Plasma vitamin A and E in type 1 (insulin-dependent) and type 2 (non-insulin-dependent) adult diabetic patients.

Vitamin A and E status was studied in 35 type 1 (insulin-dependent) and 35 type 2 (non-insulin-dependent) diabetic patients and in 30 control subjects. Vitamin A blood concentration was significantly decreased in type 1 and increased in type 2 diabetic patients as compared to control subjects. No correlation was found between vitamin A blood concentration and blood glucose control as evaluated with HbA1c. Blood Vitamin E concentrations were significantly increased in both groups of diabetic patients and were statistically correlated with blood cholesterol, apoprotein B and triglycerides, but not with HbA1c.     

Comparison of vitamin E levels in plasma,bronchoalveolar lavage,and lung tissues of adult pulmonary patients.

Plasma, bronchoalveolar lavage fluids (BAL), and lung parenchyma were analyzed for vitamin E and polyunsaturated fatty acid (PUFA) concentrations in three groups of patients routinely receiving oxygen therapy–two with adult respiratory distress syndrome (ARDS and SARDS), a third with pneumonia (PNEU), as well as a fourth group of patients receiving little or no oxygen therapy (OTHER). Only plasma alpha- and gamma-tocopherols were significantly lower in patients receiving oxygen therapy compared to those not requiring oxygen. Among diagnosis groups, PNEU patients exhibited highest levels of alpha-tocopherol in BAL, though all groups on oxygen had greater amounts of alpha-tocopheryl quinone in BAL as compared to those of the OTHER group. No significant differences in BAL measures were observed between oxygen and non-oxygen groups, however. No statistical tests on lung measures could be performed between these groups because of insufficient sampling for the OTHER group. A highly significant relationship was observed (r = +0.73, p less than 0.004) between plasma vitamin E and lung vitamin E when expressed in terms of PUFA, whereas no significant relationship was observed if plasma vitamin E and lung vitamin E levels were compared directly. No relationship was obtained for BAL alpha-tocopherol (expressed per number of cells) and lung alpha-tocopherol. These findings support previous reports that in an appropriate setting plasma vitamin E:PUFA ratios along with smoking status may be used to evaluate lung vitamin E levels when also expressed in terms of PUFA.     

Comparison of vitamin E levels in plasma, bronchoalveolar lavage, and lung tissues of adult pulmonary patients

Plasma, bronchoalveolar lavage fluids (BAL), and lung parenchyma were analyzed for vitamin E and polyunsaturated fatty acid (PUFA) concentrations in three groups of patients routinely receiving oxygen therapy--two with adult respiratory distress syndrome (ARDS and SARDS), a third with pneumonia (PNEU), as well as a fourth group of patients receiving little or no oxygen therapy (OTHER). Only plasma alpha- and gamma-tocopherols were significantly lower in patients receiving oxygen therapy compared to those not requiring oxygen. Among diagnosis groups, PNEU patients exhibited highest levels of alpha-tocopherol in BAL, though all groups on oxygen had greater amounts of alpha-tocopheryl quinone in BAL as compared to those of the OTHER group. No significant differences in BAL measures were observed between oxygen and non-oxygen groups, however. No statistical tests on lung measures could be performed between these groups because of insufficient sampling for the OTHER group. A highly significant relationship was observed (r = +0.73, p less than 0.004) between plasma vitamin E and lung vitamin E when expressed in terms of PUFA, whereas no significant relationship was observed if plasma vitamin E and lung vitamin E levels were compared directly. No relationship was obtained for BAL alpha-tocopherol (expressed per number of cells) and lung alpha-tocopherol. These findings support previous reports that in an appropriate setting plasma vitamin E:PUFA ratios along with smoking status may be used to evaluate lung vitamin E levels when also expressed in terms of PUFA.     

