Navegando por Palavras-chave "hypercholesterolemia"
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- ItemSomente MetadadadosEndothelial dysfunction, oxidized lipoproteins and nitric oxide in hypercholesterolemia(Federacion Bioquimica Provincia Buenos Aires, 2002-06-01) Moriel, P.; Ajzen, Sergio Aron [UNIFESP]; Bertolami, Marcelo Chiara; Abdalla, Dulcineia Saes Parra [UNIFESP]; Universidade de São Paulo (USP); Inst Dante Pazzanese Cardiol; Universidade Federal de São Paulo (UNIFESP)Endothelial dysfunction plays an important role in the pathogenesis of coronary artery disease. Plasma cholesterol, particularly that associated to LDL, has been suggested to be an important risk factor in the development of cardiovascular diseases. Moreover, LDL oxidation is a crucial event in the pathogenesis of atherosclerosis, By the other hand, a reduced bioactivity of endothelial nitric oxide ((.)NO) has been implicated in the pathogenesis of atherosclerosis. The reduction of (.)NO activity in hypercholesterolemia and in other metabolic disorders associated with atherogenesis appears to be multifactorial, However, the alterations of (.)NO production in hypercholesterolemia is still controversial. The purpose of this study was to examine the relationship of lipid peroxidation, antioxidants and nitric oxide bioavailability with the impairment of endothelium dependent vasodilation in hypercholesterolemic (HC) (n = 18) and normolipidemic subjects (N) (n = 11). Ascorbate, urate, a-tocopherol, lycopene and beta-carotene, as well as, lipid hydroxyl hydroperoxides were determined by HPLC. Endothelin was determined by ELISA. The kinetics of LDL oxidation was monitored by incubating LDL with Cu(2+). Oxysterols were determined by GC. Mode B ultrasonography was used to measure the blood flow and diameter in response to reactive hyperemia of brachial artery. The concentrations of nitrate and S-nitrosothiols in blood plasma were determined by chemiluminescence elicited by reaction of (.)NO with ozone in the (.)NO analyzer (NOA(TM280), Sievers, Corp,), The content of nitrotyrosine of blood plasma and LDL was determined by a new chemiluminescence competitive ELISA developed in our laboratory with a polyclonal antibody, Plasma ascorbate, lipid soluble antioxidants, the resistance of LDL to oxidation (lag time) and the endothelium dependent vasorelaxation were lower in HC than in N. Lidid hydroxy / hydroperoxides, endothelin, nitrate, S- nitrosothiols, total cholesterol, apo B, LDL-nitrotyrosine and LDL-cholesterol were significantly higher in HC than in N subjects. LDL cholesterol was negatively correlated to the percentage of diameter increase in response to hyperemia, The concentration of lipid soluble antioxidants was inversely related to the impairment of endothelial dependent vasodilation, In conclusion, the high level of oxidized lipids and endothelin, associated to a decrease of antioxidants and (.)NO bioavailability, can play a role in the impairment of endothelial function, which is crucial to the development of atherosclerosis in hypercholesterolemic patients.
- ItemSomente MetadadadosIron overload in hypercholesterolemic rats affects iron homeostasis and serum lipids but not blood pressure(Amer Inst Nutrition, 2003-01-01) Turbino-Ribeiro, Silvana ML; Silva, Marcelo E.; Chianca, Deoclécio A.; Paula, Herberth de; Cardoso, Leonardo M.; Colombari, Eduardo; Pedrosa, Maria Lucia; Univ Fed Ouro Preto; Universidade Federal de São Paulo (UNIFESP)Epidemiologic and experimental data suggest that excess iron may contribute to the development of cardiovascular diseases (CVD). Because increased LDL cholesterol, decreased HDL cholesterol and alteration of systolic blood pressure (SBP) have all been implicated as risk factors for atherosclerosis and related CVD, the present study was designed to determine whether excess iron alters serum lipids and SBP in control and hypercholesterolemic rats. Female Fischer rats were divided into four groups. The control group (C) was fed the control diet, the Cl group was fed the control diet and given iron dextran injections, the hypercholesterolemic group (H) was fed a 1 g/100 g cholesterol diet, and the HI group was fed the cholesterol diet and given iron dextran injections. The rats were fed the diets for 8 wk and iron dextran injections were given during wk 6 at doses of 10 mg/d for 5 d. Excess iron reduced (P < 0.01) plasma total cholesterol in rats fed the cholesterol diet (5.31 +/- 0.83 and 3.17 +/- 0.31 mmol/L for H and HI], respectively). Excess iron also resulted in a redistribution of cholesterol among the various lipoprotein fractions, with an increase (P < 0.01) in HDL cholesterol (0.56 +/- 0.12 and 0.85 +/- 0.16 mmol/L for H and HI, respectively) and a decrease (P < 0.01) in LDL cholesterol (4.49 +/- 0.77 and 2.09 +/- 0.26 mmol/L for H and HI, respectively). This redistribution also occurred in the rats fed the control diet. The treatments did not affect SBP or heart rate. The high cholesterol diet affected iron homeostasis; group H had lower transferrin saturation than group C (P < 0.01); group HI had a lower serum iron concentration than group Cl but did not differ from group H (P < 0.05). Therefore, we conclude that if iron has any effect on CVD, it is not through its influence on serum lipids and blood pressure.
