Elina Porkkala-Sarataho

Six-Year Effect of Combined Vitamin C and E Supplementation on Atherosclerotic Progression The Antioxidant Supplementation in Atherosclerosis Prevention (ASAP) Study

Background—Self-selected supplementation of vitamin E has been associated with reduced coronary events and atherosclerotic progression, but the evidence from clinical trials is controversial. In the first 3 years of the ASAP trial, the supplementation with 136 IU of vitamin E plus 250 mg of slow-release vitamin C twice daily slowed down the progression of carotid atherosclerosis in men but not women. This article examines the 6-year effect of supplementation on common carotid artery (CCA) intima-media thickness (IMT). Methods and Results—The subjects were 520 smoking and nonsmoking men and postmenopausal women aged 45 to 69 years with serum cholesterol ≥5.0 mmol/L (193 mg/dL), 440 (84.6%) of whom completed the study. Atherosclerotic progression was assessed ultrasonographically. In covariance analysis in both sexes, supplementation reduced the main study outcome, the slope of mean CCA-IMT, by 26% (95% CI, 5 to 46, P =0.014), in men by 33% (95% CI, 4 to 62, P =0.024) and in women by 14% (not significant). In both sexes combined, the average annual increase of the mean CCA-IMT was 0.014 mm in the unsupplemented and 0.010 mm in the supplemented group (25% treatment effect, 95% CI, 2 to 49, P =0.034). In men, this treatment effect was 37% (95 CI, 4 to 69, P =0.028). The effect was larger in subjects with either low baseline plasma vitamin C levels or CCA plaques. Vitamin E had no effect on HDL cholesterol. Conclusions—These data replicate our 3-year findings confirming that the supplementation with combination of vitamin E and slow-release vitamin C slows down atherosclerotic progression in hypercholesterolemic persons.

Lipoprotein Oxidation and Progression of Carotid Atherosclerosis

BACKGROUND Epidemiological studies and animal experiments have provided evidence supporting the role of lipid peroxidation in atherogenesis and cardiovascular diseases. Direct evidence linking lipid oxidation to atherosclerotic progression in humans, however, has been lacking. We investigated the association of lipid oxidation products with the progression of early carotid atherosclerosis in hypercholesterolemic men from eastern Finland. METHODS AND RESULTS Twenty subjects with a fast progression and 20 with no progression of carotid atherosclerosis in 3 years were selected from > 400 participants in the Kuopio Atherosclerosis Prevention Study. Progression of carotid atherosclerosis was assessed by high-resolution B-mode ultrasonography. Serum 7 beta-hydroxycholesterol, a major oxidation product of cholesterol in membranes and lipoproteins, and seven other cholesterol oxidation products were measured by isotope dilution-mass spectrometry, lipid hydroperoxides in LDL fluorometrically as thiobarbituric acid-reactive substances (TBARS) and oxidation susceptibility of LDL and VLDL kinetically. High concentrations of serum 7 beta-hydroxycholesterol (beta = 47, P = .0005), cigarette smoking (beta = .35, P = .0167), and LDL TBARS (beta = .23, P = .0862) and an increased oxidation susceptibility of VLDL + LDL (beta = .22 P = .1114) were the strongest predictors of a 3-year increase in carotid wall thickness of more than 30 variables tested in step-up least-squares regression models. A 10-variable model explained 60% of the atherosclerotic progression. In a multivariate logistic model, the risk of experiencing a fast progression increased by 80% (P = .013) per unit (microgram/L) of 7 beta-hydroxycholesterol. CONCLUSIONS The findings of this study provide further evidence to support an association between lipid oxidation and atherogenesis in humans.

Ascorbate and urate are the strongest determinants of plasma antioxidative capacity and serum lipid resistance to oxidation in Finnish men