Effects of dietary vitamin E and high supplementation of vitamin C on plasma glucose and cholesterol levels

Weanling male Sprague Dawley rats were fed ad libitum a purified basal diet free of vitamins E and C. In Experiment I (4 weeks), 24 rats were divided into four groups with 2×2 factorial design. They were supplemented with 0 or 45 IU/kg diet of vitamin E, and O or 2.0 g/kg diet of vitamin C. In Experiment II (16 weeks), 36 rats were divided into six groups with 2×3 factorial design. Vitamin E was supplemented at the level of O or 45 IU/kg diet, and vitamin C was supplemented at the level of O, 1.5, or 3.0 g/kg diet, respectively. Plasma glucose level and cholesterol level were determined in both experiments. The plasma levels of glucose and cholesterol were significantly and negatively correlated. Plasma glucose level was significantly increased and plasma cholesterol level significantly decreased by the high supplementation of vitamin C with or without vitamin E in the diet. Vitamin E deficiency decreased plasma glucose level and increased plasma cholesterol level significantly with or without vitamin C supplementation. The groups with adequate level of vitamin E (45 IU/kg diet) and no vitamin C showed moderate plasma glucose and cholesterol levels.     

Effect of concomitant consumption of fish oil and vitamin E on T cell mediated function in the elderly: a randomized double-blind trial

OBJECTIVES: To determine if concomitant consumption of fish oil and vitamin E would modify the vitamin E level needed for improving T cell mediated function in elderly. METHODS: A randomized and double-blind study was conducted using 40 healthy male and female elderly subjects (>65 y) who were randomly assigned to one of 4 groups (n = 10/group). All the subjects received 5 g of fish oil daily containing 1.5 g eicosapentaenoic acid (EPA) and 1 g docosahexaenoic acid (DHA), and a capsule containing different doses of dl-alpha-tocopherol (0, 100, 200 or 400 mg/day) for 3 mo. Plasma vitamin E and fatty acid levels, and in vivo [delayed-type hypersensitivity skin response (DTH) and T cell sub-population analysis] and ex vivo [mitogen-stimulated peripheral blood mononuclear cells (PBMC) proliferation and interleukin (IL)-2 production] immune functions were determined at baseline and after supplementation. RESULTS: The control group (fish oil only) did not show a statistically significant change in either DTH or PBMC proliferation. DTH response, however, was significantly increased from baseline in all groups supplemented with fish oil plus vitamin E and a significant positive correlation between DTH response and plasma concentrations of alpha-tocopherol was observed. PBMC proliferation was only significantly increased in the group supplemented with fish oil plus 200 mg vitamin E. However, the changes caused by fish oil plus vitamin E in either DTH or PBMC proliferation were not significantly different from those observed in control group. Plasma levels of alpha-tocopherol were significantly increased in all three fish oil plus vitamin E groups and the increase in plasma alpha-tocopherol level was less profound than that previously reported when vitamin E was given alone. CONCLUSIONS: The immuno-enhancing effect of vitamin E in the elderly is dampened when it is concomitantly consumed with fish oil. This may be due to the smaller increase in plasma concentrations of vitamin E in the presence of fish oil.     

Vitamin E in plasma and platelets of human diabetic patients and control subjects

Vitamin E concentrations were determined in plasma and platelet samples from 23 diabetic and 30 control human subjects. The mean concentrations of alpha and total tocopherols in the plasma and platelets of the diabetics were higher than that of the controls. The mean gamma tocopherol concentrations in both plasma and platelets were similar in diabetics and controls. The platelet vitamin E concentrations decreased significantly with age in only the controls and not in the diabetics. Thus diabetics have higher concentrations of tocopherols in blood platelets and plasma. The total plasma tocopherol concentrations correlated significantly with total plasma cholesterol, triglyceride, and total lipid concentrations in both diabetic and control groups. However, no significant correlations were observed between platelet tocopherol levels and plasma lipids in either group. In five subjects plasma and platelet vitamin E concentrations remained unchanged during standard glucose tolerance tests.     

