Increased ApoB/ApoA1 ratio is associated with excess weight, body adiposity, and altered lipid profile in children / A razão ApoB/ApoA1 aumentada está associada ao excesso de peso, de adiposidade corporal e ao perfil lipídico alterado em crianças

Abstract Objective: To investigate ApoB/ApoA1 ratio and its association with cardiovascular risk factors in children. Methods: Cross-sectional study with 258 children aged 8 and 9 years old, enrolled in all urban schools in the city of Viçosa-MG. Anthropometric and body composition assessment, as well as biochemical profile of the children was performed. Socioeconomic variables and sedentary lifestyle were evaluated through a semi-structured questionnaire. Results: Many children had excess weight (35.2%), abdominal adiposity (10.5%), and body fat (15.6%), as well as increased ApoB/ApoA1 ratio (14.7%), total cholesterol (51.8%), and triglycerides (19.8%). Children with excess weight and total and central fat had a higher prevalence of having a higher ApoB/ApoA1 ratio, as well as those with atherogenic lipid profile (increased LDL-c and triglycerides and low HDL-c). A direct association was found between the number of cardiovascular risk factors and the ApoB/ApoA1 ratio (p = 0.001), regardless of age and income. Conclusion: The increased ApoB/ApoA1 ratio was associated with excess weight, body adiposity (total and central), and altered lipid profile in children. Children with a higher number of cardiovascular risk factors had higher ApoB/ApoA1 ratio, in both genders.

Resumo Objetivo: Investigar a razão ApoB/ApoA1 e sua relação com fatores de risco cardiovascular em crianças. Métodos: Estudo transversal com 258 crianças de 8 e 9 anos, matriculadas em todas as escolas urbanas de Viçosa-MG. Foi feita avaliação antropométrica, da composição corporal e bioquímica das crianças. As variáveis socioeconômicas e o sedentarismo foram avaliados por questionário semiestruturado. Resultados: Muitas crianças apresentaram excesso de peso (35,2%), de adiposidade abdominal (10,5%) e de gordura corporal (15,6%), bem como a razão ApoB/ApoA1 (14,7%), colesterol-total (51,8%) e triglicerídeos (19,8%) aumentados. Crianças com excesso de peso e de gordura total e central apresentaram maiores prevalências de maior razão ApoB/ApoA1, bem como as com perfil lipídico aterogênico (LDL-c e triglicerídeos aumentados e baixo HDL-c). Foi encontrada associação direta entre o número de fatores de risco cardiovascular e a razão ApoB/ApoA1 (p = 0,001), independente da idade e renda. Conclusão: A razão ApoB/ApoA1 aumentada esteve associada ao excesso de peso, de adiposidade corporal (total e central) e ao perfil lipídico alterado nas crianças. As crianças com maior número de fatores de risco cardiovascular apresentaram maior razão ApoB/ApoA1, em ambos os sexos.

Increased ApoB/ApoA1 ratio is associated with excess weight, body adiposity, and altered lipid profile in children.

OBJECTIVE: To investigate ApoB/ApoA1 ratio and its association with cardiovascular risk factors in children. METHODS: Cross-sectional study with 258 children aged 8 and 9 years old, enrolled in all urban schools in the city of Viçosa-MG. Anthropometric and body composition assessment, as well as biochemical profile of the children was performed. Socioeconomic variables and sedentary lifestyle were evaluated through a semi-structured questionnaire. RESULTS: Many children had excess weight (35.2%), abdominal adiposity (10.5%), and body fat (15.6%), as well as increased ApoB/ApoA1 ratio (14.7%), total cholesterol (51.8%), and triglycerides (19.8%). Children with excess weight and total and central fat had a higher prevalence of having a higher ApoB/ApoA1 ratio, as well as those with atherogenic lipid profile (increased LDL-c and triglycerides and low HDL-c). A direct association was found between the number of cardiovascular risk factors and the ApoB/ApoA1 ratio (p=0.001), regardless of age and income. CONCLUSION: The increased ApoB/ApoA1 ratio was associated with excess weight, body adiposity (total and central), and altered lipid profile in children. Children with a higher number of cardiovascular risk factors had higher ApoB/ApoA1 ratio, in both genders.