Copper-induced plasma lipoprotein oxidation resistance has usually been determined in separated low density lipoprotein (LDL) fractions, that do not contain water-soluble antioxidants present in blood plasma. The aim of this study was to find the main determinants of the measurements of copper-induced lipid oxidation resistance (lag time) in whole serum and plasma total peroxyl radical trapping capacity (TRAP) in a population sample of smoking (n = 25) or non-smoking (n = 26) middle aged men at high risk of cardiovascular diseases. Smokers had significantly lower plasma ascorbic acid values, but only slightly lower alpha-tocopherol, beta-carotene and serum urate values than non-smokers. Plasma ascorbic acid concentration explained 23.5% of the lag time variation (standardized regression coefficient beta = 0.48; P = 0.004) in smokers and 5.6% in non-smokers. Serum urate concentration was the strongest determinant of lag time in non-smokers (beta = 0.64, P < 0.001). In addition, serum albumin, lipid standardized alpha-tocopherol and serum high density lipoprotein (HDL) cholesterol entered the multivariate regression mode for lag time. For plasma TRAP, only urate and ascorbic acid entered the multivariate regression model. Lag times in serum and in isolated very low density lipoprotein (VLDL) and LDL fraction did not correlate, but the maximal rate of these reactions correlated significantly. These results confirm that lipid peroxidation resistance in serum or plasma are associated with ascorbic acid, urate, alpha-tocopherol, albumin and HDL concentrations. The measurement of lipid oxidation resistance in whole serum might be more physiological than in isolated lipoprotein fraction, as the effects of water-soluble antioxidants are not artificially removed.

The Kuopio Atherosclerosis Prevention Study (KAPS): Effect of pravastatin treatment on lipids, oxidation resistance of lipoprotems, and atherosclerotic progression

The Kuopio Atherosclerosis Prevention Study is the first population-based, double-blind trial in the primary prevention of carotid and femoral atherosclerosis. A total of 447 subjects with serum low density lipoprotein (LDL) cholesterol levels > or = 155 mg/dl (> or = 4.0 mmol/liter) and total cholesterol levels < 290 mg/dl (< 7.5 mmol/liter) were randomly assigned to receive either pravastatin 40 mg/day or placebo for 3 years. Atherosclerotic progression in 424 men was assessed with B-mode ultrasonography. Pravastatin reduced the rate of progression by 45% (95% confidence interval [CI]: 16-69%, p = 0.005) in carotid arteries and by 66% (95% CI: 30-90%, p = 0.002) in the common carotid arteries. The treatment effect in the carotid arteries was greater in subjects with thick arterial walls at baseline, in smokers, and in subjects with low plasma alpha-tocopherol. Subjects who received pravastatin had a higher antioxidative capacity of LDL, a longer oxidation lag of very low density lipoprotein (VLDL) plus LDL, and a reduced oxidation rate of VLDL plus LDL in vitro. These data establish the antiatherogenic effect of lowering LDL cholesterol levels by pravastatin therapy in hypercholesterolemic men in a primary prevention setting and suggest that part of the antiatherogenic effect of pravastatin may be due to an improvement in the resistance of atherogenic lipoproteins to oxidation.

Long-Term Effects of Vitamin E, Vitamin C, and Combined Supplementation on Urinary 7-Hydro-8-Oxo-2′-Deoxyguanosine, Serum Cholesterol Oxidation Products, and Oxidation Resistance of Lipids in Nondepleted Men

We studied the long-term effects of vitamins E and C and their combination on lipid peroxidation in vivo and in vitro. The Antioxidant Supplementation in Atherosclerosis Prevention (ASAP) trial is a double-masked placebo-controlled randomized clinical trial to study the effects of vitamin C (500 mg of slow release ascorbate per day), vitamin E (182 mg of RRR-&agr;-tocopherol acetate per day), and the combination of both antioxidants. Lipid peroxidation measurements were carried out for 48 male participants at entry and at 12 and 36 months. Compared with placebo, vitamin E and the vitamin combination increased plasma lipid–standardized &agr;-tocopherol during the first 12 months by 68.2% and 65.2% (P <0.001 for both), respectively, and reduced serum 7&bgr;-hydroxycholesterol by 50.4% (P =0.013) and 44.0% (P =0.041), respectively. The net change of lipid standardized &agr;-tocopherol was 63.8% after 36 months of vitamin E supplementation and 43.3% for the combination. Vitamin C supplementation elevated plasma total ascorbate level by 30.1% (P =0.043) in 12 months and by 91.1% (P =0.001) in 36 months. Neither vitamin E, vitamin C, nor the combination influenced the urinary excretion rate of 7-hydro-8-oxo-2′-deoxyguanosine or the antioxidative capacity of plasma. Vitamin E and the combination of vitamins E and C enhanced the oxidation resistance of isolated lipoproteins and total serum lipids. Our data indicate that long-term supplementation of nondepleted men with a reasonable dose of vitamin E alone or in combination with slow release vitamin C reduces lipid peroxidation in vitro and in vivo, whereas a relatively high dose of vitamin C alone does not.