Effects of alpha-tocopherol supplementation and continuous subcutaneous insulin infusion on oxidative stress in Korean patients with type 2 diabetes

BACKGROUND: Most Koreans with type 2 diabetes are insulin deficient and insulin resistant. Continuous subcutaneous insulin infusion (CSII) provides a suitable amount of insulin to overcome insulin deficiency and achieve near-normal blood glucose concentrations. Our previous study showed, however, that CSII does not reduce oxidative stress even though it normalizes blood glucose concentrations. OBJECTIVE: The purpose of this study was to determine whether CSII plus alpha-tocopherol supplementation for 2 mo would alter oxidative stress in Korean patients with type 2 diabetes. DESIGN: Ninety-eight subjects received CSII plus either 200 mg alpha-tocopherol/d (n = 48) or a placebo (n = 50) for 2 mo. The general characteristics (age, duration of diabetes, body mass index, and blood glucose concentrations) of the 2 groups were not significantly different. RESULTS: Fasting and postprandial blood glucose concentrations of all subjects were normalized after CSII. Fasting plasma insulin concentrations did not differ significantly between the 2 groups after CSII. Lipid peroxide concentrations in plasma and red blood cells decreased and alpha-tocopherol concentrations in plasma and red blood cells increased after alpha-tocopherol supplementation. However, these changes were not affected significantly by CSII. Plasma vitamin C concentrations increased significantly after CSII plus alpha-tocopherol supplementation. However, the activities of antioxidant enzymes in red blood cells did not change significantly after CSII plus alpha-tocopherol supplementation. CONCLUSION: alpha-Tocopherol supplementation was beneficial in decreasing blood lipid peroxide concentrations without altering antioxidant enzyme activities in Korean patients with type 2 diabetes treated with CSII.     

Effect of plant sterols and glucomannan on lipids in individuals with and without type II diabetes

OBJECTIVE: The purpose of this study was to determine whether supplements of plant sterols and/or glucomannan improve lipid profile and cholesterol biosynthesis in mildly hypercholesterolemic type II diabetic and non-diabetic subjects and to compare the response of these two subject groups to the treatments. DESIGN: A randomized, crossover study consisting of four phases of 21 days, with each phase separated by a 28-day washout. SETTING: The Mary Emily Clinical Nutrition Research Unit of McGill University. SUBJECTS: Eighteen non-diabetic individuals and 16 type II diabetic individuals aged 38-74 years. INTERVENTIONS: Subjects were supplemented with plant sterols (1.8 g/day), glucomannan (10 g/day), a combination of glucomannan and plant sterols, and a placebo, provided in the form of bars. RESULTS: Overall plasma cholesterol concentrations were lowered (P<0.05) after combination treatment (4.72+/-0.20 mmol/l) compared to control (5.47+/-0.18 mmol/l). Plasma low-density lipoprotein (LDL) cholesterol concentrations were decreased (P<0.05) after glucomannan (3.16+/-0.14 mmol/l) and combination treatments (2.95+/-0.16 mmol/l) compared to control (3.60+/-0.16 mmol/l). The results of lipid profiles did not differ between subject groups. Overall plasma lathosterol concentrations, an index of cholesterol biosynthesis, were lowered (P<0.05) after the combination treatment compared to the plant sterol treatment. CONCLUSIONS: The results suggest that glucomannan and a combination of glucomannan and plant sterols substantially improves plasma LDL cholesterol concentrations. SPONSORSHIP: Forbes Medi-Tech Inc., Vancouver, British Columbia, Canada.     

Effects of a dietary oxidized fat on cholesterol in plasma and lipoproteins and the susceptibility of low-density lipoproteins to lipid peroxidation in guinea pigs fed diets with different concentrations of vitamins E and C

To investigate the effect of a dietary oxidized fat on the concentrations of cholesterol in liver, plasma, and lipoproteins and the susceptibility of low-density lipoproteins (LDL) to lipid peroxidation, and to explore the effects of vitamins E and C, male guinea pigs were divided into five groups. Four groups were fed diets with an oxidized fat supplemented with 35 or 175 mg alpha-tocopherol equivalents/kg and 300 or 1000 mg of vitamin C/kg for 29 days. One group, used as a control, was fed the same basal diet with fresh fat with 35 mg alpha-tocopherol equivalents/kg and 300 mg of vitamin C/kg. Guinea pigs fed the oxidized-fat diets, irrespective of dietary vitamin E and C concentrations, had significantly lower concentrations of total cholesterol in the liver and a lower concentration of cholesterol in LDL than the control animals fed the fresh fat. According to the lag time before onset of lipid peroxidation, LDL of guinea pigs fed the oxidized-fat diet with 35 mg alpha-tocopherol equivalents and 300 mg vitamin C/kg were significantly more susceptible to copper-induced lipid peroxidation than those of guinea pigs fed the fresh fat diet. Within the groups fed the oxidized fat diets, increasing the dietary vitamin E concentration from 35 to 175 mg/kg significantly (p < 0.05) and increasing the dietary vitamin C concentration from 300 to 1000 mg/kg in tendency (p < 0.10) reduced the susceptibility of LDL to oxidation. LDL of guinea pigs fed the oxidized fat diets with 175 mg alpha-tocopherol equivalents/kg were even more resistant to oxidation than LDL of guinea pigs fed the fresh diet. In conclusion, the study shows that dietary oxidized fat influences the cholesterol metabolism and the susceptibility of LDL to lipid peroxidation; the latter can be modified by dietary vitamins E and C.     

