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Abstract(s)
Introdução: As partículas de HDL são pequenas lipoproteínas de grande importância
no metabolismo dos lípidos. Vários estudos demonstraram uma associação inversa entre
a concentração sérica de HDL e a mortalidade. Esta relação é maioritariamente resultado
da capacidade de efluxo do colesterol dos macrófagos, durante o processo de transporte
reverso pela partícula de HDL. Deste modo, a concentração de HDL tem sido utilizada
como variável em muitos sistemas de avaliação de risco cardiovascular. Apesar disto, as
tentativas de redução da mortalidade e de eventos cardiovasculares através do aumento
dos níveis de HDL não têm sido bem-sucedidas e estudos recentes têm demonstrado que
esta associação entre a concentração de HDL e a mortalidade pode não ser linear.
Objetivo: Realizar uma revisão sistemática sobre a relação entre concentrações muito
elevadas de HDL e a mortalidade da população. É também objetivo realizar uma análise
das causas desta mortalidade e tentar estabelecer a concentração máxima (limite
máximo) que está associada ao aumento da mortalidade.
Métodos: A pesquisa foi conduzida nas plataformas PubMed, Web of Science e Scopus.
Nesta revisão foram incluídos artigos em inglês, com estudos retrospetivos e prospetivos
publicados entre 2010-2021, inclusive. Estes estudos incidiam sobre a população
humana adulta, com ou sem doenças prévias e onde foram avaliadas a mortalidade e os
níveis de HDL, incluindo indivíduos com níveis muito elevados. Foram seguidas as
Guidelines PRISMA 2020.
Resultados: Foram extraídos 23 artigos que cumpriam os critérios de inclusão. As
amostras analisadas englobaram as populações de vários países, variaram de 2113 a
15860253 indivíduos e eram constituídas por adultos saudáveis, à exceção de quatro. A
maioria mostrou que existiu uma relação positiva entre valores muito elevados de HDL
e o aumento de mortalidade e treze mostraram que esta relação tinha a forma de U ou J.
As concentrações de HDL elevadas foram associadas ao aumento de diferentes tipos de
mortalidade: por todas as causas, cardiovascular, não cardiovascular, como por cancro e
doenças infeciosas. Os valores de HDL a partir dos quais existiu um aumento da
mortalidade foram muito variáveis, desde 47,5 mg/dL até 100 mg/dl, mas a maioria
encontrava-se na faixa dos 70-90 mg/dL. Discussão: Com este trabalho podemos concluir que existe uma mudança de
paradigma no que concerne ao fator protetor cardiovascular de concentrações elevadas
de HDL. Apesar disso, há uma heterogeneidade entre os valores considerados como
elevados nas diferentes investigações. Adicionalmente, ainda é desconhecido o
mecanismo subjacente a esta relação. Existem propostas para justificar este paradoxo,
como a contribuição de variantes genéticas, composição da partícula e desregulação dos
mecanismos protetores da aterosclerose.
Conclusão: Existe uma associação entre concentrações elevadas de HDL e a
mortalidade, contudo a definição dos valores limite de concentração de HDL que
aumentam a mortalidade ainda não foi estabelecida. É assim fundamental considerar
esta relação para a predição do risco cardiovascular na população.