Association of postalimentary lipemia with atherosclerotic manifestations

We identified different lipemic and metabolic responses after the ingestion of a standardized meal by healthy adults and related them to atherosclerotic markers. Samples from 60 normolipidemic adults were collected before and after a liquid meal (40 g fat/m² body surface) at 0, 2, 4, 6, and 8 h for measurements of lipids, free fatty acids (FFA), insulin, cholesteryl ester transfer protein (CETP), autoantibodies to epitopes of oxidized LDL (oxLDL Ab), lipolytic activities, and apolipoprotein E polymorphism. Mean carotid intima-media thickness (cIMT) was determined by Doppler ultrasound. The volunteers were classified into early (N = 39) and late (N = 31) triacylglycerol (TAG) responders to the test meal. Late responders showed lower HDL cholesterol concentration at fasting and in the TAG peak, lower insulin and higher FFA concentrations compared to early responders. Multivariate regression analyses showed that mean cIMT was associated with gender (male) and age in early responders and by cholesterol levels at the 6th hour in late responders. oxLDL Ab were explained by lipoprotein lipase and negatively by hepatic lipase and oxLDL Ab (fasting period) by CETP (negative) and FFA (positive). This study is the first to identify a postalimentary insulin resistance state, combined with a reduced CETP response exclusively among late responders, and the identification of the regulators of postalimentary atherogenicity. Further research is required to determine the metabolic mechanisms described in the different postalimentary phenotypes observed in this study, as well as in different pathological states, as currently investigated in our laboratory.

Association of postalimentary lipemia with atherosclerotic manifestations.

We identified different lipemic and metabolic responses after the ingestion of a standardized meal by healthy adults and related them to atherosclerotic markers. Samples from 60 normolipidemic adults were collected before and after a liquid meal (40 g fat/m² body surface) at 0, 2, 4, 6, and 8 h for measurements of lipids, free fatty acids (FFA), insulin, cholesteryl ester transfer protein (CETP), autoantibodies to epitopes of oxidized LDL (oxLDL Ab), lipolytic activities, and apolipoprotein E polymorphism. Mean carotid intima-media thickness (cIMT) was determined by Doppler ultrasound. The volunteers were classified into early (N = 39) and late (N = 31) triacylglycerol (TAG) responders to the test meal. Late responders showed lower HDL cholesterol concentration at fasting and in the TAG peak, lower insulin and higher FFA concentrations compared to early responders. Multivariate regression analyses showed that mean cIMT was associated with gender (male) and age in early responders and by cholesterol levels at the 6th hour in late responders. oxLDL Ab were explained by lipoprotein lipase and negatively by hepatic lipase and oxLDL Ab (fasting period) by CETP (negative) and FFA (positive). This study is the first to identify a postalimentary insulin resistance state, combined with a reduced CETP response exclusively among late responders, and the identification of the regulators of postalimentary atherogenicity. Further research is required to determine the metabolic mechanisms described in the different postalimentary phenotypes observed in this study, as well as in different pathological states, as currently investigated in our laboratory.

[Effect of conjugated linoleic acid (CLA) on human lipid profile]. / Efecto del ácido linoleico conjugado (CLA) sobre el perfil lipídico en humanos.

The term conjugated linoleic acid (CLA) concerns a group of isomers of linoleic acid, which are characterized by having conjugated double bonds in several positions and conformations. CLA is found naturally in some foods, but since CLA was first held to cause beneficial effects on various health-related issues, many investigations have been conducted to elucidate the effects of dietary supplementation with CLA. The effects of CLA on lipid profiles on animals have been extensively studied, and there is sound evidence of its benefits in blood metabolic markers. However, clinical trials in humans have provided ambiguous results. The aim of this review was to gather up-to-date available data about the effects of CLA on human lipid profile. Although most studies did not show any significant effect in none of the studied variables, some trials reported both beneficial and detrimental effects on total cholesterol, LDL-c, HDL-c, atherogenic index, triglycerides and lipoprotein(a). This discrepancy could be due to differences in dosage, isomer composition, duration of the study, placebo and participating subjects, among others. However, studies with a duration of two weeks, carried out using a mix of equal amounts of the two main CLA isomers (9-cis, 11-trans and 10-trans, 12-cis) and with doses of 3 to 4 grams per day, seem to offer the most beneficial results.