Age-related changes in plasma lycopene concentrations, but not in vitamin E, are associated with fat mass

The aim of the present study was to assess the influence of age on plasma concentration of alpha-tocopherol, retinol and carotenoids with a special attention paid to natural differences in body composition. Forty healthy subjects were recruited: twenty were less than 35 years old and twenty above 60 years old. Males and females were equally represented in each age group. Subjects were kept in energy balance and received controlled diets for 36 h. Fat mass and fat-free mass were determined with the (18)0-enriched water dilution technique. Plasma vitamins A and E, and carotenoid levels were determined after 12 h fasting and were shown to be similar in women and men. Plasma alpha-tocopherol concentration increased with age (+44 % elderly v. young), and correlated with % fat mass and plasma cholesterol. After adjustment for plasma cholesterol, the effect of age and % fat mass disappeared. In contrast, plasma lycopene level was 2-fold lower in the elderly than in the young group, and was inversely correlated with fat mass. When lycopene values were adjusted for fat mass, the effect of age disappeared. These results suggest that plasma levels of vitamin E and lycopene differed in the two age groups and that differences in plasma cholesterol and fat mass might participate in such an effect. Short-term vitamin intake did not appear to influence plasma vitamin concentrations.     

Plasma and red blood cell vitamin E status of patients on total parenteral nutrition

Plasma and red blood cell (RBC) tocopherol isomer (alpha, beta, delta, and gamma) concentrations were measured prior to, and following total parenteral nutrition (TPN), with Intralipid. Before feeding, nine of 13 patients had plasma total tocopherol levels less than 0.6 mg/dl (normal range 0.63-1.24 mg/dl) and 10 of 13 had total RBC tocopherol levels less than 0.2 mg/dl (normal range (0.20-0.39 mg/dl). Following 7 days TPN plasma vitamin E status increased significantly (p less than 0.001). However, this was due mostly to increases in the circulating level of beta + gamma-tocopherols. RBC vitamin E status was also significantly increased (p less than 0.001) following TPN, however, this was again due to incorporation of non-alpha-tocopherols. In a second study a alpha-tocopherol supplement, Vitlipid N, (9.1 mg alpha-tocopherol/day) was included in the feed. In these patients, large increases in plasma concentrations of non-alpha-tocopherol isomers were accompanied by an apparent improvement in alpha-tocopherol status (0.64 vs 0.44 mg/dl after 7 days). However, RBC alpha-tocopherol concentration did not change appreciably in these patients following either 7 or 14 days feeding. It is concluded that RBC vitamin E status is markedly influenced by the available plasma tocopherol pool and that provision of a small supplement of alpha-tocopherol is not sufficient to compete with the high concentration of non-alpha-isomers present in Intralipid. TPN utilizing fat emulsions containing high levels of non-alpha-tocopherol isomers (even when accompanied by alpha-tocopherol supplements) does not improve alpha-tocopherol status.     