Introduction: HDL particles are small lipoproteins of great importance in lipid metabolism. Several studies have shown an inverse association between serum HDL concentration and mortality. This ratio is mostly a result of the cholesterol efflux capacity of macrophages, during the process of reverse transport by HDL particle. Thus, HDL concentration has been used as a variable in many cardiovascular risk assessment systems. Despite this, attempts to reduce mortality and cardiovascular events by increasing HDL levels have not been successful and recent studies have shown that this association between HDL concentration and mortality may not be linear. Aim: To conduct a systematic review on the relationship between very high HDL concentrations and population mortality. It is also a goal to perform an analysis of the causes of this mortality and try to establish the maximum concentration (maximum limit) that is associated with increased mortality. Methods: The research was conducted on Pubmed, Web of Science and Scopus platforms. This review included articles in English, with retrospective and prospective studies published between 2010 and 2021, including. These studies were focused on the adult human population, with or without previous diseases, and where mortality and HDL levels were evaluated, including individuals with very high levels. The PRISMA 2020 Guidelines were followed. Results: Twenty-three articles that met the inclusion criteria were extracted. The samples analysed included populations from several countries, ranged from 2113 to 15860253 individuals and consisted on healthy adults, except for four. The majority showed that there was a positive relationship between very high HDL values and increased mortality and thirteen showed that this relationship was U or J shaped. High HDL concentrations were associated with increased distinct types of mortality: all causes, cardiovascular and non-cardiovascular, such as cancer and infectious diseases. HDL values from which there was an increase in mortality were very variable, from 47.5 mg/dL to 100 mg/dl, but most was in the range of 70-90 mg/dL. Discussion: With this work we can conclude that there is a paradigm shift regarding the cardiovascular protective factor of high HDL concentrations. Nevertheless, there is a heterogeneity between the values considered as high in the several investigations. Additionally, the mechanism underlying this relationship is still unknown. There are proposals to justify this paradox, such as the contribution of genetic variants, particle composition and deregulation of the protective mechanisms of atherosclerosis. Conclusion: There is an association between high HDL concentrations and mortality, however the definition of HDL concentration limit values that increase mortality has not yet been established. It is therefore essential to consider this relationship for the prediction of cardiovascular risk in the population.
Introduction: HDL particles are small lipoproteins of great importance in lipid metabolism. Several studies have shown an inverse association between serum HDL concentration and mortality. This ratio is mostly a result of the cholesterol efflux capacity of macrophages, during the process of reverse transport by HDL particle. Thus, HDL concentration has been used as a variable in many cardiovascular risk assessment systems. Despite this, attempts to reduce mortality and cardiovascular events by increasing HDL levels have not been successful and recent studies have shown that this association between HDL concentration and mortality may not be linear. Aim: To conduct a systematic review on the relationship between very high HDL concentrations and population mortality. It is also a goal to perform an analysis of the causes of this mortality and try to establish the maximum concentration (maximum limit) that is associated with increased mortality. Methods: The research was conducted on Pubmed, Web of Science and Scopus platforms. This review included articles in English, with retrospective and prospective studies published between 2010 and 2021, including. These studies were focused on the adult human population, with or without previous diseases, and where mortality and HDL levels were evaluated, including individuals with very high levels. The PRISMA 2020 Guidelines were followed. Results: Twenty-three articles that met the inclusion criteria were extracted. The samples analysed included populations from several countries, ranged from 2113 to 15860253 individuals and consisted on healthy adults, except for four. The majority showed that there was a positive relationship between very high HDL values and increased mortality and thirteen showed that this relationship was U or J shaped. High HDL concentrations were associated with increased distinct types of mortality: all causes, cardiovascular and non-cardiovascular, such as cancer and infectious diseases. HDL values from which there was an increase in mortality were very variable, from 47.5 mg/dL to 100 mg/dl, but most was in the range of 70-90 mg/dL. Discussion: With this work we can conclude that there is a paradigm shift regarding the cardiovascular protective factor of high HDL concentrations. Nevertheless, there is a heterogeneity between the values considered as high in the several investigations. Additionally, the mechanism underlying this relationship is still unknown. There are proposals to justify this paradox, such as the contribution of genetic variants, particle composition and deregulation of the protective mechanisms of atherosclerosis. Conclusion: There is an association between high HDL concentrations and mortality, however the definition of HDL concentration limit values that increase mortality has not yet been established. It is therefore essential to consider this relationship for the prediction of cardiovascular risk in the population.
Description
Keywords
Doenças Cardiovasculares Endocrinologia Hdl Lipoproteínas Mortalidade