[Isolation of periodontal bacteria from blood samples and atheromas in patients with atherosclerosis and periodontitis]. / Aislamiento de bacterias periodontopáticas desde hemocultivos y ateromas obtenidos de pacientes con aterosclerosis y periodontitis.

BACKGROUND: Periodontitis is a common oral disease produced by bacterial species that reside in the subgingival plaque. These microorganisms have been associated to atherosclerosis and it is suggested that periodontitis is a cardiovascular risk factor. AIM: To isolate periodontal bacteria from blood and atheroma samples, from patients with atherosclerosis and periodontitis. MATERIAL AND METHODS: Twelve patients with periodontitis and a clinical diagnosis of atherosclerosis and 12 patients with periodontitis but without atherosclerosis were studied. Blood samples were obtained immediately before and after scaling and root planing. The samples were incubated in aerobic and anaerobic conditions. One week after scaling, atheromatous plaques were obtained during endarterectomy in the 12 patients with atherosclerosis. These were homogenized and cultured for aerobic and anaerobic bacteria. Microorganisms were identified by means ofPCR. RESULTS: Five patients with and two without atherosclerosis, had bacteremia after scaling and root planing. Bacterial species isolated from blood samples were the same found in periodontic pockets. Four atheromatous plaques of patients with bacteremia yielded positive cultures. The isolated bacteria were the same found in blood samples and periodontal pockets. CONCLUSIONS: Bacteremia occurred in seven of 24 patients after scaling and root planing. In four patients, the same species found in periodontic pockets and blood cultures were detected in atherosclerotic plaques obtained one week after the dental procedure.

Aislamiento de bacterias periodontop ticas desde hemocultivos y ateromas obtenidos de pacientes con aterosclerosis y periodontitis / Isolation of periodontal bacteria from blood samples and atheromas in patients with atherosclerosis and periodontitis

Background: Periodontitis is a common oral disease produced by bacterial species that reside in the subgingival plaque. These microorganisms have been associated to atherosclerosis and it is suggested that periodontitis is a cardiovascular risk factor. Aim: To isolate periodontal bacteria from blood and atheroma samples, from patients with atherosclerosis and periodontitis. Material and methods: Twelve patients with periodontitis and a clinical diagnosis of atherosclerosis and 12 patients with periodontitis but without atherosclerosis were studied. Blood samples were obtained immediately before and after scaling and root planing. The samples were incubated in aerobic and anaerobic conditions. One week after scaling, atheromatous plaques were obtained during endarterectomy in the 12 patients with atherosclerosis. These were homogenized and cultured for aerobic and anaerobic bacteria. Microorganisms were identified by means ofPCR. Results: Five patients with and two without atherosclerosis, had bacteremia after scaling and root planing. Bacterial species isolated from blood samples were the same found in periodontic pockets. Four atheromatous plaques of patients with bacteremia yielded positive cultures. The isolated bacteria were the same found in blood samples and periodontal pockets. Conclusions: Bacteremia occurred in seven of 24 patients after scaling and root planing. In four patients, the same species found in periodontic pockets and blood cultures were detected in atherosclerotic plaques obtained one week after the dental procedure.

Sex-dependent variables in the modulation of postalimentary lipemia.

OBJECTIVE: To quantify in young adults the sex-dependent differences in lipemic responses to a fat meal, we measured the association of these responses with markers of atherosclerosis and determined their metabolic regulators. METHODS: Forty-nine normolipidemic volunteers, 25 women and 24 men, were matched according to age, body mass index, waist circumference, diet, physical activity, and apolipoprotein-E phenotyping. After receiving a standardized fat meal (40 g of fat/m2 of body surface area), serial blood samples were drawn for laboratory analysis. Common carotid intima-media thickness was measured. RESULTS: The lipemic responses were much greater in men than in women for plasma triacylglycerol (TAG), cholesterol, and TAG in TAG-rich lipoproteins, non-esterified fatty acids, phospholipids, and apolipoprotein-B100. Men presented with increased blood pressure, carotid intima-media thickness, TAG, hepatic lipase, and insulin and lower high-density lipoprotein cholesterol, apolipoprotein-AI, and non-esterified fatty acid concentrations. Only in men did carotid intima-media thickness correlate marginally with titers of autoantibodies to epitopes of oxidized low-density lipoprotein; in addition, phospholipids and cholesteryl esters were negatively related to autoantibodies. Multivariate analysis indicated that age (R2 = 45%), waist circumference (R2 = 19%), phospholipids (R2 = 39%), non-esterified fatty acids (R2 = 29%), insulin (R2 = 17%), lipoprotein lipase activity (R2 = 16%), and cholesteryl ester transfer protein (an exploratory variable; R2 = 6%) are strong determinants of postalimentary lipemia in women and that only insulin (R2 = 55%) and phospholipids (R2 = 37%) are determinants in men. CONCLUSIONS: We have provided data explaining that postalimentary lipemia is differently regulated by sex. Several risk factors for coronary heart disease and significant associations with atherosclerosis biomarkers were found only in men.