Plasma retinol and a-tocopherol status of the Taiwanese elderly population

Biochemical assessment of vitamin A and vitamin E status of Taiwanese elderly persons was conducted by quantitative analysis of the concentration of retinol and alpha-tocopherol in plasma samples collected in the Elderly Nutrition and Health Survey in Taiwan (1999-2000). Plasma samples were analyzed by a reverse phase HPLC that can detect retinol and alpha-tocopherol simultaneously. The mean (SE) plasma retinol and alpha-tocopherol values in the 2373 valid samples were 2.73 (0.03) and 27.12 (0.47) microM, respectively, after weighting to the whole population using the SUDDAN program. Among the elderly persons studied, 99.52% of the population demonstrated normal plasma vitamin A status (plasma retinol equal to or greater than 0.7 microM or 0.2 microg/mL). The prevalence of deficient (less than 11.63 microM or 5 microg/mL) and marginal (greater than or equal to 11.63, but less than 16.28 microM or 7 g/mL) plasma alpha-tocopherol concentrations in the elderly population in Taiwan were 2.91% and 10.61%, respectively. However, the prevalence of low or inadequate vitamin E status decreased to 4.20% when the plasma alpha-tocopherol/cholesterol ratio was used as the indicator (less than 2.8 microg/mg). Results of the multiple linear regression analysis revealed that serum lipids had a strong influence on plasma alpha-tocopherol concentration. The results also showed that elderly men, those living in two Central Taiwan regions, and subjects with plasma cholesterol levels higher than 200 or lower than 174 mg/dL all had higher risk of low or inadequate alpha-tocopherol status than their counterparts. In conclusion, the plasma vitamin A and vitamin E status in the Taiwanese elderly are comparable to those reported for adults of developed Western societies.     

Plasma folate levels in men with type 2 diabetes

Limited data suggest that folate levels are higher in patients with type 2 diabetes than in subjects with normal glucose tolerance (NGT). We compared the fasting plasma folate, glucose (FPG), body mass index (BMI), and supplementary vitamin use among male subjects with NGT, those with impaired glucose tolerance (IGT), those with newly diagnosed type 2 diabetes, and those with previously diagnosed type 2 diabetes. Plasma folate of patients with newly diagnosed diabetes and that of patients with previously diagnosed diabetes was significantly higher than that of NGT subjects (p < 0.001). Prevalence of vitamin use was lower in newly diagnosed or previously diagnosed diabetic patients compared with non-diabetic subjects. Self-rated vegetable intake was similar among the four groups. FPG, BMI, triglycerides, and systolic blood pressure correlated with plasma folate levels independently of lifestyle factors studied. These results suggest that plasma folate levels are elevated in male diabetic patients independently of health-conscious behavior that is recommended for diabetic people.     

Vitamin E status of Alaskan Eskimos.

A survey was conducted during 1971-1973 on the vitamin E status of Alaskan Eskomos. The subjects were 315 residents of the northern coastal villages of Wainwright and Point Hope and the southwestern inland villages of Kasigluk and Nunapitchuk. Plasma vitamin E levels for the 6- to 17-year-old subjects at Wainwright, Point Hope, and Nunapitchuk were 0.81 plus or minus 0.26, 0.90 plus or minus 0.20, and 0.84 plus or minus 0.25 mg/100 ml (mean and standard deviation), respectively. The values for adults at Wainwright, Point Hope, and Kasigluk were 1.23 plus or minus 0.27, 1.23 plus or minus 0.27, and 1.27 plus or minus 0.33 mg/100 ml, respectively. No value less than 0.30 mg/100 ml was observed. Alpha-tocopherol was the only isomer present in significant amounts. Plasma vitamin E levels did not change significantly between 6 and 17 years of age; however, a steady increase with age was observed in the 18- to 69-year-old groups. Plasma alpha-tocopherol concentrations were significantly lower in children than in adults but there were no differences attributable to sex or geographic location. Vitamin E concentration in the blood plasma was linearly correlated with cholesterol concentration. Values are reported for the vitamin E content of some native foods. This study indicates that plasma vitamin E levels in Alaskan Eskimos consuming a high meat or fish diet are comparable to those in adults of the United States consuming a mixed diet.     