- ItemSomente MetadadadosOne-month therapy with simvastatin restores endothelial function in hypercholesterolemic children and adolescents(Springer, 2007-02-01) Ferreira, Waldinai Pereira; Bertolami, Marcelo Chiara; Santos, Simone Nascimento; Barros, Marcos Roberto A. C.; Matos Barretto, Rodrigo Bellio de; Pontes, Rgio Cunha; Pontes, Sergio Cunha; Fonseca, Francisco Hermann; Carvalho, Antonio Carlos; Universidade Federal de São Paulo (UNIFESP); Inst Dante Pazzanese CardiolSimvastatin has been shown to restore endothelial function in children with familial hypercolesterolemia after 28 weeks of treatment. the aim of this study was to evaluate 1-month simvastatin treatment effect on endothelial function in hypercholesterolemic children and adolescents. Eighteen hypercholesterolemic patients (HC group) and 18 healthy controls, aged 6-18 years, were studied with medical history, physical examination, full lipid profile, serum apolipoprotein B (apo B), fibrinogen, hepatic transaminases, and creatine kinase concentrations. Flow-mediated dilatation (FMD) was performed by high-resolution ultrasound of the brachial artery. the HC group received simvastatin 10 mg/day for 1 month. Arterial diameter was measured by two experienced sonographers who were unaware of subjects' conditions. At baseline, FMD was impaired in the HC group (mean, 5.27 +/- 4.67%) compared to controls (mean, 15.05 +/- 5.97%) (p < 0.001). After treatment, we observed a significant reduction in total cholesterol (TC) (29%), low-density lipoprotein cholesterol (LDL-C); (37%), apo B concentrations (36%) and FMD restoration (mean, 12.94 +/- 7.66%), with an absolute increase of 7.66 +/- 8.58 (p = 0.001). These results show that children and adolescents with hypercholesterolemia present endothelial dysfunction, and simvastatin, in addition to significantly reducing TC, LDL-C, and apo B concentrations, restores endothelial function with 1-month treatment.
- ItemAcesso aberto (Open Access)Prevenção da aterosclerose e tratamento medicamentoso de anormalidades lipídicas de alto risco em crianças e adolescentes(Sociedade Brasileira de Pediatria, 2009-02-01) Castro, Priscilla Severino Gonçalves De [UNIFESP]; Oliveira, Fernanda Luisa Ceragioli [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)OBJECTIVE: To discuss risk factors of atherosclerosis in pediatrics, dietary and physical activity guidelines, and, mainly, drug treatment of high-risk lipid abnormalities. SOURCES: Data were obtained from articles indexed in MEDLINE, published over the last 5 years. SUMMARY OF THE FINDINGS: Children with severe dyslipidemia or additional risk factors such as family history of early cardiovascular disease or other signs of metabolic syndrome may need treatment with hypolipidemic drugs. New recommendations from the U.S. guidelines indicate drug treatment before the age of 10 years according to the magnitude of the additional risk factors for cardiovascular disease. Pediatricians should know when to diagnose dyslipidemia, when to indicate drug treatment and which medication can be used in children and adolescents with the least risk or harm to their development. CONCLUSIONS: The first-line treatment of dyslipidemia consists of lifestyle changes, focusing on prevention. Children with high-risk lipid abnormalities should be considered for drug treatment. Decisions to be made together with the parents must be evaluated taking into consideration risks and benefits of the medication to the patient.