I Diretriz sobre o consumo de Gorduras e Saúde Cardiovascular Definição do grau dos níveis de evidência Recomendações Classe I: Condições para as quais há evidências conclusivas e, na sua falta, consenso geral de que o procedimento é seguro útil/eficaz. Classe II: Condições para as quais há evidências conflitantes e/ou divergência de opinião sobre segurança e utilidade/ eficácia do procedimento. Classe IIa: Peso ou evidência/opinião a favor do procedimento. A maioria aprova. Classe IIb: Segurança e utilidade/eficácia menos bem estabelecidas, não havendo predomínio de opniões a favor. Classe III: Condições para as quais há evidências e/ou consenso de que o procedimento não é útil/eficaz e, em alguns casos, pode ser prejudicial. Evidências Nível A: Dados obtidos a partir de múltiplos estudos randomizados de bom porte, concordantes e/ou de Metanálise robusta de estudos clínicos randomizados. Nível B: Dados obtidos a partir de Metanálise menos robusta, a partir de um único estudo randomizado ou de estudos não randomizados (observacionais). Nível C: Dados obtidos de opiniões consensuais de especialistas.

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The association of cardiovascular events with Lp-PLA2 has been studied continuously today. The enzyme has been strongly associated with several cardiovascular risk markers and events. Its discovery was directly related to the hydrolysis of the platelet-activating factor and oxidized phospholipids, which are considered protective functions. However, the hydrolysis of bioactive lipids generates lysophospholipids, compounds that have a pro-inflammatory function. Therefore, the evaluation of the distribution of Lp-PLA2 in the lipid fractions emphasized the dual role of the enzyme in the inflammatory process, since the HDL-Lp-PLA2 enzyme contributes to the reduction of atherosclerosis, while LDL-Lp-PLA2 stimulates this process. Recently, it has been verified that diet components and drugs can influence the enzyme activity and concentration. Thus, the effects of these treatments on Lp-PLA2 may represent a new kind of prevention of cardiovascular disease. Therefore, the association of the enzyme with the traditional assessment of cardiovascular risk may help to predict more accurately these diseases.

Oxidative modifications in lipoproteins (LP), especially in low-density lipoproteins (LDL), are associated with initiation and progression of atherosclerosis. The levels of a sub-fraction of LDL with oxidative characteristics, named electronegative LDL [LDL(-)], minimally oxidized LDL, and minus LDL, are known to be increased in subjects with familial hypercholesterolemia, hypertriglyceridemia, nonalcoholic steatohepatitis, diabetes mellitus, coronary artery disease, patients undergoing hemodialysis, and athletes after aerobic exercise. In addition to the oxidative profile, physical and biological characteristics of LDL(-) consist of nonenzymatic glycosylation, increased expression and activity of platelet-activating factor acetylhydrolase (PAF-AH) and phospholipase A(2) (PLA(2)), enriched NEFA content, hemoglobin and ApoB-100 cross-linking, and increase in ApoC-III and ApoE in LDL. Herein, we summarize the state of the art of the up-to-date body of knowledge on the possible origin and impact of LDL(-) in health and disease. Further, the potential perspectives of using LDL(-) as a biomarker in conditions under metabolic stress are also discussed.