Effect of 17β-Estradiol on Plasma Lipids and LDL Oxidation in Postmenopausal Women With Type II Diabetes Mellitus

Brussaard, H. E.; Leuven, J.A. Gevers; Kluft, C.; Krans, H. M. J.; Duyvenvoorde, Wim van; Buytenhek, R.; Laarse, Arnoud van der; Princen, H.M.G.

doi:10.1161/01.atv.17.2.324

Cited by 66 publications

(46 citation statements)

References 47 publications

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“…Many studies support the role of estrogens in the primary and secondary prevention of CHD among women (38,39), particularly in normalizing blood lipids or inducing endothelium-dependent vasodilation stimulating nitric oxide synthetase (40 -42). It has recently been demonstrated in premenopausal diabetic women that there is a decreased estrogeninducing endothelium-dependent vasodilation (43), which can explain the increased risk of cardiovascular mortality in diabetic women.…”

Section: Results -As Shown Inmentioning

confidence: 99%

Early Increase of Oxidative Stress and Reduced Antioxidant Defenses in Patients With Uncomplicated Type 1 Diabetes

et al. 2002

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OBJECTIVE -Diabetes increases the risk of coronary heart disease (CHD) to a greater extent in women than in men. We investigated whether type 1 diabetic patients with short duration of disease and without complications have an altered oxidative status and whether there are differences between men and women.RESEARCH DESIGN AND METHODS -We investigated oxidative status in 29 control subjects and 37 patients with uncomplicated type 1 diabetes with duration of 6 Ϯ 3 years.RESULTS -Compared with control subjects, type 1 diabetic patients had lower total plasma antioxidant capacity (TRAP) (720.3 Ϯ 111.2 vs. 972.5 Ϯ 97.7 mol/l in men, P Ͻ 0.001; 579.8 Ϯ 95.4 vs. 930.1 Ϯ 84.2 in women, P Ͻ 0.001), higher lipid hydroperoxide (ROOH) levels (6.4 Ϯ 2.2 vs. 2.0 Ϯ 0.7 mol/l in men, P Ͻ 0.001; 8.1 Ϯ 1.9 vs. 2.2 Ϯ 0.6 in women, P Ͻ 0.001), higher total conjugated diene (CD) levels (0.037 Ϯ 0.003 vs. 0.033 Ϯ 0.002 A.U. in men, P Ͻ 0.001), lower 246-nm CD levels (0.0032.Ϯ 0.0010 vs. 0.0070 Ϯ 0.0012 A.U. in men, P Ͻ 0.001; 0.0022 Ϯ 0.0011 vs. 0.0072 Ϯ 0.0014 A.U. in women, P Ͻ 0.001), and higher 232-nm CD levels (0.0348 Ϯ 0.0041 vs. 0.0257 Ϯ 0.0022 A.U. in men, P Ͻ 0.001; 0.0346 Ϯ 0.0031 vs. 0.0246 Ϯ 0.0074 A.U. in women, P Ͻ 0.001). Compared with diabetic men, diabetic women had lower TRAP (P Ͻ 0.01), higher ROOH levels (P Ͻ 0.01), and lower 246-nm CD levels (P Ͻ 0.05). Plasma concentration of uric acid was significantly lower in patients with type 1 diabetes than in control subjects (3.3 Ϯ 0.3 vs. 4.3 Ϯ 0.2 mg/dl; P ϭ 0.009) with a significant difference between women and men with type 1 diabetes (2.6 Ϯ 0.3 vs. 3.9 Ϯ 0.3, respectively; P ϭ 0.009).CONCLUSIONS -Our findings suggest that reduced antioxidant activity and increased oxidative stress occur early after the diagnosis of type 1 diabetes, especially in women, and this might explain, at least in part, the increased susceptibility of diabetic women to cardiovascular complications.

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Section: Results -As Shown Inmentioning

confidence: 99%

Early Increase of Oxidative Stress and Reduced Antioxidant Defenses in Patients With Uncomplicated Type 1 Diabetes

et al. 2002

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“…The addition of estrogens to a system of LDL oxidation mediated by copper showed an increase in the initiation time of LDL oxidation 26 . Several studies have shown the effect of the administration of estrogens on human LDL oxidation [50][51][52] . Therefore, the reduced concentration of estrogens could partially explain the increase in lipid peroxidation in postmenopausal women observed in this study.…”

Section: Discussionmentioning

confidence: 99%

Lipid peroxidation and nitric oxide inactivation in postmenopausal women

Pereira

Bertolami

Faludi

et al. 2003

Arq. Bras. Cardiol.

