in IGT group compared to control. More significant increase was observed in type-2 DM group.ConclusionWe concluded that the concentration of Ox-LDL increased in subjects with type-2 DM and IGT compared to controls. Moreover, oxidation of native LDL was associated with low levels of TAC and positively correlated with LDL levels, total cholesterol, HbA1c, body mass index (BMI) and increased age.

Decreased total antioxidant levels and increased oxidative stress in South African type 2 diabetes mellitus patients

“…[41][42][43] A significant decrease in TAO levels among T2DM patients was observed in this study and has also been reported by various other authors in their studies. 21,23,42 This reduction in TAO levels could be attributed to increased oxidative stress. This is evidenced by increased lipid peroxidation as well as by the excess utilisation of antioxidants against oxidative stress to minimise the damage.…”

Aspalathin from Rooibos (Aspalathus linearis): A Bioactive C-glucosyl Dihydrochalcone with Potential to Target the Metabolic Syndrome

“…Avci et al [117] recently showed that enhanced lipid peroxidation inversely correlates with GSH content in individuals with metabolic syndrome. This was supported by others demonstrating that systemic markers of lipid peroxidation such as oxidised LDL and TBARS are elevated in individuals with metabolic syndrome compared to control subjects [118,119]. Such findings have also been supported by data from animal models of metabolic syndrome with increased liver dysfunction, muscle insulin resistance, and subsequent cardiomyocyte remodelling and apoptosis [83,84,88].…”

Oxidized low‐density lipoprotein stimulates epithelial sodium channels in endothelial cells of mouse thoracic aorta

“…The ox‐LDL concentration in the circulation of healthy subjects is normally maintained at a very low level (~0.14 μg·mL −1 ) (Wang et al , ). However, ox‐LDL levels are significantly elevated in patients with hyperlipidaemia (Owens et al , ), type 2 diabetes mellitus (Nour Eldin et al , ), unstable or stable angina (Neri Serneri et al , ) or even coronary heart disease (Holm et al , ). Not surprisingly, ox‐LDL stimulates ENaC in aortic endothelial cells in a dose‐ and time‐dependent manner, suggesting that the elevated ENaC activity evoked by the chronically enhanced ox‐LDL levels may contribute to vasculature dysfunction induced by oxidative stress.…”