Determinants of serum lipoprotein(a) concentration in normolipidaemic individuals without clinical atherosclerosis.

BACKGROUND: Lipoprotein(a) (Lp(a)) is an independent risk factor for coronary artery diseases. The main objective of this work was to evaluate the determinants of plasma Lp(a) concentrations in normolipidaemic individuals. METHODS: Immunonephelometric quantification of Lp(a) was made in 177 volunteers. A multivariate analysis was employed to verify the influence of clinical and biochemical parameters on plasma Lp(a) concentration. RESULTS: The serum Lp(a) concentration in this population ranged from 0.7 to 40 nmol/L. The Lp(a) predictors were: sex (female), HDL2 triglyceride (negative) and LDL-cholesterol (positive). CONCLUSIONS: The modulation of plasma Lp(a) concentration in this study points to pro-atherogenic lipoprotein associations.

[Serum lipids in school kids and adolescents from Florianópolis, SC, Brazil--Healthy Floripa 2040 study]. / Lípides séricos em crianças e adolescentes de Florianópolis, SC--Estudo Floripa saudável 2040.

OBJECTIVE: To determine the distribution of serum lipids in children and adolescents of Florianopolis, Santa Catarina State, Brazil. To determine the association between undesirable levels for total cholesterol (>170 mg/dL) and others coronary heart disease risks factors. METHODS: A questionnaire, physical examination and blood analyses were collected from randomized sample from school kids aged range from 7 to 18 years old. RESULTS: 1,053 students participated, aged between 7 and 18 years old. They presented a total cholesterol mean of 162+/-28 mg/dl, triglyceride mean of 93+/-47 mg/dl, HDL-cholesterol mean of 53+/-10 mg/dl, LDL-cholesterol mean of 92+/-24 mg/dl and non-HDL cholesterol mean of 109+/-26 mg/dl. The TC/HDL and LDL/HDL mean rates were, respectively, 3.1+/-0.6 and 1.8+/-0.5. Findings showed that private school children, 10 years old or less, girls and black children had higher lipids values. Overall findings suggest that the best logistic regression model which explained abnormal total cholesterol levels included: obesity, stroke and heart attack familial history, feminine gender, age of 10 years old or less and overweight body image determined on inspection. CONCLUSION: In comparison to international literature, our results, showed intermediated total cholesterol, lower LDL-cholesterol and non-HDL-cholesterol and higher HDL-cholesterol. Therefore, primary prevention programs are needed to be carrying out, especially among overweight children and adolescents so to prevent ischemic heart disease as adulthood.

Lípides séricos em criancas e adolescentes de Florianópolis, SC: Estudo Floripa saudável 2040 / Serum lipids in school kids and adolescents from Florianópolis, SC, Brazil: Healthy Floripa 2040 study