Retinol and alpha-tocopherol in serum of type 1 diabetic patients with intensive insulin therapy: a long term follow-up study

OBJECTIVE: We evaluated the effect of intensive insulin therapy and glycemic control in patients with type 1 diabetes on biochemical markers of vitamin A and E. METHODS: Fifty-seven patients with type 1 diabetes were enrolled in a follow-up study for 3 to 33 mo. At entrance, all patients were on conventional insulin therapy or recently had been diagnosed with the disease. Intensive insulin therapy (multiple daily glycemia records and at least three insulin doses daily) was established, and every 3 to 6 mo patients were screened for clinical, biochemical, and hematologic indexes. Biochemical markers of vitamin A and E nutrition status were measured at each visit by a quality-controlled high-performance liquid chromatography. RESULTS: At entrance, serum retinol concentrations, but not the ratio of alpha-tocopherol to cholesterol, showed a negative correlation with increasing values of HbA1c and insulin dose, neither of which was significant in multiple regression models. With intensive insulin therapy, a trend to normalize parameters of glycemic control (HbA1c and fructosamine) was observed within subjects and on a group level. However, no significant changes were observed in serum retinol or alpha-tocopherol:cholesterol ratio according to the metabolic control of the disease. CONCLUSIONS: Patients with type 1 diabetes under intensive insulin therapy tend to normalize the clinical parameters of glycemic control, although this improvement does not significantly affect biochemical markers of vitamin A and E status.     

Effects of vitamin E on toxicity by minute amounts of paraquat fed continuously to rats

The effects of vitamin E on toxicity by minute amounts of paraquat fed continuously for some period to rats were investigated. Two experiments were carried out as experiments 1 and 2. In both experiments, weaning rats were divided at first into two groups; one group was given a vitamin E-deficient diet, and the other a vitamin E-supplemented control diet (50 mg alpha-tocopherol/kg of diet). They were fed on these diets for 40 days. After that, in both experiments, the rats that had been fed the vitamin E-deficient diet were further divided into two groups, which were either given a paraquat-added diet (+PQ-E) or continuously fed the same vitamin E-deficient diet (-E). The amount of paraquat added was 250 mg of methyl viologen per kg of diet. After the addition of paraquat, these two groups were pair-fed. In experiment 1, paraquat was given to all the rats fed the vitamin E-supplemented control diet (+PQ+E). In experiment 2, rats fed the control diet were divided into paraquat-added (+PQ+E) and non-paraquat-added (+E) groups, similar to those of vitamin E-deficient rats. These two groups were also pair-fed thereafter. In both experiments, about 35 days after paraquat addition, they were sacrificed. Plasma and liver alpha-tocopherol contents were measured by HPLC, and liver peroxidation value was measured by chemiluminescence and the TBA method. And, as parameters of vitamin E deficiency, plasma pyruvate kinase and GOT activities and alpha-cysteine proteinase inhibitor (alpha-CPI) level were measured. When the analyzed values were compared between paraquat-added and the corresponding not-added control groups (+PQ-E vs. -E, +PQ+E vs. +E), the following results were obtained. In experiment 1, the values of plasma and liver alpha-tocopherol levels were significantly lower in the +PQ-E group than those of the -E group; however, liver peroxidation values and values of the three parameters of vitamin E deficiency were not different significantly. In experiment 2, the value of liver alpha-tocopherol level was significantly lower in the +PQ+E group than that of the +E group.(ABSTRACT TRUNCATED AT 400 WORDS)     

Disposition kinetics and dosage regimen of vitamin E administered intramuscularly to sheep

Three experiments were conducted to estimate the effects of single intramuscular (IM) administrations of vitamin E on blood plasma and tissue concentrations of alpha-tocopherol in sheep. In Expt 1, plasma kinetics of alpha-tocopherol in sheep (n 30) were investigated following IM administration of three doses (ten sheep/dose) of DL-alpha-tocopheryl acetate, (20, 40 and 60 mg/kg live weight). Plasma profiles of alpha-tocopherol consisted of a lag phase followed by an apparent first-order absorption and elimination phase. The rate of absorption and elimination, as well as the lag phase, were independent of the dose, but the extent of absorption was directly proportional to dose. In Expt 2 (eighteen experimental and five control sheep), the animals were injected as in Expt 1 and were killed at 0, 80 and 176 h. Increases in alpha-tocopherol levels in organs were much higher than in plasma. Some tissues such as liver, spleen, lung and adrenal appeared to exhibit rapid absorption and elimination phases. The amount absorbed was proportional to the dose administered. Other organs such as heart, kidney and pancreas had a slow elimination rate. In Expt 3, D-alpha-tocopherol was injected IM into ten sheep at either 604 mg or 1208 mg. The mean hepatic alpha-tocopherol concentrations in both groups rose rapidly and after 4 weeks of dosing its concentrations were higher than the predosing levels. The increase in hepatic tocopherol concentrations were higher following 1208 mg dosing than 604 mg D-alpha-tocopherol. No simple relationship existed between plasma and hepatic alpha-tocopherol concentrations. This suggests a difference in body mechanisms controlling vitamin E in blood and liver.     

