ascorbic-acid and Hyperlipidemia--Familial-Combined

To measure endothelium-dependent vascular relaxation in children with two genetic hyperlipidemias and to assess the effect of antioxidant vitamins on endothelial dysfunction.. Vascular reactivity in the brachial artery was measured in 45 individuals between 6 and 21 years of age (18 with familial hypercholesterolemia [FH], 15 with familial combined hyperlipoproteinemia [FCH], 12 control subjects) with the use of high-resolution two-dimensional ultrasonography. Follow-up studies were done for 11 children after 6 weeks of treatment with tocopherol (400 IU twice a day) and ascorbic acid (500 mg twice a day).. The mean percent change in diameter during reactive hyperemia was 2.1 +/- 2.2 (SD) and 2.7 +/- 4.4, in FH and FCH, respectively, compared with 12. +/- 4.9 among control subjects (p < 0.001 in each case). The mean percent dilation was significantly increased (2.8 +/- 1.6 to 9.1 +/- 2.3) (p < 0.001) after antioxidant therapy.. Impaired endothelium-dependent vasoregulation occurs in children with FCH as well as in those with FH. The improvement in vascular reactivity observed during supplementation with antioxidant vitamins suggests that reactive oxygen species derived from oxidized lipoproteins may be responsible for the impairment of vasoregulation in subjects with hyperlipidemia.

Topics: Adolescent; Adult; Ascorbic Acid; Brachial Artery; Child; Endothelium, Vascular; Female; Humans; Hyperlipidemia, Familial Combined; Hyperlipoproteinemia Type II; Male; Nitric Oxide; Vasodilation; Vitamin E

The effects of marine omega-3 polyunsaturated fatty acids (FAs) and antioxidants on the oxidative modification of LDL were studied in a randomized, double-blind, placebo-controlled trial. Male smokers (n = 41) with combined hyperlipidemia were allocated to one of four groups receiving supplementation with omega-3 FAs (5 g eicosapentaenoic acid and docosahexaenoic acid per day), antioxidants (75 mg vitamin E, 150 mg vitamin C, 15 mg beta-carotene, and 30 mg coenzyme Q10 per day), both omega-3 FAs and antioxidants, or control oils. LDL and human mononuclear cells were isolated from the patients at baseline and after 6 weeks of supplementation. LDL was subjected to cell-mediated oxidation by the patients' own mononuclear cells, as well as to Cu(2+)-catalyzed and 2,2'-azobis-(2-amidinopropane hydrochloride) (AAPH)-initiated oxidation. Extent of LDL modification was measured as lag time, the formation rate of conjugated dienes (CDs), the maximum amount of CDs formed, formation of lipid peroxides, and the relative electrophoretic mobility of LDL on agarose gels. Dietary supplementation with omega-3 FAs increased the concentration of total omega-3 FAs in LDL and reduced the concentration of vitamin E in serum. The omega-3 FA-enriched LDL particles were not more susceptible to Cu(2+)-catalyzed, AAPH-initiated, or autologous cell-mediated oxidation than control LDL. In fact, enrichment with omega-3 FAs significantly reduced the formation rate of CDs when LDL was subjected to AAPH-induced oxidation. Supplementation with moderate amounts of antioxidants significantly increased the concentration of vitamin E in serum and increased the resistance of LDL to undergo Cu(2+)-catalyzed oxidation, measured as increased lag time, reduced formation of lipid peroxides, and reduced relative electrophoretic mobility compared with control LDL. Supplementation with omega-3 FAs/antioxidants showed oxidizability of LDL similar to that of control LDL and omega-3 FA-enriched LDL. In conclusion, omega-3 FAs neither rendered the LDL particles more susceptible to undergo in vitro oxidation nor influenced mononuclear cells' ability to oxidize autologous LDL, whereas moderate amounts of antioxidants protected LDL against oxidative modification.

Topics: Administration, Oral; Adult; Antioxidants; Ascorbic Acid; beta Carotene; Coenzymes; Copper; Double-Blind Method; Drug Synergism; Fatty Acids, Omega-3; Fish Oils; Humans; Hyperlipidemia, Familial Combined; Leukocytes, Mononuclear; Lipid Peroxidation; Lipoproteins, LDL; Male; Middle Aged; Oxidants; Oxidation-Reduction; Particle Size; Phospholipids; Smoking; Static Electricity; Ubiquinone; Vitamin E

Diet can influence on the balance between antioxidants and prooxidants in the organism. The activity of enzymatic components of antioxidant system can be changed, the amount of harmful substances can be increased. The purpose of this study was to assess the effect of diet on vitamin A, E, C serum concentration in patients with combined hyperlipidemia. The studied group consisted of 38 subjects, aged 20-60 years. Dietary assessment was based on 24-h dietary recall. Serum lipids concentrations were assessed by enzymatic methods, serum vitamins concentrations were assessed by HPLC method. The energy intake in men was 2269.6 kcal, vitamin A consumption was 888.3 microg, vitamin E 8.7 mg and vitamin C 68.6 mg. In women energy intake was 2112 kcal, consumption of vitamin A was 580 mcirog, vitamin E 7.8 mg and vitamin C 68.6 mg. Only in 1 men deficient concentration of vitamin C was stated. Deficient concentration of vitamin A was not found but the desirable concentration was stated only in 5 men. The desirable vitamin E level was found only in men, not in women. The correlation between vitamin intake and its serum level was not observed. However, in women the correlations between intake of protein, dietary fiber, percentage of energy derived from fat and vitamin A serum level were found. To conclude, the serum concentration of antioxidant vitamins is determined by diet composition, adequate in energy and nutrients content.

Topics: Adult; Antioxidants; Ascorbic Acid; Body Mass Index; Body Weight; Energy Intake; Female; Humans; Hyperlipidemia, Familial Combined; Lipids; Lipoproteins; Male; Middle Aged; Population Surveillance; Vitamin A; Vitamin E

Oxidative stress has been postulated to play important roles in the pathogenesis of various diseases such as atherosclerosis in hyperlipidemic subjects. Although the possible role of oxidation of low-density lipoprotein (LDL) in the etiology of atherosclerosis has been studied extensively, the turnover of endogenous antioxidants, which is an important protection system against oxidative stress, remains to be elucidated. The aim of our study was to determine the change of the turnover of endogenous antioxidants such as glutathione and ascorbic acid in case of hyperlipidemia, using Japanese white rabbits (JW) and Watanabe heritable hyperlipidemic rabbits (WHHL). The levels of total glutathione and low molecular weight thiols in the liver, kidney, and other organs in both strains of rabbits were similar. However, a kinetic analysis using L-buthionine-(S,R)-sulfoximine revealed that the rate of glutathione turnover in the liver and kidney of WHHL was about 50%) lower than that of JW. Furthermore, intravenously administered ascorbic acid disappeared more slowly in WHHL than in JW. These results indicate that the turnovers of both glutathione and ascorbic acid in WHHL are depressed in comparison with that in JW. These changes would be closely related to the increased oxidizability of lipids in the circulation of hyperlipidemic subjects.

Topics: Animals; Antioxidants; Arteriosclerosis; Ascorbic Acid; Disease Models, Animal; Glutathione; Hyperlipidemia, Familial Combined; Kidney; Lipoproteins, LDL; Liver; Male; Oxidative Stress; Rabbits