OBJETIVO: Determinar a distribuicão dos lipídeos séricos em criancas e adolescentes de Florianópolis, SC. Determinar a associacão entre colesterol não-desejável (>170 mg/dL) e outros fatores de risco para aterosclerose. MÉTODOS: Amostra aleatória estratificada (por idade e tipo de escola) de alunos da rede escolar de Florianópolis. Dados sobre fatores de risco, antropometria, pressão arterial e concentracão sérica de lípides foram coletados. RESULTADOS: Participaram 1.053 indivíduos com idade entre 7 e 18 anos. A concentracão sérica do colesterol (médianDP) foi 162n28 mg/dL; dos triglicerídeos 93n47 mg/dL; do HDL-colesterol 53n10 mg/dL; do LDL-colesterol 92n24 mg/dL e do colesterol não-HDL 109n 26 mg/dL. As médias das relacões CT/HDL e LDL/HDL foram, respectivamente, 3,1n0,6 e 1,8n0,5. Os lípides foram mais elevados nas criancas de escola privada, nos menores de 10 anos, no sexo feminino e nos de cor negra. O modelo de regressão logística que melhor previu os níveis de colesterol anormal incluía: obesidade, história familiar de acidente vascular cerebral ou infarto do miocárdio, sexo feminino, idade inferior a 10 anos e a imagem corporal definida pelo médico como sobrepeso/obesidade. CONCLUSAO: As concentracões de lipídeos em criancas e adolescentes mostraram valores intermediários quando comparados a estudos semelhantes. Uma grande parcela dos indivíduos apresenta níveis de colesterol sérico classificados como não-desejáveis para idade. Pela significância da associacão do colesterol com o excesso de peso, o controle deste fator na infância deve ser tomado como prioridade nos programas de prevencão primordial com o objetivo de reduzir a incidência das doencas relacionadas à aterosclerose na idade adulta.

High glucose levels abolish antiatherosclerotic benefits of ACE inhibition in alloxan-induced diabetes in rabbits.

Renin-angiotensin system activation is recognized to play an important role in atherosclerosis. This study aimed to verify the antiatherosclerotic effects of ACE inhibition on an experimental model of diabetes and hypercholesterolemia. Diabetes was induced in New Zealand male rabbits with a single dose of alloxan (100 mg/kg, i.v.), and, according to plasma glucose levels obtained after 1 week, the animals were divided into 2 groups (> or =250 mg/dL or <250 mg/dL). Each group was randomly assigned to receive or not quinapril (30 mg/d) added to a 0.5% cholesterol-enriched diet. Animals with high glucose levels at 1 week and that remained high after 12 weeks presented higher triglyceride levels (P < 0.02 versus basal). Those initially hyperglycemic but presenting <250 mg/dL glucose at the end of study formed an additional group. Plasma ACE activity was lower in quinapril-treated animals (P < 0.01 versus untreated groups). However, aorta intima/media ratio and intima area were lower only in the subgroups of quinapril-treated animals with low glucose levels (P < 0.05). Our results support the hypothesis that high plasma glucose may abolish the antiatherosclerotic effect of ACE inhibitors.

Early onset of subclinical atherosclerosis in young persons with type 1 diabetes.

OBJECTIVE: To evaluate the degree of atherosclerosis and its risk factors in adolescents and young adults with type 1 diabetes. STUDY DESIGN: We measured carotid artery intima-media thickness (IMT) in 142 subjects with type 1 diabetes (mean [SD] age = 16.0 [2.6] years) and 87 control subjects (18.8 [3.1] years). Fasting lipid and homocysteine levels, degree of glycemic control, blood pressure, and body mass index were measured in persons with diabetes. RESULTS: The mean carotid IMT was greater in persons with diabetes ( P = .002). Among subjects with type 1 diabetes, lipid levels were significantly higher in female subjects compared with male subjects. The mean carotid IMT was significantly higher in persons with a diabetic complication (including hypertension, retinopathy, or microalbuminuria). In male subjects but not female subjects, HDL cholesterol and the LDL/HDL ratio were correlated with carotid IMT. CONCLUSIONS: Adolescents with type 1 diabetes have increased atherosclerosis compared with control subjects. Risk factors for increased carotid IMT in these younger patients include diabetic complications and HDL cholesterol and the LDL/HDL ratio, which may be sex-specific.

[Risk factors for atherosclerosis in children and adolescents with family history of premature coronary artery disease]. / Fatores de risco para aterosclerose em crianças e adolescentes com história familiar de doença arterial coronariana prematura.