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Original ArticleCardiovascular diseases are less prevalent in premenopausal women and in those receiving hormone replacement therapy as compared with postmenopausal women and men 1 . This protective effect is attributed to estrogens, and one of the mechanisms of action may be related to the metabolism of plasma lipoproteins 2 .Estrogens reduce LDL-cholesterol and increase HDLcholesterol 3 . However, these changes in lipid profile only contribute to approximately 25% of the protective effect of estrogens 4 . Other potential mechanisms of action of estrogens may include protection against LDL oxidation 5 , reduction in lipoprotein(a), potentiation of fibrinolysis 6 , and increase in insulin sensitivity. In the arteries, estrogens improve vasodilating function, decrease calcification, secretion of cell adhesion molecules (E-selectin, ICAM-1, and VCAM-1), and formation of atherosclerotic lesions 7 .Direct action of estrogens on the arterial wall has also been demonstrated. The administration of estrogens for prolonged periods inhibits the deposition of cholesterol in the arteries and thickening of the intima in monkeys and rabbits fed an atherogenic diet 8 . However, the mechanisms determining the direct effects of estrogens on the arterial wall have not been completely elucidated. The hemodynamic effects may be partially measured by the activity of estrogens on the synthesis of endothelial nitric oxide 9 . Estrogens have been suggested to possibly improve endothelial function and decrease the risks of atherosclerosis in premenopausal women. Nitric oxide has its bioactivity reduced in postmenopausal women. However, it is not clear whether this occurs due to its lower production by nitric oxide synthase, or whether nitric oxide is inactivated by reaction with the superoxide radical also generated by endothelial cells, forming the peroxynitrite anion (ONOO -), which is a strong oxidizing agent.Peroxynitrite is decomposed into other reactive oxygen species ( fig. 1) 10 and reacts with tyrosine residues of proteins to form nitrotyrosine 11 . Although little is known NOx, nitrotyrosine, COx, CE 18:2 -OOH, and PC-OOH were higher in the postmenopausal period (33.8±22.3 µM; 230±130 nM; 55±19 ng/µL; 17±8.7 nM; 2775±460 nM, respectively) Objective -To assess the effect of endogenous estrogens on the bioavailability of nitric oxide (·NO) and in the formation of lipid peroxidation products in pre-and postmenopausal women. Methods -NOx and S-nitrosothiols were determined by gaseous phase chemiluminescence, nitrotyrosine was determined by ELISA, COx (cholesterol oxides) by gas chromatography, and cholesteryl linoleate hydroperoxides (CE 18:2 -OOH), trilinolein (TG 18:2 -OOH), and phospholipids (PC-OOH) by HPLC in samples of plasma. Results -The concentrations of

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“…42,48,50 Briefly, from each subject 3.5 mL of frozen plasma, stored at Ϫ80°C, was rapidly thawed and used for isolation of LDL by ultracentrifugation at 4°C in the presence of 10 mol/L EDTA. To minimize the time between isolation and oxidation, the LDL was not dialyzed.…”

Section: Preparation and Oxidation Of Ldlmentioning

confidence: 99%

“…By omitting dialysis we obtained a more stable LDL preparation, which can be stored in the dark at 4°C under nitrogen for several days without effect on resistance time and propagation rate. 48,50 This improves the precision of the method, because each LDL preparation can be oxidized consecutively in triplicate. In a representative experiment, lag time was 90Ϯ2 minutes at 1 hour after LDL isolation in a LDL preparation that had not been dialyzed; 24 hours after LDL isolation, lag time was 91Ϯ3 minutes (nϭ3).…”

Section: Preparation and Oxidation Of Ldlmentioning

confidence: 99%

“…In addition, no differences in these parameters were found on storage of plasma at Ϫ80°C up to 18 months. 50 In a representative experiment, the lag time and propagation rate of a reference LDL prepared from freshly collected plasma were 91Ϯ2 minutes and 8.7Ϯ0.3 nmol/mg per minute (nϭ5), respectively. After freezing of the plasma in liquid nitrogen, storage for 3 hours at Ϫ80°C, and rapid thawing at 37°C, these data were 90Ϯ3 minutes and 8.8Ϯ0.3 nmol/mg per minute (nϭ5) on oxidation in the same oxidation run.…”

Section: Preparation and Oxidation Of Ldlmentioning

confidence: 99%

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No Effect of Consumption of Green and Black Tea on Plasma Lipid and Antioxidant Levels and on LDL Oxidation in Smokers

Princen

Duyvenvoorde

Buytenhek

et al. 1998

ATVB

Self Cite

164

115

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Abstract-Intake of flavonoids is associated with a reduced cardiovascular risk. Oxidation of LDL is a major step in atherogenesis, and antioxidants may protect LDL from oxidation. Because tea is an important source of flavonoids, which are strong antioxidants, we have assessed in a randomized, placebo-controlled study the effect of consumption of black and green tea and of intake of isolated green tea polyphenols on LDL oxidation ex vivo and on plasma levels of antioxidants and lipids. Healthy male and female smokers (aged 34Ϯ12 years, 13 to 16 per group) consumed during a 4-week period 6 cups (900 mL) of black or green tea or water per day, or they received as a supplement 3.6 grams of green tea polyphenols per day (equivalent to the consumption of 18 cups of green tea per day). Consumption of black or green tea had no effect on plasma cholesterol and triglycerides, HDL and LDL cholesterol, plasma vitamins C and E, ␤-carotene, and uric acid. No differences were found in parameters of LDL oxidation. Intake of green tea polyphenols decreased plasma vitamin E significantly in that group compared with the control group (Ϫ11% Pϭ.016) but had no effect on LDL oxidation ex vivo. We conclude that consumption of black or green tea (6 cups per day) has no effect on plasma lipids and no sparing effect on plasma antioxidant vitamins and that intake of a high dose of isolated green tea polyphenols decreases plasma vitamin E. Although tea polyphenols had a potent antioxidant activity on LDL oxidation in vitro, no effect was found on LDL oxidation ex vivo after consumption of green or black tea or intake of a green tea polyphenol isolate. (Arterioscler Thromb Vasc Biol. 1998;18:833-841.)

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Effect of 17β-Estradiol on Plasma Lipids and LDL Oxidation in Postmenopausal Women With Type II Diabetes Mellitus

Cited by 66 publications

References 47 publications

Early Increase of Oxidative Stress and Reduced Antioxidant Defenses in Patients With Uncomplicated Type 1 Diabetes

Early Increase of Oxidative Stress and Reduced Antioxidant Defenses in Patients With Uncomplicated Type 1 Diabetes

Lipid peroxidation and nitric oxide inactivation in postmenopausal women

No Effect of Consumption of Green and Black Tea on Plasma Lipid and Antioxidant Levels and on LDL Oxidation in Smokers

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