Effect of combined coenzyme Q10 and d-alpha-tocopheryl acetate supplementation on exercise-induced lipid peroxidation and muscular damage: a placebo-controlled double-blind study in marathon runners.

To test the effects of combined coenzyme Q10 (Q10) and d-alpha-tocopheryl acetate supplementation on exercise-induced oxidative stress and muscular damage we conducted a double-blind study in 37 moderately trained male marathon runners. These were randomly allocated to receive either an antioxidant cocktail: 90 mg of Q10 and 13.5 mg of d-alpha-tocopheryl acetate daily (18 men) or placebo (19 men) for three weeks before a marathon (42km) run. Just before the run, plasma Q10 was 282% (p < 0.0001) and plasma vitamin E 16% (p < 0.007) higher in the supplemented group, than in the placebo group. Also the proportion of plasma ubiquinol of total Q10, an indication of plasma redox status in vivo, was significantly higher in the supplemented group. Furthermore, the susceptibility of the VLDL + LDL fraction, to copper-induced oxidation, was significantly reduced in the supplemented group, compared to the placebo group. The exercise increased lipid peroxidation significantly in both study groups, as assessed by the elevated proportion LDL of LDL and the increased susceptibility of lipoproteins to copper induced oxidation. However, the supplementation had no effect on lipid peroxidation or on the muscular damage (increase in serum creatine kinase activity or in plasma lactate levels) induced by exhaustive exercise. Plasma ascorbate, Q10, whole blood glutathione and serum uric acid concentrations increased during the exercise, elevating significantly the TRAP value of plasma by 10.3% and the proportion of plasma ubiquinol of total Q10 by 4.9%. These results suggest that even though exercise increases plasma lipid peroxidation, it also elevates the antioxidative capacity of plasma, as assessed by the increased plasma TRAP and the proportion of Q10H2 of total Q10. However, prior supplementation with small doses of Q10 and d-alpha-tocopheryl acetate neither attenuates the oxidation of lipoproteins nor muscular damage induced by exhaustive exercise such as encountered in a marathon run.

Effect of oral coenzyme Q10 supplementation on the oxidation resistance of human VLDL+LDL fraction: absorption and antioxidative properties of oil and granule-based preparations.

Coenzyme Q10 (Q10) is supposed to be an important endogenous lipid-soluble antioxidant. We studied 60 healthy 46 +/- 7 (mean +/- SD)-year-old smoking men. They were randomized into three groups to receive oil-based or granular Q10 (90 mg/d) or placebo for 2 months. Oil-based capsule elevated Q10 in plasma by 178% and in VLDL+LDL fraction by 160%. The granular preparation increased Q10 in plasma by 168% and in VLDL+LDL by 127%. However, the 2-month Q10 supplementation did not increase the oxidation resistance of VLDL+LDL fraction, as assessed by copper induced VLDL+LDL oxidation, haemin+H(2)O(2)-induced VLDL+LDL oxidation, total antioxidative capacity of LDL, and plasma malondialdehyde measurements. The first and the last dose was used to carry out a 12 h pharmacokinetic study (five subjects per group), which indicated that only a small part of supplemented Q10 was absorbed to the circulation in 12 h and that the absorption varied extensively between subjects. Our results suggest that at least among smoking men, 90 mg of orally supplemented Q10 daily does not increase the oxidation resistance of VLDL+LDL. Bioavailability of both the granular and the oil-based Q10 preparation was similar during the long-term supplementation, but one dose of 30 mg had only a marginal effect on the plasma levels of Q10.

Supplementation with vitamin E but not with vitamin C lowers lipid peroxidation in vivo in mildly hypercholesterolemic men

Although the use of vitamin E supplements has been associated with a reduction in coronary events, assumed to be due to lowered lipid peroxidation, there are no previous long-term clinical trials into the effects of vitamin C or E supplementation on lipid peroxidation in vivo. Here, we have studied the long-term effects of vitamins C and E on plasma F2-isoprostanes, a widely used marker of lipid peroxidation in vivo. As a study cohort, a subset of the “Antioxidant Supplementation in Atherosclerosis Prevention” (ASAP) study was used. ASAP is a double-masked placebo-controlled randomized clinical trial to study the long-term effect of vitamin C (500 mg of slow release ascorbate daily), vitamin E (200 mg of d-α-tocopheryl acetate daily), both vitamins (CellaVie®), or placebo on lipid peroxidation, atherosclerotic progression, blood pressure and myocardial infarction (n = 520 at baseline). Lipid peroxidation measurements were carried out in 100 consecutive men at entry and repeated at 12 months. The plasma F2-isoprostane concentration was lowered by 17.3% (95% CI 3.9–30.8%) in the vitamin E group (p = 0.006 for the change, as compared with the placebo group). On the contrary, vitamin C had no significant effect on plasma F2-isoprostanes as compared with the placebo group. There was also no interaction in the effect between these vitamins. In conclusion, long-term oral supplementation of clinically healthy, but hypercholesterolemic men, who have normal vitamin C and E levels with a reasonable dose of vitamin E lowers lipid peroxidation in vivo, but a relatively high dose of vitamin C does not. This observation may provide a mechanism for the observed ability of vitamin E supplements to prevent atherosclerosis.