OBJECTIVES: To identify the prevalence of dyslipidemia in a group of 109 children and adolescents with a family history of premature coronary artery disease and to investigate the association between dyslipidemia and other risk factors for atherosclerosis. METHODS: Total cholesterol, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), triglycerides, body mass index, blood pressure, physical activity, smoking, per capita income and maternal schooling were investigated. RESULTS: Total cholesterol and LDL-C levels were higher than desirable in 27.5% and 19.3%, respectively, of our patients; 13.8% had lower HDL-C values and 13.0% presented hypertriglyceridemia. Obesity and excess weight were observed in 25.7% of the cases. Out of these, 57.1% had abnormal lipid values. Dyslipidemia was observed in 38.5%, either alone or in combination with other risk factors. Smoking was observed in 3.6%, hypertension in 2.7% and physical inactivity in 72.5%. There was no relationship between dyslipidemia and per capita income, maternal schooling and physical inactivity. However, obesity and excess weight were identified as significantly associated with the occurrence of dyslipidemia (p = 0.02; odds ratio = 2.82, 95% CI = 1.6-6.81). CONCLUSION: In children and adolescents with a family history of premature coronary artery disease, early identification of the risk factors for atherosclerosis is essential to allow the implementation of preventive measures.

Fatores de risco para aterosclerose em crianças e adolescentes com história familiar de doença arterial coronariana prematura / Risk factors for atherosclerosis in children and adolescents with family history of premature coronary artery disease

OBJETIVOS: Analisar a prevalência de dislipidemia em 109 crianças e adolescentes com história familiar de doença arterial coronariana prematura e a associação com outros fatores de risco para aterosclerose. MÉTODOS: Foram determinados valores séricos de colesterol total, de lipoproteínas de baixa densidade (LDL-C), alta densidade (HDL-C), triglicérides, índice de massa corpórea e pressão arterial. Foram também avaliados: prática de atividade física, tabagismo, renda familiar e escolaridade da mãe. RESULTADOS: Do total, 27,5 e 19,3 por cento apresentaram, respectivamente, valores de colesterol total e LDL-C acima do normal, 13,8 por cento valores de HDL-C diminuídos e 13,0 por cento trigliceridemia elevada. Excesso de peso (obesidade e sobrepeso) foi detectado em 25,7 por cento dos casos; destes, 57,1 por cento apresentavam valores anormais de lipídios. A prevalência de dislipidemia, isolada ou concomitante com outros fatores de risco, foi de 38,5 por cento. Hábito de fumar ocorreu em 3,6 por cento dos casos, hipertensão arterial em 2,7 por cento, e 72,5 por cento não praticavam atividade física. Não houve associação entre as variáveis renda familiar, escolaridade da mãe e prática de atividade física e dislipidemia. Entretanto, observou-se associação significativa entre dislipidemia e excesso de peso (p = 0,02; odds ratio = 2,82; IC 95 por cento = 1,16-6,81). CONCLUSAO: Fatores de risco para aterosclerose em crianças e adolescentes com história familiar de doença arterial coronariana prematura devem ser identificados o mais cedo possível para que sejam adotados programas preventivos de saúde.

High insulin levels and increased low-density lipoprotein oxidizability in pediatric patients with systemic lupus erythematosus.

OBJECTIVE: To examine low-density lipoprotein (LDL) size, LDL susceptibility to oxidation, and plasma insulin levels in children with systemic lupus erythematosus (SLE). METHODS: Fifty-nine SLE patients and 59 healthy, age-matched control subjects were studied. LDL size was determined by gradient gel electrophoresis. LDL oxidizability was assessed by lag time for conjugated diene formation during copper incubation. Plasma levels of fasting insulin, glucose, lipids, lipoproteins, apolipoproteins B and A-I, and fatty acids were also measured. RESULTS: Compared with control subjects, SLE patients showed significantly higher plasma insulin levels and increased susceptibility of LDLs to oxidation. Patients with active disease were more likely than patients with inactive disease or control subjects to have the following lipid characteristics: small, dense LDL subclass, elevated total cholesterol levels, elevated LDL cholesterol levels, elevated triglyceride levels, and low levels of high-density lipoprotein cholesterol (HDL-C). Statistically significant direct correlations were observed between disease activity and triglyceride levels and between disease activity and lag time, whereas significant inverse correlations were found between disease activity and HDL-C levels and between disease activity and LDL size. Prednisone dosage explained only 15.6% of the variance in insulin levels. CONCLUSION: SLE patients have higher plasma insulin levels and increased LDL oxidizability compared with healthy control subjects. These abnormalities may contribute to the accelerated atherosclerosis observed in patients with SLE.

Hydrochlorothiazide abolishes the anti-atherosclerotic effect of quinapril.

