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Abstract Objectives Because the plasma campesterol/cholesterol ratio does not differ between groups that absorb different amounts of cholesterol, the authors investigated whether the plasma Phytosterols (PS) relate to the body's cholesterol synthesis rate measured as non-cholesterol sterol precursors (lathosterol). Method The authors studied 38 non-obese volunteers (58±12 years; Low-Density Lipoprotein Cholesterol ‒ LDL-C ≥ 130 mg/dL) randomly assigned to consume 400 mL/day of soy milk (Control phase) or soy milk + PS (1.6 g/day) for four weeks in a double-blind, cross-over study. PS and lathosterol were measured in plasma by gas chromatography coupled to mass spectrophotometry. Results PS treatment reduced plasma total cholesterol concentration (-5.5%, p < 0.001), LDL-C (-7.6%, p < 0.001), triglycerides (-13.6%, p < 0.0085), and apolipoprotein B (apo B) (-6.3%, p < 0.008), without changing high density lipoprotein cholesterol (HDL-C concentration), but plasma lathosterol, campesterol and sitosterol expressed per plasma cholesterol increased. Conclusions The lathosterol-to-cholesterol plasma ratio predicted the plasma cholesterol response to PS feeding. The highest plasma lathosterol concentration during the control phase was associated with a lack of response of plasma cholesterol during the PS treatment period. Consequently, cholesterol synthesis in non-responders to dietary PS being elevated in the control phase indicates these cases resist to further synthesis rise, whereas responders to dietary PS, having in the control phase synthesis values lower than non-responders, expand synthesis on alimentary PS. Responders absorb more PS than non-responders, likely resulting from responders delivering into the intestinal lumen less endogenous cholesterol than non-responders do, thus facilitating greater intestinal absorption of PS shown as increased plasma PS concentration.
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INTRODUCTION: The development of research for diagnosis, prevention and treatment of atherosclerotic cardiovascular disease is of utmost importance due to the fact that it is the main cause of morbidity and mortality in Brazil. OBJECTIVE: To demonstrate the phases of the selection process for candidates with the aim to develop a clinical-laboratorial database of hyper alpha lipoproteinemic patients (hyper A) - high density lipoprotein cholesterol (HDL-C) ≥ 68 mg/dl) and hypo alpha lipoproteinemic patients (hypo A) - HDL-C < 39 mg/dl. MATERIAL AND METHODS: The volunteers were contacted after selection of lipid profiles from individuals treated at the Sistema Único de Saúde (SUS), Campinas-SP and neighboring area. Afterwards, the selected patients went through blood collection, clinical examinations and answered questionnaires on dietary frequency and physical activity. After this preliminary evaluation, some individuals were convened to another blood collection and, subsequently, were submitted to an ultrasonographic exam of the carotid arteries. RESULTS: Only 0.6% and 0.3% from 598,288 lipid profiles were selected for hyper A and hypo A groups, respectively, including gender disparity. Lack of effective questionnaires (75%), missing calls (60%) and non-inclusion were the major hindrances in the construction of this database. DISCUSSION: The difficulties to obtain eligible candidates were also due to the low prevalence of both groups hypo A and hyper A and the high prevalence of pathologies that contribute to non-genetic variations of HDL-C. CONCLUSION: In spite of the obstacles in the development of this database, this study brought about several scientific publications. Furthermore, the development of molecular analyzes and functionality will shortly generate other findings, contributing to the diagnosis and follow-up of HDL dyslipidemias.
INTRODUÇÃO: O desenvolvimento de pesquisa para diagnóstico e prevenção da doença aterosclerótica cardiovascular no Brasil é de grande importância por esta ser a principal causa de morbimortalidade no país. OBJETIVO: Demonstrar as etapas do processo de seleção de voluntários para a construção de um banco de dados clínico-laboratorial de indivíduos hiperalfalipoproteinêmicos (hiper A) - colesterol da lipoproteína de alta densidade (HDL-C) ≥ 68 mg/dl - e hipoalfalipoproteinêmicos (hipo A) - HDL-C < 39 mg/dl. MATERIAL E MÉTODOS: Os voluntários são contatados a partir de resultados de perfis lipídicos de indivíduos atendidos pelo Sistema Único de Saúde (SUS) de Campinas-SP e região e, se selecionados, são convidados para coleta de sangue, exames clínicos e responder a questionários de atividade física e de frequência alimentar. Após essa avaliação, os indivíduos podem ser convocados para nova coleta de sangue e, posteriormente, para a ultrassonografia de carótidas. RESULTADOS: Entre 598.288 perfis lipídicos recebidos das redes públicas, apenas 0,6% e 0,3% compuseram os nossos grupos hiper A e hipo A, com disparidade entre os gêneros. A falta de questionários efetivos (75%), das chamadas não atendidas (60%) e a não inclusão foram os pontos mais difíceis na construção do banco de dados. DISCUSSÃO: A dificuldade de obtenção de voluntários elegíveis também se deve à baixa prevalência de hipo A e hiper A e à alta prevalência de patologias que contribuem para variações não genéticas do HDL-C. CONCLUSÃO: Apesar das dificuldades na criação da base de dados, este estudo gerou várias publicações e, com o desenvolvimento das análises moleculares e da funcionalidade, muitas outras seguirão em curto período, fatos contribuintes para o diagnóstico e o acompanhamento das dislipidemias envolvendo a HDL.
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The relationship between hypercholesteroemia and coronary heart disease is well established. Clinical and experimental investigations have shown that high serum levels of cholesterol are associated wuth increased atherogenesis. The author presentes and extensive revisión about hypercholesterolemia, its classification and treatment. Reogarding the treatment, astects of the diet and the current available drugs are considered in detail