Effect of oral contraceptives on plasma lipoproteins,cholesterol and alpha-tocopherol levels in young women

The effects of oral contraceptives (OC) on plasma lipoprotein, cholesterol, and alpha-tocopherol levels were studied in 400 women volunteers. OC use caused plasma cholesterol levels to increase by about 7% and tocopherol levels to decrease by about 20%. The changes in cholesterol and tocopherol levels were significantly greater in women receiving vitamin E supplements (p less than .03; p less than .04, respectively). Plasma alpha-lipoproteins increased by 16%, while beta-lipoprotein levels decreased by 20%, resulting in a 30% decrease in the alpha-beta ratio. OC use diminished the usually high correlation between tocopherol and beta-lipoproteins. Plasma triglyceride and total lipid levels were significantly increased among OC users (p less than .05). Since the most pronounced changes occurred in the early stages of OC treatment, an adaptation with time is suggested.     

Antibodies against low density oxidized lipoproteins in type 2 diabetics

Oxidative modification of low density lipoproteins (LDL) is an important factor in the development of macrovascular atherosclerotic complications in patiens with type 2 diabetes mellitus. Recently autoantibodies against oxidized LDL (anti-oxLDL) have been suggested as a potential marker of LDL oxidation in vivo. The purpose of this study was to investigate the presence and levels of anti-oxLDL in patients with type 2 diabetes compared to healthy persons. We determined the serum concentrations of anti-oxLDL in 20 type 2 diabetic patiens with different degree and type of atherosclerotic vascular damage. Two healthy population groups: 20 young blood donors and 20 age and gender matched persons were used as controls. Anti-oxLDL positivity rates were distinctively higher in both control groups. Concentrations of anti-oxLDL were significantly lower in diabetic patients compared to both control groups. The incidence rates and levels of anti-oxLDL in both control groups were similar. Anti-oxLDL levels in the diabetes group did not correlate with the degree of macrovascular damage, serum total cholesterol, LDL cholesterol and triglyceride concentrations. We did not find any significant relationship between anti-oxLDL and other oxidative stress factors (superoxide dismutase, malondialdehyde, C and E vitamins). We suppose that anti-oxLDL may have an antiatherogenic protective role in healthy people but are not applicable to be an in vivo marker of LDL oxidation and macrovascular atherosclerotic vascular damage.     

Influence of apolipoprotein E phenotype on metabolism of lipids and apolipoproteins after plant stanol ester ingestion in Japanese subjects

OBJECTIVE: We investigated the effect of apolipoprotein E phenotype on changes in plasma levels of lipids and apoproteins by plant stanol ester (PSE) ingestion in Japanese subjects whose diet is low in fat and cholesterol. METHODS AND RESULTS:The effect of PSE-containing spread was studied in a randomized, placebo-controlled trial. One hundred five healthy volunteers were enrolled for this study. Apolipoprotein E phenotyping was done in 96 of 105 subjects. We compared plasma levels at the start and end of the test period (4 wk). The daily ingestion of 2 g of plant stanols from the PSE spread significantly reduced plasma levels of low-density lipoprotein cholesterol by 8.9 +/- 6.6% (mean +/- standard deviation) in the E(3) group and 10.4 +/- 8.0% in the E(4) group. The daily ingestion of 2 g of plant stanols from the PSE spread significantly decreased plasma levels of apoprotein B by 5.4 +/- 7.9% in the E(3) group and 8.9 +/- 7.0% in the E(4) group. No further reductions of low-density lipoprotein cholesterol and apoprotein B were observed with 3 g/d of plant stanols from the PSE spread. CONCLUSION: The ingestion of PSE spread significantly reduced plasma levels of total cholesterol, low-density lipoprotein cholesterol, and apoprotein B. However, the response to PSE ingestion was not influenced by apolipoprotein E phenotype.