1. Antihypertensive treatment has been demonstrated to result in persistent reductions in morbidity and mortality due to stroke. However, the coronary risk attributable to hypertension has been only partially reversed. We hypothesized that diuretics could have unfavourable effects on atherosclerosis. 2. New Zealand rabbits were fed a 0.5% cholesterol-enriched diet for 12 weeks, followed by a 0.1% cholesterol diet for another 12 weeks. During the last 12 week period, 40 animals were randomly assigned to one of four groups: (i) group I was the control group; (ii) group II received hydrochlorothiazide (10 mg/day); (iii) group III received quinapril (30 mg/day); and (iv) group IV was treated with hydrochlorothiazide (10 mg/day) plus quinapril (30 mg/day). 3. The treatments did not affect either the lipid profile or serum electrolytes and oxidative stress. However, endothelium-dependent vasorelaxation in isolated aortic rings was significantly improved with quinapril (group III) treatment (P < 0.001 vs other groups). In addition, therapy with quinapril promoted a significant reduction in atherosclerosis (intima area, intima/media ratio and perimeter of vessel with plaque; P < 0.05 vs other groups), as well as in cholesterol content of the aorta (P < 0.05 vs groups II and IV). 4. In conclusion, hydrochlorothiazide did not modify atherosclerosis and, when added to quinapril treatment, impaired the anti-atherosclerotic effect seen with quinapril alone.

Variations in the lipid profile of patients with chronic renal failure, treated with folic acid.

Dyslipidemia and increases in plasma homocysteine usually occur at end-stage renal disease; both are recognized as risk factors for atherosclerosis. Folate administration reduces homocysteine concentration. In this study we determined the effect of a high dose of folic acid (40 mg intravenous injection three times a week) on plasma and red blood cell lipid profiles in twelve chronic renal failure patients on regular hemodialysis. Fasting blood samples were taken at the beginning of the study (baseline) and after 21, 42, and 64 days of treatment. Folic acid supplementation decreased plasma homocysteine. Plasma triglyceride levels decreased whereas polyunsaturated fatty acid values increased after 21 days; then they returned to baseline levels at the end of treatment. Total cholesterol and low-density lipoprotein (LDL) cholesterol were higher than those of the baseline during all the study, whereas high-density lipoprotein (HDL) cholesterol was reduced. In erythrocyte membranes, folic acid therapy enhanced cholesterol/phospholipid ratios and the fluorescence anisotropy of diphenyl-hexatriene. We conclude that large doses of folic acid produce a favorable effect, reducing plasma homocysteine levels and protecting patients from atherosclerosis. However, as this therapy induces significant alterations in both plasma and erythrocyte membrane lipid profiles, plasma lipid values should be controlled throughout the treatment of patients with renal failure.

Cholesteryl ester transfer protein expression attenuates atherosclerosis in ovariectomized mice.

Reduced estrogen levels result in loss of protection from coronary heart disease in postmenopausal women. Enhanced and diminished atherosclerosis have been associated with plasma levels of cholesteryl ester transfer protein (CETP); however, little is known about the role of CETP-ovarian hormone interactions in atherogenesis. We assessed the severity of diet-induced atherosclerosis in ovariectomized (OV) CETP transgenic mice crossbred with LDL receptor knockout mice. Compared with OV CETP expressing ((+)), OV CETP non-expressing ((-)) mice had higher plasma levels of total, VLDL-, LDL-, and HDL-cholesterol, as well as higher antibodies titers against oxidized LDL. The mean aortic lesion area was 2-fold larger in OV CETP(-) than in OV CETP(+) mice (147 +/- 90 vs. 73 +/- 42 x 10(3) micro m(2), respectively). Estrogen therapy in OV mice blunted the CETP dependent differences in plasma lipoproteins, oxLDL antibodies, and atherosclerosis severity. Macrophages from OV CETP(+) mice took up less labeled cholesteryl ether (CEt) from acetyl-LDL than macrophages from OV CETP(-) mice. Estrogen replacement induced a further reduction in CEt uptake and an elevation in HDL mediated cholesterol efflux from pre-loaded OV CETP(+) as compared with OV CETP(-) macrophages. These findings support the proposed anti-atherogenic role of CETP in specific metabolic settings.