Increased oxidation resistance of atherogenic plasma lipoproteins at high vitamin E levels in non-vitamin E supplemented men

The oxidative modification of human low density lipoprotein (LDL) has been widely investigated. However, there are no data concerning the oxidation susceptibility of combined very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL) and low density lipoprotein fraction, although all of them are atherogenic and contain antioxidants such as alpha-tocopherol. We investigated the oxidation susceptibility and oxidation resistance of VLDL + LDL (including IDL) fraction by induction with CuCl2 and its relation to plasma alpha-tocopherol concentration and lipid standardised alpha-tocopherol concentration in 406 non-vitamin E-supplemented men from eastern Finland. Even thought we did not give oral vitamin E or any other antioxidant supplementation to our study participants, we observed a significant, consistent relationship between measurements of oxidation resistance and plasma content of vitamin E. In the multivariate regression model, a high plasma content of vitamin E or lipid standardised vitamin E concentration were the most important determinants of lag time to maximal oxidation rate (standardised regression coefficient = 0.244, P < 0.0001 for vitamin E and 0.211, P < 0.0001 for lipid standardised vitamin E). After statistical adjustment for age, use of cigarettes, hypolipidemic medication (yes vs. no), month of the measurements, plasma concentrations of total ascorbic acid (ascorbic acid + dehydroascorbic acid), beta-carotene and phospholipids, serum concentrations of LDL cholesterol and triglycerides and dietary intake of linoleic acid, the lag time to maximal oxidation rate was 10% (95% C.I. 6.0-13.5%) longer in men in the highest fifth than in the lowest fifth of plasma vitamin E content (P < 0.0001 for trend). When the fifths of lipid standardised vitamin E were compared, the lag time to maximal oxidation rate was 6% (95% C.I. 1.8-10.1%) longer in men in the highest than in the lowest fifth (P < 0.0001 for trend). Our data suggest that alpha-tocopherol is an important antioxidant preventing the in vitro oxidation of VLDL + LDL fraction even in non-supplemented subjects.

Antioxidative efficacy of parallel and combined supplementation with coenzyme Q10 and d-α-Tocopherol in mildly hypercholesterolemic subjects: a randomized placebo-controlled clinical study

It has been claimed that coenzyme Q10 (Q10) would be an effective plasma antioxidant since it can regenerate plasma vitamin E. To test separate effects and interaction between Q10 and vitamin E in the change of plasma concentrations and in the antioxidative efficiency, we carried out a double-masked, double-blind clinical trial in 40 subjects with mild hypercholesterolemia undergoing statin treatment. Subjects were randomly allocated to parallel groups to receive either Q10 (200 mg daily), d-α-tocopherol (700 mg daily), both antioxidants or placebo for 3 months. In addition we investigated the pharmacokinetics of Q10 in a separate one-week substudy. In the group that received both antioxidants, the increase in plasma Q10 concentration was attenuated. Only vitamin E supplementation increased significantly the oxidation resistance of isolated LDL. Simultaneous Q10 supplementation did not increase this antioxidative effect of vitamin E. Q10 supplementation increased and vitamin E decreased significantly the proportion of ubiquinol of total Q10, an indication of plasma redox status in vivo. The supplementations used did not affect the redox status of plasma ascorbic acid. In conclusion, only vitamin E has antioxidative efficiency at high radical flux ex vivo. Attenuation of the proportion of plasma ubiquinol of total Q10 in the vitamin E group may represent in vivo evidence of the Q10-based regeneration of the tocopheryl radicals. In addition, Q10 might attenuate plasma lipid peroxidation in vivo, since there was an increased proportion of plasma ubiquinol of total Q10.