Antioxidant Status and Lipid Peroxidation in Type II Diabetes Mellitus with and without Complications

Sundaram, Ranjini K.; Bhaskar, Anusha; Vijayalingam, S.; Viswanathan, M; Mohan, Rema; Shanmugasundaram, K. Radha

doi:10.1042/cs0900255

Cited by 257 publications

(162 citation statements)

References 9 publications

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“…Previously reported increases in plasma F 2 -isoprostanes and their diminution in diabetes with antioxidant vitamins referred to patients with poorer glycaemic control than our study group [29,30]. We found that plasma antioxidant capacity was decreased in our patients in agreement with previous reports showing that diabetic patients have decreased plasma concentrations of antioxidant vitamins [32]. However, low plasma ORAC was not corrected by CoQ supplementation, suggesting that CoQ might not contribute to plasma antioxidants measured by this assay.…”

Section: Discussionsupporting

confidence: 90%

Coenzyme Q10 improves endothelial dysfunction of the brachial artery in Type II diabetes mellitus

et al. 2002

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In Type II (non-insulin-dependent) diabetes mellitus the pathogenesis of vascular disease, its most common complication, remains unclear [1]. Endothelial dysfunction reflects the disordered physiology of several endothelium-derived vasoactive factors, in particular nitric oxide [2]. Endothelial dysfunction occurs commonly in diabetes and is an early feature of vasculopathy [3,4]. Increased oxidative stress due to the effects of hyperglycaemia and its sequelae is a recognized feature of diabetes [5]. It might cause endothelial dysfunction through the inactivation and Abstract Aim/hypothesis. We assessed whether dietary supplementation with coenzyme Q 10 improves endothelial function of the brachial artery in patients with Type II (non-insulin-dependent) diabetes mellitus and dyslipidaemia. Methods. A total of 40 patients with Type II diabetes and dyslipidaemia were randomized to receive 200 mg of coenzyme Q 10 or placebo orally for 12 weeks. Endothelium-dependent and independent function of the brachial artery was measured as flowmediated dilatation and glyceryl-trinitrate-mediated dilatation, respectively. A computerized system was used to quantitate vessel diameter changes before and after intervention. Arterial function was compared with 18 non-diabetic subjects. Oxidative stress was assessed by measuring plasma F 2 -isoprostane concentrations, and plasma antioxidant status by oxygen radical absorbance capacity. Results. The diabetic patients had impaired flow-mediated dilation [3.8 % (SEM 0.5) vs 6.4 % (SEM 1.0), p = 0.016], but preserved glyceryl-trinitrate-mediated dilation, of the brachial artery compared with non-diabetic subjects. Flow-mediated dilation of the brachial artery increased by 1.6 % (SEM 0.3) with coenzyme Q 10 and decreased by ±0.4 % (SEM 0.5) with placebo (p = 0.005); there were no group differences in the changes in pre-stimulatory arterial diameter, post-ischaemic hyperaemia or glyceryl-trinitrate-mediated dilation response. Coenzyme Q 10 treatment resulted in a threefold increase in plasma coenzyme Q 10 (p < 0.001) but did not alter plasma F 2 -isoprostanes, oxygen radical absorbance capacity, lipid concentrations, glycaemic control or blood pressure. Conclusion/interpretation. Coenzyme Q 10 supplementation improves endothelial function of conduit arteries of the peripheral circulation in dyslipidaemic patients with Type II diabetes. The mechanism could involve increased endothelial release and/or activity of nitric oxide due to improvement in vascular oxidative stress, an effect that might not be reflected by changes in plasma F 2 -isoprostane concentrations. [Diabetologia (2002) 45: 420±426]

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Section: Discussionsupporting

confidence: 90%

Coenzyme Q10 improves endothelial dysfunction of the brachial artery in Type II diabetes mellitus

et al. 2002

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“…These findings are similar to results of other investigators studying antioxidant vitamins in relation to risk factors in diabetic subjects [18,45]. The sex of diabetic or control subjects had no significant influence on a -tocopherol levels.…”

Section: Discussionsupporting

confidence: 82%

“…Some investigators have reported an association between TBARS and diabetic complications [16,18] while other have not [14]. Jennings et al [41] reported that elevated levels of conjugated dienes in plasma from diabetic subjects are associated with microangiopathy.…”

Section: Discussionmentioning

confidence: 99%

“…This problem has been approached in two ways: 1) measurement of reaction products of oxidative damage such as lipid peroxides; and 2) measurement of the depletion of antioxidants. Enhanced lipid peroxidation in diabetic patients has been reported using thiobarbituric acid reactive substances (TBARS) as an assay [14][15][16][17][18]. However, interpretation of the relationship between lipid peroxidation and diabetes has yielded contradictory results [14,15,18,19].…”

Section: © Springer-verlag 1997mentioning

confidence: 99%

“…Enhanced lipid peroxidation in diabetic patients has been reported using thiobarbituric acid reactive substances (TBARS) as an assay [14][15][16][17][18]. However, interpretation of the relationship between lipid peroxidation and diabetes has yielded contradictory results [14,15,18,19]. The simple TBARS assay measures many parameters in addition to lipid peroxidation and is affected by the lipid content of the sample [20].…”

confidence: 99%

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Relationships between plasma measures of oxidative stress and metabolic control in NIDDM

et al. 1997

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Reduction of activity, but no decrease in concentration, of erythrocyte Cu,Zn-superoxide dismutase by hyperglycaemia in diabetic patients

et al. 1998

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Cu,Zn-superoxide dismutase(SOD) activity in erythrocytes is affected by various diseases, including diabetes mellitus (DM). We investigated changes in the Cu,Zn-SOD activity compared to changes in the Cu,Zn-SOD concentration in erythrocytes obtained from patients with Type 2 (non-insulin-dependent) diabetes mellitus. Cu,Zn-SOD activity in erythrocytes was significantly lower in Type 2 DM patients than in healthy non-diabetic subjects. The activity correlated negatively with HbA1c, but not with other indicators of metabolic control, such as fasting blood glucose or plasma cholesterol or triglyceride. However, there was no statistically significant difference in erythrocyte concentration of Cu,Zn-SOD between diabetic and control samples. Concentration did not correlate with enzymatic activity or HbA1c. These findings indicate that the inactivation of Cu,Zn-SOD activity in erythrocytes of Type 2 DM patients by hyperglycaemia may be slow, because there is a negative correlation between the enzyme activities and HbA1c levels, but not fasting blood glucose levels. This is consistent with glycosylation of the active site of Cu,Zn-SOD, without any effect of hyperglycaemia on the concentration of Cu,Zn-SOD.

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Antioxidant Status and Lipid Peroxidation in Type II Diabetes Mellitus with and without Complications

Cited by 257 publications

References 9 publications

Coenzyme Q10 improves endothelial dysfunction of the brachial artery in Type II diabetes mellitus

Coenzyme Q10 improves endothelial dysfunction of the brachial artery in Type II diabetes mellitus

Relationships between plasma measures of oxidative stress and metabolic control in NIDDM

Reduction of activity, but no decrease in concentration, of erythrocyte Cu,Zn-superoxide dismutase by hyperglycaemia in diabetic patients

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